不同熟期杂交早稻发育进程及产量性状比较研究

Comparison of Growth and Developmental Process and Yield Characteristics of Early Hybrid Rice Combinations with Different Maturity

将6个熟期不同的杂交早稻组合分为早熟组与迟熟组对其发育进程和产量性状进行了比较研究。结果表明:早熟组与迟熟组在抽穗灌浆历期、幼穗分化历期及速率、相对出叶速率方面差异不显著,其全生育期的显著差异主要是营养生长期长短不同造成的;早熟组因为幼穗分化起始时间早、营养生长期短而表现早熟;早熟组的有效穗、每穗总粒数、每穗实粒数、结实率与迟熟组无显著差异,但经济产量与单株生物产量均极显著低于迟熟组,其主要原因分别是千粒重较低和植株较矮。指出提高营养生长期出叶速率是协调早熟与高产矛盾的关键,通过筛选营养生长期短、出叶速率快、主茎叶片数较多、千粒重较高、株高适宜的亲本进行配组有可能实现早熟高产杂交早稻选育的突破。

Six early hybrid rice combinations were divided into two maturing groups： early group and late group, and a comparison was conducted on the growth and developmental process and yield characteristics between these two groups. The results showed that there was not a significant difference between early maturing hybrids and late matu- ring ones in leafing rate, young panicle differentiation duration （from young panicle initiation to heading） and young panicle differentiating rate, and grain filling duration （from heading to ripening）. The significant difference in whole growth duration between them resulted primarily from their difference in vegetative growth stage. The earlygroup hybrids had a shorter vegetative growth duration and started young panicle initiation earlier so that they could get matured earlier than the late-group hybrids. In addition, there was not much difference between the early and late groups in such yield characteristics as effective panicles, spikelets per panicle ,filled grains per panicle and seed setting rate. However, the economic yield and biomass of the early hybrids were very significantly lower than those of the late hybrids ,resulting mainly from a lower 1000-grain weight and a shorter plant height for the early hybrids. It is indicated that enhancing leafing rate in vegetative growth period could be the key to coordinate early maturity and high yield for early hybrid rice, and it would be possible to achieve a breakthrough in breeding of early hybrid rice with both early maturity and high yield by selecting such cultivars with the characteristics of shorter vegetative growth duration, higher leafing rate, more main stem leaves, higher 1000-grain weight and properly higher plant height as parents to make hybrids.