大豆上部节位叶片生产效率的初步研究

以5个亚有限型大豆品种和3个有限型大豆品种为试材，研究了主茎上部各节位的叶面积、粒重及粒叶比。结果表明，两种结荚习性大豆品种均存在顶端结荚优势，使倒数第2节位的粒重受到很大影响。亚有限型大豆品种植株上部9个节位的叶面积与粒重极显著相关，而有限型品种因受顶端结荚优势影响较大，植株上部5个节位的叶面积与粒重不相关。不同品种间植株不同节位的叶面积大小不能直接反应其对应节位的粒重大小。换算成各节位单位叶面积的籽粒生产能力时发现，存在较大的品种间差异，高产品种的叶片具有较高的籽粒生产效率。

Grain Productivity from Leaves at Upper Nodes of Soybean

Eight soybean cultivars with similar growth duration were chosen for this study, including five semi-determinate cultivars and three determinate ones. Tfifoliolate leaf area was measured after the top leaf was fully expanded, seed weight each node was measured after harvest, and the ratio of seed weight/leaf area each node was calculated. Results showed that apical dominance of podding existed in both semi-determinate and determinate cuhivars, and assimilates in the top grain were also from leaves of the penultimate node. Through the correlation analysis between leaf area and its corresponding seed weight, it was found that there were highly significant correlations among semi-determinate cultivars, while no significant correlations among determinate cuhivars. A significant difference of grain productivity per leaf area at the upper nodes was observed among different soybean cuhivars. Results revealed that high-yield cuhivars had higher ratio of seed weight/leaf area at each node; therefore, leaf productivity could be evaluated by ratio of seed weight/leaf area at each node of upper nodes in soybean.