水稻籼粳杂种多倍体亲本开花习性的研究

对强优势水稻四倍体杂交组合的亲本HN2026、SG99012、培矮64S及二倍体不育系培矮64S的开花习性进行观察研究．结果表明：具有高结实率特性的四倍体品系HN2026、SG99012如同二倍体的培矮64S一样，开花习性较为正常，即开花期和开花时间集中，表现出明显的高峰期；而四倍体的培矮64S则表现异常，主要表现为：颖花开张持续时间长、日开花时间分散、缺少明显的日开花高峰期，而且随着气温的升高，有颖花开张持续时间缩短、日开花高峰期后移的趋势，并对这种异常情况的可能原因进行了粗略的分析．

Studies on flowering behavior of polyploid parents of indica-japonica hybrids in rice

Observation and study were performed for the flowering behavior of three tetraploid lines, HN2026, SG99012, Peiai'64S-4X and a diploid male sterile line Peiai'64S-2X. The three tetraploid lines were parents of two tetraploid rice hybrids with strong heterosis. The results showed that the two tetraploid lines with high seed set propagation coefficients (HN2026, SG99012) as the diploid sterile line Peiai'64S-2X were normal relatively, i.e. each of them had a concentrated flowering stage and day flowering time, as well as an obvious peak time. On the other hand, the tetraploid sterile line Peiai'64S-4X was abnormal in flowering behavior. For example, the spikelet had long-opening lasting time, the day flowering time scatter and lacking of an obvious day flowering's peak time. Moreover, when daylight temperature rised,the spikelet's opening lasting time showed a tendency to shorten, the day flowering peak time backward shift etc. A sketchy interpretation about likely reason to these unusual circumstances were put forward.