In order to exploit this novel male sterility in heterosis breeding, characterization of new TGMS lines and finding out critical stages for expression of sterility and fertility are very essential. In this context, the present study was taken up to fix the duration of critical sterility temperature expression of selected TGMS lines for hybrid seed production. | 2017 6 5 2128-2135 International Journal of Current Microbiology and Applied Sciences ISSN 2319-7706 Volume 6 Number 5 2017 pp. 2128-2135 Journal homepage http Original Research Article https Study on Critical Stages and Critical Sterility Point of Thermo-Sensitive Genic Male Sterile Lines of Rice for Two Line Hybrid Production K. Sai Rekha1 M. Kumar2 R. Saraswathi S. Mannonmani3 and M. Raveendran4 1 Department of Rice 2Department of Cotton 3Department of Oilseeds 4 Centre for Plant Molecular Breeding and Biotechnology Tamil Nadu Agricultural University Coimbatore-003 India Corresponding author ABSTRACT The genic male sterile rice GMS sensitive to temperature during the panicle development period is a novel type of germplasm in rice which is sterile under high temperature Keywords condition but fertile in low temperature condition. A number of TGMS lines have been popularly used in commercial seed production of hybrid rice in China and India. To fix the TGMS duration of critical sterility temperature expression of TGMS lines for hybrid seed Critical Sterility production eight TGMS lines developed by Department of Rice Tamil Nadu Agricultural Point University were sown in weekly intervals from December 16 2015 to January 27 2016. Two line hybrid Heading date and pollen sterility were observed on each line during every planting Critical stage interval. The data showed that the critical stage for most of the TGMS lines occurred Critical sterility during panicle development stages and approximately 26 to 5 days before heading. The temperature pollen sterility recorded on the plants raised at weekly interval revealed that all lines had Article Info stable sterile phase with 100 pollen sterility for more than 40 consecutive days during high temperature conditions. TGMS lines TNAU45S TNAU60S TNAU95S GDR 61S Accepted and GDR 70S were identified to have critical sterility point CSP at a mean .
