大豆F3世代同源长,圆叶植株差异的初步研究

大豆同一杂交组合内同源圆叶植株和长叶植株的主茎叶面积指数,圆叶显著地大于长叶,而在分枝上,二者并无显著差异。在农艺性状方面,存在差异,在产量上,二者没有显著差异。因此,在一般的育种实践中,如果不考虑到生态条件所需要的类型,只根据叶形进行高产育种意义不大。

PRELIMINARY STUDY ON DIFFERENCE OF SOYBEAN NARROW-BROAD LEAFLET ISOGENOUS PLANTS IN F_3 GENERATION

The investigation was under taken in Harbin to study leaf area index and performance on yield and agronomic characters of narrow-broad leaflet lines derived from same cross. The object was to find out the leaf type well adapted to Harbin condition, and to provide theoretical guide for soybean breeding and production.In 1986, two crosses(F2 generation)were used for selection of leaf types in the bulk selection plots. Leaf types were classified according to leaf type index. All plants selected were grown in F 3 plant rows in 1987.The conclutions drawn from this experiment are as follow:( 1) LAI of lines derived from plants with oval leaves ( LDPOL) is significantly greater than that of lines derived from plants with narrow leaves (LDPNL) of the same cross. The difference is especially apparent on leaves of main stem rather than of branches.(2) As soybean growth stage is on proceeding, there is an increasing trend in the relationship between LAI uf main stem, branches, whole plant and its corresponding pod number on LD-POI, and LDPNL. the relationship is especially obvious on branches.(3) As soybean growth stage is on proceeding, the variation of extinction coefficient (k) of LDPNL is paralled to that of K LDPOL. K of former is higher than K of the latter in every growth stage.(4) There may be some difference on agronomic charcters between LDPOL and LDPNL. but there is no significant difference on yield between them. Therefore, in breeding for high-yielding varieties basing solely on leaf type is not reliable.