杂交水稻改二、三期父本为一期父本制种,在苗期采取不同密度寄插,利用植株所处外界条件的差异,使个体生长发育产生叶差,蘖差和播始历期差,达到既可简化制种程序,适当拉开花期,确保花期相遇,又能克服多期父本制种花期拉得过长,花粉密度小,花粉利用率低的缺点,是提高制种结实率的 The hybrid rice changed the second and the third period of the male parent to the first-stage parental seedling. The seedlings were fed with different density, and the differences in the external conditions of the plants were used to make the individuals have poor leaf growth, poor tillering and initial duration Poor, to achieve not only can simplify the seed production process, appropriate flowering florescence, to ensure that the flowering meet, but also to overcome the multi-stage parental flowering too long pull, pollen density is low, the shortcomings of low utilization of pollen is to improve seed production Rate