我国常规籼稻品种更替过程中根系特性和物质积累与转运的演变及与产量性状的关系

Evolutions of Root System Characteristics and Substance Accumulation and Transfer of Rice in Replacement Course of Conventional Indica Rice Varieties in China,and Their Relations to Yield Traits

以20世纪60-90年代推广的7个常规籼稻品种为材料，研究了我国常规籼稻品种更替过程中根系特性和物质积累与转运的演变及其与产量性状的关系。结果表明：随着品种更替，水稻地上部鲜重与干重、根系重和根体积不断增加，单茎伤流强度增大，干物质转运量、干物质转运率和转运干物质贡献率不断增加，穗长、二次枝梗数、总枝梗数、每穗总粒数、着粒密度、千粒重和单株产量不断增加，而根冠比有所减少，结实率和有效穗数有所下降；在品种更替过程中，着粒密度、二次枝梗数、干物质转运率和转运干物质贡献率与产量呈极显著相关。依据上述品种演变规律，讨论了进一步提高我国常规籼稻产量的技术途径。

Taking 7 conventional indica rice varieties widely popularized during 1960s ~ 1990s as experimental materials, the author studied the evolutions of root system characteristics and matter accumulation and transfer of rice in the replacement course of conventional indica rice varieties in China, as well as their relations to yield traits. The results showed that： along with the replace- ment of rice varieties, the fresh weight and dry weight of aboveground part, root system weight, and root volume of rice increased gradually; the bleeding intensity per stem enlarged; the transfer quantity of dry matter, transfer rate of dry matter, and contribution rate of the transferred dry matter rose continuously; the panicle length, number of secondary branches, sum of all branches, number of total grains per panicle, grain-setting density, thousand-grain weight and yield per plant escalated; the root-shoot ratio, seed- setting rate, and number of effective panicles decreased to some extent. In the course of variety replacement, the rice yield was very significantly correlated with the grain-setting density, number of secondary branches, transfer rate of dry matter, and contribution rate of the transferred dry matter of rice. Based on the above evolution laws of rice varieties, this paper discussed the technological approaches to further enhance the yield of conventional indica rice varieties in China.