海拔与黄花苜蓿表型性状的相关性研究

黄花苜蓿表型性状具有丰富的多态性,受生境影响较大,尤其是经纬度、海拔,研究黄花苜蓿表型性状与海拔的相关性对揭示黄花苜蓿遗传变异规律具有重要的意义。试验以新疆黄花苜蓿为材料,通过测量同一经纬度(N 43°43',E 86°94')不同海拔(2100~2350 m)下株高、分枝数、叶、茎、花等18个表型性状,探索其变化规律,为进一步开展黄花苜蓿遗传多样性及种质创新研究提供基础数据。研究表明:海拔对表型性状的影响较大,随着海拔降低,株高、叶长、叶宽、节间长、茎粗、小花长等数值总体呈现“降-升-降”的趋势,均在海拔2150 m时有明显升高,随后降低;表型指标的变异范围为1.30%~22.83%,平均变异系数为8.49%;海拔与株高、花序长、花柄长、龙骨瓣宽等相关性显著,相关系数分别为0.490、0.601、-0.449、-0.421,与其他指标间的相关性不显著。综合分析认为,黄花苜蓿适宜生长在海拔为2150 m左右的区域。

A study of the correlation between altitude and Medicago falcata phenotypic traits

Medicago falcata possesses an abundantly diverse array of phenotypic traits, which are influenced by habitat, and so are correlated with climatic gradients linked to altitude, latitude and longitude. This research aimed to characterise the genetic variation in M. falcata through study of correlation between the phenotypic characters of M. falcata and altitude. In this experiment, M. falcata (Variety Xinjiang) was used as the study material, and 18 phenotypic traits were studied, including plant height, number of branches, leaves, stems and flowers under the same latitude and longitude (N 43°43', E 86°94') over an altitude range of 2100-2350 m. These data provide a basis data for further research on genetic diversity and germplasm development in M. falcata. It was found that phenotypic traits are most variable with change in altitude. Plant height, leaf length, leaf width, internode length, stem diameter and floret length within inflorescences showed a trajectory across the altitude gradient of “declining-rising-declining” with decreasing altitude, with peak values at 2150 m of altitude. The values obtained for the phenotypic index ranged from 1.30%-22.83%, and the average coefficient of variation was 8.49%. There was a significant correlation between altitude and plant height, inflorescence length, petal length and keel width, with correlation coefficients of 0.490, 0.601, -0.449 and -0.421, respectively. Other phenotypic traits of M. falcata showed no significant correlation with altitude, and considering the data as a whole, an altitude of 2150 m is best suited for growth of M. falcata.