河西走廊不同红砂天然群体种子表型性状相关性研究

采用方差分析、多重比较、相关分析、聚类分析等多种分析方法对河西走廊红砂天然分布区10个群体种子千粒重、种子长、种子宽、种子长宽比4个表型性状进行研究,以系统揭示不同群体红砂种子表型性状的变异程度和变异规律。研究结果表明,4性状在群体间差异极显著(P<0.01),在群体内没有显著差异;4性状平均变异系数为0.019 3,变异幅度0.001 8～0.068 5,其中千粒重最大,为0.068 5,种子长最小,为0.001 8,各群体4性状平均变异系数最大的是张掖1,为0.048 4,最小的是酒泉2,为0.006 6;各性状变异来源以群体间为主,占到总变异的68%以上;各表型性状均呈现出以经度、纬度和海拔为主的梯度变异规律;通过对4个表型性状各测量值的聚类分析,将10个天然群体拟划分为4个类群。对不同群体红砂种子表型性状的研究,初步了解和掌握河西走廊红砂种子的变异趋势和变异规律,可为今后开展种质资源收集与保存、遗传评价及种质创新利用以及人工辅助更新及群体遗传多样性研究提供理论依据。

Correlation analysis of phenotypic traits of Reaumuria soongorica seed in different natural populations in the Gansu Corridor

Reaumuria soongorica, a drought-tolerant shrub typical of Tamaricaceae, is one of the dominant species in desert areas of northwest China. It functions as a key biotic barrier against desertification due to its strong sand fixation ability and is therefore critical for maintaining the stability of desert ecosystems. The Gansu Corridor (in west Gansu province), is the main distribution range of R. soongorica in China and is characterized by environmental harshness associated with long-term aridity, rare precipitation, high evaporation, extremely high temperatures in summer and freezing conditions in winter. As a consequence, variations in plant morphological traits in this area are primarily accounted for by abiotic factors. Variations in four phenotypic traits of seed including thousand-kernel weight (TKW), seed length, seed width, seed length/seed width in 10 natural populations of R. soongorica in the Gansu Corridor, China, were examined using variance (ANOVA), correlation analysis and cluster analysis to reveal the pattern of variability in seed phenotype. The four phenotypic traits of R. soongorica seeds differed significantly between populations (P<0.01), but showed no significant difference within populations. The average coefficient of variance (CV) between populations across the four traits was 0.019 3, ranging from 0.001 8 for seed length to 0.068 5 for TKW. The average coefficient of variance for each population was the highest for Zhangye1 (0.048 4) and the lowest for Jiuquan2 (0.006 6). The main source of variation was in groups, which accounted for more than 68% of the total variance. All traits were spatially correlated with longitude, latitude, and altitude. Cluster analysis (using Euclidean distances) for all four seed traits revealed that the 10 sampled populations can be grouped into four clusters. The understanding of the seed phenotypic traits of R. soongorica in different populations and the spatial variation in the Gansu Corridor will be fundamental for future research projects on the collection, conservation, genetic evaluation, and utilization of its germplasm. The results can help to design artificial supplementary regeneration and enhance population genetic diversity.