The yield of japonica hybrid rice affected by impurity on the basis of CMS-D1.

Hybrid seed often get contaminated with other fertile seed during the CMS line multiplication.Use of such CMS lines in hybrid seed production results in the production of a genetically impure hybrid seed,which would reduce the expected yield.It was estimated that every increase 1% mixture of the fertile seed in the Japonica hybrid rice of CMS-D1 type results in yield reduction of 50-450 kg per hectare,and the yield that more produce in hybrid rice than purity line was countervailed by over 8% mixture of fertile seed.So ensuring the genetic purity of hybrids is a prerequisite to realize their full potential.