Genetic bases of instability of male sterility and fertility reversibility in photoperiod-sensitive genic male sterile rice
He, Y. Q. J. Yang, C. G. Xu, Z. Zhang and Q. Zhang.
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1999. Theor. Appl. Genet. 99:683-693.
Photoperiod sensitive genic male sterile (PSGMS) rice, with its male fertility regulated by photoperiod length, is very useful for hybrid rice development. However, the breeding for new PSGMS lines has confronted two major difficulties, the stability of male sterility and reversibility of male fertility. In this study we assessed the genetic bases of stability of sterility and fertility reversibility using a molecular marker-based approach. A cross was made between two newly bred PSGMS lines: Peiai 64S that has a stable sterility but is difficult to reverse to fertility, and 8902S that has a unstable sterility but is easy to reverse to fertility. The fertility of the parents, F1 and F2 populations was repeatedly examined under eleven different long-day and short-day conditions. The genetic effects were assayed by interval mapping and two-way analyses of variance using the F2 data of 128 polymorphic loci representing all the 12 rice chromosomes. The analyses resolved a number of single locus QTLs and two-locus interactions under both long-day and short day conditions. The interactions involved a large number of loci, most of which were not detectable on single locus basis. The results showed that genetic bases of both stability of sterility and reversibility of fertility were the joint effects of the additive effects of the QTLs and additive by additive components of two-locus interactions. The implications of these findings in hybrid rice development were also discussed.
Genetic analysis, Molecular marker, Quantitative trait locus (QTL), Epistasis, Hybrid rice