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2019 Vol.36(3)

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2019, 36(3): 1-4.
[Abstract](667) [FullText HTML] (380) [PDF 452KB](9)
Characteristics of restorable plant communities on land used for engineering construction in different elevation belts in Qinghai-Tibet Plateau
WANG Juan, SHU Chaocheng, ZHANG Hongyan, ZHANG Jing, ZHANG Wenna, GUO Zhenggang
2019, 36(3): 601-611. doi: 10.11829/j.issn.1001-0629.2018-0260
[Abstract](995) [FullText HTML] (688) [PDF 1105KB](16)
Restoration of vegetation in a linear project is an important component of grassland ecosystem restoration in Qinghai-Tibet Plateau. In this study, variation of the plant community along the elevation gradient on the land used for engineering construction (approximately 30 cm deep) was analyzed from two levels of total plant population indicators and the economic value of plants indicators, which were based on the natural undegraded grassland plant community. The results showed that the aboveground biomass, height, and coverage of the natural undegraded grassland plant community decreased with the increase in elevation, whereas the aboveground biomass, height, and coverage in the restoration of regional plant communities first increased and then decreased with elevation. The height, coverage, and aboveground biomass of Leguminosae and Cyperaceae in the natural and restoration plant communities first increased and then decreased with increasing elevation. Although the height and coverage of weed families in the natural and restoration plant community first increased and then decreased with the increase of elevation, their aboveground biomass gradually decreased with increasing elevation. The coverage and aboveground biomass of Gramineae in the natural and restoration communities and the height of Gramineae in the natural undegraded grassland plant communities decreased with increasing elevation gradient; however, the height of Gramineae in the restoration of regional plant communities first increased and then decreased with increasing elevation gradient. The diversity index in both natural and restoration plant communities was first increased and then decreased with the elevation gradient, whereas the richness index and evenness index did not differ significantly with the elevation gradient. This indicates that the changes in height, coverage, biomass, and diversity index in the total communities were consistent with the increase in elevation of the restoration of regional plant communities and natural undegraded grassland plant communities. However, the height, coverage, and biomass values of each economic group were inconsistent.
Study on carbon storage and soil nutrient changes at different restoration stages of Potentilla parvifolia shrubs in Eastern Qilian Mountains
HE Xiang, XU Changlin, SONG Meijuan, WANG Pengbin, YU Xiaojun
2019, 36(3): 612-622. doi: 10.11829/j.issn.1001-0629.2018-0651
[Abstract](1022) [FullText HTML] (694) [PDF 841KB](22)
This study aimed to scientifically evaluate the change rule of carbon storage and soil nutrients at different habitat restoration stages. This study used a " spatial for temporal gradient” methodology, which compared changes in carbon storage and soil nutrient content at different restoration stages of Potentilla parvifolia shrubs over a period of nearly 20 years (from 1997 to 2018). It provides a theoretical basis for the management of P. parvifolia. The results showed that the carbon storage of shrubs increased by 1.4 to 6.2 times, the carbon storage of the herbaceous understory decreased by 0.9 to 1.7 times, and the carbon storage of the community increased by 1.1 to 2.0 times, with restoration of P. parvifolia. The soil bulk density decreased in the top soil layer (from 0 to 10 cm), and initially decreased and then increased in the 10 to 30 cm soil layer. With the progression succession of P. parvifolia, the total phosphorus, the available phosphorus, and the available potassium content in the soil between shrubs decreased by 0.7% to 6.0%, 6.3% to 28.8%, and 53.9% to 61.0%, respectively; the organic matter and available nitrogen content increased first and then decreased, and the total potassium content first decreased and then increased in the 0 to 30 cm soil layer. The trends observed in the organic matter, total potassium, available nitrogen, available phosphorus, and available potassium content in the soil between the shrubs were same as those observed under the shrubs. To summarize, with restoration of P. parvifolia vegetation, the soil fertility either decreased or first increased and then decreased, and carbon storage increased. Therefore, it is recommended that the large-scale expansion of P. parvifolia shrubs on the grassland for grazing purpose should be controlled, while the progressive succession on the grassland should be promoted to provide environmental benefits.
Analysis of the spatio-temporal patterns of vegetation fractional coverage in the Hexi arid area
YU Hui, WU Yufeng, JIN Yi, NIU Liting
2019, 36(3): 623-631. doi: 10.11829/j.issn.1001-0629.2018-0236
[Abstract](1002) [FullText HTML] (632) [PDF 770KB](19)
Taking grassland vegetation as the research object, we examined the applicability of three types of existing vegetation fractional coverage estimation method in arid areas based on long-time series MODIS and field measured data in the Hexi arid area. To this end, we analyzed the spatio-temporal dynamics of grassland vegetation fractional coverage in the test area from 2001 to 2015. The results indicated that an empirical model between the index TVI and vegetation fractional coverage had the highest precision, and is thus considered suitable for estimating the vegetation fractional coverage in the study area. The spatial distributions of the maximum vegetation coverage of grassland were significantly different, and the vegetation coverage decreased gradually from southeast to northwest. Overall, there was an extremely significant increase in vegetation coverage during the period from 2001 to 2015, albeit with spatial heterogeneity (P < 0.01). Restored areas were mainly concentrated in the central and western regions of the Hexi arid area, whereas degraded areas were scattered in the northern part of Mazong Mountain, the western region of the Shiyang River basin, and the east section of the Qilian Mountains.
Isolation, identification, and genomic sequencing analysis of an endophytic biocontrol strain of Pennisetum giganteum
SONG Zhaozhao, JIA Yulei, HUANG Zaixing, LIN Biaosheng, MEI Lan, LIN Zhanxi
2019, 36(3): 632-639. doi: 10.11829/j.issn.1001-0629.2018-0375
[Abstract](1115) [FullText HTML] (694) [PDF 933KB](11)
This study used Pennisetum giganteum as an experimental material to isolate and purify strains with strong biological and defensive effects, which were then analyzed using genome sequencing. Strains with strong antibacterial effects were screened using plate confrontation. The strains were sequenced using the Illumina Miseq PE150, and the data were analyzed using the relevant software for genome analysis, gene prediction and functional annotation, and direct homologous cluster analysis. Streptomyces sp. JK7-2 was isolated from the bacteria of Pennisetum giganteum, and the genome of the strain was sequenced and analyzed. A total of 290 contiguous sequences were obtained. The whole genome size was about 8.4 Mb and the GC content was 73.17%. The sequence has been submitted to the NCBI database and BioProject under ID:PRJNA451251. In addition, it was predicted that 7 432 genes were encoded and several genes related to the streptomycin, penicillin, and tetracycline metabolic pathways were found. The results provide a theoretical basis for further study of the antibacterial mechanisms of the bacteria in the Pennisetum sp. and the genes related to the secondary metabolites of these bacteria.
Residues and degradation dynamics of two herbicides in oat field soil
YAN Chetai, ZHAO Guiqin, CHAI Jikuan, GOU Zhiqiang, XU Xingze
2019, 36(3): 640-650. doi: 10.11829/j.issn.1001-0629.2018-0224
[Abstract](1602) [FullText HTML] (639) [PDF 856KB](13)
In order to study the residues and natural degradation characteristics of quinclorac and bensulfuron-methyl in oat (Avena sativa) field soil, we sprayed oat seedlings at the three- to four-leaf stage with the recommended dosage (225 g a.i.·hm–2) and 1.5 times the recommended dosage (337.5 g a.i.·hm–2) of quinclorac, and the recommended dosage (34 g a.i.·hm–2) and 1.5 times the recommended dosage (51 g a.i.·hm–2) of bensulfuron-methyl in April 2016. Residues were determined by high-performance liquid chromatography and the results showed that the degradation patterns of the two herbicides were consistent with a first order kinetic model. The half-lives of quinclorac and bensulfuron-methyl in oat field soil were 23.6~26.7 d and 17.9~20.1 d, respectively, and thus, it can be concluded that both pesticides are readily degradable. Under experimental conditions, the average recovery rates of quinclorac and bensulfuron-methyl at fortified levels of 0.05, 0.5, and 1.0 mg·kg–1 were 85.63%~89.27% and 80.26%~91.61%, respectively, with relative standard deviations of 2.17%~6.33% and 3.28%~6.52%, respectively.
Effect of cadmium tolerance and accumulation in soil on Calendula officinalis
HU Yunlong, ZHANG Weixiong, ZHAI Xianghua, ZHANG Qiong, LU Jin, LIU Jinrong
2019, 36(3): 651-657. doi: 10.11829/j.issn.1001-0629.2018-0261
[Abstract](911) [FullText HTML] (596) [PDF 849KB](14)
Heavy metal pollution is a global environmental problem that threatens ecosystems and human health. Cadmium (Cd) pollution is the most prominent heavy metal pollution due to its high toxicity, strong migration, and the large area it affects globally. A pot culture experiment with five concentrations of cadmium Cd (0, 10, 30, 50, and 100 mg·kg–1 in dry soil) was conducted to investigate Cd accumulation and tolerance in the roots and shoots of Calendula officinalis and its potential for phytoremediation. The results indicated that the growth of Calendula officinalis was not significantly inhibited and there was no evidence of toxicity. The plant height and biomass of C. officinalis first increased and then decreased with increasing Cd concentrations. When the concentration of Cd was 30 mg·kg–1, the plant height and biomass of C. officinalis reached its peak and was significantly higher than that of control, whereas there was no significant difference between 100 mg·kg–1 and control. The transfer coefficients of C. officinalis were less than 1 under each treatment; the enrichment coefficients of plants under all treatments were greater than 1. The accumulation of heavy metal Cd by C. officinalis increased with increases in Cd concentrations in the soil. At 100 mg·kg–1, the accumulation of Cd per normal growth of C. officinalis reached 908 μg·plant–1. Considering its rapid growth, high biomass, and adaptive properties, C. officinalis could be a valuable tool for the phytoremediation of Cd contaminated soils, especially in highly Cd-contaminated soil, as it can have a good enrichment effect.
The diurnal variation of photosynthesis and effect of drought stress on photosynthetic characteristics of Lysimachia davurica
LEI Lei, ZHANG Yanni
2019, 36(3): 658-665. doi: 10.11829/j.issn.1001-0629.2018-0299
[Abstract](849) [FullText HTML] (637) [PDF 1052KB](18)
This study aimed to clarify the photosynthetic characteristics of Lysimachia davurica under natural conditions and drought stress conditions. The diurnal variation in photosynthesis under natural conditions, and the light response curve under natural drought conditions for 5, 10, and 15 days, were measured using a LI-6400 portable photosynthetic apparatus with young seedlings of Lysimachia davurica used as samples. The results showed that the net photosynthetic rate (Pn) of Lysimachia davurica appeared to have an " unimodal” pattern that lacked a " midday depression” on one day , which reached a peak of 9.18 µmol·(m2·s)–1 at 14:00. Under drought stress conditions, Pn, stomatal conductance (Gs), and transpiration rate (Tr) decreased, while the internal CO2 concentration (Ci) increased. The apparent quantum efficiency (AQE) decreased and the light compensation point (LCP) increased. The light saturation point (LSP) initially increased and then decreased. In addition, the net photosynthetic rate decreased to a negative value at 15 days after the application of stress. This indicated that Lysimachia davurica is only weakly able to adapt to dry environments. It can withstand drought stress for up to 10 days.
Mechanism analysis of melatonin pretreatment to improve drought tolerance of perennial ryegrass (Lolium perenne)
LI Benfeng, DU Hongmei
2019, 36(3): 666-676. doi: 10.11829/j.issn.1001-0629.2018-0397
[Abstract](919) [FullText HTML] (557) [PDF 800KB](13)
In order to further analyze the mechanism of melatonin (MT) pretreatment on drought resistance in perennial ryegrass (Lolium perenne), the effects of 25 μmol·L–1 MT pretreatment on the antioxidant enzyme activities and the accumulation of metabolites were analyzed. The results showed that MT pretreatment significantly delayed decreases in turf quality, photochemical efficiency, and relative water content; it also increased the rate of relative conductivity and the malondialdehyde content in perennial ryegrass. MT pretreatment maintained the stability of cell membrane systems by increasing the activities of superoxide dismutase, catalase, and peroxidase under drought stress. MT pretreatment may improve the osmotic adjustment ability and oxidative resistance of perennial ryegrass by improving the accumulation of related metabolites, such as isoleucine, proline, ornithine, erythrulose, and glucosamine, which lead to an increase in drought resistance for perennial ryegrass.
Research advances in using plant hedges and filter strips to reduce soil and water erosion and non-point pollution
ZHANG Xuelian, ZHAO Yongzhi, LIAO Hong, LI Xiaona, ZHANG Guofang, WEN Fangfang, LIU Zifei, ZHANG Mengjia
2019, 36(3): 677-691. doi: 10.11829/j.issn.1001-0629.2018-0355
[Abstract](1093) [FullText HTML] (724) [PDF 720KB](14)
Soil erosion on sloping land induces soil and water loss and non-point pollution, causing serious adverse effects on ecology and environment quality in hilly areas. Use of plant hedges or filter strips is an effective method to prevent soil and water loss and to protect ecology and environment quality. It can effectively increase soil infiltration and reduce the runoff, sediment, nitrogen (N), phosphorus (P), and pollutants through the combined action of plants, soil, and microorganisms. This manuscript summarizes the effect of different plant hedges and filter strips in reducing the runoff, sediment, N, P, and pollutants, analyzes the associated impact factors, discusses the interrupting mechanisms, and, finally, proposes contents that need further study in the future. It can provide a reference for further research and the application of plant hedges or filter strip technology and provides evidence for sustainable utilization of cultivated land and ecological agriculture construction in hilly areas.
Research progress on the stability of turfgrass rootzone for sports field
WANG Cheng, XU Wei, CHANG Zhihui
2019, 36(3): 692-703. doi: 10.11829/j.issn.1001-0629.2018-0360
[Abstract](1692) [FullText HTML] (1086) [PDF 683KB](122)
The fundamental function of the sports field turf is to provide a safe and stable playing surface for the sports it carries, so as to maximize the athletes’ competitive level and prolong their sports career. This paper summarized the methods to improve the stability of turfgrass rootzone for sports field by consulting the related literature at home and abroad, including the selection of sand particles and the use of reinforcing materials in the rootzone, the application of hybrid turf system establishment technology, scientific and reasonable turf cultural practices and so on. At the same time, the paper also discussed the problems existing in the current research on the stability of the sports field rootzone, and it is believed that compared with the developed countries in the west, there is still a big gap in the research on the reinforcement of the rootzone for sports field in China, and further research is needed.
Cloning and expression analysis of SgSTOP1 and SgSTOP2 in Stylosanthes guianensis
LUO Jiajia, XIANG Chenying, LIU Pandao, HU Xuan, TANG Jun, WANG Wenqiang, LIU Guodao, CHEN Zhijian
2019, 36(3): 704-712. doi: 10.11829/j.issn.1001-0629.2018-0497
[Abstract](912) [FullText HTML] (549) [PDF 1347KB](14)
Aluminium (Al) toxicity is one of the major factors limiting crop growth and production in acid soils. Transcription factor STOP is an important Al tolerance candidate gene in plants, as it can regulate the expression of Al-tolerant genes in response to Al toxicity. In this study, SgSTOP1 and SgSTOP2, which encode the zinc finger protein, were cloned from Al-tolerant stylo (Stylosanthes guianensis) genotype ‘TPRC2001-1’ using RT-PCR. The full lengths of SgSTOP1 and SgSTOP2 were 1 515 and 1 077 bp, which encoded 504 and 358 amino acid residues, respectively. The protein molecular weights of SgSTOP1 and SgSTOP2 were 56.2 and 39.7 kDa, respectively. Subcellular localization prediction showed that both SgSTOP1 and SgSTOP2 were located in the nucleus. Furthermore, SgSTOP1 and SgSTOP2 belonged to the ZF-C2H2 family, and both contained four conserved zinc finger domains. The expression of SgSTOP1 was significantly enhanced in leaves and roots of stylo subjected to Al treatment (P < 0.05), whereas the transcript of SgSTOP1 was not regulated by Al toxicity (P > 0.05), suggesting that SgSTOP1 may be involved in stylo adaptation to Al toxicity. Taken together, this study provided candidate genes for further analysis of the molecular mechanisms underlying stylo adaptation to Al toxicity.
Dynamic changes of leaf parameters of PSⅡ fluorescence kinetics and fast photosynthetic response curves in Artemisia ordosica
ZHANG Jingbo, ZHANG Jinxin, LU Qi, XIN Zhiming, LI Xinle, LIU Qingxin, LI Hongliang
2019, 36(3): 713-719. doi: 10.11829/j.issn.1001-0629.2018-0691
[Abstract](1200) [FullText HTML] (741) [PDF 749KB](14)
To explore the mechanisms of adaptive physiological and ecological responses of Artemisia ordosica to desert environments, the dynamic changes of the specific leaf area (SLA), leaf nitrogen content (Nmass), photosynthetic physiological parameters of PSⅡ fluorescence kinetics, and fast photosynthetic response curves of A. ordosica during growth periods were analyzed. The results showed that SLA was the highest in August, but decreased significantly in September (P <0.05), and Nmass showed the opposite tendency. The initial fluorescence (Fo), maximum fluorescence (Fm), and maximum photochemistry efficiency (Fv/Fm) of A. ordosica maintained relatively stable values throughout the growth periods. The minimum fluorescence yield (Fo′) and maximum fluorescence yield (Fm′) under stabilization light varied significantly in different growth stages, with the highest values recorded in August and the lowest in September (P < 0.05). The photosynthetic electron transfer quantum efficiency (ΦPSⅡ) and photochemistry quenching (qP) decreased with the increase of light intensity, while the non-photochemical quenching (NPQ) and photosynthetic electron transfer rate (ETR) showed the opposite trend. The ETR and NPQ of the A. ordosica leaves were the highest in September and the lowest in August under the same light intensity. The results indicated that the leaves of A. ordosica had a high ability to regulate light capture and resist photoinhibition as an adaptation to light environmental changes.
Effects of exogenous 6-BA on photosynthesis, physiological characteristics of alfalfa leaves at flowering stage and rate of podding
SONG Jiaqi, WANG Yuxiang, ZHANG Bo
2019, 36(3): 720-728. doi: 10.11829/j.issn.1001-0629.2018-0327
[Abstract](906) [FullText HTML] (574) [PDF 776KB](18)
The role of exogenous 6-benzylaminopurine (6-BA) in the regulation of photosynthesis and the antioxidant system in alfalfa leaves was evaluated to provide a theoretical and research basis the application of this cytokinin in the growth and development of alfalfa. Xinmu No. 4 alfalfa (Medicago sativa ‘Xinmu No. 4’) plants were examined in this study. 6-BA solutions at concentrations of 10, 20, and 30 mg·L–1 were sprayed onto the leaves of alfalfa during the squaring period; the control plants were sprayed with water. The effects of exogenous 6-BA on photosynthetic parameters, fluorescence parameters, antioxidant enzyme activities, osmotic adjustment substances, and rate of podding were examined during the flowering stage of alfalfa. The results showed that after treatment with 20 mg·L–1 6-BA, the photosynthetic rate, transpiration rate, and maximum photochemical efficiency of the alfalfa leaves were significantly increased and the activities of superoxide dismutase, peroxidase, and catalase in the leaves of alfalfa were enhanced. The increase accumulation of proline and soluble sugars and the reduced accumulation of hydrogen peroxide in the leaves significantly improved the fruiting rate and seed yield per plant. In the 30 mg·L–1 treatment, although the antioxidative enzyme activity was increased and the main fluorescence parameters were higher than those of the control, the rate of photosynthesis was decreased compared to the control. The decrease in the photosynthetic rate under this treatment was dominated by non-stomatal limiting factors. In conclusion, 20 mg·L–1 6-BA can increase the photosynthetic rate and antioxidant enzyme activity as well as reduce damage to the photosynthetic mechanism of alfalfa leaves at the flowering stage. Moreover, increasing photosynthesis in the alfalfa leaves can increase the fruiting rate and seed yield.
Genetic diversity and population structure analysis of Stylosanthes germplasm resources based on SSR markers
BIAN Hua, SHEN Qing, WEI Haiyan, JIANG Yajun, DING Xipeng, BAI Changjun
2019, 36(3): 729-743. doi: 10.11829/j.issn.1001-0629.2018-0574
[Abstract](848) [FullText HTML] (560) [PDF 1086KB](13)
Correlation analysis of complex traits is based on the genetic diversity and population structure analysis of germplasm resources. In this paper, genetic diversity and population structure of 68 Stylosanthes materials were analyzed using SSR molecular markers. The results showed that a total of 146 alleles were detected in the 68 germplasm materials of 30 polymorphic markers, with an average of 4.867. The Shannon information index (I) and polymorphism information content (PIC) of each SSR marker was 0.676~1.690 and 0.363~0.764, respectively, with an average of 1.195 and 0.577. According to the genetic diversity analysis based on SSR marker data, 68 germplasm resources of Stylosanthes can be divided into six clusters. In the analysis of population structure, when ΔK reached a maximum, i.e., K = 6 , the 68 Stylosanthes accessions were divided into six groups. Our result was consistent with the results of the genetic diversity analysis. This study could provide a basis for correlation analysis and for mining elite genes of Stylosanthes.
Effect of different nitrogen levels on the physiology and ecology of Paspalum wettsteinii
WANG Wenjuan, ZHAO Lili, WANG Puchang, CHEN Chao, YU Qingqing, ZHANG Yujun
2019, 36(3): 744-753. doi: 10.11829/j.issn.1001-0629.2018-0240
[Abstract](822) [FullText HTML] (491) [PDF 770KB](14)
To understand the adaptive mechanisms of Paspalum wettsteinii in response to nitrogen and explore the level of nitrogen suitable for its growth, five nitrogen levels (1, 3, 5, 7, and 9 mmol·L–1) were used in a pot experiment and morphological, physiological, and photosynthetic characteristics of P. wettsteinii were studied. The results showed that when P. wettsteinii was treated with 3 mmol·L–1 of nitrogen, its growth index, biomass, and nitrogen content were higher; soluble protein (SP) content and proline (Pro) content, peroxidase, catalase, and superoxide dismutase activities were higher; chlorophyll content, net photosynthetic rate, transpiration rate, and stomatal conductance were higher; while malondialdehyde content and intercellular CO2 concentration were lower (P < 0.05). Under nitrogen deficiency (1 mmol·L–1) and excess nitrogen (7~9 mmol·L–1) conditions, SP and Pro content, enzyme activities, and chlorophyll content of P. wettsteinii were reduced and plant growth was inhibited. Principal component analysis and fuzzy membership function were used to evaluate the effects of the five nitrogen levels on the performance of P. wettsteinii. The results showed that the optimum nitrogen level for the growth of P. wettsteinii is 3 mmol·L–1.
Effect of different altitudes on the morphological traits of Phleum pratense
ZHU Wenhui, ZHANG Xianhua, ZHU Jinzhong
2019, 36(3): 754-762. doi: 10.11829/j.issn.1001-0629.2018-0332
[Abstract](949) [FullText HTML] (616) [PDF 697KB](13)
The effects different altitudes on the morphological characteristics of the wild species Phleum pratense on the Shaertao Mountain, Zhaosu, Xinjiang, were investigated by measuring the morphological indexes from 1 700 m to 2 200 m. The results showed that: 1) There were significant differences in the morphological characteristics of stem diameter, length of boot, breadth of boot leaf, ear length, small spike width, and spikelet number at different elevations (P < 0.05). Other morphological characteristics did not show regular changes; at 1 900 m above sea level, plants had the longest leaves and the highest number of spikelets. 2) The altitude also has a significant effect on the leaf stomata (P < 0.05), with elevation the upper epidermis cuticular stomatal length grew significantly, and the number of stomata decreased. 3) It was preliminarily indicated that the altitude gradient had a certain influence on the plant morphological characteristics of wild grass, and was the most suitable environment for the growth of the ladder grass at the altitude of 1 900 m.
Forage nutrition from different grassland types at different growth stages on the northeast margin of the Qinghai–Tibet Plateau
ZHANG Chunlin, HAN Xiangmin, LANG Xia, WANG Cailian
2019, 36(3): 763-771. doi: 10.11829/j.issn.1001-0629.2018-0226
[Abstract](1398) [FullText HTML] (593) [PDF 487KB](23)
The purpose of this study was to explore the changes in the nutritional quality of the natural mixed pasture in an alpine meadow, swampy meadow, shrubland, and mountain meadow in Maqu County, and to provide basic data for the rational feeding of grazing livestock in different periods for specific pasture types. Study by the in vitro fermentation method was used to determine the digestibility and nutrient content of natural mixed herbage at different growth stages, including the grass period, early turning green period, and withering period in Maqu County, in an alpine meadow, swamp meadow, shrubland, and mountain meadow. The results are as follows: The growth period had significant influence on the DM, CP, EE, NDF, ADF, GE, Ca, P, NDF digestibility, OM digestibility, and DM digestibility (P < 0.05), but did not significantly affect the ash (P > 0.05); the grassland types had significant effects on the digestibility of ADF, ash, GE, ADF, and the digestibility of OM in Maqu natural grasslands (P < 0.05); and the interaction between growth stages and grassland types had significant effects on DM, CP, NDF, ADF, GE, Ca, P, NDF digestibility, and OM digestibility (P < 0.05). This showed that the seasonal difference in nutritional quality of herbage in Maqu is large.
Effect of different sowing patterns on production performance and soil nutrients in Avena sativa + Vicia sativa mixtures
GUAN Zhengxuan, Naerkezi, ZHU Yaqiong, ZHENG Wei, LIU Yuehan, Ailifeire
2019, 36(3): 772-784. doi: 10.11829/j.issn.1001-0629.2018-0341
[Abstract](1186) [FullText HTML] (664) [PDF 594KB](22)
The productivity performance of legume–grass mixtures was analyzed by comparing forage yield, forage nutrients, seed yield, and soil nutrients inVicia sativa + Avena sativa mixtures with different sowing patterns (mixed cropping, intercropping, and different mix ratios). The effects of sowing pattern on the relationships between soil nutrient characteristics, productivity performance, and the advantages of mixed sowing were discussed. The results showed that 1) V. sativa + A. sativa mixtures can gain advantages from mixed sowing. The legume : grass mix ratios of 50 : 50 with mixed cropping, 50 : 50 with intercropping, and 75 : 25 with mixed cropping all displayed obvious advantages in forage yield and seed yield. 2) Mixed sowing patterns had little effect on soil organic matter or soil total nutrient content. Monocultures of A. sativa had higher soil available phosphorus contents. The biological nitrogen fixation of V. sativa increased the supply of soil nitrogen, and mixed cropping is therefore beneficial for the accumulation of soil alkali nitrogen. 3) When a mixed community structure was used as a control factor, forage yield and crude protein yield were dependent on soil nitrogen nutrition and negatively correlated with soil available phosphorus. When a mixed, high V. sativa ratio (80% and 100%) was used as a control factor, soil nitrogen nutrition negatively affected forage yield, crude protein yield, and forage yield advantage. At lower ratios the relationships were positive. Soil available phosphorus negatively affected forage yield, crude protein yield, and yield advantage, but positively affected grain yield advantage, and showed no correlation with mixed planting proportion. In conclusion, A. sativa + V. sativa mixtures with a legume : grass mix ratio of 75 : 25 with a mixed cropping pattern conferred higher mixed advantages in these cool climate pastoral areas. The mixed pattern could not only improve soil fertility, but also increase harvest forage yield and improve the quality of grass products.
Forage rapeseed yield and nutrition following carpet-seedling transplantation on different planting dates
TAO Yueyue, TANG Yunlong, XU Jian, WANG Haihou, HUANG Meng, SUN Hua, SHEN Mingxing
2019, 36(3): 785-792. doi: 10.11829/j.issn.1001-0629.2018-0300
[Abstract](878) [FullText HTML] (532) [PDF 914KB](11)
A field experiment on carpet-seedling planting techniques of forage rapeseed was conducted from 2016 to 2017 on five different transplanting dates (from 10 to 30 October at 5-day intervals), in the Yangtze river delta. Growth parameters, biomass yield, and nutritional content were analysed to clarify the optimal planting and harvest dates of forage rapeseed in rice fields. The results showed that the biomass of forage rapeseed increased rapidly from the seedling to final flowering stages, which was stable until the podding stage. The crude protein content was decreased at the podding stage. A delay in transplanting inhibited leaf growth and rhizome width at the seedling stage and plant height at the flowering stage. Compared to late transplantation (25 and 30 October), the biomass yield and crude protein content were improved when transplantation was conducted from 10 to 20 October. Whereas, in the plants transplanted on 10 October, the neutral detergent fibre content was significantly increased compared to the other treatments (P < 0.05). Furthermore, a significantly positive correlation was observed between forage yield and secondary branch number, rhizome width, first branch number, and effective leaf number pre-winter. Considering yield, nutrition, and storage, it is optimal to transplant seedlings from 15 to 20 October and harvest at the final flowering until the podding stage for forage rapeseed using the carpet-seedling planting technique in the Yangtze river delta .
Effects of different fertilization schemes on alfalfa performance and nutritional quality
WANG Yang, CUI Guowen, YIN Hang, YANG Liu, ZHANG Yaling, YAN Depeng, GONG Lin
2019, 36(3): 793-803. doi: 10.11829/j.issn.1001-0629.2018-0328
[Abstract](935) [FullText HTML] (591) [PDF 472KB](21)
In this experiment, Medicago sativa ‘Dongnong No.1,’ which was planted in the second year was treated with a newly developed special compound fertilizer (patent number: 201810193040.0). The experiment was conducted in a two-factor random block design using 18 fertilization schemes using different amounts of fertilizer (225, 300, 375, 450, 525, 600 kg·ha–1) and varying periods of fertilization (regreening stage, after the first harvest, and after the second harvest) to determine the effects of the amount and time of fertilization on the yield and quality of alfalfa. No fertilizer was used for the control experiment . We found that fertilizing at various stages and at all the tests concentrations improved both the yield and quality of alfalfa. The highest annual hay yield was 12.15 t·ha–1 following fertilization at 525 kg·ha–1 once during the regreening period, which 38.54% higher than that of the control and 12.50% and 18.42% higher than fertilization with the same concentration after the first and second harvest, respectively. Lower or higher levels of fertilizer used once during the same period affected the hay yield of alfalfa. The highest hay yield was obtained following fertilization with 525 kg·ha–1 once during the regreening period. This was 25.65% and 5.29% higher than fertilization at 225 and 600 kg·ha–1, respectively. The highest crude protein content for the annual average was 23.54% when 450 kg·ha–1 fertilizer was applied during regreening period, which was 14.83% higher than that of the control.
Effect of sowing methods on the productivity of mixed Avena sativa and Vicia sativa pastures
GOU Rong, YOU Minghong, LIU Jinping, LEI Xiong, JI Xiaofei
2019, 36(3): 804-812. doi: 10.11829/j.issn.1001-0629.2018-0382
[Abstract](1336) [FullText HTML] (525) [PDF 521KB](29)
Based on the technical requirements of constructing annual artificial grassland in the Western Sichuan Plateau, Avena sativa and Vicia sativa were used as experimental materials for mixed meadows. Under the same seed quantity conditions, five types of sowing methods, including broadcast and drilling sowing, were used for crops arranged in lines 20 or 30 cm apart. Plant height, tiller number, biomass structure, fresh grass and hay yield, nutrient component, and energy yield were measured for hay grass to analyse the effect of mixed sowing methods on forage productivity. Results show that sowing method had a significant effect on plant height and tiller number for oats and V. sativa, as well as biomass and distribution ratios of individual plants (P < 0.05). Sowing method also had a highly significant effect on density of oats and V. sativa and grassland community composition (P < 0.01). For broadcast sowing, oats reached the maximum yield and V. sativa was at the minimum yield. However, the opposite pattern was observed in the 30 cm inter-row drilling treatment. The total grassland yield was highest in the 20 cm same-row drilling treatment. The nutrient value of forage was highest in the 30 cm inter-row drilling treatment, while the content of crude protein (CP), crude fat (EE) and nitrogen-free extract (NFE) was lowest in this treatment. The effect of mixed sowing methods on the energy of 1 kg of dry matter was ME > DE > TDN > GE, and the influence of energy yield was DE > ME > TDN > GE. Hay grass yield and energy yield were both highest in the 20 cm same-row drilling treatment, which is suitable for application in production.
Adaptation of the DSSAT model under different farming practices in the Loess hilly region
WANG Haiyan, YAN Lijuan, LI Guang, WU Jiangqi, CHEN Guopeng
2019, 36(3): 813-820. doi: 10.11829/j.issn.1001-0629.2018-0000
[Abstract](927) [FullText HTML] (569) [PDF 571KB](15)
Based on test data from a spring wheat field and daily meteorological data for 2016 to 2017 from the Loess hilly region, model parameters were calibrated using the glue parameter estimation module and the "trial and error method," and the root mean square error method was used to test the DSSAT model to evaluate its adaptation under different farming practices. The results showed that the error between the estimated yield simulation and measured yield was in the range of 8.89%~10.98%, and the error for soil moisture content in each layer of the soil profile was 10.39%~14.91%. The error between the simulated and measured values for the main growth period in days was less than 9.09%. Therefore, the DSSAT model may be used to simulate crop yield, growth period in days, and soil water dynamics under different tillage practices, and the model could be used to guide crop production and optimal management of tillage measures in this area.
Advances in studies on morphological plasticity of Leymus chinensis rhizome
BAI Wuyun, HOU Xiangyang, WU Zinian, REN Weibo, ZHAO Qingshan
2019, 36(3): 821-834. doi: 10.11829/j.issn.1001-0629.2018-0378
[Abstract](1512) [FullText HTML] (749) [PDF 627KB](13)
Leymus chinensis is one of the typical rhizomatous grasses, of which rhizome morphological plasticity is the major strategy to adapt to different adversities. This paper includes a review on research achievements on the effects of environmental (such as salt and alkali stress, soil, and water) and ecological (such as community environment and grassland use) factors on the morphological plasticity of L. chinensis rhizomes. The future research in this field is also prospected. Leymus chinensis rapidly escaped from patches with saline alkali stress by increasing spacer length. In poor soil, the length of the internode was shortened and the number increased, which increased fibrous roots to obtain nutrients. Loose soil and adequate moisture were beneficial for the growth and clonal reproduction of L. chinensis. Community environment has complex effects on clonal reproduction via the rhizomes. Long-term overgrazing was not conducive to clonal reproduction of L. chinensis, which showed that the length of rhizomes and the number of buds and ramets decreased. Mowing time and frequency also had an effect. In future studies on rhizomatous plants, such as L. chinensis, research indexes should be simplified, the influence of community environment and disturbance should be mainly studied, and we should try to reveal the mechanisms of adaptations to adversities via rhizomes using modern science and technology.
Research progress on the molecular mechanism of flowering time in forage grasses
WANG Na, XIE Wen'gang
2019, 36(3): 835-848. doi: 10.11829/j.issn.1001-0629.2018-0229
[Abstract](1523) [FullText HTML] (715) [PDF 871KB](19)
Flowering time is an important agronomic trait, and has an important influence on the yield, quality, and utilization of forage grasses. Flowering time is controlled by micro-effect polygenes and the regulatory network is complex. Research on flowering genes and the molecular mechanisms of flowering regulation will facilitate the exploration and utilization of flowering genes, and lead to the development of new forage varieties with different maturities to meet different production requirements. Although flowering genes have been extensively and systematically studied in model plants such as Arabidopsis thaliana, rice (Oryza sativa), wheat (Triticum aestivum), and other crops, there has been comparatively little study of these genes in forage grasses. In this paper, we review the latest advances in the study of flowering genes in order to provide a theoretical reference for the study of these genes in forage grasses.
Effect of autotoxicity and allelopathy on alfalfa and wheat
ZHENG Rui, SHI Shangli, MA Shichen
2019, 36(3): 849-860. doi: 10.11829/j.issn.1001-0629.2018-0223
[Abstract](1111) [FullText HTML] (615) [PDF 1313KB](11)
The continuous cropping and rotation of alfalfa and wheat seedlings were used to simulate the growth and growth of alfalfa and wheat. The results showed that the concentration of the leaching solution was greater than 0.1 g·L–1, and that the autotoxic effect increased with an increase in the concentration of the extract solution. When the leaching solution was used for irrigation at 0.1, 0.25, and 0.5 g·L–1, there was a positive effect of sensation on glutinous wheat, and 0.25 g·L–1 extract had the strongest positive effect, and the wheat extract had a positive effect on quail. The positive effect on wheat was higher than that of other extracts. At a concentration of 1 g·L–1, the activities of antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase, showed a continuous decrease, resulting in an increase in malondialdehyde and H2O2 content and an enhancement in relative membrane permeability. Furthermore, there was a high accumulation of active oxygen, the living system is maintained to be destroyed, growth was inhibited, and glutinous wheat exhibited negative effects. The autotoxic effect of continuous cropping of alfalfa and wheat, thus, increases with an increase in the concentration of the extract. Low concentrations and high concentrations of extracts affected the rotation-heterogeneity of alfalfa and wheat.
Effects of mulberry leaves on blood biochemical parameters and histopathology in rats
CAI Ming, MU Lan, LIU Jianyong, WANG Zongli, HUANG Bizhi
2019, 36(3): 861-870. doi: 10.11829/j.issn.1001-0629.2018-0734
[Abstract](837) [FullText HTML] (536) [PDF 1067KB](16)
Mulberry (Morus alba) is a high-quality protein resource, which contains various anti-nutritional factors and biological active substances that could pose certain risks when present in animal feed. Therefore, the safety of mulberry for use in feed and the appropriate allowable concentration in feed requires investigation. This study aimed to observe the possible toxic responses in Sprague-Dawley rats (SD) rats administered a long-term gavage of mulberry leaves and thus evaluate its safety in addition to providing a basis for the development and utilization of mulberry leaves. Sixty SD rats were selected and divided according to the randomized complete block design. Doses of 1 and 2 g·kg–1 of mulberry leaf extract were administered, as the low and high dose, respectively, in addition to a solvent control group. There were ten male and ten female SD rats in each group. The gavage treatment and recovery periods were 28 days and 14 days, respectively. When the gavage treatment and recovery period ended, the rats were collected to determine the biochemical, organ coefficient, and histopathology indexes. The results showed that most indicators of the physical symptoms in SD rats showed no significant difference compared with those in the control group (P > 0.05). Factors that remained unchanged in each dose group were the biochemical, organ coefficient, and histopathology indexes. However, a few individual indicators were observed to be abnormal, but these were due to normal physiological phenomena and had no toxicological significance. Thus, it was preliminarily verified that mulberry leaves are safe for use in feed. Under the conditions of this experiment, the NOAEL (no-observed-adverse-effect-level) of the mulberry leaf was found to be 2.00 g·kg–1.
Effect of growth stage on the quality of hay and silage of Amaranthus hypochondriacus
MA Jian, SUN Guoqing, Cardela ·Kurban, ZHAO Shangshang, QIU Haori, Senbati ·Heilimubuick, LI Shengli, YU Xiong
2019, 36(3): 871-877. doi: 10.11829/j.issn.1001-0629.2018-0309
[Abstract](993) [FullText HTML] (580) [PDF 565KB](18)
This experiment was conducted to investigate the effects of growth stage on the quality of Amaranthus hypochondriacus hay and silage and thus determine the optimum cutting time for A. hypochondriacus. A. hypochondriacus at the squaring stage, initial bloom stage, full-bloom stage, and mature stage were used as experimental materials to make hay and silage, and to compare the nutrient composition of hay and silage and the fermentation quality of the silage. The results were as follows: 1) with the extension of growth stage, the contents of neutral detergent fiber and acid detergent fiber in A. hypochondriacus hay gradually increased, but the relative feed value decreased; meanwhile, the content of crude protein gradually decreased. 2) The pH was less than 4.2 in all silages except squaring stage silage, and the quality of silage in the squaring stage was poor. Compared with the squaring stage and initial bloom stage, the content of lactic acid in the mature stage was significantly increased (P < 0.05), but it was not significantly different from that of the full-bloom stage (P > 0.05). In addition, the content of acetic acid was lowest, and the ammonia nitrogen: total nitrogen ratio was remarkably lower than that of squaring stage silage. The relative feed value of A. hypochondriacus silage showed a tendency to be gradually reduced with the extension of growth stage, as did the content of crude protein. In contrast, the contents of neutral detergent fiber and acid detergent fiber both had an inverse trend. The contents of water soluble carbohydrates and starch in the mature stage were significantly higher than those in other stages (P < 0.05). It can be concluded that to make hay and silage, it is best to cut A. hypochondriacus during the mature stage.
Effect of steam explosion treatments on nutritional quality of corn–wheat mixed straw
RAN Fu, LEI Zhaomin, JIAO Ting, CHENG Qiang, ZHAO Shengguo, GAO Xuemei, LI Changning
2019, 36(3): 878-887. doi: 10.11829/j.issn.1001-0629.2018-0607
[Abstract](1149) [FullText HTML] (609) [PDF 763KB](10)
To determine the effects of steam explosions on straw feed processing, corn straw silage residue after feeding and wheat straw (7∶3 mixed) were used as test materials. The nutritional value of straw products was evaluated by measuring the conventional nutrients, CNCPS components, gas production in vitro, and physical structure of straw before a steam explosion and at different times (0, 24, and 120 h) after the explosion. We found that crude fat (EE), acid detergent insoluble protein (ADIP), neutral detergent insoluble protein (NDIP), monosaccharide (ESC), soluble protein (SP), total volatile fatty acid (VFA), and calcium (Ca) of mixed straw at different times after the steam explosion were significantly higher than before the steam explosion (P < 0. 05). In contrast, dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (ADL), starch, and phosphorus (P) content were significantly (P < 0. 05) lower than before the steam explosion. The CNCPS component, CHO, starch (CB1), soluble fiber (CB3), non-digestible fiber (CC), insoluble true protein (PB1), and fiber-binding protein (PB2) in the steam explosion group were significantly lower than those in the control (P < 0.05). However, non-fibrous carbohydrate (NFC), volatile fatty acid (CA1), lactic acid (CA2), water-soluble carbohydrate (CA4), ammonia (PA1), soluble true protein (PA2). non-degraded protein (PC), and soluble true protein (PA2) were significantly higher than those in the control (P < 0. 05). Steam explosions could eliminate some anti-digestion materials in straw, increase the contact unit area for microbial activity, gas production, dry matter digestibility, and the relative feeding value (RFV) of corn-wheat straw (P < 0.05). Scanning electron microscopy (SEM) showed that the fiber bonds in corn stalks and panicle skin were broken, the cell wall of the mesophyll was destroyed, only the filamentous veins and filamentous lignin, which were difficult to break, remained, and fibers and fiber bundles became soft and curled after steam explosion treatments. Thus, steam explosions used could significantly change straw’s physical and chemical properties and improve its nutritional value and feeding quality. It is a very effective way to treat straw so that it can be used as feed.
Study on forage products trade and its efficiency in China
SHI Zizhong, WANG Mingli
2019, 36(3): 888-897. doi: 10.11829/j.issn.1001-0629.2018-0348
[Abstract](892) [FullText HTML] (574) [PDF 565KB](23)
Based on the import and export unbalance panel data of forage and forage seed from 1992 to 2016, using a stochastic frontier gravity model, we analyze the trade of forage products and its efficiency in China. The results showed that the import of forage products increased rapidly in recent years, while their export was maintained at low levels for a long time. Alfalfa hay was the main forage variety in the import market, and there were many types of imported forage seeds in China. The market concentration was high in the forage trade market, while forage seed was dispersive. Furthermore, there was a downward trend in forage products export efficiency in China and its trading partners, and the rate of descent of forage seed’s export efficiency was much faster than forage’s export efficiency. The trade efficiency of the forage was higher than that of the forage seed. China’s forage export efficiency was higher than that of its trading partners, while that of the forage seeds was the opposite. Moreover, the regional distribution of the trade efficiency of the forage products was unbalanced, and that of the forage seed was particularly prominent. In recent years, the efficiency of forage export from China to Korea was the highest, whereas the efficiency of forage seed export from China to Netherlands and USA were the highest. The efficiency of forage export from USA to China was the highest for China’s trading partners, and that of forage seed exports from Chile and USA to China were the highest.
Analysis of the circular agricultural model “Animal husbandry–Tea planting–Tea culture tourism” in south Shaanxi
YU Chao, NIE Miao, SUN Bofei
2019, 36(3): 898-905. doi: 10.11829/j.issn.1001-0629.2018-0376
[Abstract](1135) [FullText HTML] (544) [PDF 639KB](18)
With the development and transformation of the livestock industry, the scale and intensification of animal farming has risen rapidly. Hence, the amount of animals per unit of land area has been increasing. Environmental pressure has also increased, and resource utilization of livestock and poultry breeding waste has become a major problem for the animal husbandry industry in southern Shaanxi. The " Animal Husbandry–Tea Planting–Tea Culture Tourism” model combines animal farming, tea planting, and tea culture tourism. It is an innovative model for the recycling of livestock manure. Here, we summarize and discuss the industrial foundation, benefits, restrictive problems, and development proposals of this advanced model, aiming to provide a theoretical basis for the recycling of livestock manure and sustainable development in South Shaanxi.
Changes in land use and landscape patterns in Xanadu site
BAI Lijun, Baoyintaogetao, SU Jinhua, Burentuya, WAN Zhiqiang
2019, 36(3): 906-914. doi: 10.11829/j.issn.1001-0629.2018-0346
[Abstract](866) [FullText HTML] (638) [PDF 5513KB](11)
Cultural grassland relics are the soul of national grassland culture, and have great significance for strengthening the protection of cultural grassland relics. Using remote sensing, geographic information system technology, and landscape analysis software, this study selected single land-use dynamics, comprehensive land-use dynamics, land-use transfer matrix, and landscape pattern index to analyze changes in land-use and landscape patterns of Xanadu site over the past 30 years. The following results were obtained: 1) Grassland is the most important land-use type of the Yuanshangdu site, and the area fluctuated during the study period. 2) In the past 30 years, grassland, woodland, and farmland of the Xanadu site have been frequently transformed, with constant changes in landscape indicators. 3) From 2000 to 2005, the comprehensive dynamic degree of land use was the highest, the single land-use dynamics of forest changed at the highest change. 4) Overall, the landscape is fragile and is becoming more and more diversified and fragmented; however, it has gradually stabilized. The development of an ecological construction project and the constant change of farmer and herdsman production modes are the main reasons for the change. Maintaining the stability of grassland-type area and grassland landscapes, and preventing grassland degradation, is important for protecting the Xanadu site.
Exploration of teaching practice and existing problems in the public elective course “Grassland Culture and Tourism”
SUN Feida, LIU Lin, LIU Wei, ZHOU Jiqiong, ZHAO Jingxue, GONG Siyue
2019, 36(3): 915-920. doi: 10.11829/j.issn.1001-0629.2018-0379
[Abstract](904) [FullText HTML] (545) [PDF 671KB](15)
Public elective courses are an important component of the college curriculum teaching system and undergraduate talent training system. They are also a key method in the promotion of comprehensive quality and humanities education to undergraduates. A new public elective course, " Grassland Culture and Tourism,” was used as a study case. From the perspective of teaching practice and students’ course selection attitude, four aspects were analyzed with 20 questions through the methods of anonymous class questionnaires and individual interviews, in order to evaluate the purpose of public elective course of study, attitudes to learning, the acceptance of the test methods, and teaching ability. The aim of this study was to analyze the existing problems and the reasons for teaching practice in public elective courses and to put forward management suggestions and improvement measures, such as the provision of more high-quality public courses to meet the demand for students’ course learning.
Progress in research on medicinal plant galactagogue feed additives
MA Zhenzhu, SHI Huaiping, KOU Jiancun
2019, 36(3): 921-932. doi: 10.11829/j.issn.1001-0629.2018-0256
[Abstract](1145) [FullText HTML] (637) [PDF 511KB](9)
Medicinal plants have rich resources and diverse biological activities that can be used to replace antibiotic feed additives. Many studies have found that medicinal plant galactagogues can improve milk production, milk quality, immunity, and more. This paper reviews the types of medicinal plant galactagogues used as feed additives. The problems and prospects for use of medicinal plant galactagogues are also discussed.