Flower shedding control mechanism as an adaptive strategy in the soybean plants

本研究将大豆植株的落花视为个体的适应性策略，从农艺学角度阐明了落花的机理。2001年：以大豆祖先野生种为样本，与栽培品种进行比较。(1)通过野生种驯化为栽培种，藤蔓感消失。(2)结果表明，大豆生长、干物质生产、结实和籽粒肥大的适宜温度高于常规栽培温度。2002年：有限型和无限型大豆品种开花和成熟特性的差异。(1)开花期由低总状花序序向高总状花序序的转变在两种类型中趋于一致。(2)在花脱落上，有限型的总状花序顺序越高，脱落数越多，而不定型的总状花序顺序越高，脱落数越多。2003年：研究全球警告等温度条件变化时的花脱落控制机制的对策。(1)TGC（温度梯度室），其中只有白天的温度上升。试验结果表明，温度升高对大豆开花、成熟和籽粒产量的影响是显著的。(2)花数不受高温抑制。高温处理的结实率、籽粒产量和干物质生产量最高。(3)据估计，大豆的生产力也因全球变暖等高温条件而提高。但是，选择避开花期高温的作物和品种，当高温灾害发生时，就会产生落花现象。

This study catches the flower shedding in the soybean plants as individual adaptive strategy, and it is made that the mechanism of the flower shedding is clarified in agronomics. Following results were obtained.Year 2001 : Soybean ancestor wild species was offered as sample, and it was compared with the cultivated varieties. (1) By domestication process to cultivated species from the wild species, the vine-ness disappeared. (2) It became clear that the moderate temperature of growth and dry matter production and fruiting and grain hypertrophy of the soybean was higher than the temperature in the usual cultivation.Year 2002 : The differences between determinate types and indeterminate types in flowering and ripening characteristic of the soybean cultivar. (1) The transition of the flowering which shifted to the high raceme order from the lowraceme order tended to be equal among both types. (2) On the flower shedding, the falling number increased, as it becomes the high raceme order in determinate type, and in the indeterminate, it became a maximum in 1st order and secondary.Year 2003 : It intended to examine the strategy of flower shedding control mechanism for the change of temperature conditions such as Global Warning. (1) TGC (Temperature Gradient Chamber) in which only the temperature in the daytime rises. It was produced, and the effect of the temperature rise on flowering and ripening and grain yield of the soybean was examined. (2) The flower number was not suppressed by the high temperature. Bearing rate, grain yield and dry matter production are the most in the high temperature. (3) It is also estimated that the productivity of the soybean is improved by high-temperature conditions such as the global warming. However, cropping season and cultivars which avoid high temperature in time of flowering are chosen, when the high-temperature failure is generated, and it produces and does the flower shedding.