蔗糖和激素对水稻离体培养穗籽粒生长的影响

 应用离体穗培养技术研究了蔗糖浓度和不同植物激素对不同源库类型水稻品种籽粒的溶液和蔗糖吸收以及干物积累的影响。离体培养穗的籽粒吸收溶液量随培养液蔗糖浓度的升高而增加，但高蔗糖浓度(盐粳2号为160 mmol／L，亚优2号和汕优63为320 mmol／L)时有抑制作用。离体培养穗对蔗糖的吸收随蔗糖浓度升高而增加。供试的不同源库类型品种籽粒干物质和淀粉的积累均受低蔗糖浓度促进，但进一步提高蔗糖浓度则抑制了盐梗2号和汕优63的籽粒增重和淀扮积累。 GA₃和玉米素对汕优63籽粒的溶液吸收和干物质积累有促进作用，GA₃ 对盐粳2号和玉米素对亚优2号籽粒干物质积累有促进效应，但溶液的吸收则有抑制作用。由此初步认为籽粒对水分和蔗糖吸收是两个既相互依赖又相互独立的过程，籽粒糖分的积累与同化物的供应及库强的调节有关。本文还对激素的可能作用进行了讨论。

Effects of Sucrose Concentration and Hormones on the Grain Development of Detached Rice Panicles in vitro Culture

The influences of sucrose concentrations and different kinds of plant hormones on the solution and sucrose absorption and dry matter accumulation were invcstigated, with detached panicles of three different source-sink types of rice varieties cultured for 10 days in liquid culture. The results indicated that, with the some range of sucrose concentration, the volume of solution taken up by the grains increased with the increment of sucrose concentration, and decreased when the sucrose concentration was 320 mmol/L for Yayou 2 and Shanyou 63 and 160 mmol/L for Yanjing 2. Increasing the sucrose supply in the liquid culture from 20 to 320 mmol/L resulted in significant increase in the sucrose absorption by grains of all three rice varieties. When the sucrose concentration was between 20 and 160 mmol/L, the dry matter and starch accumulation of grains was stimulated by increasing sucrose supply, but when the sucrose concentration was higher, the dry matter and starch accumulation of grains of Shanyou 63 and Yanjing 2 was inhibited. The solution and sucrose uptake and dry matter and starch accumulation were regulated by plant hormones, but there were significant differences in the re sponses of rice varieties to hormones. It suggested that the sucrose and water moved to the grains be both dependently and independently, and sugar accumulation by grains be determined by grain sink strength as well as carbohydrate supply. The possible regulation of hormones on these processes was also discussed.