【摘要】 以扁茎大豆、正常圆茎大豆、扁茎大豆与正常圆茎大豆杂交选育的高代品系为材料,分别进行短日照(12h)和长日照(16h)处理,观察光周期对扁茎大豆及正常圆茎大豆发育速度和形态特征的影响。结果表明,光周期不仅明显影响大豆的开花期、成熟期,而且调控顶端花序的形态。在长日照下,供试大豆品种生殖发育明显受到抑制,开花期延迟,在北京夏播条件下不能正常成熟;扁茎大豆、扁茎大豆与正常圆茎大豆杂交选育的高代品系植株顶端花序轴伸长,部分材料的花序轴上产生侧生花序,但均未象在原产地一样出现扁平、加宽的花序。在短日照条件下,不论是扁茎大豆还是正常圆茎大豆,发育速度均加快,植株顶端为典型的总状花序,花序轴较短,扁茎大豆也未出现扁茎及顶端花序簇集的现象。本实验的结果说明扁茎大豆植株顶端的茎秆扁化、花荚簇集的性状可因光周期等环境因素的变化而变化,是不稳定的性状。对扁茎性状形成和变化的原因亦进行了分析。更多还原

【Abstract】 Fasciated soybean is a spontaneous mutant in soybean. Up to now, it is still unknown if the expression of fasciation character is controlled by photoperiod. In the present study, both short-day (SD, 12h) and long-day (LD, 16h) treatments were conducted to investigate the photoperiod effects on developmental rate and morphology of fasciated and normal round-shaped soybean genotypes, by using the materials of 1 fasciated soybean, 1 wild type, and 3 fasciated lines selected from the crosses between a fasciation mutant and a wild type. The result showed that photoperiod not only influenced flowering and maturity dates, but also altered the morphology of terminal inflorescences of soybean. In LD treatment, the reproductive development of all genotypes was inhibited, the dates for flowering and maturity were delayed, and all genotypes failed to mature before mid-October in Beijing. The rachis length of terminal inflorescences in all genotypes was prolonged, and branch inflorescence rachises were produced in some fasciated genotypes, but no fascination characters were found in any genotype in LD treatment although the fasciated soybeans bore fasciated stems and inflorescences in their original sites of Northeast China or Midwest in the US. In SD treatment, the developmental rate was increased, typical racemes were found in all genotypes, and no fasciation characters were found in fascinated soybeans. The results of this study indicated that the fasciation characters of fasciated soybeans could be altered by photoperiod and other environmental factors. The reasons for the formation and change of fasciation characters were also analyzed in this paper.更多还原