MADRAS AGRICULTURAL JOURNAL

Characterization of Thermo sensitive Red Rice Line for itsSuitability in the State of Kerala, India

Abstract

      Hybrid rice technology has guaranteed the food supply for the ever growing population in the world. The identification of male sterility in rice was a breakthrough in the development of rice hybrids since hybrids have a yield advantage over conventional varieties. The hybrid seed production utilizing cytoplasmic male sterility is the widely adopted method in which a cytoplasmic male sterile source, a maintainer and a restorer line should be maintained for successful hybridization. The two line breeding system exploiting thermo-sensitive genic male sterility (TGMS) has a great potential to overcome the difficulties in three line system of hybrid rice development and can successfully be utilized in tropical countries where significant variations in temperature exist between season and between altitudes. TGMS lines are responsive to the temperature during a specific stage between panicle initiation and flowering for the expression of their single recessive nuclear male sterility gene(s). This trait can be transferred to any line of interest by backcrossing. TGMS lines will remain sterile when temperature is above Critical Sterility Temperature (CST) and it will become fertile if the temperature is below the CST. Stable TGMS line EC720903 was imported from International Rice Research Station (IRRI), Philippines and transferred male sterile gene to popular red rice variety Jyothi through backcross breeding. The seeds were sown at monthly interval for twelve months to evaluate the environmental conditions required for complete male sterility during 2017-2018. The TGMS red rice developed was found to be completely pollen sterile with pollen free anthers. On the other hand it was fully fertile at high altitude region with 82.08% seed setting. Therefore the new TGMS red rice line can be considered as a better choice as a female parent for Kerala condition for commercial hybrid rice seed development. Key words: TGMS Rice, Male st.
Key Words: : TGMS Rice, Male sterility, Pollen sterility