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2021 Vol.38(11)


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2021, 38(11): 0-0.
[Abstract](1035) [FullText HTML] (571) [PDF 1943KB](100)
2021, 38(11): 1-4.
[Abstract](811) [FullText HTML] (462) [PDF 363KB](101)
Effects of grazing intensity on community characteristics and vegetation living states in alpine meadows
LUO Fanglin, ZHANG Fawei, ZHANG Guangru, WANG Chunyu, ZHU Jingbin, YANG Yongsheng, LI Yingnian
2021, 38(11): 2097-2105. doi: 10.11829/j.issn.1001-0629.2021-0179
[Abstract](1599) [FullText HTML] (779) [PDF 1067KB](55)
Changes in plant community characteristics and vegetation living states may reflect interspecific relationships and succession processes within plant communities. This study used the cold-season grazing grassland of the alpine meadow in Haibei, Qinghai Province as its research object to analyze and compare the characteristics of the vegetation community and the plant living state resulting from four different grazing management practices, including grazing prohibition (CK, no grazing), light grazing (LG, 4.5 sheep·ha−1), moderate grazing (MG, 7.5 sheep·ha−1), and heavy grazing (HG, 15 sheep·ha−1). The results showed that 1) Gramineae, Cyperaceae, and weeds had the highest importance value indexes in LG, CK, and HG plots, respectively; 2) the Shannon-Wiener index, Simpson index, and Patrick richness showed an increasing trend with increasing grazing intensity; and 3) Elymus nutans and Poa orinosa had the highest survival status indexes in the LG plots, whereas Kobresia humilis and Saussurea nigrescens had the highest survival status indexes in the CK plots. Noteworthy, with the increase in grazing intensity, the survival status index of Saussurea nigrescens also increased. The results of this study showed that, as the grazing intensity increased, the community diversity of the alpine meadows and the survival status and dominant position of weeds in the community increased; in contrast, the survival status and dominant position of grasses in the community and the quality of the grassland decreased.
Shrub and herb flora and vertical distribution patterns in Shangri-La, China
LIU Wendou, WU Wenjun, WANG Zizhi, ZHOU Junhong, GUAN Yuan, LIAO Shengxi
2021, 38(11): 2106-2116. doi: 10.11829/j.issn.1001-0629.2021-0127
[Abstract](1732) [FullText HTML] (702) [PDF 1630KB](28)
As the most important components of global ecosystem functional services, grasslands are the basis for the development of agriculture, forestry, and animal husbandry; thus, a study of the characteristics of shrub and herb flora and geographical distribution is of great value, in particular to reveal regional species diversity and conservation strategies. In this study, the diversity, floristic characteristics, and vertical distribution patterns of shrubs and herbaceous (including graminoid) plants in Shangri-La were systematically analyzed with the use of field surveys and historical records database and applying the Wu Zhengyi flora zoning method. The results show that 1) the region is rich in shrub and herb (including graminoid) species, with 121 families, 619 genera and 2 442 species, and most of this richness can be attributed to herbs, with 94 families, 514 genera and 2 048 species. 2) In the composition of families and genera, the dominant families and genera were obvious, and the proportion of single species families and oligospecific genera was high, accounting for 32.23% and 51.05%, respectively, of the community composition. As well, the surveyed areas are extremely rich in endemic Chinese genera (28). 3) The regional components are diverse, containing 13 families and 15 genera of geographical distribution types. The distribution types of the family are mainly world distribution, pantropical distribution, and north temperate distribution. The ratio value of the tropical distribution and the temperate distribution is 1.29, which indicates that the tropical distribution type is slightly dominant. The distribution types of the genera are mainly north temperate distribution, East Asian distribution and pantropical distribution, and the ratio value of tropical distribution and the temperate distribution is 0.39, which indicates that the temperate distribution type is dominant. 4) In terms of vertical distribution, with the increase in elevation, the proportion of tropical zone components gradually decreases and temperate zone components gradually increase, and the species richness shows a single-peak distribution pattern of rising and then decreasing, with the peak of shrub and herb species richness located at 2 600 ~ 2 900 m and 3 200 ~ 3 500 m, respectively, and the number of herbaceous plants is more than that of shrubs in each altitude section (P < 0.01). With this study we have produced an altitudinal inventory of plant diversity and zone characteristics in the central area of the Three Parallel Rivers World Natural Heritage Site. This altitudinal inventory is expected to be a valuable reference for the selection and rational use of species for ecological restoration of regional shrublands and herbaceous vegetation.
GIS-based regionalization of cultivated forages in Shaanxi Province, China
CAO Xinyue, LI Tengfei, WANG Yingying, JIN Xumei, LIU Chongyi, CHEN Xinyi, LIU Mengyun, LONG Mingxiu
2021, 38(11): 2117-2125. doi: 10.11829/j.issn.1001-0629.2021-0172
[Abstract](1281) [FullText HTML] (641) [PDF 1273KB](40)
Improved animal husbandry is needed in order to fully modernize the agricultural sector in Shaanxi Province, China. The zoning of cultivated forage grass is an important strategy for addressing the shortage of high-quality forage grass and promoting the development of the Shaanxi grass cultivation industry. In this study we developed a model based on Geographic Information System (GIS) spatial analysis, fuzzy mathematics, and analytic hierarchy process. Using topographic data, main meteorological data, and the soil properties of Shaanxi Province, we selected five main indicators that affect the growth of forage grass, including annual precipitation, annual average temperature, soil pH, topography, and slope. The cultivated forages in Shaanxi Province were systematically sorted out, and a zoning model for the suitability of cultivated forages with comprehensive module functions and strong adaptability was constructed. Four major cultivated forages, including alfalfa (Medicago sativa), sainfoin (Onobrychis viciaefolia), perennial ryegrass (Lolium), and crested wheatgrass (Agropyron cristatum), were used as examples to carry out the model analysis. Crested wheatgrass was used as an example for verification. The results showed that this model is effective and could provide scientific predictions and decisions for the introduction of new forage varieties and the production of high-quality forage, as well as laying a foundation for the development of computer-assisted forage production in Shaanxi Province.
Effects of grazing on composition and concentration of polyphenols in vegetation – soil of alpine meadow in Qinghai-Tibet Plateau
CHEN Ling, WANG Luhui, GUO Hui, YANG Zhen’an
2021, 38(11): 2126-2134. doi: 10.11829/j.issn.1001-0629.2021-0276
[Abstract](1092) [FullText HTML] (549) [PDF 1123KB](37)
As secondary metabolites of plants, polyphenols not only affect the palatability and nutritional value of forage, but also affect soil carbon stability through the accumulation of litter and root exudates in the soil. Previous studies have shown that grazing can change the content and composition of vegetation phenols, but few studies have specifically investigated the variation of vegetation-soil polyphenols under the influence of grazing. To fill this knowledge gap, an alpine meadow (grazing and grazing prohibition) in the Hongyuan county region of the Qinghai-Tibet Plateau was selected as the research object, where we analyzed the variation in vegetation community characteristics, composition, and content of polyphenols in the vegetal-soil system under winter grazing and grazing prohibition, respectively. The results showed that: 1) grazing decreased the coverage of grass, but increased the coverage of forbs such as Ranunculaceae, Rosaceae, and Polygonaceae. 2) Grazing decreased the coverage of the vegetation community (P = 0.643) and the concentration of simple phenol in the 0 – 20 cm soil layer (P = 0.190), and significantly decreased the biomass of the vegetation community (above- and belowground parts), the concentration of simple phenol in the aboveground part of vegetation, and the total phenol and tannin in the 0 – 30 cm soil layer (P < 0.05). 3) However, grazing increased the species richness of the vegetation community (P = 0.357), as well as the concentration of simple phenol in the belowground part (P = 0.369), and significantly increased the concentration of total phenol and tannin in the above- and belowground parts of the vegetation (P < 0.05). The results of this study provide a new idea for protecting and maintaining the healthy and sustainable development of alpine meadows on the Qinghai-Tibet Plateau.
Effects of grazing exclusion years on module structure and growth pattern of Stipa grandis clones in a typical steppe
PING Weimeng, ZHAO Lingping, LIANG Fanghui, TAN Shitu, WANG Dong, SUN Ping, ZHAO Furong
2021, 38(11): 2135-2143. doi: 10.11829/j.issn.1001-0629.2021-0233
[Abstract](1006) [FullText HTML] (492) [PDF 946KB](24)
In this study, we selected different grasslands subjected to varying periods of grazing exclusion (10 and 20 years) and grazed grassland (control) as sites on the Loess Plateau. We harvested the whole clones to study the effects of number of grazing exclusion years on module structures and growth patterns of Stipa grandis clones, which provides a theoretical basis for studying module structures and resource allocation. We found that: 1) compared with grazing, grazing exclusion for 10 years significantly increased the size, reproductive height, and inflorescence height of S. grandis (P < 0.05), and grazing exclusion for 20 years markedly improved the size, total tillers, reproductive tillers, vegetative tillers, total buds, reproductive height, inflorescence height, total aboveground biomass, biomass of vegetative tillers, and biomass of inflorescence (P < 0.05). In addition, grazing exclusion reduced the coefficient of variation (CV) of reproductive tillers, reproductive height, inflorescence height, total aboveground biomass, biomass of reproductive tillers, and biomass of inflorescence. 2) For the biomass allocation ratio, vegetative tiller significantly increased, reproductive tiller decreased, and inflorescence showed no significant change (P > 0.05) with increase in grazing exclusion years (P < 0.05). 3) The biomass of vegetative tillers was significantly higher in grazing exclusion grasslands than in grazed grasslands (P < 0.05); however, there was no significant difference in the biomass of reproductive tillers and total tillers (P > 0.05). 4) The S. grandis size showed a significant positive correlation with the total aboveground biomass, reproductive tiller number, biomass of reproductive tiller, and biomass of inflorescence (P < 0.001). It also showed a significant positive correlation with biomass of vegetative tillers (P < 0.01) and a positive correlation with total tiller numbers (P < 0.05). Total aboveground biomass had a significant positive correlation with reproductive tiller numbers, vegetative tiller numbers, total tillers, and biomass of vegetative tillers (P < 0.001); it also had a significant positive correlation with total buds, biomass of reproductive tillers, and biomass of inflorescence (P < 0.01). Finally, total bud numbers showed a significant positive correlation with vegetative tiller numbers, total tiller numbers, and biomass of vegetative tillers (P < 0.001) and a significant positive correlation with total aboveground biomass (P < 0.01). In conclusion, short-term grazing exclusion improves the reproductive allocation of S. grandis and results in S. grandis rapidly becoming the dominant species, while long-term exclusion results in generation of S. grandis mainly through asexual reproduction.
Effects of simulated precipitation changes and nitrogen deposition on biomass allocation patterns of Reaumuria soongarica and Salsola passerina seedlings under different growth modes
LU Wentao, CHONG Peifang, TIAN Yanli, JIA Xiangyang
2021, 38(11): 2144-2154. doi: 10.11829/j.issn.1001-0629.2021-0118
[Abstract](1104) [FullText HTML] (603) [PDF 1102KB](11)
Water and nitrogen are important resources for plant biomass accumulation, as well as the main factors that regulate biomass allocation in different plants and their growth patterns under adverse conditions. In this study, the seedlings of two dominant desert plants, Reaumuria soongarica and Salsola passerina, were used as test materials to study the synergistic effect of precipitation [–30% (low water), 0 (medium water), +30% (high water)] and nitrogen [0 (N0, no nitrogen, 4 g·(m2·a)−1 (N1, low nitrogen), and 8 g·(m2·a)−1 (N2, high nitrogen)] on biomass distribution and related growth relationships under different growth modes (R. soongarica grown separately, S. passerina grown separately, and R. soongarica and S. passerina grown together). The results showed that: 1) R. soongarica and S. passerina seedlings were significantly affected by water and nitrogen (P < 0.01). With separate R. soongarica, the root biomass increased under low nitrogen and high water conditions and the biomass of stems and leaves increased under high nitrogen and medium water, while the distribution of the biomass between organs was root > stem > leaf. The root, stem, and leaf biomass of mixed R. soongarica increased as the conditions went from no nitrogen and low water, to no nitrogen and medium water, and then to low nitrogen and high water, and the biomass distribution was leaf > stem > root. The organ biomass of both separate and mixed S. passerina increased under low nitrogen and high water, and its distribution remained as leaf > stem > root. 2) The leaf-root weight ratio, leaf weight ratio, and source to sink weight ratio of R. soongarica under the mixed mode were higher than those under the separate mode, whereas, the root-shoot ratios under the mixed mode were reduced compared with the separate mode by 52.63% (R. soongarica) and 37.45% (S. passerina), indicating that both species could allocate more biomass to the above-ground parts when grown combinedly. In the future, under changes in precipitation patterns and nitrogen deposition, mixed communities of R. soongarica and S. passerina may be more conducive to adapting to global climate changes than those grown separately, which will lead to the mixed state having an advantage in the desert ecosystems.
A preliminary study on the morphological characteristics of phytoliths of desert plants in Gonghe Basin, Qinghai Province
HUANG Lili, DUAN Zhonghua, QUAN Xiaolong, LI Xiaoqing, CHEN Mengci, SHI Huilan, WANG Zhanqing
2021, 38(11): 2155-2165. doi: 10.11829/j.issn.1001-0629.2021-0269
[Abstract](1431) [FullText HTML] (731) [PDF 1049KB](56)
This study aimed to explore the morphological characteristics of phytoliths in different plants and different parts of the same plant under alpine and arid climate conditions, to enrich the research results about plant phytoliths. It is expected to provide a reference point for the reconstruction of ancient vegetation and plant classification in this area. In this study, the wet digestion method was used to extract phytoliths from common desert plants in the Tala Shoal of the Gonghe Basin, and the types of the extracted phytoliths were identified and the morphological parameters were measured. A total of 81 298 phytoliths were counted in 10 plant samples, and 20 main types of phytoliths were identified, including rondel, elongate, trapeziform, lanceolate, bilobate, and blocky irregular. The parameter sizes of the six main types of phytoliths in the aboveground and underground parts of plants were 0.9~40.1 and 1.1~42.6 µm, respectively. Desert plants have typical phytolith types that are unique for different families, and the main types of phytoliths are different in different plant parts. The percentage content and parameter size of the same phytolith form were also different in different plants and different parts of the same plant. In general, among the plants sampled, the types and number of phytoliths in the aboveground parts were greater than those in their underground parts, and were the most abundant in Poaceae.
Physiological response to salt tolerance of a waxy mutant of Dianthus spiculifolius
WANG Jingang, LIU Jianhua, WANG Aofu, GONG Shufang, QIAO Kun, ZHOU Aimin
2021, 38(11): 2166-2175. doi: 10.11829/j.issn.1001-0629.2021-0274
[Abstract](1163) [FullText HTML] (564) [PDF 1779KB](19)
Salt stress can cause osmotic stress and ion toxicity, leading to cell dehydration, inhibition of photosynthesis and respiration, and further effects on the growth and development of plants. Plant cuticular wax can prevent non-stomatal water loss from leaves, reduce transpiration, and slow down physiological drought caused by stress. In this study, the wild-type (WT) and a mutant with increased cuticular wax (WM) of Dianthus spiculifolius ornamental ground-cover species were used, and their phenotypic, physiological, and biochemical indicators under NaCl stress were compared. The results showed that, under NaCl stress, the waxy mutant showed a more salt-tolerant phenotype resulting from its higher water content. In addition, the waxy mutant showed higher peroxidase (POD) and catalase (CAT) activity, soluble sugar content, proline content, photosynthetic capacity, and lower malondialdehyde (MDA) content under NaCl stress. Dewaxing experiments showed that the difference in relative water content and water retention between the waxy mutant and the wild-type under NaCl stress was directly related to cuticular wax. These results suggest that cuticular wax plays an important role in the plant’s response to salt stress.
Photosynthesis, antioxidant enzyme activity, and transcriptome sequencing analyses of Glycyrrhiza uralensis seedlings in response to drought stress
GUAN Sijing, WANG Nan, XU Rongrong, GE Tiantian, GAO Jing, PENG Liang, ZHANG Gang, CHEN Ying
2021, 38(11): 2176-2190. doi: 10.11829/j.issn.1001-0629.2020-0647
[Abstract](1276) [FullText HTML] (629) [PDF 2393KB](33)
To explore the physiological and molecular mechanisms of Glycyrrhiza uralensis under drought stress simulated by polyethylene glycol 6000 (PEG-6000), transcriptome sequencing, photosynthetic characteristics, and antioxidant enzyme activity analyses were performed. The results showed that the values of net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) were the lowest at 7 d under drought stress. Relative chlorophyll content [soil and plant analysis development (SPAD)] first increased and then decreased. Oxidative stress was induced by drought stress on G. uralensis. Catalase (CAT) activity of the leaves increased, whereas CAT activity of the roots decreased after 1 day of treatment. After 7 days of treatment, peroxide (POD) and superoxide dismutase (SOD) activities increased and decreased in the roots, respectively. Transcriptomic analysis identified a total of 7 500 differentially expressed genes (DEGs) in the aboveground parts and 5 298 DEGs in the underground parts. Gene ontology (GO) enrichment results showed that the DEGs of the aboveground and underground parts were both significantly enriched for cellular process, metabolic process, cell structure, catalytic activity, transporter activity, etc. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that DEGs in the aboveground and underground were both significantly enriched in transcription factors, protein kinases, phenylpropanoid biosynthesis, and cytochrome P450, etc. Transcriptional regulatory network analysis predicted that transcription factors such as ethylene responsive factor (ERF), basic helix-loop-helix (bHLH), NAM/ATAF/CUC (NAC), v-myb avian myeloblastosis viral oncogene homolog (MYB), and WRKY may be involved in regulating the expression of secondary metabolism genes. In conclusion, this study revealed the effects of drought stress on physiological characteristics of G. uralensis, and analyzed gene expression profiles in different parts of G. uralensis. Our results provide valuable information for understanding drought-resistance mechanisms of G. uralensis.
Effects of different additives and densities on silage quality of hybrid Pennisetum
LU Guicong, XU Hui, YU Yongxiong, JIANG Caode
2021, 38(11): 2191-2199. doi: 10.11829/j.issn.1001-0629.2021-0199
[Abstract](1073) [FullText HTML] (491) [PDF 836KB](28)
In order to improve the quality of hybrid Pennisetum silage, an orthogonal design was adopted in this study, with four factors at three levels, namely corn flour (A) (0, 3%, and 6%), urea (B) (0, 0.3%, and 0.6%), lactic acid bacteria (C) (0, 5, and 10 g·t−1), and density (D) (700, 800, and 900 kg·m−3), to explore the effects of the four factors on quality and nutritional value of Pennisetum silage and to screen the optimum silage density and additive amount of corn meal, lactic acid bacteria, and urea. The results showed that: 1) The comprehensive scores of sensory assessment in the six treatment groups ranged from 9 to 15, with a grade 2 or above. 2) Corn flour significantly increased crude protein (CP) and relative feeding value (RFV) (P < 0.01) and significantly decreased neutral detergent fiber (NDF), acid detergent fiber (ADF), crude ash (Ash), pH value, and ammonia nitrogen content in a dose-dependent manner (P < 0.01). 3) Urea dose-dependently enhanced CP and RFV values (P < 0.01) but significantly reduced NDF and ADF content (P < 0.05). When urea was added to 0.6%, CP increased by 7.05%, but NDF and ADF decreased by 1.38% and 1.45%, respectively. 4) When treated with lactic acid bacteria at 5 g·t−1 and density at 700 kg·m−3, respectively, the silage possessed the highest RFV but the lowest values of NDF and dry matter (DM) in the treatments. In conclusion, the three additives improve the fermentation effect of hybrid Pennisetum silage in the order of flour > urea > lactic acid bacteria, with the best effect at 700 kg·m−3. The optimal combination includes 6% corn flour, 0.6% urea, 5 g·t−1 lactic acid bacteria, and density of 700 kg·m−3.
Physiological response of different salt-tolerant oats to salt stress
WANG Miaomiao, ZHAO Guiqin, LIANG Guoling, CHAI Jikuan, LI Juanning, ZHOU Xiangrui
2021, 38(11): 2200-2209. doi: 10.11829/j.issn.1001-0629.2020-0357
[Abstract](1330) [FullText HTML] (608) [PDF 1249KB](87)
This study aimed to investigate the physiological response of different salt-tolerant oats to salt stress, using Qingyongjiu 195 (salt-tolerant) and 709 (salt-sensitive) as test materials. Three-week-old oat seedlings grown in sand culture were treated with Hoagland nutrition containing 150 mmol·L−1 NaCl for 0 (CK), 6, 24, and 72 h, and the effects of salt stress on photosynthesis, antioxidant properties, and osmotic regulation of the two oat seedlings were investigated. The results showed that the chlorophyll content, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci), and K+ content of oat seedling leaves showed a decreasing trend with the extension of treatment time. The trend of peroxidase (POD), superoxide dismutase (SOD) activity, proline, and soluble sugar content first increased and then decreased, while other indices, including catalase (CAT) activity, malondialdehyde (MDA), and Na+ content showed an increasing trend. Under salt stress, the range of descent of chlorophyll content, Pn, Tr, and Gs in salt-tolerant Qingyongjiu 195 was less than that in salt-sensitive 709, whereas its SOD, CAT, proline content, and soluble sugar content were higher than that in 709, and MDA content was lower than that in 709. After salt stress at 6 and 24 h, the contents of K+ and Na+ in the roots of Qingyongjiu 195 were lower than that in 709, and higher than that in 709 at 72 h. After salt stress at 6 and 24 h, the content of K+ in the leaves of Qingyongjiu 195 was higher than in 709, whereas the content of Na+ was lower than that in 709. Overall, our study showed that salt-tolerant Qingyongjiu 195 possessed superior adjustment ability, antioxidant enzyme activity, and biofilm stability.
Response of three dominant forages to drought stress at different growth stages
Wurina, ZHANG Xingdong, WANG Yan, ZHANG Jiquan
2021, 38(11): 2210-2220. doi: 10.11829/j.issn.1001-0629.2021-0223
[Abstract](935) [FullText HTML] (460) [PDF 1094KB](18)
To quantitatively evaluate the effects of different levels of drought stress on the morphological characteristics and drought resistance of three dominant grass species at different growth stages, field drought stress experiments, membership functions, and fixed-point real-time observations were carried out in the Songnen grassland. The results showed that, at the same growth stage, the higher the degree of drought, the greater the influence of drought stress on plant height, leaf length, chlorophyll content, and yield. Consequently, the morphological characteristics of the three types of forage were most seriously affected under extreme drought stress. Under steady drought stress conditions, the plant height, leaf length, chlorophyll content, and yield gradually decreased with growth stage, and the morphological characteristics of all three types of forage were most seriously affected in the turning green stage. When both the growth stage and drought grade were superimposed, a synergistic effect on the morphological characteristics of all three forages was observed. The drought resistance of the forages during their growth periods showed a certain trend. All three showed their strongest responses at the flowering stage. However, while Leymus chinensis and Kalimeris integrifolia had a stronger response to drought stress during the turning green stage than at the heading stage, Artemisia anethifolia showed a higher resistance during the heading stage than at the turning green stage. The results of this study may be used as a guide when planning for contingencies involving drought stress faced by grasses at different growth stages. It may also provide a reference for cultivating excellent drought-tolerant grass species and for the sustainable development of grassland ecosystems.
Effect of the sowing period on the yield and quality of seven oat varieties grown in the semi-arid region of Longxi
TONG Yongshang, LIU Yaofeng, XU Changlin, ZHANG Xuanming, YU Xiaojun
2021, 38(11): 2221-2236. doi: 10.11829/j.issn.1001-0629.2021-0002
[Abstract](1236) [FullText HTML] (658) [PDF 1356KB](24)
In order to select suitable varieties for Avena sativa cultivation in the semi-arid mountainous region of western Gansu and to determine the best sowing date, the production performance and nutritional quality of seven oat varieties at four sowing dates (May 6th, 15th, and 26th, and June 5th, 2020) were studied, and a comprehensive evaluation was carried out using the grey correlation cluster analysis. The results showed that, together, the sowing date and variety had significant effects on hay yield, forage quality, and seed yield (P < 0.01). Among the 28 treatments, ‘Menglong’ variety sown on May 26th had the highest hay yield at 13 550.80 kg·ha−1, ‘Monika’ sown on June 5th had the highest seed yield at 2 147.31 kg·ha−1, and ‘Qingyan No. 1’ sown on May 26 had the highest crude protein content at 6.94%. Based on the relative values of hay yield, crude protein content, neutral detergent fiber, acid detergent fiber, and soluble sugar content, the comprehensive evaluation of the grey correlation degree showed that ‘Longyan No. 3’ planted on May 6 was the best variety/sowing date combination, followed by that of ‘Menglong’ planted on May 26th. Through systematic clustering, the 28 treatments were divided into four groups according to hay yield, seed yield, and crude protein content. Thus, selecting the appropriate sowing date is a suitable management strategy for oat grasslands in this area.
Comprehensive evaluation of production performance and nutritional quality of 16 Bromus inermis germplasm resources
HUANG Wei, CHANG Wei, YU Shuyan, LI Xiaoyun, GAO Xueqin, FU Bingzhe
2021, 38(11): 2237-2246. doi: 10.11829/j.issn.1001-0629.2021-0246
[Abstract](1328) [FullText HTML] (660) [PDF 1071KB](40)
To select the Bromus inermis germplasm materials with excellent performance and nutritional quality, performance and nutritional quality indicators of 16 germplasm resources were measured and analyzed, and a comprehensive evaluation was performed using gray relational and cluster analyses. The results showed that there were significant differences in the production performance and nutritional quality of the different B. inermis germplasm materials (P < 0.05). The fresh yield of Q6, Q8, and Q2 and the hay yield of Q16 and Q4 were significantly higher than the other germplasm materials (P < 0.05), which can be used as basic materials for obtaining high grass yield. Q16 had high crude protein content, low acid detergent fiber content, high forage digestibility, and excellent nutritional quality. The leaf-stem ratios of Q2, Q4, Q10, and Q14 were significantly higher than those of the other germplasm materials (P < 0.05). The cluster analysis divided the 16 germplasm materials into four categories, and the clustering results had little relationship with the place of origin. Based on the gray correlation analysis, the leaf-stem ratio, hay yield, crude ash, and crude protein had the largest weights in the comprehensive evaluation of production performance and nutritional quality of B. inermis, which can be used as key traits in the evaluation and selection of B. inermis varieties. Q6, Q4, Q10, Q16, Q2, and Q8 had the highest correlation coefficients with ideal strains and the best comprehensive performance, and could provide the basic materials for the improvement and breeding of new B. inermis varieties.
Combined effect of water and nitrogen application on yield and silage quality of silage maize
WANG Ye, SHI Yaqi, LIU Cheng, LIU Yaran, NAN Zhangjie, ZHANG Qiuzhi, PAN Jinbao
2021, 38(11): 2247-2254. doi: 10.11829/j.issn.1001-0629.2021-0280
[Abstract](1171) [FullText HTML] (611) [PDF 914KB](38)
This research was conducted to investigate the effect of combining water and nitrogen supplementation on yield, nutritional value, and silage quality of silage maize (Zea may, improving its comprehensive utilization value. The silage maize hybrid cultivar Beinong silage 368 was used as experimental material. The experimental design included three water irrigation application rates, i.e., 2 250, 2 025, and 1 800 m3·ha−1 (designated as W1, W2, and W3, respectively), and three nitrogen application rates, i.e., 420, 378, and 336 kg·ha−1 (designated as N1, N2, and N3, respectively). The results showed that the highest yields of silage maize were obtained when W2 and N2 treatments were combined; this yield was 5.02% higher than that obtained with the traditional water and fertilizer application volumes (W1N1). The dry matter loss rate of silage resulting from W1N1, W2N2, or W2N3 treatments was less than 1.0% after a year. However, there were significant differences in neutral and acid detergent fiber content, starch content, and crude ash of whole maize plants between treatments (P < 0.05) but not in ether extract concentration. After the first anniversary, the pH of the maize silage was stable at about 4.0, its relative feed value was 136.04 ~ 164.35, and its lactic and acetic acid contents were 3.33 ~ 4.34% and 1.63% ~ 2.29%, respectively. The lactic acid content resulting from the treatments was higher than that of W1N1, and the acetic acid content resulting from W2N2 and W3N3 treatments was significantly lower than that from other treatments (P < 0.05). In conclusion, considering the yield, dry matter content loss rate, and silage quality, W2N2 was the best treatment for producing high quality silage.
Effects of alfalfa mosaic virus and white clover mosaic virus co-infection on the contents of five endogenous hormones in Nicotiana benthamiana
YUE Yang, LIANG Qiaolan, WEI Liexin, HE Hui, MENG Xiupeng, JIANG Yuling, LIN Ke, CHEN Ying’e
2021, 38(11): 2255-2265. doi: 10.11829/j.issn.1001-0629.2021-0017
[Abstract](1136) [FullText HTML] (555) [PDF 1698KB](6)
This study aimed to explore the synergism pathogenic mechanism of alfalfa mosaic virus (AMV) and white clover mosaic virus (WCMV) in co-infected host. To achieve this, Nicotiana benthamiana was co-inoculated with AMV+WCMV as treatment, and N. benthamiana was noculated with AMV, WCMV alone and phosphate buffer solution (pH 7.0, PBS) as controls respectively, the viral content present in the host plant leaves when different inoculated with viruses for 72 h and the content and changes of salicylic acid (SA), jasmonic acid (JA), strigolactones (SLs), brassinolide (BR), and ethylene (ETH) within 72~720 h, were detected using the double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) method under laboratory conditions. The results showed that the symptoms of leaves inoculated with AMV + WCMV (3 ꞉ 1) were more serious than those inoculated with a single virus (AMV or WCMV), the main symptoms were light mosaic, mottled mosaic, heavy mosaic, clear veins and shrinkage. The virus concentration detection results showed that the concentration of AMV virus in leaves inoculated with AMV + WCMV (3 ꞉ 1) was higher than that in leaves inoculated with single virus and AMV + WCMV (1 ꞉ 1, 1 ꞉ 3); the concentration of WCMV was slightly lower than that of its single infection, and higher than that of AMV + WCMV (1 ꞉ 1, 1 ꞉ 3) co-infection at 72 hours after inoculation. Simultaneously, it was found the content of SA, JA, SLs, BR, and ETH differed significantly in the Nicotiana benthamiana leaves co-infected with AMV and WCMV and those infected with AMV or WCMV alone from that in the control treatment (P < 0.05). Among the conditions treatedt, co-infection of AMV and WCMV (3 ꞉ 1) could increase the content of SA, SLs, BR, and ETH in N. benthamiana leaves, and reduce the content of JA. The content of SA, SLs, BR, and ETH in the leaves co-infected with AMV and WCMV (3 ꞉ 1) was higher than that in those infected with AMV or WCMV alone and in healthy plants (CK), which was an increase of more than 36.27%. The JA content in the co-infected leaves was reduced by 59.09% or more compared to those infected with AMV and WCMV alone, and healthy plants (CK) from 72 to 720 h, respectively.
Identification of a biocontrol strain of oat root rot and its control effect
ZHANG Jianqiang, WU Kangli, ZHANG Xiaomeng, LI Zhaoyu, LI Jiajia, QI Yonghong, TIAN Yongqiang
2021, 38(11): 2266-2273. doi: 10.11829/j.issn.1001-0629.2020-0713
[Abstract](1644) [FullText HTML] (718) [PDF 1054KB](83)
Fusarium avenaceum is one of the main pathogens causing root rot in oats (Avena sativa). In order to develop a green biological inoculant for effective prevention and control of oat root rot, we isolated from healthy oatmeal rhizosphere soil F. avenaceum, an efficient oat antagonist bacteria YF, carried out morphological and molecular identification of the antibacterial spectrum of this bacterium, and investigated through an indoor control test the mechanism of this bacterium against F. avenaceum. The strain was identified as Paenibacillus polymyxa. The activity test showed that the strain had an inhibition rate of 70.69% against the mycelial growth of F. avenaceum and 85.92% against spore germination. Through bacteriostatic spectrum screening, it was found that this strain is effective in controlling eight common pathogenic fungi. The mycelia of F. avenaceum treated with the fermentation broth showed abnormal branching, vesicular deformities, and rupture of the cell wall. In the potted experiment, the control effect of this strain on oat root rot reached 81.45%, which was significantly higher than that of carbendazim (61.87%) (P < 0.05). In addition, this strain showed a better growth promoting effect on oat plant. Therefore, this strain of P. polymyxa has potential as a biological control agent against oat root rot.
Mixture combination and mixed ratio of triticale and legumes in the eastern agricultural region of Qinghai
GANG Yonghe, ZHANG Haibo, CHEN Yonglong, DU Jiang, AN Linchang, NIU Yong, Sarenhua, XU Qiang
2021, 38(11): 2274-2285. doi: 10.11829/j.issn.1001-0629.2021-0182
[Abstract](1127) [FullText HTML] (638) [PDF 1171KB](54)
This study investigated the optimum mixed seeding planting ratio of legumes and triticale in the eastern agricultural region of Qinghai Province. Herein, the effects of mixed cropping the feed pea Pisum sativum variety ‘Qingjian No. 1’ (Q1) and hairy vetch, sown with the triticale variety ‘Gannong No. 2’ (G2) at different mixing ratios (0 ꞉ 100, 20 ꞉ 80, 30 ꞉ 70, 40 ꞉ 60, 50 ꞉ 50, 60 ꞉ 40, 70 ꞉ 30, 80 ꞉ 20, 100 ꞉ 0) were evaluated. The results showed that the average fresh weight (41.80 t·ha–1) of G2 × Q1 was the highest among the tested treatments. The average fresh weights (44.45 t·ha–1) were the highest for the planting ratio of 50 ꞉ 50; the fresh weights of triticale and legume were 17.94% and 17.53% higher than their respective monocultures, respectively. For the interaction between the species combination and the mixing ratio, the best performing treatment was G2 × Q1, planted at a ratio of 40 ꞉ 60, with a total fresh weight of 45.55 t·ha–1; the fresh weights of triticale and P. sativum were 20.09% and 17.00% higher than their respective monoculture, respectively. The results of the index correlation study revealed that the fresh weight of the mixed population was significantly positively correlated with the plant height of both triticale (P < 0.05) and legumes (P < 0.01). In summary, we suggest for G2 and Q1, a mixing ratio of 40 ꞉ 60 is optimal for mixed cropping in the eastern agricultural region of Qinghai Province.
Effects of dietary probiotics on slaughter performance, meat quality and organ development in goats
ZHAN Jinshun, ZHAN Kang, YANG Fuyu, ZHONG Xiaojun, HUO Junhong, YAN Xuebing
2021, 38(11): 2286-2293. doi: 10.11829/j.issn.1001-0629.2021-0286
[Abstract](1342) [FullText HTML] (527) [PDF 886KB](24)
The aim of this study was to investigate the effect of dietary probiotics on slaughter performance, meat quality and organ development of goats. Thirty-six healthy Nubian ewes aged around 2 months and of similar weight were selected and divided into three groups, n = 12 per group. The goats in the three groups were fed a basal diet containing 0 (group Ⅰ), 0.5‰ (group Ⅱ), and 1.0‰ (group Ⅲ) of probiotics for an experimental period of 70 days. We subsequently found that: 1) The weights of the carcasses and hind legs of goats in group Ⅱ were significantly higher than those in group Ⅲ (P < 0.05). The live weights before slaughter, dressing percentages and loin muscle areas of the goats in group Ⅱ were higher than those in the other two groups (P > 0.05). 2) The muscle pH, cooked meat percentage, water loss rate, shear force and meat color of the goats showed no significant differences between the groups (P > 0.05). 3) The heart weight and heart index of goats in group Ⅲ were significantly lower than those in group Ⅰ (P < 0.05), whereas the other indexes showed no significant differences between the groups (P > 0.05). 4) The villus height and villus height/crypt depth (VH/CD) of the duodenum were significantly higher in goats in group Ⅱ than in goats in group Ⅲ (P < 0.05). The crypt depth of the jejunum was significantly lower in goats in group Ⅰ than those in group Ⅱ (P < 0.05), while the villus height of the ileum was significantly greater in goats in group Ⅰ than those in group Ⅲ (P < 0.05). The other indexes showed no significant differences between the groups (P > 0.05). In conclusion, a low level of probiotic supplementation in the diet can improve slaughter performance and organ development in goats to a certain extent.
Defense enzyme activity of dallisgrass in response to grasshopper feeding
HE Ying, MA Xiangli, REN Jian, DAI Weiran, MAO Ruzhi
2021, 38(11): 2294-2300. doi: 10.11829/j.issn.1001-0629.2021-0394
[Abstract](1077) [FullText HTML] (563) [PDF 1099KB](13)
Defense enzymes are potential defense mechanisms against herbivorous insects in plants. It is important to learn about the changes in protective enzymes in response to insect-induced stresses in excellent forages, such as dallisgrass (Paspalum dilatatum). In the present study, total antioxidant capacity (T-AOC), peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), tyrosine ammonia-lyase (TAL), lipoxygenase (LOX), polyphenol oxidase (PPO), glutathione S-transferase (GST), and phenylalanine ammonia-lyase (PAL), as well as total phenol (TP) content of dallisgrass were investigated at 0, 24, 48, 72, and 96 h after grasshopper (Oxya chinensis) feeding. The results showed that the activities of POD, LOX, CAT, PPO, TAL, and GST as well as the TP content in dallisgrass were significantly increased after grasshopper feeding compared with the control (P < 0.05). T-AOC increased significantly 24 h after feeding (P < 0.05). Moreover, the activities of PPO, TAL, and GST first increased and then decreased over time. At 48, 72, and 24 h of treatment, the activity of TAL, PPO, and GST peaked at 3.71, 2.10 and 21.25 times of CK, respectively. In contrast, grasshopper feeding significantly reduced the activity of SOD and PAL (P < 0.05). Overall, it could be speculated that protective enzymes such as POD, CAT, PPO, TAL, GST, and LOX play very important protective roles against insect herbivores.
Effect of different biological probiotics on the quality of cassava root silage and the impact on microbial flora diversity
PAN Jiahui, YU Shan, CAI Jie, LI Kaimian, OU Wenjun, WANG Zhiyong
2021, 38(11): 2301-2312. doi: 10.11829/j.issn.1001-0629.2021-0285
[Abstract](1293) [FullText HTML] (657) [PDF 1304KB](28)
We performed an experiment using fresh cassava root (South China No. 9) tubers under four different treatments: microbial fermenting agent (C1), high efficiency complex bacterial enzyme preparation (C2), biological feed fermenting agent (C3), and the control group (CK), with equal volumes of distilled water. The nutrient composition, fermentation quality, and microbial community structure were measured after 30 days of closed fermentation after the tuber material and bacterial agent were thoroughly mixed. The objective was to discover the effect of adding different biological probiotics on silage quality and microbial diversity of cassava tubers.The results showed that the dry matter and lactic acid content were significantly elevated in each treatment group after the addition of bio-probiotics (P < 0.05), and there were no significant differences in soluble sugars, neutral detergent fiber content, and lactic acid/acetic acid (P > 0.05). The crude protein content of the C2 group was significantly lower than that of the CK group(P < 0.05). The acid detergent fiber content was significantly lower in the C1 and C3 groups than in the CK group (P < 0.05). The level of acetic acid in the C1 group was significantly higher than that in the CK group (P < 0.05). The pH of all four treatment groups was below 4.2; a small amount of propionic acid was detected, but no butyric acid was detected, and ammoniacal nitrogen/whole nitrogen was below 10% in all the treatment groups. It shows that the four treatment groups are of excellent quality. The microflora structure was then analyzed and we found that the abundance, diversity, and uniformity of distribution of the flora were reduced. At the phylum level, the addition of bioprobiotics resulted in a significant increase in the abundance of the thick-walled phylum (P < 0.05), and a significant decrease in the abundance of the cyanobacterial phylum, unclassified bacteria, and other bacteria (P < 0.05). Among them, the phylum Proteobacteria was significantly reduced in group C3 (P < 0.05). At the genus level, the addition of bio-probiotics increased the abundance of dominant genera, such as Lactobacillus and Lactococcus and decreased the abundance of miscellaneous bacteria, such as unclassified Enterobacter and Serratia. The combined analysis showed that the effect of adding different biological probiotics to cassava tubers was C3 > C1 > C2.
Competitiveness analysis of forage enterprises in Northwest China based on a structural equation model
WANG Lijia
2021, 38(11): 2313-2325. doi: 10.11829/j.issn.1001-0629.2021-0230
[Abstract](1110) [FullText HTML] (620) [PDF 1075KB](30)
The purpose of this research was to analyze the competitiveness of Chinese forage enterprises using a factor analysis method and a structural equation model. A total of 122 forage enterprises from the predominant area of pasture in Northwest China were investigated. An index system for the competitiveness of forage enterprises was built from five aspects: development ability, asset strength, financial ability, management ability, and technology research and development ability. Factors affecting the competitiveness of forage enterprises were analyzed. The results showed that higher education levels of the employees, larger-scale loans, a greater degree of mechanization, a stronger impact on the local economy, and a faster business growth rate contributed to stronger competitiveness of forage enterprises. Higher input into fixed assets, financial ability and profitability also strengthened their competitiveness. Policy suggestions that were highly recommended included increasing the degree of mechanization of forage processing and broadening their business scope, focusing on the pertinence of fixed asset investment, adjusting and reforming the business model, establishing a sound mechanism for introducing talent, giving full play to forage industry advantages, and cultivating and improving their management levels and the technical skills of their employees.