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.     

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.     

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.     

High-resolution leaf area index inversion based on the Kernel Ridge Regression algorithm and PROSAIL model北大核心CSCD

Accurate estimation of leaf area index（LAI）plays an important role in ecological,environmental and climate change research. Large-scale LAI estimates can be obtained from satellite remote sensing technology,but they rely on a large amount of ground-measured data with and they have low spatial resolution,which often does not meet the needs of high-precision and large-scale research. In this study,using surface reflectance data with a spatial resolution of 30 m,we tested an inversion method combining the Kernel Ridge Regression（KRR）algorithm and the PROSAIL physical model to invert LAI without a large number of ground measured data. First,the sensitivity analysis was performed on the input parameters of the PROSAIL model to determine the input parameters and generate the simulated data sets. Then,the KRR model inversion between the simulated reflectance and LAI was established. For comparison,we linked two other models,the Multilayer Perceptron（MLP）algorithm and the Random Forest Regression（RFR）algorithm,with the PROSAIL model,to perform high spatial resolution LAI inversion. Finally,we used ground measured data to compare the outputs and performance of the three inversion models. We found that the LAI inversion accuracy of the KRR-PROSAIL model was the highest with an R2 of 0. 8089 and root-mean-square error（RMSE）of 0. 2492. The inversion accuracies of the PROSAIL model linked with MLP and RFR were inferior with R2 values of 0. 7726 and 0. 7118,respectively and RMSE values of 0. 2781 and 0. 2432,respectively. Based on this study we recommend the combination of the Kernel Ridge Regression algorithm and PROSAIL models to invert satellite data to LAI for improved accuracy and high spatial resolution of the inverted LAI data. This methodology provides a method for rapid and accurate inversion of regional high-precision LAI information. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Evaluation of adaptability of naked oat varieties in the alpine region of North China based on the AMMI model and GGE Biplot北大核心CSCD

In order to comprehensively evaluate the productivity, stability and adaptability of varieties of naked oats, as well as the discriminative power and representativeness of testing sites in the alpine region of North China, data for six naked oat varieties and six testing sites in 2019 were analyzed and evaluated using the AMMI （additive main effects and multiplicative interaction） model and GGE （genotype main effect plus genotype-environment interaction） biplot. It was found that analyses of naked oats regional trial results using the two methods together reduced the statistical error and increased the ability to declare variety means significantly different, compared to traditional ANOVA methods. It was found that genotype, environment, and genotype×environment interaction effects all contributed to differences in grain yield. Variety 200910-28-4-3（G2） showed the best performance in both grain yield and stability of yield across sites, followed by varieties 200910-5-2（G3） and 200910-22-1（G4）. In terms of the selection of regional adaptability test sites for varieties, Ulanqab pilot in Inner Mongolia had both good representativeness and strong discriminability, and was the most ideal test site. Chongli Shizigou Seed Farm and Zhangbei Base were also comparatively good test sites. This study provided a scientific evaluation of methodology for performance testing of naked oat varieties in the alpine region of north China and the results basis will assist future breeding and promotion. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

Physiological effects of different Cd concentrations on maize root architecture and classification北大核心CSCD

In this research, a hydroponics experiment was conducted to apply different concentrations of cadmium (Cd) (0, 5, 10, 25, 50, 100, 200 μmol·L-1) to maize seedlings with two leaves and one new leaf, in order to explore the effects of the different Cd concentrations on the maize seedling growth, Cd absorption kinetics and root morphology and classification. After 5 days of Cd stress, the maize seedings were sampled, the plant height, main root length, aboveground and underground biomass, root architecture, Cd content and photosynthesis and related parameters were measured. It was found that with increasing Cd stress, the plant height, main root length, biomass and tolerance index of shoots and roots, total root length, root surface area, root volume, root forks and root tips all decreased significantly; Root average diameter and root:shoot increased significantly (P<0.05). Meanwhile root parameters (root length, root surface area and root volume) of root diameter classes designated Ⅰ-Ⅲ (0-1.5 mm) showed a decreasing trend, which had a significant (P<0.05) negative correlation with root Cd concentration. The proportion of root length, root surface area and root volume with diameter between 0-0.5 mm showed a downward trend under Cd stress. Under Cd stress, Cd concentration and accumulation in underground and aboveground parts of maize seedlings increased significantly, chlorophyll content decreased, and photosynthesis was inhibited. This study has shown that Cd affected root development mainly by inhibiting the growth and morphology of fine roots, and inhibited photosynthesis, elongation and biomass accumulation of the aboveground and underground parts of the maize seedings. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

分子标记与地方猪品种的遗传多样性研究

分子标记已成为目前家畜遗传多样性研究的主要工具。本文简要综述了多种分子标记(RFLPs，nat-DNA，RAPD，DNA指纹图谱，微卫星DNA，AFLP，SNPs)的检测方法及其在地方猪品种遗传变异和遗传关系检测分析中的应用，为类似研究提供参考材料。     

东方白鹳微卫星遗传标记的筛选及其在种群遗传分析中的应用

东方白鹳(Ciconia boyciana)是分布于东亚的大型濒危涉禽,亟待深入开展其种群的保护遗传学研究.本研究采用微卫星标记技术筛选东方白鹤的微卫星位点,并进行种群的遗传多样性分析.所用的36对微卫星引物7对来自白鹳(Ciconia ciconia),12对来自朱鹮(Nipponia nippon),17对来自大蓝...     

四川常羽乌骨鸡群体遗传多样性分析

利用选自家禽基因组的10个微卫星标记,对四川常羽乌骨鸡5个群体(四川山地乌骨鸡白羽系、黑羽系;黄忠山地乌骨鸡;黄忠山地乌骨鸡绿壳蛋系;草科乌骨鸡)的遗传多样性进行了检测,计算了各群体的群体杂合度、群体间遗传距离,并根据遗传距离进行了聚类分析。结果表明所选择的微卫星标记在各群体中表现出较高的多态性;四川5个乌骨鸡群体遗传多样性比较丰富,群体平均杂合度为0.5383到0.6659;各群体间的遗传距离有一定的差异;聚类分析将5个群体聚为三类。     

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.     

披碱草属植物分类和遗传多样性的研究现状

披碱草属Elymus是小麦、大麦的近缘属,同时蕴藏着丰富的优良基因,是改良小麦、大麦和黑麦的最有前途的植物.披碱草属植物也是草原和草甸的重要组成成分,具有极高的饲用价值和重要的水土保持功能,我国具有丰富的披碱草属资源,但对其的研究和利用却十分匮乏.现从国内外分类系统的不统一和遗传多样性方面进行阐述,为充分开发利用我国丰富的披碱草属植物资源提供信息.     

遗传标记在苜蓿遗传多样性研究中的应用

介绍了当前广泛应用的苜蓿遗传多样性研究技术及其研究现状,包括苜蓿Medicago形态学和等位酶分析、种质资源和种内杂合性、进化与亲缘关系、抗逆性以及遗传连锁作图等几个方面的研究概况,同时提出了今后苜蓿遗传多样性分子标记研究的重点发展方向.     

青藏高原老芒麦和垂穗披碱草SSR分子标记鉴别

垂穗披碱草(Elymus nutans)和老芒麦(E.sibiricus)是青藏高原高寒区广泛种植的优质牧草草种,由于生态适应性变异,在对一些野生种质资源鉴定中,二者常易混淆。为了区别鉴定垂穗披碱草和老芒麦,本研究结合细胞学鉴定,利用不同来源的老芒麦和垂穗披碱草种质材料,对源于普通小麦(Triticum aestivum)的42对SSR引物进行筛选。结果表明,筛选出的小麦EST SSR引物Xcwem38c在垂穗披碱草中的多态性标记可以有效区分垂穗披碱草和老芒麦。     

2020年地方鸡种遗传资源研究动态

掌握地方鸡种遗传资源起源与驯化、开展遗传多样性和群体结构研究、解析各资源优势特色遗传性状,是进行地方鸡种有效保护和新品种培育的关键.文章通过查阅NCBI、Highwire等数据库,搜集了2020年全球地方鸡种遗传资源研究相关文章100余篇,从鸡的起源与进化、遗传多样性研究、优势特色性状研究与分子标记筛选等对该领域相关研...     

AFLP分子标记在牦牛遗传分析中的初探

利用扩增片段长度多态性(amplification fragment length polymorphism简作AFLP)分子标记技术研究了30头麦洼牦牛的遗传多样性,从40对AFLP引物中筛选出了4对多态性高,分辨率强的引物,利用AFLP数据进行聚类分析。结果表明,AFLP在分析牦牛遗传多样性中的应用是可行的。     

20份燕麦种质遗传多样性分析

【目的】 了解20 份燕麦种质间的相对亲缘关系。【方法】 利用8 对SSR 多态性引物对20 份燕麦种质进行遗传多样性分析。【结果】 8 对引物共扩增出44 个位点,其中多态性位点有40 个,平均每对引物扩增出5. 5 个位点。SSR 标记位点平均多态性信息含量、平均有效等位基因数、平均香农指数、平均期望杂合度和平均观测杂合度分别为0. 630 8、3. 052 4、1. 271 0、0. 673 1 和0. 552 1。聚类结果表明：20 份燕麦种质的遗传相似系数变幅为0. 14~1. 00,在相似系数0. 59 处,可将20 份材料分为7 组。主成分分析结果显示前3 个主成分占总变异的83. 44%,根据第一及第二主成分可将20 份种质分为4 个大组,且与聚类结果基本一致。【结论】 所选用引物多态性较好,遗传多样性较高,不同燕麦种质间遗传关系与其地理来源具有一定相关性,研究结果可为燕麦遗传改良及分子育种提供参考。