Characterization and fine mapping of RTMS10, a semi-dominant reverse thermo-sensitive genic male sterile locus in rice
- Journal of Integrative Agriculture 2022年02期
The discovery and application of environment-sensitive genic male sterile（EGMS） rice germplasm provide an easy method for hybrid rice breeding and have made great contributions to hybrid rice production. Typically, the photoperiod-and thermosensitive GMS（P/TGMS） lines utilized in two-line hybrid systems are male sterile under long day or/and high temperature but fertile under short day or/and low temperature conditions. However, Yannong S（Yn S）, a reverse TGMS（rTGMS） line, is sterile under low temperature（<29℃） and fertile under high temperature（>29.5℃）. Here, we report a genetic study on the rTGMS trait in Yn S. Interestingly, the F1 plants of the cross between Yn S and a cultivar, L422, were male sterile at 22℃ and completely fertile at 27℃. Moreover, the segregation ratio of fertile and sterile individuals in Yn S/L422 F2 populations changed from 1:3.05 to 2.95:1 when the ambient temperature increased, showing that the rTGMS trait exhibits semidominance in Yn S. We further found a locus on chromosome 10, termed RTMS10, which controls the rTGMS trait in Yn S. We then finely mapped RTMS10 to a ～68 kb interval between markers ID13116 and ID1318 by Yn S/L422 BC6 F2 populations. A near iso-genic line（NIL） NL1 from the BC6 F3 generation was developed and the pollen of NL1 became abnormal from the meiosis stage under low temperature. In summary, we identified an rTGMS locus, RTMS10, and provided co-segregated markers, which could help to accelerate molecular breeding of rTGMS lines and better understand the rTGMS trait in rice.
1. Introduction 2. Materials and methods 2.1. Plant materials 2.2. Pollen fertility assessment 2.3. DNA extraction and development of the fertile and sterile bulks 2.4. DNA marker analysis 2.5. Development of NILs carrying RTMS10 locus 2.6. Cytological observations and scanning election microscopy (SEM) 3. Results 3.1. Yn S is a reverse thermo-sensitive GMS (r TGMS)line 3.2. The r TGMS trait in Yn S is semi-dominant 3.3. Genetic analysis and gene mapping of RTMS10 3.4. RTMS10 affects meiosis during microsporogenesis under low temperature 4. Discussion 5. Conclusion Declaration of competing interest