Vol. 7, Issue 6 (2019)
Studies on sterility behaviour in thermo-sensitive genic male sterile lines of rice
Author(s): M Vinodhini, R Saraswathi, PL Viswanathan, M Raveendran and P Jeyakumar
Abstract: In hybrid rice, Thermo sensitive Genic Male Sterility (TGMS) system has several advantages compared to CMS system as it does not require maintainers for seed multiplication. In TGMS, the sterility/ fertility behavior is controlled by temperature. For successful utilization of TGMS lines in hybrid seed production, information on flowering behavior of the lines, critical stage of thermo sensitivity, critical sterility temperature, period of sterility and genotypic responses is indispensable. In this study, 25 TGMS lines from Paddy Breeding Station, Coimbatorewere sown at weekly intervals from January 2, 2018 to January 31, 2018. Heading date (days), pollen sterility (%) and spikelet sterility (%) was recorded in each line for all the five staggered sowings. Information on maximum, minimum temperature and rainfall during the crop growth period was collected from meteorological observatory at the farm.
Based on flowering, 14 and 11 lines were identified to be medium and long in duration respectively. The sensitive stage for the TGMS lines was taken as 5 to 24 days before heading that coincided with the differentiation of secondary branch primordium and the filling stage of pollen. For the medium duration genotypes, critical stage fell between 65 and 99 days and for the long duration lines it fell between 80 and 112 days. The staggered sowings spread over a month had differential expression on days to heading among the TGMS lines which was narrow (< four days) in TNAU 14S, 18S, 71S and 116S and wider (12-10 days) in TNAU 136S, 139S and 137S. Altogether, 17 lines (eight medium and nine long duration) were 100% sterile in all the five staggerings that extended for a month. The critical sterility point (CSP) of the lines ranged from 28°C (TNAU 147S and TNAU 151S) to 31.7°C (TNAU 101S). Two other lines with low CSP were TNAU 45S and TNAU 71S. A total of 145mm rainfall received over a period of ten days during May 2018 which coincided with the sensitive stage in the last staggering of 10 TGMS lines resulted in the identification of 100% sterile lines with low CSP. Genotypic differences for expression of sterility existed even among the lines derived from same TGMS source.
Pages: 55-61 | 545 Views 64 Downloads
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How to cite this article:
M Vinodhini, R Saraswathi, PL Viswanathan, M Raveendran, P Jeyakumar. Studies on sterility behaviour in thermo-sensitive genic male sterile lines of rice. Int J Chem Stud 2019;7(6):55-61.
