Gene mapping and transcriptome profiling of a practical photo-thermo-sensitive rice male sterile line with seedling-specific green-revertible albino leaf.

Abnormal environment weather can cause rice photoperiod-thermo-sensitive genic male sterile (PTGMS) lines fertile or partially fertile and thus cause the mixture of true hybrids with selfing seeds. Seedling-specific green-revertible albino leaf color mutant can be used to distinguish the real hybrids. Besides, it can also be used as an ideal material to research the development of chloroplast and biosynthesis of chlorophyll. The phenotype of leaf color mutants includes light green, yellowing, albino, green-revertible albino. Gene mutations affecting the synthesis and degradation of photosynthetic pigments, lycopene and heme, the differentiation and development of chloroplast, gibberellins (GAs) biosynthesis, can change the leaf color. We have created a PTGMS line with seedling-specific green-revertible albino leaf named W01S. The leaf phenotype, pollen sterility and fertility, agronomic traits, heredity, gene mapping and RNA-Seq of the differentially expressed genes between albino and green-revertible leaves were investigated. The results showed that W01S is a practical PTGMS line as Pei'ai 64S. The mutation of candidate gene Os03g0594100 (ent-isokaurene C2-hydroxylase-like) in W01S can be related to the biosynthesis of GAs, indole acetic acids, ethylene.

Genetic analysis of the low critical sterility temperature point in photoperiod-thermo sensitive genic male sterile rice.

It has been a long haul but photoperiod- and thermo-sensitive genic male sterile (PTGMS) rice has not been freely used in hybrid rice production because there are two perplexing problems corresponding to the critical sterility temperature point (CSTP): the uncertainty of the CSTP segregating pattern and the instability of CSTP for every originally useful line. N5088S, the most widely commercialized japonica-type PTGMS line in China, also saw that its CSTP variants have been isolated but with all other agronomic characteristics unchanged. In this report we analyzed the genetic basis of CSTP, by employing the iterated expectation and conditional maximization (IECM) algorithm on four tiller-splitting-formed sets of seven generations from N5088S and its CSTP-variant H5088S, each set treated with one temperature regime. The main results indicated that there are two dominant major genes and polygene, as well as their respective epistasis conditioning the CSTP in the 23.5 degrees C regime. Based on the results obtained, the strategy for breeding of PTGMS lines with stable low CSTP was outlined.