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2019 Vol.36(12)

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2019, 36(12): 1-4.
[Abstract](3276) [FullText HTML] (1147) [PDF 383KB](26)
2019, 36(12): 1-12.
[Abstract](1998) [FullText HTML] (1190) [PDF 721KB](613)
Roles of plant growth regulators during abiotic stress responses of turfgrass and forage
CHAN Zhulong, ZHANG Hui, LIU Mengyao
2019, 36(12): 3007-3023. doi: 10.11829/j.issn.1001-0629.2019-0510
[Abstract](22944) [FullText HTML] (19923) [PDF 898KB](149)
Plant growth, development, and metabolism are severely affected under abiotic stress conditions. Exogenous plant hormones and small molecule compounds improve the growths of turfgrass and forages and alleviate damages caused by abiotic stresses. This review summarizes the effects of plant hormones, plant growth regulators, osmolytes, ions, amino acids, and gaseous molecules on the abiotic stress responses of turfgrass and forage. These compounds functioned antagonistically or synergistically to modulate downstream gene expression, regulate physiological pathways, detoxify reactive oxygen species, mitigate cell membrane damage, and regulate compartmentation of toxic ion, resulting in delayed senescence, increased abiotic stress tolerance, and improved turf quality. Future studies are proposed based on the progress of model plants.
Morphological and physiological responses of four ornamental grasses under drought stress
JIANG Qian, ZHANG Rui, LI Xiang, GAO Jingya, WANG Ning, ZHANG Chaocheng, JIANG Kai
2019, 36(12): 3024-3032. doi: 10.11829/j.issn.1001-0629.2019-0085
[Abstract](23104) [FullText HTML] (19516) [PDF 1027KB](96)
In this study, we examined the physiological characteristics of the ornamental plants Miscanthus sinensis, Pennisetum alopecuroides, Calamagrostis epigeios, and Carex lanceolata in response to drought stress. Using the potted water control method, two treatments of normal and deficient water supply were set up to determine the changes in withered leaf rate, relative water content, relative electrical conductivity, free proline and soluble protein contents, and superoxide dismutase activity of the four ornamental grasses under drought stress. The results showed that with the prolongation of drought stress, there were increases in the dry leaf rate, proline content, and relative conductivity of all four ornamental grasses, whereas the relative water content of leaves gradually decreased, and the activity of superoxide dismutase and the content of soluble protein initially increased and then decreased. The rate of leaf withering, relative electrical conductivity, and changes in relative water content of Erigeron tenuifolia and C. lanceolata were lower than those of P. alopecuroides and Brucea gracilis, whereas the superoxide dismutase activity and soluble protein content were higher than those of P. alopecuroides and B. gracilis. According to the membership function, comprehensive evaluation of each index showed that the drought resistance of Elsholtzia tenuifolia was the strongest and that this species could maintain high leaf water content and grows well under long-term drought stress, followed by C. lanceolata and P. alopecuroides, which had the worst drought resistance among the four tested grass species. Therefore, our data, obtained from an examination of the physiological and biochemical characteristics of four ornamental grasses in response to drought stress, provide a reference source for adaptation strategies in drought-prone environments.
Effects of toxic plants on soil physicochemical properties and soil microbial abundance in an alpine meadow on the Qinghai-Tibetan Plateau
MA Jianguo, HOU Fujiang, Saman BOWATTE
2019, 36(12): 3033-3040. doi: 10.11829/j.issn.1001-0629.2019-0405
[Abstract](22418) [FullText HTML] (19420) [PDF 848KB](105)
The fast spread of toxic plants promoted by ongoing grassland degradation has become a serious threat to plant diversity and productivity in alpine meadows on the Qinghai-Tibetan Plateau (QTP) in China. The impacts of toxic plant invasions on plant community characteristics have been well defined, but studies into their effects on belowground organisms and processes are rare. In this study, we investigated the effects of five dominant toxic plants growing in an alpine meadow grassland on the QTP (Oxytropis kansuensis, Stellera chamaejasme, Thermopsis lanceolata, Gentiana straminea, and Ligularia virgaurea) on soil parameters and microbial abundance. We also compared these effects with a non-toxic forage grass Elymus nutans. The results indicated that, compared to E. nutans, all toxic plants tested, except G. straminea, significantly increased total soil carbon, total soil nitrogen, and microbial biomass carbon (P < 0.05). The soil pH was not effected by plant species. The toxic plants tested in this study had significant effects on the abundance of soil bacteria, ammonia oxidizing bacteria, and denitrifying bacteria (P < 0.05), whereas the abundance of fungi was not affected by the toxic plants. These results indicated that the spread of toxic plants on the QTP could be of significant consequence to belowground soil properties, functions, and microorganisms, and they could have a significant effect on grassland productivity.
Effects of grazing and topography on α diversity and physical properties of the soil of alpine meadow communities in the Qinghai-Tibet Plateau
XIAO Xiang, Gericaidan, HOU Fujiang
2019, 36(12): 3041-3051. doi: 10.11829/j.issn.1001-0629.2019-0392
[Abstract](23304) [FullText HTML] (2112) [PDF 996KB](91)
To explore the effects of grazing intensity and topography on the alpha diversity, soil’s physical properties, and the relationship between alpine meadow plant communities, three alpine meadow yak ranches in the northeastern Tibetan Plateau were selected. We were able to obtain results from our experiment, which are detailed as follows (1) Grazing intensity significantly impacted α diversity. The abundance index, Shannon–Wiener diversity index, dominance, and evenness were the highest during moderate grazing and were the lowest during heavy grazing, which were consistent with the " moderate disturbance hypothesis”. (2) The dominance and evenness of the shady slope reached the highest value during light grazing. (3) With the increase in grazing intensity, the soil’s bulk density increased and porosity and soil’s water content decreased, while the soil’s conductivity increased first and then decreased. (4) The porosity of the shady slope was higher than that of the sunny slope and the flat land; the soil’s water content, porosity, and conductivity of 0 – 10 cm layer were higher than that of the 10 – 20 cm layer, which was in contrast to the soil’s bulk density. (5) The correlation between soil’s physical properties and plant community’s diversity was significant in 0 – 10 cm soil layer; and soil’s bulk density was the closest. Topography and grazing intensity play an important role in the changes of the plant communities’ alpha diversity and soil’s physical properties in alpine meadow.
Responses of soil respiration to shrub introduction in the desert steppe of the eastern Ningxia
GUO Tiandou, ZHAO Ya'nan, ZHOU Yurong, WANG Hongmei
2019, 36(12): 3052-3064. doi: 10.11829/j.issn.1001-0629.2019-0404
[Abstract](22760) [FullText HTML] (1778) [PDF 1442KB](58)
We aimed to study the responses of soil respiration to shrub introduction in the desert steppe of eastern Ningxia. We selected an enclosed grassland, grazing grassland, and Caragana korshinskii shrubland of different shrub years (22, 12, 3 a) and intervals (40, 6, 2 m) to study the association between soil respiration, moisture, carbon, nitrogen, and microorganisms during grassland grazing and shrub introduction. The results showed that the soil’s moisture in 0 – 10 cm layer had obvious seasonal dynamics, and the introduction of shrubs could consumed much more water in deeper soil. The seasonal changes of soil respiration had correspondence with surface soil moisture. Soil respiration decreased after the introduction of shrubs, and there was no significant difference in different shrub years between the enclosed and grazing grassland, but there were significant differences with the decrease of intervals. Soil’s organic carbon decreased with the deeper soil layer, which decreased with the increasing shrub year and decreasing shrub interval. Soil’s total nitrogen in enclosed grassland was higher than that in shrublands, while that of grazing grassland was comparatively lower. The total nitrogen content increased with increasing shrub year and decreasing shrub interval, but there was no significant difference (P > 0.05). The introduction of shrubs caused significant increase in the number of each microbial community (P < 0.05), but significantly decreased when the planting intervals are 2 m. After the introduction of shrubs, the quantity of microorganisms significantly increased, but significantly decreased with the high density. Soil’s microbial biomass carbon decreased with the introduction of shrubs and increased with the growth of years and reduced with the decreasing shrub interval after growth in certain years. The qCO2 level decreased with the extension of years and increased with the decrease of intervals. Soil respiration was positively correlated with soil moisture and soil microbial carbon quantity. Soil respiration had significant positive correlation with soil moisture (P < 0.01), negative correlation with soil organic carbon, total nitrogen, and microbial quantity, and the differences significantly negatively correlated between soil respiration and actinomycetes (P < 0.05).
Effects of nitrogen and phosphorus addition on forage and soil nutrients in alpine grasslands around Qinghai Lake
WANG Ling, SHI Jianjun, SHI Huilan, OU Weiyou, WANG Chao, XING Yunfei
2019, 36(12): 3065-3075. doi: 10.11829/j.issn.1001-0629.2019-0359
[Abstract](4618) [FullText HTML] (1022) [PDF 977KB](40)
This study explored the suitable amount of nitrogen (N) and phosphorus (P) in the alpine grassland in the surrounding area around Qinghai Lake. Using a randomized block design, three levels of N (35, 70, 140 kg·ha–1) and three levels of P (26, 52, 65 kg·ha–1) were set, and all combinations of N and P levels were used: N1P1(35, 26 kg·ha–1), N1P2 (35, 52 kg·ha–1), N1P3 (35, 65 kg·ha–1), N2P1 (70, 26 kg·ha–1), N2P2 (70, 52 kg·ha–1), N2P3 (70, 65 kg·ha–1), N3P1 (140, 26 kg·ha–1), N3P2 (140,52 kg·ha–1), N3P3 (140, 65 kg·ha–1). These nine fertilization gradients, as well as no fertilization as a control, were used to study the effects of combined N and P application on forage nutrients and soil nutrients. The results showed that: 1) combined N and P significantly increased the total phosphorus content of forage grasses and forage (P < 0.05). With the increase of fertilization amount, the content of crude fiber of forage decreased, while the crude fat and crude of forage. The increase in ash content plays a catalytic role. 2) Combined N and P significantly increased the total nutrient of the soil (P < 0.05). The soil available phosphorus, ammonia nitrogen and nitrate nitrogen increased by 7.41%~150.00%, 3.92%~108.28% and 3.33%~169.73%, respectively. 3) The fertilization range for the best economic benefit of N and P application was 70 ~ 140 kg·ha–1 and 26 ~ 52 kg·ha–1, respectively; these ranges resulted in higher dry weight of pasture, which increased by 1 646.74~5 797.68 CNY·ha–1 compared to the control.
Research progress on Claviceps fungus
ZHANG Haijuan, HE Yali, LI Xiuzhang, LI Chunjie
2019, 36(12): 3076-3084. doi: 10.11829/j.issn.1001-0629.2019-0315
[Abstract](19420) [FullText HTML] (2385) [PDF 701KB](49)
Claviceps is a genus of ergot fungus. The ergot alkaloid toxins produced by Claviceps, on the one hand, are highly toxic to humans and livestock. On the other hand, ergot alkaloids have many biological activities and have been widely used in medicine. This paper reviews the recent research progress on ergots in detail, both locally and abroad. Claviceps originated in South America during the Upper Cretaceous period and was mainly transported by insects to new areas or new hosts. The distribution of Claviceps is now divided into six regions globally: Africa, South America, Eurasia, North America, Australia, and India. The ergots can infect more than 400 gramineous plants of more than 70 genera in 7 families or subfamilies. The ergots are mainly parasitic on grain crops and the ears of grasses; consequently, livestock are easily poisoned by ingesting the infected grains. There have been countless ergot poisoning incidents throughout history. There are the following primary methods to control ergot disease outbreaks: the selection of disease-resistant varieties with short flowering periods, spraying of fungicides during flowering, and timely harvesting of sclerotia to reduce the source of initial infection. The ergot alkaloids produced by Claviceps have been widely used in medicine. They are mainly used for the treatment of migraines, postpartum hemorrhage, breast disease, Parkinson's disease, cerebrovascular insufficiency, and cancer. At present, the focus of international research includes the genetic evolution of ergots, the medical application of ergot alkaloids, the creation and cultivation of ergot-resistant pasture varieties that have not yet been studied, screening of high-yield alkaline strains, and the study of the interaction between endophytic fungi and ergots.
Effects of several environmental factors on seed germination of Macrotyloma uniflorum ‘Yazhou’
CAO Min, ZHANG Rui, ZHONG Ting, YU Daogeng, CHEN Yinhua, LUO Kai
2019, 36(12): 3085-3092. doi: 10.11829/j.issn.1001-0629.2019-0394
[Abstract](3174) [FullText HTML] (785) [PDF 783KB](20)
The effects of light, temperature, water, salinity, and burial depth on seed germination of Macrotyloma uniflorum ‘Yazhou’ was analyzed using petri-dish and pot-culture methods in this study. The results indicated that light, temperature, and their interaction significantly affected seed germination percentage (P < 0.05). Germination percentage and germination rate (1/t50) first increased and then declined with increasing temperature. The seeds of M. uniflorum ‘Yazhou’ could germinate between 15~40 ℃, but the optimum germination temperature was 32.8 ℃ under light conditions and 32.4 ℃ under dark conditions. With increasing PEG and NaCl stress, the germination percentage and germination rate (1/t50) gradually decreased, although germination rate (1/t50) decreased faster than did germination percentage. The seeds of M. uniflorum ‘Yazhou’ could not germinate when the osmotic potential and NaCl concentration reached –1.2 MPa and 400 mmol·L–1, respectively. The seedling percentage was highest at 1 cm burial depth, indicating that M. uniflorum ‘Yazhou’ is possibly suitable for shallow seeding.
Effect of nitrogen priming on the seed germination characteristics of Puccinellia distans
WANG Yacong, WANG Fei, WANG Congcong, YANG Yeyan, MA Jieyu, TIAN Rong, XIA Fangshan
2019, 36(12): 3093-3099. doi: 10.11829/j.issn.1001-0629.2019-0403
[Abstract](1266) [FullText HTML] (812) [PDF 604KB](21)
In this study, we examined the influence of different concentrations (0, 0.01%, 0.04%, 0.08%, 0.16%, 0.32%, 0.64%, and 1.28%; w/w) of ammonium nitrate solution and priming time (0, 3, 6, and 12 h) on the seed germination characteristics of Puccinellia distans, in order to provide a reference for gaining a better understanding of the effects of nitrogen deposition on the seed reproduction of grassland plants. The results showed that the germination percentage, germination index, and seedling vigor index of P. distans seeds were significantly (P < 0.05) related to nitrogen concentration, priming time, and their interaction. The germination ability of P. distans seeds increased after priming with 0~0.08% ammonium nitrate, but declined in seeds primed with 0.16%~1.28% ammonium nitrate, and reached the highest level in seeds primed with 0.08% ammonium nitrate for 3 h. This indicated that moderate priming with nitrogen can promote the germination of P. distans seeds, whereas excessive nitrogen priming appeared to have an inhibitory effect. Therefore, whereas a moderate deposition of nitrogen might promote the germination of P. distans seeds in saline-alkali grassland, excess deposition could inhibit germination.
Effects of exogenous betaine on alfalfa seed germination and seedling resistance under NaCl stress
MA Tingyan, LI Yanzhong
2019, 36(12): 3100-3110. doi: 10.11829/j.issn.1001-0629.2019-0361
[Abstract](2805) [FullText HTML] (998) [PDF 883KB](30)
As an important osmotic regulator, glycine betaine is could improve plant stress resistance. To explore the effects of exogenous betaine on alfalfa seed germination and seedling stress resistance under NaCl stress, Gannong 3 was selected as the alfalfa in this experiment and moderate salt stress was simulated using an NaCl solution of 150 mmol·L–1. Additionally, six gradient concentrations of exogenous betaine (0, 10, 20, 30, 40, and 50 mmol·L–1) and two application modes, via leaf or root, were used as treatments to assess seed germination and potted seedling growth. The physiological mechanism of exogenous betaine in alleviating NaCl stress in alfalfa was explored by analyzing the related indicators during seed germination and seedling growth. The results showed that: 1) after NaCl stress, alfalfa seed germination potential, germination rate, germination index, vigor index, germ radicle length, plant height, tissue water content, chlorophyll, soluble sugar, and free proline decreased significantly, whereas MDA content, and SOD, POD, and CAT activities increased significantly; and 2) after adding different concentrations of exogenous betaine, six germination traits and 8 physiological stress resistance indexes were significantly increased and MDA was significantly decreased. When leaf application was 30 mmol·L–1 and root injection was 40 mmol·L–1, the stress resistance effects were optimal. It not only effectively improved salt resistance of alfalfa seeds and seedlings, but also promoted the growth and development of alfalfa in saline environments.
Growth dynamics and optimum cutting period of hybrid Broussonetia papyrifera
GUO Qi, LI Xin, YANG Hui, GONG Xiaofang, WANG Peiya, ZHANG Jun, PENG Xianjun
2019, 36(12): 3111-3119. doi: 10.11829/j.issn.1001-0629.2019-0093
[Abstract](2492) [FullText HTML] (1261) [PDF 908KB](127)
The dynamic change in the growth and nutrient composition of hybrid Broussonetia papyrifera under two water and fertilizer conditions in the Lanzhou area was studied. A grey relational analysis and weight assignment method were adopted for the comprehensive evaluation of plant height, yield, crude protein (CP), ash, neutral detergent fiber (NDF), and acid detergent fiber (ADF) from each of two mowing events to determine the optimal cutting period. The results showed that hybrid Broussonetia papyrifera in the high-fertility area entered the fast-growing period for plant height and yield in the third growing month. For the hybrid Broussonetia papyrifera in the low-fertility area, the time of entering the fast-growing period was one month later than that in the high-fertility area. CP content in the two fertility areas was the highest in the third growing month when the plants entered the fast-growing period and then decreased significantly (P < 0.05). In both fertility areas, the ash content showed a continual downward trend. The two fertility areas showed a significant decline in ash content by month (P < 0.05). The low-fertility area presented a highly significant decline in ash content one month earlier than that of the high-fertility area. The content of NDF and ADF exhibited the same increasing trend in the two fertility areas, and reached the highest level in the fifth growing month. The results of the grey relational analysis and weight assignment demonstrated that the comprehensive evaluation value was the highest when the hybrid Broussonetia papyrifera were cut in the second and fourth growing months under the two water and fertilizer conditions. The second and fourth growing months are suggested as the suitable cutting periods for hybrid Broussonetia papyrifera in Lanzhou.
Effects of multiple mowing on hay yield and nutritional quality of oat in the Loess Plateau
XU Ranran, YANG Tianhui, CHANG Shenghua, LIU Yongjie, JIA Qianmin, HOU Fujiang
2019, 36(12): 3120-3129. doi: 10.11829/j.issn.1001-0629.2019-0383
[Abstract](3451) [FullText HTML] (1040) [PDF 901KB](43)
Presently, oat (Avena sativa) is the most abundant imported commercial grass of Gramineae in China, and the volume of such import is still increasing; however, the forage production gap in China is widening. It is of great practical significance to explore the management strategies of high hay yield and nutritional quality of oats for promoting the sustainable development of animal husbandry in China. In this study, a 2-year field experiment was carried out in the Loess Plateau of China, where the effects of multiple mowing on oat hay yield and nutritional quality were studied. The results showed that 1) the average plant height, tiller number, and hay yield of multiple mowing in two years were significantly lower than those of normal mowing (P < 0.05). Nonetheless, the 2-year average plant height accumulation, total tiller number, and total yield increased by 99.6%, 315.0%, and 255.5%, respectively, compared with normal mowing (P < 0.05). The tiller number and hay yield of the second mowing (M2) were significantly higher than those of the other mowing treatments (P < 0.05). 2) The multiple mowing treatment significantly reduced the average NDF and ADF content and increased the average CP and Ash content. The CP content of M2 was the highest in the five times mowing. Compared with normal mowing, multiple mowing significantly increased the total yield of Ash, CP, EE, decreased the total yield of NDF and ADF. 3) Under multiple mowing conditions, the oat hay yield was positively correlated with NDF, ADF and CP content (P < 0.01). In conclusion, multiple mowing in the Loess Plateau can increase the oat hay yield and its nutritional quality. Thus, multiple mowing is a suitable management strategy for oat grassland in this area.
Prediction of forage yield and nutritional quality of Cichorium intybus in the Loess Plateau
Zhuomacao, YANG Tianhui, LI Guang, CHANG Shenghua, HOU Fujiang
2019, 36(12): 3130-3144. doi: 10.11829/j.issn.1001-0629.2019-0386
[Abstract](2123) [FullText HTML] (1206) [PDF 2050KB](21)
To reveal the effects of simulated rotational grazing on Cichorium intybus and determine the appropriate utilization modes in the Loess Plateau, we evaluate and predict the forage yield and nutritional quality of. C intybus under the two utilization modes in the Loess Plateau. C. intybus " Puna Ⅱ” and " Choice” were used to analyze the correlation between growth time and ≥ 0 ℃ accumulated temperature, and forage yield and nutritional quality were predicted and evaluated by conducting field trials such as regular cutting and simulated rotational grazing in 2012 and 2013. The results revealed that during simulated rotational grazing, with the increase in growth time and ≥ 0 ℃ accumulated temperature, the forage yield of Cichorium intybus and the yield of each nutrient index increased, while the quality content decreased. The crude protein, digestibility, and nutrition level of Cichorium intybus during simulated rotational grazing were significantly higher than those of onetime harvested hay (P < 0.01). Simulated rotational grazing retained the yield and nutritional quality of Cichorium intybus at a higher level. The nutritional value of Puna Ⅱ was significantly higher than that of Choice (P < 0.01). The growth time and ≥ 0 ℃ accumulated temperature were used to predict the forage yield and nutritional quality of Cichorium intybus; the accuracy of these prediction models was high and fit was good.
Effects of fertilization on hay yield and quality of alfalfa on the Loess Plateau
CHEN Xianglai, PAN Jia, CHEN Lijun, YUAN Zhen, HU Xiaowen
2019, 36(12): 3145-3154. doi: 10.11829/j.issn.1001-0629.2019-0388
[Abstract](1474) [FullText HTML] (867) [PDF 622KB](25)
A 3-year field experiment was conducted to study the effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizers applied on the hay yield and quality of alfalfa (Medicago sativa). The results showed that the hay yield of alfalfa was increased to varying degrees. According to the actual total hay yield over three years, hay yield was the highest, 39.76 t·ha–1, with an increase of 44% compared to that of the control when N was 50 kg·ha–1, P 120 kg·ha–1, and K 60 kg·ha–1. Based on the function relationship between 3-year hay yield and fertilization treatment, a maximum hay yield of 41.18 t·ha–1 occurred when N was 68.3 kg·ha–1, P 130.7 kg·ha–1, and K 55.0 kg·ha–1. The crude protein and relative feeding value were significantly increased (P < 0.05) and varied among three years, being the highest in the second year. The neutral detergent fiber and acid detergent fiber were significantly decreased (P < 0.05). There was no significant difference for crude ash among different fertilization treatments and years (P > 0.05).
Evaluation of resistance to aphids and barley yellow dwarf virus in 33 oat germplasms
WANG Jun, ZHAO Guiqin, CHAI Jikuan, GUO Jianguo, JIAO Run’an
2019, 36(12): 3155-3165. doi: 10.11829/j.issn.1001-0629.2019-0712
[Abstract](3036) [FullText HTML] (867) [PDF 791KB](26)
Barley yellow dwarf virus (BYDV) is one of the main oat diseases in China. The present study aimed to confirm the resistance of different oat cultivars to aphids and barley yellow dwarf virus. Using fuzzy synthetic assessment and through observations under field conditions, the resistance of 33 oat germplasm resources against naturally inoculated viruliferous aphids and BYDV was evaluated in 2015–2017. The number of aphids and disease severity at the filling stage were investigated, the ratio of rating scale infested by aphid and average severity were calculated, and resistance to aphids and BYDV was examined. The results showed that eight oat cultivars, including Lingdang oat, Qingyongjiu 420, Qingyongjiu 119, Baiyan No.1, Nongda 360, MN10253, Ningyou No.1, and Zhongsui, showed resistance to aphids over the three years, accounting for 24.24% of the tested cultivars. Jim 1, Huawan No.6, and MN11213 cultivars were consistently sensitive to aphids over the three years, accounting for 9.09% of the tested cultivars. Ten of the tested oat cultivars were resistant to BYDV, including Lingdang, Duji, Nongda 360, Qingyongjiu 119, Qingyongjiu 260, Qingyongjiu 420, Keyan No.1, Qingyongjiu 355, Ningyou No.1, and Qingyongjiu 9, accounting for 30.3% of the tested cultivars. Dingyou NO.4 and Jim 1 were consistently sensitive to BYDV over the three years, accounting for 6.06% of the tested cultivars. Lingdang oat, Qingyongjiu 119, Qingyongjiu 420, Nongda 360, and Ningyou No. 1 were the optimal germplasm resources, as they were the most resistant to aphids and BYDV among the 33 test resources during the three-year period. Jim 1 was the only sensitive variety to both aphids and BYDV over the three years. The ratio of aphid numbers was significantly positively correlated with the severity of BYDV disease. Baiyan No. 15 was an outlier cultivar and was easily infected by BYDV. In this study, the resistance of oat germplasm resources to aphids and BYDV was studied, and the resistant oat germplasms were identified. This has extremely important guiding significance for the selective breeding of oats against pests and diseases.
Effects of total mixed rations with different concentration-roughage ratios on meat quality, serum indices, and intestinal tract development in Hu sheep
ZHAN Jinshun, YANG Qun, ZHONG Xiaojun, FANG Shaopei, HUO Junhong
2019, 36(12): 3166-3174. doi: 10.11829/j.issn.1001-0629.2019-0176
[Abstract](1996) [FullText HTML] (1014) [PDF 667KB](46)
Forty healthy Hu lambs with similar body weights and in good body condition were chosen in order to study the effects of different concentration-roughage ratios with equal protein to energy ratios on meat quality, serum indices, and intestinal tract development. Lambs were randomly divided into four groups with 10 sheep per group (5 male and 5 female). Sheep in each group were fed total mixed rations with concentration-roughage ratios of 70∶30 (Group Ⅰ), 60∶40 (Group Ⅱ), 50∶50 (Group Ⅲ), or 40∶60 (Group Ⅳ). The experimental period was 70 days, and consisted of a 14-day pre-experiment and a 56-day experiment. The results were as follows: 1) The serum urea nitrogen content was significantly higher in group Ⅳ lambs than in group Ⅰ lambs (P < 0.05), whereas urea glucose content was significantly lower in group Ⅳ lambs than in group Ⅲ lambs on day 14 of the experiment (P < 0.05). Serum urea nitrogen and serum total cholesterol content were significantly higher in group Ⅳ lambs than in group Ⅲ lambs (P < 0.01 or P < 0.05) on day 35 of the experiment (P < 0.05). The serum urea nitrogen content was significantly higher in group Ⅳ lambs than in lambs from groups Ⅰ and Ⅱ (P < 0.01 or P < 0.05) on day 56 of the experiment, but glucose content showed the opposite pattern. 2) Cooked meat percentage was significantly higher in group Ⅰ lambs than in group Ⅲ lambs, whereas shear force and rate of water loss were higher in group Ⅲ lambs than in group Ⅰ lambs. The percentage of crude fat in the leg muscles of group Ⅰlambs was significantly higher than in group Ⅳ lambs, whereas the meat of group Ⅰ lambs was less yellow than the meat of group Ⅳ lambs. 3) The villus height and the VH/CD of the duodenum were significantly higher in group Ⅳ lambs than in lambs from groups Ⅰ and Ⅲ (P < 0.01). The villus and the cryptic height of the jejunum were significantly higher in group Ⅲ lambs than in group Ⅰ lambs (P < 0.05). The VH/CD of the jejunum was significantly higher in group Ⅳ lambs than in group Ⅰ lambs (P < 0.05). In conclusion, meat quality could be improved by increasing the concentration-roughage ratio of diets with equal protein to energy ratios. However, higher concentration-roughage ratios were detrimental to intestinal development. The total mixed ration with a concentration-roughage ratio of 60∶40 produces the optimal results in this experiment.
Spatial and temporal characteristics of sheep displacement during grazing
CHEN Yishi, CHE Zhaobi, CAO Jiamin, GUO Yaya, LU Weihua
2019, 36(12): 3175-3181. doi: 10.11829/j.issn.1001-0629.2019-0362
[Abstract](3164) [FullText HTML] (773) [PDF 989KB](18)
The study of sheep grazing behavior can a provide a basis for grazing management measures. The aim of this study was to explore the spatial and temporal variation in sheep displacement during grazing in Seriphidium desert grassland in Yidatan and Ziniquan sheep farms in Shihezi City. The real-time tracking data of grazing sheep were obtained by using GPS and analyzed by ArcGIS to determine the sheep grazing track and explore the variations in walking speed, time, and slope. The results showed that the walking speed of sheep increased at first, then tended to remain constant, and then decreased and increased in line with the seasonal movement of the grazing season. In the daily variation, the walking speed of sheep showed a trend of initially increasing, then decreasing, and then increasing again. As the slope increased, the velocity changed parabolically. At a slope of 43°, the velocity reached its maximum value. The feeding path and walking speed of grazing sheep were significantly different in different seasons and times, and were closely related to the growth of grassland vegetation and terrain.
Effect of light intensity and photoperiod on the biological characteristics of pea aphid (Acyrthosiphon pisum) offspring
MA Yaling, LIU Changzhong, LI Chunjie
2019, 36(12): 3182-3190. doi: 10.11829/j.issn.1001-0629.2019-0398
[Abstract](1694) [FullText HTML] (850) [PDF 868KB](22)
The present study was conducted to examine the influence of light intensity and photoperiods on the offspring of two color morphs (i.e., red and green) of pea aphid (Acyrthosiphon pisum), and to explore the role of the light intensity and photoperiods in the color morphs of aphids. Under the artificial bioclimatic condition, the adult pea aphids of red and green morphs were treated with different light intensities [low (5 722 lx), medium (11 778 lx), and high (17 389 lx)] and photoperiods (10 h L/14 h D, 16 h L/8 h D, 22 h L/2 h D). The impacts were subsequently measured based on developmental duration, weight difference, mean relative growth rate (MRGR), the alate rate, and nymphal survival rate of the 1st generation aphid’s offspring. The results indicated that, in the low light intensity, the nymphal survival rate and alate rate were increased, and the relative growth rate was decreased by 10.26% (P < 0.05) for the red morph compared to the green morph at the 10 h L/14 h D photoperiod. Meanwhile, the MRGR was decreased by 13.95% (P < 0.05) and alate rate was increased for green morph compared to red morph at the 16 h L/8 h D photoperiod. Furthermore, development duration was prolonged by 0.53 d (P < 0.05) f and alate rate was increased for green morph compared red morph at the 22 h L/2 h D. At medium light intensity, development duration was prolonged by 0.30 d (P < 0.05), and alate rate was increased for green morph compared to red morph at 10 hL/14 hD. Nymphal survival rate was decreased and MRGR increased by 13.04% (P < 0.05) for red morph compared to green morph at 16 h L/8 h D. Nymphal survival rate and alate rate were increased for red morph compared to green morph at 22 h L/2 h D. At high light intensity, nymphal survival rate was increased and the alate rate decreased for red morph compared to green morph at 10 h L/14 h D. The nymphal survival rate was increased, development duration was delayed by 1.93 d (P < 0.05), and the alate rate was decreased for red morph compared to green morph at 16 h L/8 h D. Nymphal survival rate and alate rate were increased for red than morph compared to green morph at 22 h L/2 h D. Therefore, with light intensity (17 389 lx), the offspring of pea aphids of two color morphs had significantly longer development duration and less relative daily growth rate with the shortening of light time. Furthermore, the environment of light intensity was not suitable for the growth of pea aphids, and the red pea aphids were more sensitive compared to the green morph.
Effects of herdsmen's livelihood capital on drought response strategies: A case study from Inner Mongolia
DING Wenqiang, HOU Xiangyang, DONG Haibin, LI Xiliang, YIN Yanting, LIU Huihui
2019, 36(12): 3191-3202. doi:  10.11829/j.issn.1001-0629.2019-0020
[Abstract](3261) [FullText HTML] (1471) [PDF 628KB](21)
Based on the framework of sustainable livelihood analysis, this study used survey data from 848 herdsmen in 15 banners (counties) in 5 grassland types in the Inner Mongolia Autonomous Region. Using this sample, we evaluated the weight of different types of livelihood capital using the entropy method and established a binary logit regression model to quantitatively analyze the relationship between the livelihood capital and drought response strategies. The results showed that: 1) 50.12% of herdsmen in the Inner Mongolia Autonomous Region think that there has been drought in the past 5 years, and 47.52% of herdsmen adopted drought response strategies; 2) The strategies of herdsmen to deal with the drought were mainly to buy forage, sell livestock, and move to pasture, accounting for 33.02%, 15.80%, and 10.38%, respectively; and 3) The livelihood capital stock of herdsmen had a significant effect on the measures they took to deal with the drought, such as purchasing forage, selling livestock, grazing on the farm, fostering livestock, and going out to work. Because of the low stock of livelihood capital, the herdsmen in the Inner Mongolia Autonomous Region have few strategies for dealing with the risk of drought. Therefore, we should strengthen herdsmen's ability to resist drought by conducting technical training, developing diversified credit supply modes, and establishing a professional herdsmen's association.
Natural lactic acid bacterial community and screening of high-quality lactic acid bacteria in silage in southwest China
GUAN Hao, ZENG Tairu, SHUAI Yang, YAN Yanhong, ZHANG Xinquan
2019, 36(12): 3203-3213. doi: 10.11829/j.issn.1001-0629.2019-0371
[Abstract](22550) [FullText HTML] (2070) [PDF 951KB](52)
To improve the quality of silage in hot and humid areas, the community of 227 natural lactic acid bacteria isolated from silage in a hot and humid areas of Southwest China was analyzed. Four high-quality lactic acid bacteria (LAB) strains (LP149, LS358, LR753, and LPA761) were screened based on their growth activity and acid-producing ability under high temperature, and their physiological and biochemical characteristics, growth, and acid-production efficiency were determined. Lactobacillus plantarum was the most common LAB strain in the silage (62.55%), followed by L. rhamnosus and L. paracasei, accounting for 13.21% and 9.25% of the total strains, respectively. The four selected strains were gram-positive, catalase-negative, and rod shaped, and could grow at pH 3.5 and 45℃. According to the physiological and biochemical characteristics and 16S rRNA sequencing analysis, the four strains (LP149, LS358, LR753, and LPA761) were identified as L. plantarum, L. salivarius, L. rhamnosus, and L. paracasei, respectively. The results of growth and acid-production efficiency of the strains at 37 and 45 ℃ demonstrated that the four screened LAB strains exhibited good adaptability at high temperatures (45 ℃). They not only grow fast, with strong acid-producing ability and salt-tolerance, but also exhibited good adaptability to an acidic environment. This indicated they could be candidate strains for subsequent high temperature silage tests.
In vitro fermentation characteristics of peanut vines and peanut shells in Jilin Province
ZHENG Lin, WEI Bingdong, ZHANG Lichun, HE Zhongguo, YU Wei, ZHAO Lingle, WANG Xin
2019, 36(12): 3214-3221. doi: 10.11829/j.issn.1001-0629.2019-0178
[Abstract](3456) [FullText HTML] (829) [PDF 480KB](17)
To evaluate the nutritional value of two kinds of peanut (Arachis hyprogaea) by-products (peanut vines and peanut shells) in the Jilin Province using the in vitro gas production technique, three steppe red cattle with permanent rumen fistulas were used as experimental animals. The cumulative gas production at different time points (2, 4, 6, 8, 12, 24 h) and volatile fatty acid yield content, pH, ammonia nitrogen concentration, and microbial protein content after 24 h of in vitro fermentation of peanut vines, peanut shells, and Chinese leymus (Leymus chinensis) were determined. The results showed as follows: 1) the cumulative gas production, theoretical maximum gas production, and gas production rate when gas production was 1/2 of the maximum for peanut vines were significantly higher than those for peanut shells and Chinese leymus (P < 0.05). The gas production rate and lag time of gas production of Chinese leymus were significantly higher than those of peanut vines and shells (P < 0.05); 2) the pH of Chinese leymus was significantly higher than that of peanut vines and shells (P < 0.05), the total volatile fatty acid yield and propionic acid ratio of the peanut vines were significantly higher than those of peanut shells and Chinese leymus (P < 0.05), and the butyric acid ratio and acetic acid / propionic acid value of Chinese leymus were significantly higher than those of peanut vines and shells (P < 0.05). There was no significant difference in the acetic acid ratio among three groups (P > 0.05); and 3) the microbial protein content of peanut vines was significantly higher than that of peanut shells and Chinese leymus (P < 0.05) and the ammonia nitrogen concentration of Chinese leymus was significantly higher than that of peanut vines and shells (P < 0.05). In conclusion, in vitro fermentation of peanut vines exhibited the best effects and high nutritional value. The utilization rate of peanut shells was low and their proportion in dietary supplementation should not be large.