杂交水稻制种产量的高低不仅取决于不育系,还受恢复系的制约。过去,由于不育系开花分散,花期较长和制种花期调节技术不高,因而普遍采用三期父本制种,即用时差和叶差的“两差法”来确定二、三期父本播差期,以达到父母本花期全遇的目的。但是,随着制种配套技术的不断进步,母本密 The yield of hybrid rice seed production not only depends on the sterile line, but also by the restoring system constraints. In the past, due to the flowering and dispersion of sterile lines, longer flowering and flowering seasoning technology is not high, so commonly used three paternal species, that is, the use of time difference and leaf difference “two difference method” to determine the second and third period father The sowing period, in order to achieve full flowering parental purposes. However, with the continuous improvement of seed production technology, the mother of the close