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2019 Vol.36(5)

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2019, 36(5): 1-4.
[Abstract](796) [FullText HTML] (420) [PDF 456KB](5)
Ecological stoichiometry characteristics of soil and plant of alfalfa with different growing years on the Loess Plateau
ZHAO Rumeng, ZHANG Bingxue, WANG Xiaoxia, HAN Fengpeng
2019, 36(5): 1189-1199. doi: 10.11829/j.issn.1001-0629.2018-0475
[Abstract](1273) [FullText HTML] (689) [PDF 702KB](27)
To investigate the changes inw nutrients in soil-vegetation ecosystems, Medicago sativa at different ages (1, 10, 20, 30 years) was selected to analyze variations in the nutrient content and characteristics of eco-chemical stoichiometry. The results showed that: 1) the content of soil organic carbon (SOC) and total nitrogen (TN) first increased and then decreased as age increased, the vertical distribution of SOC and TN at a soil depth of 0–200 cm was consistent at all alfalfa grasslands, and the content of SOC and TN at a soil depth of 0–30 cm was higher than that at 30–200 cm. However, the content of soil total phosphorus (TP) was stable throughout the soil layer. The ratios of soil C∶N, C∶P, and N∶P showed similar dynamic patterns to soil carbon and nitrogen. 2) The content of C, N, and P in the leaf was similar to that in soil, with maximum values observed at 10 years. The ratios of leaf C∶N, C∶P, and N∶P first decreased and then increased. 3) There was no significant correlation between the stoichiometry characteristics of the soil and plant (P > 0.05). These results indicate that after 10 years, some management measures should be taken to improve the quality of soil and growth of alfalfa.
C, N, and P stoichiometric characteristics of plant communities and dominant plants from different vegetation restoration periods in typical Ningxia grasslands
LU Ying, WANG Baolin, SHEN Yan
2019, 36(5): 1200-1206. doi: 10.11829/j.issn.1001-0629.2018-0357
[Abstract](1052) [FullText HTML] (611) [PDF 502KB](16)
Plant C, N, and P stoichiometric characteristics are directly related to the normal functioning of grassland ecosystems. To determine changes in the stoichiometric characteristics of plant communities and dominant plants from different vegetation restoration periods in the Ningxia typical steppe area, grassland from different restoration periods (21, 16, 11, 9, 5, 3, and 2 years) in southern Ningxia were analysed and the C, N, and P stoichiometric characteristics of plant communities and dominant plants, including Elymus dahuricus, Stipa bungeana, Leymus secalinus, and Poa annua were examined. The results showed that with an increase in the restoration period, the C content of the aboveground part of the plant communities had an overall upward trend, total N content fluctuated, and total P content decreased. C∶N, C∶P, and N∶P were the highest in 1995 and the lowest in 2007. The C content of the aboveground part of the dominant plants was higher than that of the underground part, whereas the total P content of the underground part was larger than that of the aboveground part. There was a positive correlation between N꞉P and total N of plant communities N∶P, total N of dominant plants showed a positive correlation, and N∶P was less than 14. The plant communities and dominant plants in the Ningxia typical steppe area were restricted by N content, and the characteristics of the plant eco-stoichiometry showed some indication of the degradation and restoration of grasslands.
Quantitative traits, age structure and self-thining rule of three shrubs on northest edge of Qinghai-Tibet plateau
XU Wenbing, ZHAO Min, Waleta, SHI Ying, HU Tinghua, YU Yingwen
2019, 36(5): 1207-1214. doi: 10.11829/j.issn.1001-0629.2018-0305
[Abstract](1314) [FullText HTML] (785) [PDF 591KB](30)
The quantitative traits (plant height, crown diameter, number of branches, plant weight and branch weight), age structure and self-thinning rule of Potentilla fruticosa, Salix cupularis and Rhododendron capitatum on the northeast margin of the Qinghai-Tibet Plateau were studied. We constructed the estimation model of plant biomass of this three shrubs, determined their age structures, and clarified the self-thinning relationship between the number of branches and branch weight for each shrub. The results showed that: 1) The impact on the plant weight by the quantitative characteristics of each species was Potentilla fruticosa > Salix cupularis > Rhododendron capitatum; 2) The crown diameter could be used as a suitable index for estimating the shrub plant weight, the estimation models of plant weight (PW, kg) basing on the crown diameters (CD, cm) were PW = –0.310 + 0.014CD for P. fruticosa, PW = –1.688 + 0.033CD for S. cupularis and PW = –0.203 + 0.013CD for R. capitatum, respectively; 3) S. cupularis and R. capitatum was a growing population and had a certain stability, while the P. fruticosa belonged to a stable population; 4) There was an obvious self-thinning law between branch weight and number of branches of R. capitatum. This research shows that the quantitative traits, age structure and self-thinning law for each species is different, which suggests that it is an adaptive result to different habitats and nutrient resources.
Effects of the expansion of Caragana shrubs on forage yield and plant diversity in desert steppe
GUO Pu, XIE Lina, MAN Liang, WANG Jinlong, LI Qingfang, MA Chengcang
2019, 36(5): 1215-1223. doi: 10.11829/j.issn.1001-0629.2018-0430
[Abstract](1052) [FullText HTML] (622) [PDF 648KB](16)
In this paper, we studied the effects of the expansion of Caragana shrub on forage yield and plant diversity in desert steppe by field sample surveys. The results showed that:1) the height of herbs inside shrub canopies was significantly greater than that of herbs outside shrub canopies and non-shrub grasslands (P < 0.05), and the average biomass of herbs in the planted-shrub grassland was significantly higher than that of the natural-shrub grassland and non-shrub grassland; 2) the forage yield in planted-shrub grassland and natural-shrub grassland was significantly higher than that in non-shrub grassland, and the forage yield in planted-shrub grassland was significantly higher than that in natural-shrub grassland, indicating that Caragana shrubs significantly increased the forage yield-this effect was more pronounced in planted-shrub grassland; 3) the species richness, Simpson index, Shannon-Wiener index, and Pielou index of the herbs in planted-shrub grassland and natural-shrub grassland were lower than those in non-shrub grassland, indicating that Caragana shrubs had negative effects on the diversity of herbs; and 4) Caragana shrubs significantly enhanced the dominance of the useful forage species Stipa krylovii.
Effects of phosphatic fertilizer addition on plant community characteristics in an alpine grassland around Qinghai Lake
WANG Ling, SHI Jianjun, SHANG Zhanhuan, SHI Huilan, CHEN Weiyuan, Genggachenlin, Gengqiubamao
2019, 36(5): 1224-1230. doi: 10.11829/j.issn.1001-0629.2018-0372
[Abstract](998) [FullText HTML] (560) [PDF 880KB](13)
To determine the suitable amount of phosphate fertilizer to be used in an alpine grassland in the area surrounding Qinghai Lake, experiments were conducted in the mildly degraded alpine grassland of Xihai Town, Haiyan County in 2017. Treatments included 0 (CK), 120 (P1), 240 (P2), 360 (P3), and 480 kg·ha–1(P4). The goal of the research was to examine the change in grassland plant community characteristics, to determine the optimal scheme for regional fertilization. The results showed that the application of diammonium phosphate significantly increased the important values for grasses, sedges, and legumes in grassland communities (P < 0.05). In particular, the coverage and importance value of lentils (Melilotoides archiducis-nicolai) (P < 0.01). The biomass of the grassland community increased significantly under different fertilization gradients(P < 0.05). The biomass of grassland community was higher, which was 31.28%~47.13% higher than that of the control, When the application rate of diammonium phosphate was 120~240 kg·ha–1. The net income increased by 28.42%~38.37% compared with the control. The economically feasible amount of DAP was 120~240 kg·ha–1 in the alpine grassland around Qinghai Lake.
Evapotranspiration and water dynamics of lucerne and following crops in the northwest Loess Plateau
SONG Liping, NIU Yining, LUO Zhuzhu, NIE Jun, LI Tengfei, LI Lingling
2019, 36(5): 1231-1239. doi: 10.11829/j.issn.1001-0629.2018-0280
[Abstract](1032) [FullText HTML] (626) [PDF 775KB](16)
The formation of a dried soil layer after the long-term cultivation of lucerne (Medicago sativa) in the northwest Loess Plateau, China, could seriously affect the growth of subsequent crops. A field study was conducted to investigate the evapotranspiration and water dynamics of crops cultivated after lucerne production. This study involved the following six treatments: lucerne-lucerne (L–L), lucerne-fallow (L–F), lucerne-wheat (Triticum aestivum, L–W), lucerne-corn (Zea mays, L–C), lucerne-potato (Solanum tuberosum, L–P), and lucerne-millet (Setaria italica, L–M). Average water use efficiency (WUE) was greater in the L–P treatment, followed by the L–C treatment, and was the lowest with the L–W treatment after 3 years of continuous production, indicating that 9-year-old lucerne rotated with potato and corn resulted in higher crop WUE than the other treatments. The L–C treatment had the highest water consumption during the crop growing period; however, it had the lowest evaporation among the different treatments, which decreased the percentage of evaporation of crop total water consumption to 17.0%, which promoted transpiration in the corn crop. Average field water content was increased by 18.4% to 34.9% compared to continuous lucerne in the 0 to 300 cm soil layer depth. The L–F treatment was the best for water restoration among the six treatments, followed by the L–P treatment. Based on the WUE and soil water characteristics, potato and corn are optimal crops for cultivation after lucerne in the northwest Loess Plateau, China. Therefore, optimising land-use management can mitigate the formation of a dried soil layer and assist the development on the northwest Loess Plateau.
Analysis of degradation response factors of a 17-year-old pasture in the source area of the Yellow River
SUN Huafang, LI Xilai, JIN Liqun, ZHANG Jing
2019, 36(5): 1240-1248. doi: 10.11829/j.issn.1001-0629.2018-0407
[Abstract](941) [FullText HTML] (606) [PDF 758KB](16)
To study the degradation of pastures in the alpine region, a 17-year-old pasture (dominant species was Elymus nutans) in the DaWu source area of the Yellow River was studied. We investigated the soil nutrients and plant community characteristics of pastures degraded to different degrees (severe degradation, moderate degradation, and non-degradation control area), which included 18 response factors. The results showed that there was no significant difference in soil nutrients among the non-degradation, moderate, and severe degradation pastures (P > 0.05). The difference in the coverage of E. nutans, Poaceae, and forbs between the moderate and severe degradation pastures was highly significant (P < 0.01). The plant diversity index in the moderate degradation area was higher than that of the other two pastures, and there was a significant difference in the Simpson index between the non-degradation and degradation pastures (P < 0.05). The different responses of 18 factors of the degraded pasture were analysed with the random forest method. Plant community characteristics such as E. nutans coverage and reproductive branch number were found to be more sensitive to degradation than the other response factors. Poaceae coverage less than 65% could not be used as an indicator to monitor the degradation of pastures. Soil organic matter content and total nitrogen content were insensitive to the degree of degradation, which indicated that the soil physical and chemical properties of pastures had stabilised during the past 17 years. Therefore, the coverage of Poaceae plants could be used as an important evaluation base for monitoring and investigating the degradation of pastures.
Effects of exogenous salicylic acid on the resistance of Kentucky bluegrass to brown patch and expression of PR1 and NPR1 resistance genes
WEI Chunxue, SU Haotian, ZHANG Xiaoyu, HE Wenhan, ZHENG Dacheng, YIN Shuxia
2019, 36(5): 1249-1254. doi: 10.11829/j.issn.1001-0629.2018-0409
[Abstract](914) [FullText HTML] (535) [PDF 744KB](12)
To explore the effect of external salicylic acid (SA) on the resistance of Kentucky bluegrass (Poa pratensis) to brown patch, Kentucky bluegrass variety ‘Midnight’ was divided into three groups and treated with 0.05 mmol·L–1 SA and Rhizoctonia solani. The percent of disease infection and disease index were measured, and the efficacy of resistance induced was calculated. The relative expression of disease resistance genes PR1 and NPR1 was assessed. The results showed that external SA could significantly (P < 0.05) decrease the plant infection percent and disease index of brown patch on Kentucky bluegrass, and the highest efficacy of resistance induced by SA was 53%. After spraying SA and inoculation, the relative expression of PR1 and NPR1 increased significantly (P < 0.05).
Cloning, transcriptional activation, subcellular localization and expression analysis of ZjERF2 from Zoysia japonica
ZHANG Rui, JIANG Hongyan, TENG Ke, TAN Penghui, WANG Cheng, LIU Lingyun, CHANG Zhihui
2019, 36(5): 1255-1265. doi: 10.11829/j.issn.1001-0629.2018-0415
[Abstract](962) [FullText HTML] (568) [PDF 1865KB](10)
In this study, ZjERF2 (GenBank No. MH479420) from Zoysia japonica was cloned using the RACE method. The open reading frame of ZjERF2 was 825 bp in length, encoding 274 amino acids. One highly conserved AP2 domain was found in ZjERF2, indicating that it is a typical ERF transcription factor. Phylogenetic analysis showed that ZjERF2 has the highest genetic relationship with ERF from Panicum hallii. The pGBKT7-ZjERF2 vector was constructed and transformed into Y2HGold yeast competent cells and was found to have strong transcriptional activation activity. Using the Genome walking method, a 1 549 bp upstream promoter sequence in front of the ATG was obtained. Prediction using the PLACE online database showed that it contained multiple cis-elements that respond to hormone and stress treatments. Next, 35S꞉꞉ZjERF2꞉YFP was generated to analyse its subcellular localization character. Transient expression analysis in Nicotiana benthamiana demonstrated that ZjERF2 was located in the nucleus. To further explore its expression characteristics, real-time quantitative PCR (qRT-PCR) was performed. qRT-PCR showed that ZjERF2 was expressed in the root, stems, and leaves of Zoysia japonica. There were differences in the expression levels of ZjERF2 in varied tissues and at different developmental stages, and it was expressed most abundantly in leaves, and particularly in mature leaves. Moreover, its expression could be induced by ET and MeJA but was suppressed by NaCl, PEG, or ABA. This study indicates that ZjERF2 is a transcription factor that can participate in a variety of signal transduction pathways.
Effects of drought stress on physiological and growth characteristics of the seedlings of three ornamental grasses
WANG Jinghong, CHEN Peng, CHEN Ai, TIAN Jingyao, MUHAMMAD Siddique, LI Yanxue
2019, 36(5): 1266-1274. doi: 10.11829/j.issn.1001-0629.2018-0388
[Abstract](965) [FullText HTML] (605) [PDF 1157KB](20)
Through the natural water loss stress test, the effects of drought stress on seedling growth and physiology of Peuuisetum alopecuroides, Festuca glauca ‘Freddy’, and Stipa tenuissima ‘Pony Tails’ were investigated, and their drought resistance was comprehensively evaluated. The results showed that during drought stress, the decreased soil water content of P. alopecuroides was lower than that in the other two groups. The average growth rate and leaf chlorophyll content decreased, while the proline content and malondialdehyde content of the plants increased as drought stress was prolonged. Moreover, the superoxide dismutase activity of the plants increased initially, and then decreased as drought stress was prolonged. As drought stress was prolonged, the soluble protein content of P. alopecuroidesfirst increased and then decreased, but the soluble protein content of F. glauca and S. tenuissima decreased initially and then increased. We performed a comprehensive evaluation of drought tolerance of the three ornamental grass seedlings with subordinate function and determined the order of drought tolerance to be S. tenuissima ‘Pony Tails’ > F. glauca ‘Freddy’ > P. alopecuroides.
Possible factors that caused weed-induced harm to Bermudagrass (Cynodon dactylon × C. transvaalensis) in Nanjing Zhongshan International Golf Course
WANG Xiuyun, XUE Guang, LI Chunyan, YE Qinmiao
2019, 36(5): 1275-1282. doi: 10.11829/j.issn.1001-0629.2018-0448
[Abstract](985) [FullText HTML] (647) [PDF 550KB](13)
Based on a survey conducted from 2000 to 2016 on weed species and their population change and by combining the practical experience of weed control in Nanjing Zhongshan International Golf Course, this study aimed to determine the possible factors that are responsible for weed-induced harm to Bermudagrass (Cynodon dactylon × C. transvaalensis). The authors considered the following aspects: 1) Geographical (natural): Neighboring Zhongshan mountain national park with high species diversity; 2) Geographical (farmland): Species seed bank change due to multiple cultivation practices; and 3) New turf varieties introduced from different places; and 4) Those introduced during turf maintenance. This paper demonstrated that the unique geographical location, along with human socio-economic activities interfere with ecosystems and exacerbate the increasing diversity and abundance of weed seed bank present in turf substrates. This continuously expanding weed seed bank is the key external factor that causes persistent damage to Bermudagrass. In accordance with the " proactive approach for turf weeds control” and weed control practices of golf courses, the authors propose a blueprint to set up weed prevention and control database, adjust turf maintenance strategies, cut off the channels of weeds reproduction, prioritize bio-control over herbicide, and to guard against herbicide resistance in turf grass.
Identification of the cyst nematode parasited on Achnatherum inebrians
ZHANG Yiwen, LI Huixia, CHEN Xiuju, XU Penggang, GUO Jing, ZHANG Shuling
2019, 36(5): 1283-1291. doi: 10.11829/j.issn.1001-0629.2018-0275
[Abstract](1028) [FullText HTML] (616) [PDF 696KB](8)
To clarify the condition of cyst nematodes on Gramineae grasses that are infested with parasites, samples from roots and rhizosphere soil of Achnatherum inebrians (Hance) Keng were collected at Tianzhu alpine meadow steppe, Gansu, China in the middle of August, 2017, and a simple flooring separation method was used to separate nematodes from the roots and soil. The result indicated that the cereal cyst nematodes are found in the soil, and the white females are present on the roots of A. inebrians. The nematodes were initially identified as Heterodera avenae Wollenweber, 1924 based on morphological measuring and characteristics of the vulval fenestra, vulval slit, underbridge, and bullae. The ITS1 and 28S regions of ribosomal DNA of nematode populations were amplified and identified, and the phylogenetic trees were determined using the Maximum Likelihood method of MEGA 6.0. The ITS1 region of rDNA were genetically close to the population of H. avenae from China. The 28S rDNA region was genetically closed to the H. avenae population from the Czech Republic. Identification using morphological and molecular characteristics confirmed that the nematode found on A. inebrians was H. avenae. This is the first report to confirm that A. inebrians can parasitized by H. avenae. The study provides a theoretical basis for the prevention of A. inebrians.
Research developments on the effects of grass – endophyte fungi symbiosis on soil physical and chemical properties and microbes
JIN Yuanyuan, SAMAN Bowatte, TIAN Pei, PENG Zechen, HOU Fujiang, LI Chunjie
2019, 36(5): 1292-1307. doi: 10.11829/j.issn.1001-0629.2018-0286
[Abstract](1456) [FullText HTML] (684) [PDF 704KB](23)
Grass-endophyte symbiosis can promote plant resistance for adversities, enhances agronomic traits, as well as reduces the feeding of herbivores. Underground processes are mainly altered through litter decomposition dynamics and roots exuding organic compounds that influence the underground biological processes. The effect of grass-endophyte symbiosis on soil physical, chemical, and biological properties and processes varies depending on the type of grass, endophyte strain, and soil type. The effects on the physical properties of soil mainly relate to soil structure, and the effects on soil chemical composition are mainly reflected in the changes to soil carbon and nitrogen. The effects on soil biology were mainly observed in soil fungi, gram-negative bacteria, and nematodes. In this paper we reviewed the responses of grass-endophyte symbiosis on soil properties and functions to elucidate the mechanisms of interactions between grasses and microorganisms in the host soil habitat and their functions, to generate new knowledge for the discovery and development of novel endophytic grass cultivars. The aims are to (1) elucidate the mechanism and function of interaction between symbionts and microorganisms in host soil habitats, (2) to identify and develop novel grass-endophytic fungi symbionts and (3) to utilize these to alter the soil microenvironment, providing a theoretical basis for the discovery and development of new grass-endophytic fungal symbionts and the use of new grass-endophytic fungi symbiosis to change the soil microenvironment.
Solanum nigrum mediated remediation of Cd contaminated soil
ZENG Xing, LI Weiya, CHEN Zhang, CHEN Guoliang, CHEN Yuanqi, LI Zhixian
2019, 36(5): 1308-1316. doi: 10.11829/j.issn.1001-0629.2018-0421
[Abstract](1532) [FullText HTML] (714) [PDF 607KB](17)
In recent years, soil cadmium (Cd) pollution has become a serious threat, and remediation of Cd contaminated soil is urgently needed. Because of the rising interest in green and environment-friendly technologies, phytoremediation is one of the most concerned in situ technologies among various remediation methods for heavy metal contaminated soil at present, which designed to use plants to absorb or stabilize the contamination in soil. Thus, proper selection of plants is key to the successful implementation of phytoremediation in the field. The accumulation characteristics and physiological response towards Cd of a typical hyperaccumulator named Solanum nigrum was reviewed in this paper. Moreover, Cd tolerance mechanisms of rhizosphere chelation, compartmentation and antioxidant system of S. nigrum under Cd stress were also discussed. Furthermore, the application of a combined remediation technology using S. nigrum and Cd-curing additives, agronomy measures or microorganisms were analysed, and the emphasis of future research on S. nigrum was proposed to improve the fixation and absorption of Cd in the soil. The discussion in this paper will provide a good reference for the future implementation of phytoremediation in heavy metal contaminated soil.
High-frequency regeneration system of mature embryos of Elytrigia elongata
ZHOU Yantong, GUO Qiang, MAO Peichun, TIAN Xiaoxia, CUI Guowen, MENG Lin
2019, 36(5): 1317-1322. doi: 10.11829/j.issn.1001-0629.2018-0419
[Abstract](1178) [FullText HTML] (588) [PDF 628KB](22)
The mature embryos of Elytrigia elongata seeds were used as explants and MS was used as the basic medium to carry out research on callus induction, green plantlet differentiation, and rooting by adding different growth regulator media. The results showed that the suitable medium for callus induction was MC (MS + 30 g·L–1 Maltose + 1 g·L–1 CH + 5 mL·L–1 200× VB + 0.5 g·L–1 L-Pro + 3 g·L–1 Phytagel) + 3 mg·L–1 2,4-D + 0.025 mg·L–1 6-BA. The induction rate was 77.78%, and the callus was visible after 4 weeks. The best differentiation medium was MC (MS + 30 g·L–1 Maltose + 1 g·L–1 CH + 5 mL·L–1 200× VB + 0.5 g·L–1 L-Pro + 3 g·L–1 Phytagel) + 0.1 mg·L–1 2,4-D + 3 mg·L–1 6-BA, and the differentiation rate was 66.67%. The budding point appeared after 4 weeks, accompanied by root hair development. The best rooting medium was MR (1/2 MS + 15 g·L–1 Maltose + 3 g·L–1 Phytagel) + 0.5 mg·L–1 NAA. All plantlets survived after transplanting. Therefore, differentiation tissue culture regeneration system for E. elongata was established, including mature embryos-inducing callus-green plantlet differentiation-rooting-transplantation, which lays an important foundation for further study of its molecular mechanism of resilience.
Effects of osmotic stress by PEG-6000 on germination of Vicia unijuga seeds under different temperature conditions
TANG Wei, NAN Zhibiao
2019, 36(5): 1323-1332. doi: 10.11829/j.issn.1001-0629.2019-0122
[Abstract](1081) [FullText HTML] (693) [PDF 768KB](14)
Our aim was to identify the response of germination and growth of Vicia unijuga seeds to temperatures and water potentials. Germination experiments were conducted at three temperatures (15, 20 and 25 ℃) controlled by constant temperature incubators and six water potentials (ψ) (0, –0.2, –0.4, –0.6, –0.8, –1.0 MPa) created using different concentrations of polyethylene glycol (PEG-6000) in distilled water. The results showed that the germination parameters (germination percentage, rate and index, and vigor index) and growth parameters (sprout and radicle length) were significantly (P < 0.05) higher at 20 ℃ than at 15 ℃ and 25 ℃, respectively. Osmotic stress inhibited seed germination and seedling growth of V. unijuga, which could be alleviated by appropriately increased temperature. A significant (P < 0.05) improvement in germination rate, vigor index, and sprout and radicle length was at the lower water potential (–0.6 to –1.0 MPa) with 20 ℃ compared with 15 ℃, whereas a significant (P < 0.05) decreased in germination percentage, rate and index and vigor index was at the lower water potential with 25 ℃ compared with 15 ℃. Hydrotime model analysis showed that the basic water potential (Ψb) of V. unijuga seed increased with increasing temperature ranging from 15 °C to 20 °C and then decreased at 25 °C. The lowest Ψb value (–1.27 MPa) was attained at 20 °C, showed that this species could germinate constrained by the relative serious drought condition at this temperature regime.
Effects of ultrasound and ascorbic acid treatments on the germination and physiological characteristics of aged Haloxylon ammodendron seeds
ZHAO Tian, LIU Xu, ZHOU Wennan, PAN Shengnan, ZHANG Yujing, ZHONG Yuan, JIANG Wenbo, WANG Quanzhen
2019, 36(5): 1333-1343. doi: 10.11829/j.issn.1001-0629.2018-0492
[Abstract](962) [FullText HTML] (616) [PDF 876KB](10)
Seeds may undergo irreversible aging during long-term storage, causing a decline in the seed quality and yield. Reasonable repair treatments can improve the vigor and quality of aged seeds. In this study, an orthogonal matrix test method was used to study the influence of ultrasound temperature, ultrasound time, ascorbic acid (AsA) concentration, and AsA soaking time, on seed germination and the physiological characteristics of artificially aged Haloxylon ammodendron seeds, to evaluate if there were repair effects on the seeds and to identify optimal treatment conditions. The results indicated that an ultrasound temperature treatment and AsA treatment had positive repair effects on the aged seeds. The treatments significantly promoted (P < 0.05) the percentage of seed germinated, the germination potential, germination index, and seedling length. Further, the soaking liquid conductivity was decreased, as were the malondialdehyde (MDA) content and the proline content; however, the soluble protein content, superoxide dismutase (SOD), peroxidase (POD), and the catalase (CAT) activity increased. Ultrasonic temperature is one of the most important factors that can influence seed germination and seed vigor, it was concluded that the optimal treatment conditions for aged Haloxylon ammodendron seeds were an ultrasound temperature of 25 ℃, an ultrasound exposure time of 20 min, an AsA concentration of 300 mg·L–1, and an AsA soaking time of 24 h.
Salt tolerance of five varieties of tall fescue at the germination stage
XIE Yuhan, HONG Sheng, ZHU Jin, WANG Jing, LIU Lu, CHAI Qi
2019, 36(5): 1344-1352. doi: 10.11829/j.issn.1001-0629.2018-0262
[Abstract](1051) [FullText HTML] (599) [PDF 671KB](19)
The top of paper (TP) germination method was used to compare the salt tolerance for five tall fescue (Festuca arundinacea) strains at the germination stage in an illumination incubator. Double-layered paper moistened with pure distilled water served as the control, whereas the papers for the experiment were moistened with 6 NaCl concentrations respectively: 50, 100, 150, 200 and 250 mmol·L–1. Germination potential, rate, and index, shoot and root length, as well as salt damage rate showed no remarkable difference between the control (P > 0.05) and the strain germinating at 50 mmol·L–1 NaCl. Relative germination potential, percentage, and index, shoot and root length, and seed vigor index decreased with increases in NaCl concentration; however, the relative salt damage increased when the NaCl stress increased from 50 to 250 mmol·L–1. At 250 mmol·L–1 NaCl, the seedings were seriously damaged, and the relative germination potential, percentage, and index, shoot and root length, and seed vigor index were at their lowest (P < 0.05). The results following comprehensive assessment indicate that the 5 strains can be arranged as follows in the decreasing order of salt tolerance: Tar Heel Ⅵ > Watchdog > RubyⅡ > Baker > Super Watchdog.
Effects of light on the germination of dominate plant seeds in an abandoned cropland in northern Shaanxi
ZHAO Fuwang, WANG Ning, GE Fanghong
2019, 36(5): 1353-1360. doi: 10.11829/j.issn.1001-0629.2018-0454
[Abstract](857) [FullText HTML] (564) [PDF 773KB](8)
During seed germination, the light sensitivity of seeds can guarantee germination and emergence of seedlings under appropriate conditions. Therefore, the presence or absence of light can affect seed germination of certain species. In this study, 10 dominate plant seeds from an abandoned cropland in northern Shaanxi were chosen as research material. Seed germination characteristics were observed under both full-light and full-darkness conditions. The results showed that most of the 10 dominate plants germinated quickly. Under light conditions, the germination of seeds of 7 species reached T50 (time at which the number of germinated seeds reaches 50% of the total number of germinated seeds) within 4 days (d), and the minimum T50 was 9 d. Among all the experimental species, there were 7 species that achieved T90 in a shorter time under light conditions. Additionally, the seed germination index of different species under light conditions was significantly different. The seeds of species, including Dracocephalum moldavica, Artemisia sacrorum, Leonurus artemisia, Potentilla tanacetifolia, and Patrinia scabiosaefolia had a significantly higher germination percentage under light conditions than that under dark conditions. Only the germination percentage of Setaria viridis was significantly greater in darkness than in light. The germination percentage of seeds of other plants was not significantly different between the two conditions studied. The above results show that light is an important factor affecting plant seed germination on the abandoned cropland in the study region and darkness had an inhibitory effect on seed germination in most species. Thus, during the soil erosion process, sediment silting and shading are potential limiting factors for plant regeneration.
Physiological response and comparison of Sorghum sudanense and S. bicolor × S. sudanense seedlings under drought stress
ZHU Yongqun, PENG Dandan, PENG Yan, ZHANG Xinquan, CHEN Shiyong, XU Wenzhi, YAO Li, WANG Xie, LIN Chaowen
2019, 36(5): 1361-1370. doi: 10.11829/j.issn.1001-0629.2018-0433
[Abstract](955) [FullText HTML] (588) [PDF 810KB](13)
The physiological responses of nine cultivars of Sorghum sudanense and three cultivars of S. bicolor × S. sudanense were studied under drought stress induced by polyethylene glycol 6000 (PEG-6000) based on a sand culture experiment. The results show that materials with better drought tolerance have better water retaining capacity, higher chlorophyll content, and better photosynthesis and membrane integrity under drought stress. The drought tolerance of the 12 cultivars were evaluated by subordinate function values analysis according to seven physiological parameters (leaf relative water content, electrolyte leakage, malondialdebyde content, chlorophyll content, photochemical efficiency, net photosynthetic rate, and water use efficiency). Three S. sudanense cultivars (No. 1, 2, and 3) and cultivar No. 10 (‘Shucao No. 2’ S. bicolor × S. sudanense), cultivar No. 11 (‘Shucao No. 1’ S. bicolor × S. sudanense), and cultivar No. 12 (‘Hay-King’ S. sudanense) had higher drought tolerance, and two S. sudanense cultivars (No. 7 and 8) and a S. bicolor × S. sudanense cultivar (No. 9) had lower drought tolerance. This study provides basal data for the cultivation and utilization of forages and selection of new cultivars with higher drought tolerance.
Effects of exogenous silicon on root morphology of Elymus nutans seedlings under simulant drought stress
YANG Zhi, CHEN Shiyong, ZHOU Qingping, WANG Hui, CHEN Youjun, HU Jian
2019, 36(5): 1371-1378. doi: 10.11829/j.issn.1001-0629.2018-0709
[Abstract](859) [FullText HTML] (518) [PDF 714KB](13)
In order to explore the effect of exogenous silicon (Si) on the root morphology of Elymus nutans seedlings under drought stress, the total root length, root surface area, root volume, average root diameter, and root branch number of seedlings were determined by adding exogenous Si under polyethylene glycol (PEG-6000) simulated drought conditions. The results showed that the total length, root biomass, root surface area, root volume, average root diameter, branch root numbers, and root tip numbers of seedlings were increased with increasing concentrations of exogenous Si when treated with 15% PEG for 7 days. Nevertheless, these indices first increased and then decreased under the condition of 15% PEG for 21 days as the concentration of Si increased, and 0.5 mmol·L–1 was found to be the best concentration for Si. Meanwhile, the root index of seedlings with the diameter range of R1 (0~0.5 mm) increased significantly (P < 0.05) with Si addition. These results indicate that Si addition enhanced the ability of fine root differentiation and alleviated the damage due to drought stress to the root system of E. nutans seedlings by adjusting the root morphology of seedlings to adapt to the arid environment. This study provides an important reference for drought resistance research and the production and utilization of E. nutans.
Physiological response and transcriptome analysis of Hordeum brevisubulatum under mixed salt and alkaline stress
SONG Shiwei, JIAO Dezhi, YANG Yunfei
2019, 36(5): 1379-1388. doi: 10.11829/j.issn.1001-0629.2018-0446
[Abstract](971) [FullText HTML] (624) [PDF 1010KB](14)
In order to study the physiological response and salt tolerance genes of wild barley (Hordeum brevisubulatum) under saline alkali stress, 45-day-old seedlings were treated with different concentrations of NaCl and NaHCO3. The critical value of saline alkali stress was determined by physicochemical analysis. The gene expression was analysed by RNA-Seq. The soluble protein content and superoxide dismutase (SOD) activity of wild barley leaves increased first and then decreased after treatment with different concentrations of NaCl and NaHCO3 (100, 200, 300, 400, 500 mmol·L–1) for 2 days. The maximum value was reached at 300 mmol·L–1, and the content of proline and soluble sugar showed a continuous upward trend. The wild barley leaves in the 300 mmol·L–1 treatment group were sequenced and analysed. Compared with the control group (treatment of salt and alkali free), 4 163 genes were up-regulated and 1 936 genes were down-regulated. The Gene Ontology (GO) function classification of the differentially expressed genes could be divided into 52 subclasses of three main categories: biological process, cell component, and molecular function. A total of 4 405 differential genes were annotated into 132 pathways, mainly involved in sucrose synthesis, proline synthesis, peroxisome metabolic pathways. The genes encoding sucrose synthase (SuS), ornithine aminotransferase (OAT), glutamate kinase (proB), glutamate-5-semialdehyde dehydrogenase (proA), superoxide dismutase (SOD) were up-regulated. Wild barley can adapt to saline alkali stress by increasing the content of some osmotic regulators, this metabolic process regulates the physiological mechanism of regulating the expression of related genes.
Effects of different concentrations of NO3-N on the growth and nutrients uptake of Festuca arundinacea
ZHANG Shen, LIU Yeping, LIU Liping, YU Cunshen, LYU Shaoyuan, LI Haiyun, SI Dongxia
2019, 36(5): 1389-1395. doi: 10.11829/j.issn.1001-0629.2018-0611
[Abstract](829) [FullText HTML] (567) [PDF 564KB](14)
In order to clarify the growth and nutrients absorption characteristics of Festuca arundinacea under different NO3-N levels and to determine the NO3-N concentration suitable for its optimal growth, Ca(NO3)2 was used as an exogenous nitrogen source in this study. The growth and nutrients uptake response to different concentrations of NO3-N (0, 5, 10, 15, 20 mmol·L–1) were studied under the conditions of quartz sand pots cultivation. The results showed that exogenous NO3-N had significant effects on the growth of both shoots and roots of Festuca arundinacea. With increased NO3-N concentrations, the plant height and dry matter accumulation of the shoots first increased and then decreased. The root dry matter accumulation, root length, and root surface area decreased with the increase in NO3-N concentration, and the mean root diameters were not statistically different between the treatments. Increasing the concentrations of NO3-N could increase phosphorus (P) concentrations and P uptake, and the suitable concentrations of NO3-N could promote the absorption and accumulation of nitrogen and potassium in the shoots. The optimal concentration of NO3-N for Festuca arundinacea’s growth was 4.3~18.2 mmol·L–1. From the above results, 4.3 mmol·L–1 NO3-N can be used as a reference for the rational level of N fertilization for Festuca arundinacea conservation and management.
Cesium accumulation and resistance of oats
QI Lin, YANG Yingbo, SHEN Zhiqiang, ZHANG Wenyan, ZHAO Wei, WANG Xiaoling
2019, 36(5): 1396-1404. doi: 10.11829/j.issn.1001-0629.2018-0411
[Abstract](959) [FullText HTML] (577) [PDF 848KB](11)
To investigate the effects of metallic cesium (Cs) on oat growth and antioxidative enzyme activity, oats (Avena sativa) were used as study material. Treatments of different concentrations of Cs (25, 100, 500, and 1 000 mg·kg–1) were applied to the soil. Oats were cultured in the soil for 30 days to study the enrichment and distribution of Cs in oats treated with different concentrations thereof. The effects on growth index, malondialdehyde (MDA) content, and superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activity were determined. The results showed that: 1) The root length, plant height, and biomass of oat seedlings increased first and then decreased with increasing concentrations of the metal yttrium in soils under different concentrations of Cs; 2) All leaves were able to accumulate Cs, but the ability to accumulate the metal gallium was significantly different among different plant organs and showed the order root > leaf > stem. The accumulation of Cs in different organs differed significantly among different concentrations of Cs. 3) The MDA content firstly decreased and then increased with the Cs concentration in soils. For Cs treatments of 25~500 mg·kg–1, SOD activity did not differ significantly from that of the controls (P > 0.05). However, there was a significant decrease in SOD activity upon treatment with 1 000 mg·kg–1 Cs (P < 0.05). The activities of POD and CAT both increased first and then decreased with the increase in Cs concentration. The results showed that the roots, stems, and leaves of oats could accumulate Cs, and the leaves were most enriched in Cs. Low concentrations of Cs could induce an increase in POD and CAT activity in oats and promote their ability tolerate and resist stress, although high concentrations of Cs inhibit the antioxidant enzyme activities of oats. This study provides a theoretical basis for the physiological and ecological effects of Cs stress on plants.
Application of CRISPR/Cas system in anti-plant virus research
YAN Hongbo, GAO Yanli, SUN Shiwei, DOU Yandan, WU Zhiming
2019, 36(5): 1405-1414. doi: 10.11829/j.issn.1001-0629.2018-0416
[Abstract](983) [FullText HTML] (631) [PDF 888KB](31)
In recent years, the CRISPR/Cas system has been widely applied for plant genome editing as well as in studies of anti-plant viruses because of its simplicity and effectiveness.In this review, progress in the use of the CRISPR/Cas system is briefly introduced, followed by a description of the applications of the CRISPR/Cas9 and CRISPR/Cas13a systems to plant viruses, introducing two basic antiviral strategies: Targeting viral genes and targeting host plant genes. Additionally, the potential applications of CRISPR/Cas12a and related prokaryotic Ago systems against plant viruses are discussed, including the challenges of applications involving CRISPR/Cas. The CRISPR/Cas system will bring revolutionary changes to plant antiviral breeding because of its advantages in anti-plant virus research.
Research status and prospect on diseases and pests of Panax notoginseng
LI Hongwei, GUO Fugui, LIU Yang, SHI Fuyun, DONG Zhixiang, ZHANG Qilin, LIN Lianbing, CUI Xiuming, YUAN Minglong
2019, 36(5): 1415-1427. doi: 10.11829/j.issn.1001-0629.2018-0583
[Abstract](1183) [FullText HTML] (758) [PDF 794KB](11)
Panax notoginseng is an upright perennial herb belonging to the family Araliaceae and is a famous Chinese herbal medicine. As an important economic plant in the balanced ecological strategy of livestock and grass on the Yunnan-Guizhou Plateau, P. notoginseng plays a key role in the economic development of Wenshan, Yunnan Province. In recent years, with the rapid increase of artificially cultivated areas of P. notoginseng, pest and disease problems have become more prominent, which has become a limiting factor for the healthy and sustainable development of P. notoginseng. Currently, there are seven types of diseases related to approximately 20 species of pathogens; at least 12 species of pests are found. Among the diseases caused by P. notoginseng, root rot disease is the most serious, with an incidence rate of more than 80%. Spider mites and thrips are important insect pests of P. notoginseng, resulting in a significant decrease in the fruiting rates of P. notoginseng. This paper reviews the existing research on diseases and pests of P. notoginseng and summarizes species and groups, symptoms, and control measures of the major pests and diseases affecting this plant. It also suggests promising research directions to promote basic plant health by applying knowledge regarding diseases and pests affecting P. notoginseng. This review provides references for the comprehensive control of these diseases and pests.
Effects of ultraviolet radiation on three types of protective enzymes in Therioaphis trifolii
LU Yafei, ZHANG Xiang, WANG Guang, MA Wen, LIU Changzhong
2019, 36(5): 1428-1434. doi: 10.11829/j.issn.1001-0629.2019-0263
[Abstract](861) [FullText HTML] (545) [PDF 562KB](10)
To clarify the effect of ultraviolet radiation (UV-B) on the activity of three protective enzymes (SOD, POD, and CAT) in Therioaphis trifolii, nymphs were exposed to 40 W UV-B radiation for 20, 30, 40, 50, and 60 min within 12 h of hatching. The nymphs were irradiated once a day continuously for 6 days and the activity of the protective enzymes was measured in the last 8 generations subjected to continuous exposure. The study showed that the activity of CAT and SOD first increased and then decreased with the extension of radiation time and the activity in all treated aphids was significantly higher than in the control (P < 0.05) in the same generation, and the maximum activity was 12.84 and 8.05 times that of the control, respectively. In each generation at 40 min of exposure, CAT activity was the highest, POD activity was the highest except in the F5 generation, and SOD activity was the highest except in the F6 generation. Secondly, the activity of CAT, SOD, and POD under the same treatment first increased and then decreased with each successive irradiated generation and the maximum activity was 12.84, 8.05, and 2.09 times that of the control, respectively. The activity of CAT and POD was the highest in the F6 generation, except at 30 min, and SOD activity was the highest in the F6 generation. These results showed that UV-B can significantly improve the activity of the protective enzymes (P < 0.05) in Therioaphis trifolii and that CAT and SOD play a key role under UV-B radiation.
Ecological management of degraded alpine pasture areas under the development of the tourism industry
LI Xiangmei, PENG Yuanliu, YUE Jie
2019, 36(5): 1435-1444. doi: 10.11829/j.issn.1001-0629.2018-0429
[Abstract](922) [FullText HTML] (545) [PDF 625KB](18)
Ecological management of degraded grassland in alpine pastoral areas is the ecological and environmental construction goal in the Tibetan Plateau. In this study, we created an Ⅳ Probit Regression Model based on an investigation of 354 households in Nam Co Lake Basin to analyze the interaction between the development of the tourism industry and the indigenous people’s behaviors. Results showed that: 1) The participation of indigenous people in the development of the tourism industry had a positive effect on the household’s behavior to choose ecological ways to manage degraded grassland; 2)The development of the tourism industry stimulated indigenous people’s willingness to participate in off-agricultural industries, improving the ability of the local government to manage rural public affairs; and 3) The bottom-up rural governance approach, which starts from the micro households’ perspective and behavior, is the basis and premise of China’s implementation of the rural revitalization strategy. We believe that the development of rural tourism in underdeveloped areas can improve the effectiveness of the ecological management of rural degraded environments, providing a theoretical basis for the rural revitalization strategy.
Evaluation of sustainable development in Qinghai based on energy ecological footprint model
SU Wenliang, LI Wenlong, ZHU Yali, CAI Dong, YU Cui, XU Jing, WEI Wei
2019, 36(5): 1445-1456. doi: 10.11829/j.issn.1001-0629.2018-0269
[Abstract](963) [FullText HTML] (583) [PDF 1139KB](17)
The ecological footprint analysis method is one of the classical methods for measuring the consumption of human social resources in ecological economics. The emergy-based ecological footprint model is the latest development and improvement in this field. In this study, we used regional standards to calculate the ecological carrying capacity and ecological footprint, which can better reflect the real supply capacity of the region and the actual consumption of resources by humans. The methods and data are better than the universally adopted global standards. We quantitatively analyzed the state of sustainable development in Qinghai Province from 2005 to 2014 based on the emergy ecological footprint model, and combined with the ecological footprint of ten thousand yuan GDP, ecological footprint diversity index and development capability index to comprehensively analyze economic development situation of Qinghai Province, and the GIS spatial analysis technology was used to analyze the spatial differences and their changes in the sustainable development of the study area. The results showed 1) The ecological footprint of Qinghai Province exceeded the ecological carrying capacity from 2005 to 2014, the ecological footprint index was less than 0 and declining, and Qinghai Province was in an unsustainable state of development. 2) The areas of unsustainable development in the study area were continuously expanding from 2005 to 2014, which were mainly concentrated in the eastern urban area and their surrounding counties. After 2011, there was a strip distribution from north to east. 3) Ecological energy footprint and multi-factor coupling analysis showed that although the resource utilization efficiency and development capability in Qinghai Province had been greatly improved, it is mainly at the expense of a large amount of resource consumption. The deterioration of ecological environment such as soil erosion, deterioration of ecological functions, decline of regional carrying capacity, and reduction of self-regulation ability was still serious. The results of this study can provide a useful reference for the sustainable development of the Qinghai-Tibet Plateau.
Effects of silage maize and Dolichos lablab intercropping on quality and yield of silage maize
TIAN Yingxue, MA Peijie, LI Yajiao, WU Jiahai, MU Qiong, XIONG Wenkang, ZHANG Zhonggui, HAN Yongfen
2019, 36(5): 1457-1465. doi: 10.11829/j.issn.1001-0629.2018-0335
[Abstract](1062) [FullText HTML] (588) [PDF 584KB](24)
To develop new methods and technologies for improving the quality and increasing the yield of silage maize, intercropping of silage maize (Zheng Silage No. 1) and Dolichos lablab was examined in Jiujiang Township, Songtao County, Guizhou Province. The effect of intercropping of multiple rows of D. lablab with silage maize on the yield and quality of silage maize was evaluated after three treatments: no intercropping (A0), a row of silage maize + a row of D. lablab (A1), and a row of silage maize + two rows of D. lablab (A2). The results showed that the yield, crude protein, crude ash, leaf length, total nitrogen, total phosphorus, and total calcium content of silage maize increased significantly with increasing rows of D. lablab intercropped with silage maize. The highest yield of silage maize was 55 350.00 kg·ha–1, which can increase farmers' income by 10 520.50 CNY·ha–1 over that from silage maize cultivated alone. The crude fat, dry matter weight, and plant height of silage maize were highest when intercropping one row of D. lablab with silage maize, and significant differences were detected among different treatments (P < 0.05). The leaf width and leaf number of silage maize decreased with increasing row numbers of intercropping D. lablab. There was no significant difference between neutral detergent fiber and acid detergent fiber in the three treatments. The yield, crude protein, crude ash, N, P, Ca, Mg, nitrogen-free extract, and leaf number of silage maize varied considerably with different interplanting treatments, and the coefficient of variation ranged from 10% to 32.9%. The intercropping of silage maize and D. lablab showed strong interplanting advantages. Therefore, to increase yield and interplanting advantages, the silage maize and D. lablab interplanting row number ratio should be 1∶2. However, based on the highest content of crude ash under this treatment, it is necessary to further evaluate intercropping treatment.
Discussion of the present situation of China’s forage grass industry development:An example using alfalfa and oats
GUO Ting, XUE Biao, BAI Juan, SUN Qizhong
2019, 36(5): 1466-1474. doi: 10.11829/j.issn.1001-0629.2018-0424
[Abstract](1333) [FullText HTML] (575) [PDF 814KB](50)
This paper discusses the development status of China's pasture industry from the perspective of demand, import and production capacity and analyzes the constraints of the development of China's pasture industry from the perspective of resources, policy, technology and market. The results show that the demand for high-quality pasture in China is rising in the future, and the gap between supply and demand is huge. Domestic pasture can not meet the huge demand of domestic animal husbandry and therefore requires a large amount of imports. However, Sino-US trade war will increase the cost of pasture import and will compress pasture in the future. The importation has forced the rapid development and transformation of the domestic pasture industry. In recent years, the planting area and output of domestic pastures have shown an obvious upward trend, and the production and processing capacity of related enterprises has been significantly enhanced, but the pasture industry still faces resource factors and policy factors. Serious constraints on technological factors and market factors.