Identification of Potential Restorers and Maintainers from Elite Germplasm and Explore the Possibility of two line Rice Hybrids Oryza Sativa l

Abstract

ABSTRACT newlineA study was conducted to identify the effective maintainers and restorers for the CMS lines. newlineExperimental materials in the present study for the identification of effective maintainers and restorers newlinecomprised of 92 tests cross progenies derived from combinations involving four CMS lines (Wild newlineabortive) and 23 pollen parents. These were grown in the experimental field of Norman E Borlaug crop newlineresearch Centre, GBPUAandT, Pantnagar during Kharif 2016-17. Identification of maintainers and newlinerestorers in the present investigation was carried out by categorizing all F1 based on spikelet fertility newlinepercentage. Among 92 test crosses two F1 (Pant CMS 3A × UPR 3807-1-1 and Pant CMS 3A × UPR newline3807-1-6) exhibited zero per cent spikelet fertility. Pollen parents of these two crosses can be newlineconsidered as effective maintainers of male sterile line Pant CMS 3 A. These pollen parents could be newlinedeveloped as new CMS lines by repeated backcross breeding with their respective F1 s. Likewise, newlineseven F1 exhibited more than 80 per cent spikelet fertility. Pollen parents of these crosses can be newlineconsidered as effective restorers of respective male sterile lines. Effective restorers can be used directly newlinein hybrid seed production programmes after evaluating yield and yield contributing characters. newlineThe present investigation was also taken up to evaluate the 10 TGMS lines for different newlinemorphological traits which favoured outcrossing. These ten TGMS lines were crossed with four testers newlineand identified the best crosses for different yield and yield contributing traits. The field experiment was newlineconducted with 10 TGMS lines, 40 F1 s and three checks in randomized complete block design with newlinethree replications during Kharif 2017 and Kharif 2018. newlineIt is revealed that mean squares due to genotypes were highly significant for all the traits newlinestudied under this investigation. The best general combiner lines for different traits viz; TGMS-10 was newlinethe best general combiner for grain yield per plant along with other component characters like days to newline50% flowering, plant height, spikelet number per panicle and 1000 grain weight. Among the testers, newlineonly one tester UPR 3607-1-2 exhibited significant and desirable GCA effects for grain yield per plant newlinealong with component characters like days to 50% flowering, effective tiller number per plant, 1000 newlinegrain weight and harvest index. Hybrid TGMS-6 × UPR 3607-1-2 found the best specific combiner for newlinespikelet number per panicle and grain number per panicle. Based on the standard heterosis five newlineeconomic crosses viz. TGMS-10 × UPR 3506-1-1, TGMS-10 × UPR 3607-1-2, TGMS-2 × UPR 3507- newline1-1, TGMS-6 × UPR 3607-1-2 and TGMS-9 × UPRI 3607-1-2 for grain yield per plant was reported newlinewhich showed high SCA effect and per se performance. Estimates of variance of specific combining newlineability (and#963;2sca) were higher than those of variance of general combining ability (and#963;2gca) for all the traits newlinestudied, which means these traits are governed by non-additive gene action. newlineThe results of morphological and floral characterisation studies show that TGMS lines viz., newlineTGMS-2, TGMS-6, and TGMS-4 had good desirable floral traits i.e. wider glume angle opening, high newlinepanicle and stigma exertion rate for the better extent of outcrossing rate. These lines can be utilized for newlinetwo-line hybrid rice breeding programme with high heterotic expression and superior yield. newline