Breeding of New Maintainer Lines for Development of CMS in Hybrid Rice Breeding in Viet Nam

Abstract

   In three-line hybrid rice system, the development of new maintainer lines (B lines) suitable to ecological conditions with good characteristics plays an important role. In this study, we had made two combinations,BoB x IR58025B and II32B x IR58025B and applied pedigree method ofselection for short stature plant, short growth duration, high stigma exsertion, pollen abundance and good grain quality. Twenty five and 23 new B lines from BoB x IR58025B and II32B x IR58025B were selected, respectively, in F6 generation in spring season 2012. Those lines showed very good characteristics that are suitable for B lines possessing the desirable traits mentioned above. Crossing these lines with CMS line (IR59025A) showed that most of the lines produced F1 with 100% sterility. Therefore, the new maintener lines can be developed by crossing between two B lines which can be maintained for two types of cytoplasm to develop new CMS background for development of three-line hybrid rice in Viet Nam.