野生大豆天然群体百粒重类型组成与地理分布调查

COMPONENTS AND DISTRIBUTION OF 100-SEED WEIGHT IN NATURAL POPULATIONS OF WILD SOYBEAN

百粒重是野生大豆重要的植物学性状之一,是Soja亚属内种的进化程度的标志。通常野生大豆天然群体都是各种百粒重组成的混合群体。我们调查了12个天然群体百粒重类型构成。结果显示,群体间的多样性(H′β=2.420),明显高于群体内的多样性(H′α=0.875),说明群体的百粒重组成的变异主要是由于群体的地理位置效应而引起。在这些天然群体内,百粒重的变动在0.76-6.0g之间,1.0-1.5g和1.5-2.0g是群体的主要优势型,小于1.0g或者较大的2.0-2.5g类型很少成为群体的优势型。大多数群体有单一优势型,少数有两个优势型。北部和中部的群体的平均百粒重大于南部群体,变异程度也高。关联分析显示百粒重越是接近的类型,他们的重叠分布性也较大;2.0g以下类型之间的重叠分布性较高,同样2.0g以上类型之间的重叠性也较高。聚类结果暗示,野生大豆天然种群组成结构与地理分布存在一定的相关性。

Weight of 100-seeds is one of important botanical traits in wild soybean, which is the indicator of evolutionary degree in the subgenus Soja. Commonly, natural populations of wild soybean all are mixed ones composed of a series of types of 100-seed weight. We investigated the component of types of 100-seed weight in 12 natural populations. The results showed that the between-population diversity values （H＇β=2.420） was higher than the within-populations value （H＇α=0. 875）, indicating that the variation of 100-seed weight components in the populations were caused mostly by the differences of the geographic locality. The 100-seed weight was varied from 0.75-6.0g in these populations and types of 1.0-1.5g and 1.5-2. 0g were principal dominance ones; types of less than 1.0g and 2.0-2.5g rarely existed as dominance types. Most populations had one single dominance type; a very few populations would have double dominance types. The mean 100-seed weights of the northern and center populations were higher than those of the southern ones. Correlation analysis showed that nearer types of 100-seed weight had higher degrees of overlapping distribution, implying that types of bigger seeds would have higher probability to grow together. Cluster analysis suggested that there was a relationship to a certain extent between the population structures and geographic distribution in wild soybean.