Effects of plateau pika on the relationship between plant species diversity and functional diversity in alpine meadow北大核心CSCD

The relationship between plant species diversity and functional diversity in grassland will change with environmental changes. The plateau pika （Ochotona curzoniae） has an effect on the hydrothermal process of alpine meadow in its nesting area. However,it is not clear whether the disturbance of plateau pika effects the relationship between plant species diversity and functional diversity in alpine meadow. A random stratified and paired design was used to select plots in Luqu county in Gansu Province,and Qilian and Gonghe Counties in Qinghai Province and a field survey was conducted to investigate the effects of plateau pika disturbance on the relationship between plant species diversity and functional diversity of the alpine meadow. It was found that plateau pika disturbance significantly increased the plant species richness index and the species diversity index but did not significantly affect the species evenness index. Plateau pika disturbance significantly increased plant functional richness index （P< 0.05） but had no significant effect on the plant functional evenness index or the functional divergence index. With plateau pika disturbance effects,the relationship between plant functional richness index and species richness index changed from a logarithmic function to a quadratic function,and the relationship between plant functional evenness index and species evenness index changed from non-significant to significantly positive. In addition, positive correlations between functional richness index and species richness index,and functional richness index and species diversity index were significantly decreased,as were negative correlations between functional divergence index and species richness index,and functional divergence index and species diversity index were significantly decreased. The findings of this study provide basic information for understanding the mechanism of species coexistence of plant communities under plateau pika disturbance and help understanding of how plant diversity effects in an alpine meadow ecosystem function under plateau pika disturbance. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

基于SSR分子标记的13个白三叶(Trifolium repens L.)品种指纹图谱构建

白三叶(Trifolium repens L.)是一种多年生冷季型豆科牧草,因其具有产量高、品质优良等特点,已成为我国西南地区重要的优质牧草.为分析国外引进的白三叶新品种的遗传多样性,本研究利用简单重复序列(Simple sequence repeats,SSR)分子标记对13个白三叶品种进行品种鉴定及DNA指纹图谱的...     

Progress on the taxonomic classification of Medicago species北大核心CSCD

This review investigates the disordered status of the classification of Medicago genus,both domestically and internationally. Several definitions of a taxonomic species were considered and the names and characteristics of 13 Medicago species in China are reported,together with a detailed summary of the names,life forms,chromosome numbers,pollination methods and natural distribution of about 90 Medicago species worldwide,including the classification of 14 sections and 10 subsections in Medicago. The molecular evolutionary relationships between different species,and the geographical origin of Medicago are discussed,and the genetic relationships between different subspecies in the alfalfa complex are further explained. This study puts forward a method of identifying Medicago species on the basis of deep understanding of the concept of species. A wide collection of global Medicago germplasm resources,aiming to further clarify the evolutionary relationship among different sections and different species by molecular evolution methods is proposed. This review provides a reference framework for future Medicago classification and alfalfa cross breeding. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Irrigation scheduling based on yield and quality in Bromus inermis北大核心CSCD

A suitably calculated irrigation regime can improve the productivity of artificial grassland,improve the quality of pasture and enhance water use efficiency in drier areas. In this research we compared the effects of two irrigation regimes（regulated deficit irrigation at different growth stages,I1;regulated deficit irrigation over the whole growth period ,I2）on yield and quality of Bromus inermis in the Hexi Corridor. Irrigation scheduling was optimized by considering the results of field trials and simulations of irrigation scheduling in typical dry years to provide a theoretical basis for local production practices. The results showed that：The yield of B. inermis in I1 initially increased and then decreased with successive increases in the amount of water applied,while in I2 B. inermis yield showed an increasing trend across the range of irrigation rates tested. In both irrigation regimes,the crude protein content of B. inermis gradually decreased with increasing water supply,while the acid detergent fiber and neutral detergent fiber contents increased somewhat. Compared with I2,B. inermis yield was increased by 23.11% on average and crude protein content by 6. 09% on average in I1;therefore,the I1 irrigation regime was superior. Based on the field trial combined with the simulation of irrigation scheduling in a typical dry year,it was found that a treatment designated ［greening stage （75%-85% θFC）,jointing stage （65%-85% θFC）,and tasseling stage （65%-85% θFC）,I1DF1］,irrigation frequency of 12 times,and a total irrigation amount of 521. 76 mm provided water-saving benefits and stable yield in B. inermis in the Hexi Corridor. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

一年生黑麦草遗传多样性分析及新品系'川饲1号'指纹图谱构建

利用SSR分子标记构建23个一年生黑麦草(Lolium multiflorum)品种(系)的指纹图谱,以实现对一年生黑麦草新品系'川饲1号'的准确及快速分子鉴定.12对SSR引物共扩增出104条谱带,多态性信息量(PIC)平均为0.613,变幅为0.392～0.822;香农指数和基因多样性指数变化范围分别为0.911～...     

Effects of slope on soil properties and post construction desertification of highway embankments in an Alpine Meadow region北大核心CSCD

This research investigated effect of slope on the performance of highway embankment soil properties post construction, as there is a demand for technical data of this nature to underpin the design of highway revetment work in alpine meadow regions of China. A section of national road G248 in Northwest Sichuan Alpine Grassland, built 10 years ago, was identified as a study site and plots were marked out for sampling on five slope classes: gentle slope, 6°-15° (GS); moderate slope, 16°-25° (MS); steep slope, 26°-35° (SS); very steep slope, 36°-45° (VS); extreme slope, >45° (ES). Undisturbed flat natural grassland >10 m distant from the roadbed was used as the control (CK). Measurements conducted included determination of particle size composition, physical and chemical parameters of the soils, vegetation cover and the proportion of the plot area exhibiting degradation or desertification. The relative reduction rate of organic matter and total nitrogen was also determined, and differences in soil water content and fertilizer retention capacity were assessed. It was anticipated these data would provide a basis for the construction of ecologically sound slope protection structures in alpine regions. It was found that: 1) Increased slope significantly decreased the proportion of clay and silt particles and increased the proportion of coarse sand and small stones (P<0.05). The greater the slope, the greater the soil bulk density and pH value, and the lower the soil water content. 2) Slope facilitated leaching of soil carbon fractions with the leaching intensity of the fractions ranking soil organic matter (SOM)>total carbon (TC)>inorganic carbon (IC)>dissolved organic carbon (DOC). For example, SOM levels were, respectively, 115, 92, 72, 30, 9 and 3 mg·kg−1 for CK, GS, MS, SS, VS, and ES slope classes while DOC levels ranged from 35.4 mg·kg−1 in CK to 9.2 mg·kg−1 in ES. 3) The ranking for the effects of slope on various soil fertility measures was: effective N>alkali-hydrolysable N>total N>available K> available P>total K>total P. Thus, available N was more easily lost than total N and alkali-hydrolysable N. Available N levels declined progressively across slope classes from 236 mg·kg−1 in CK to 6.3 mg·kg−1 in ES, while total N and alkali-hydrolysable N showed marked loss between GS and VS slope classes. A slope threshold for sharp increase in loss of total P and available P was observed between GS and MS slope classes. With increase in slope gradient, the total K increased, while the available K content decreased. 4) With respect to the influence of slope on the degree of desertification: for CK and GS >90% of the plot area was classed as non-desertified; for GS 79% of the plot area was moderately or severely desertified; for SS, VS and ES, 79, 86 and 94%, respectively, of the plot area was severely or extremely severely desertified. The proportion of severe desertification increased markedly at > 15° slope (i. e. MS) and the proportion of extremely severe desertification increased markedly at >25° slope (i. e. SS). 5) When the slope effects were expressed in relative terms, the relative increase in desertification was high and changed little at slopes >15°, while the relative decreases in organic matter and total nitrogen were high and changed little once slope exceeded 25°. As slope angle increased, relatively low rate of total coverage percentage and powder particles <0.02 mm and the relative increase rate of sand particles >0.05 mm increase significantly. In summary, as slope of the study plots increased, fine sand, silt and clay particles were progressively lost, soil fertility progressively declined, and the degree of desertification increased markedly. Therefore, the technical plan for ecologically sound slope protection in highway construction should be formulated according to the steepness of the slope. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Effects of altitude and variety on nutrient levels and epiphytes of oats北大核心CSCD

Oat crops are a major animal feed source in the Qinghai-Tibetan plateau and nearby areas. Typically,the crops are used for making silage rather than hay because of frequent rain at harvest in autumn. However,there is little data on how the yield,forage quality and levels of epiphytes that may affect silage quality of different oat varieties are affected by altitude. Therefore,four oat varieties（Longyan No. 3,Longyan No. 5,Baiyan No. 2 and Bayou No. 3） were planted in 8 localities forming an altitude gradient： Huangzhong （2295 m）,Tianzhu （2797 m）,Shandan （2860 m）,Hezuo （2957 m）,Haiyan （3052 m）,Maqu （3474 m）,Maqin （3765 m）and Chengduo （4217 m）. Measurements included crop yield and dry matter （DM）,water soluble carbohydrate （WSC）,crude protein （CP）,neutral detergent fiber （NDF）and acid detergent fiber （ADF）contents,and counts of lactic acid bacteria （LAB）,molds,yeasts and aerobic bacteria. It was found that there were significant altitude and variety effects on fresh yield,nutritional quality and microbial epiphyte counts. With increase in altitude,fresh yield,WSC,NDF and LAB counts increased（P<0.05）,as much as 284. 00%,15. 49%,10.81% and 11.60% increment were observed at Chengduo site than that at Huangzhong,respectively;meanwhile DM,CP and yeast and mold counts were reduced by 15. 67%,36.27%,23.53% and 7.75% at Chengduo compared with Huangzhong site,respectively. Among the four tested varieties,Longyan No. 5 had the highest fresh yield （75605 kg·ha−1）,WSC （201.4 g·kg-1 DM） and NDF （604. 2 g·kg-1 DM） at the Chengduo site,followed by Longyan No. 3. The highest CP （119.7 g· kg-1 DM） and mold counts （4.12 lg cfu·g-1 FM） were observed in Baiyan No. 2 at the Huangzhong site. Bayou No. 3 produced the highest LAB and yeast counts at Maqin and Chengduo sites. In general,Longyan No. 3 and Longyan No. 5 gave better performance at sites above 3000 m altitude;for sites below 3000 m,the four tested varieties were all found to be suitable for silage production. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Effects of nitrogen forms on growth and nitrogen assimilation and utilization of Buchloe dactyloides北大核心CSCD

This research explored the nitrogen (N) uptake preference of Buchloe dactyloides, in order to improve the management of this species over the whole growth cycle. The experiment included two cultivars of B. dactyloides (‘Sundancer’ and ‘Texoka’) and four different N regimes (N0: No N as the control, N1: Urea, N2: Nitrate N, N3: Ammonium N and N4: a 1:1 mixture of nitrate N and ammonium N). The rate of N applied was 500 mg N·kg soil–1 in each case. It was found that total N content, root nitrate reductase (NR) activity, glutamine synthetase (GS) activity and shoot glutamate synthase (GOGAT) activity of B. dactyloides were significantly improved by adding mixed N (P<0.05). Shoot nitrate N content of B. dactyloides was significantly improved by adding nitrate N (P<0.05). Root nitrate N and ammonium N contents of B. dactyloides were significantly improved by adding urea (P<0.05). The shoot ammonium N content and NR activity of B. dactyloides were significantly improved by adding ammonium N (P<0.05). Shoot GS activity of B. dactyloides was significantly reduced by adding ammonium N (P<0.05). Root GOGAT activity of B. dactyloides was significantly reduced by adding nitrate N (P<0.05). Mixed N can better improve the physiological activity and promote the growth of B. dactyloides, but single nitrogen source will inhibit some nitrogen assimilase activity. Based on these results, it is recommended that 1:1 mixed nitrogen should be used as the nitrogen source in the production of B. dactyloides. Where the ammonium:nitrate is not 1:1, urea should be used as the nitrogen source. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

老芒麦种质的醇溶蛋白遗传多样性研究

利用A-PAGE的醇溶蛋白标记,对来自亚洲和北美的86份老芒麦种质的遗传多样性和遗传关系进行了分析。电泳共检测到52条醇溶蛋白条带,其中47条为多态性条带,多态性带百分比达90.4%。种质间遗传相似系数的变幅为0.108~0.952,平均值为0.373。利用Shannon多样性指数反映了类似的结果,即供试种质间的多样性指数达到0.460的较高水平。基于多样性指数计算了老芒麦种质地理类群遗传分化程度,地理类群内和类群间的遗传变异分别占总变异的55.8%和44.2%,这表明种质间存在较高水平的遗传多样性。对供试种质和地理类群的聚类分析结果均显示,来源于青藏高原的种质与其他地理来源的种质具有较大的差异,可以分成明显的2支。这种聚类结果可能与老芒麦种质的地理来源和生态适应性有关。本研究结果可为老芒麦种质的收集保护及核心种质构建提供有益信息。     

青藏高原老芒麦种质基于SRAP标记的遗传多样性研究

采用SRAP分子标记技术,对采自青藏高原的52份老芒麦材料进行遗传多样性分析,结果表明,1)用16对随机引物组合共扩增出318条清晰可辨的条带,其中多态性条带275条,占86.48%,材料间的遗传相似系数(GS)范围为0.506 4～0.958 6,平均值为0.792 1,物种水平上的Nei氏遗传多样性为0.227 0,这些结果说明供试老芒麦具有较为丰富的遗传多样性;2)对所有材料的聚类分析发现,在GS=0.80的水平上,供试材料可聚为5类,大部分来自相同或相似生态地理环境的材料聚为一类,表明供试材料的聚类和其生态地理环境间有一定的相关性;3)对5个老芒麦地理类群基于Shannon-Weaver指数的遗传分化估算发现,类群内遗传变异占总变异的65.29%;而类群间遗传变异占总变异的34.71%;4)对各生态地理类群基于Nei氏无偏估计的遗传一致度聚类分析表明,各生态地理类群间的遗传分化与其所处的生态地理环境具有一定的相关性。     

多年生黑麦草种质SSR分子标记遗传多样性分析

多年生黑麦草(Lolium perenne)是广泛栽培利用的优质牧草、草坪草.为研究多年生黑麦草种质资源的遗传多样性,选用简单重复序列(SSR)分子标记技术对10份多年生黑麦草自主选育品系和75份来自于23个不同国家的种质资源进行了分析.结果表明,26对引物扩增出的多态性条带有91条,占总条带数的69.5％.每个SSR...     

垂穗披碱草种质资源繁殖相关特性遗传多样性研究

对采自甘肃、青海以及四川等地的50个垂穗披碱草居群的穗长、穗宽、每穗小穗数、种长、芒长和千粒重等6个与其繁殖相关的性状进行了遗传多样性研究。Shannon-weaver指数分析显示,50个居群在形态性状上具有丰富的遗传多样性(H′=1.873)。遗传多样性主要集中在居群内部(63.8%),居群间存在一定的遗传变异(36.2%)。各性状间的遗传变异具有不均衡性,穗宽变异较大(CV=0.347 2),种长变异最小(CV=0.118 4)。聚类分析表明,50个居群可分为3组;相关分析结果表明,海拔、经度、纬度、年均温和年均降水量对垂穗披碱草的繁殖性状变异有不同程度的影响,其中海拔和年均温对穗长和每穗小穗数影响极显著(P<0.01)。此外,提出了垂穗披碱草的利用和保护建议。     

基于SRAP标记的海雀稗遗传多样性及群体结构分析

采用SRAP标记对来自不同国家的49份海雀稗(Paspalum vaginatum)种质资源遗传多样性进行分析,探讨其群体结构及种质间亲缘关系,为海雀稗种质的开发利用奠定基础.结果表明:从100对引物中共筛选出20对扩增稳定、多态性好的SRAP引物,对49份种质进行PCR扩增,共扩增出169条带,其中多态性条带为118...     

不同放牧强度下垂穗披碱草遗传多样性分析

放牧对草地植物种群遗传与进化产生重要影响,本研究利用SSR分子标记对4个不同放牧强度下垂穗披碱草种群遗传多样性进行研究,试验地选择在甘肃省甘南自治州玛曲县的阿孜试验站,利用8对多态性强的SSR引物对不同放牧压力下4个居群的800个个体基因组进行检测,每个位点的有效等位基因数在1.2267~1.9976之间。利用popgene分析发现不放牧垂穗披碱草种群遗传多样性最高,在3种不同放牧地,中等放牧强度的遗传多样性指数较高,其次为重牧,最后为轻度放牧。在不同放牧干扰下的4个垂穗披碱草种群的遗传分化系数为0.5168,基因流N_m=0.2337,说明4个种群的遗传变异主要发生在种群之间。从种质资源保护角度来讲,不放牧对于垂穗披碱草种质资源的保护是有利的;从草地利用角度,中等放牧强度比较合理。     

披碱草属种质资源研究进展

披碱草属Elymus牧草分布广泛,种类繁多,广义的披碱草属包括近150个种,而在我国,则比较接受狭义披碱草属的概念,即有12余种.披碱草属牧草为中生-旱中生多年生优良牧草,是草原和草甸的重要组成部分,饲用价值极高.该属是禾本科小麦族中非常重要的一个类群,它具有麦类作物所缺乏的抗病、抗虫、抗旱、耐盐等优良抗逆基因,是现代麦类育种的重要种质资源.在前人研究的基础上,对国内外披碱草属种质资源的系统学分类、分布情况、遗传多样性研究进行了总结和探讨,以期为披碱草属资源的进一步研究利用提供参考依据.     

中国野生老芒麦形态多样性研究与种质利用潜力分析

为揭示野生老芒麦形态变异特征和遗传背景,对我国野生老芒麦主要分布区域不同生态类型的104个居群520份野生老芒麦种质进行了23个形态指标测定和遗传多样性分析。结果表明：不同生境老芒麦材料的形态特征存在显著差异,数量性状变异系数为9.49%～49.56%;聚类分析将104个居群分为具有各自明显特征和开发利用潜力的4类;形态特征与地理环境因子的相关性分析发现,野生老芒麦抽穗早晚及茎秆叶鞘基部小刺等特殊性状与其海拔呈显著相关;主成分分析发现,株高、抽穗、茎节数、单株干鲜重、旗叶长宽等指标代表了老芒麦67.79%形态多样性,是造成老芒麦形态特征变异的主要因素,可作为老芒麦形态分化的重要参考指标。     

利用微卫星标记分析乌骨大骨鸡的遗传多样性

利用微卫星标记分析了乌骨大骨鸡的遗传多样性和遗传结构,筛选了鸡基因组7条染色体上的7个微卫星标记位点,随机选取24羽乌骨大骨鸡个体,进行多态性检测,共检测到23个等位基因,每个座位等位基因数目从2个到5个不等,平均等位基因数为3.3个。该群体平均多态信息含量和平均杂合度分别为0.660 3和0.717 6。结果表明乌骨大骨鸡属多态性较丰富的群体。     

基于SCoT标记的饲用燕麦品种遗传结构及指纹图谱分析

采用目标起始密码子多态性标记(SCoT)对目前国内种植利用的36个饲用燕麦品种进行了遗传变异结构及指纹图谱分析.结果显示,从80个SCoT引物中筛选出多态性较好、条带清晰且重复性高的引物15个,共扩增出146条条带,不同引物扩增出的多态性条带数为3～9条,平均为6.4条,多态性比率为65.75％,平均有效等位基因数(N...