Performance of thermo-sensitive genetic male sterile (TGMS)-based two-line rice (O. sativa) hybrids
2003
dela Rosa, A.M. (Philippines Univ. Los Banos, College, Laguna (Philippines). Dept. of Agronomy) Masajo, T.M. | Escamos, S.H. | Cayaban, E.B. Jr | Lalican, D.J. | Borromeo, T.H. | Henandez, J.E.
In the Philippines, TGMS breeding is considered as one of the most viable options in enhancing further the level of heterosis in rice. The UPLB Rice Varietal Improvement Group (RVIG) requested TGMS lines from the International Rice Research Institute (IRRI) and started developing TGMS-based two-line hybrids. A total of 53 experimental 2-line hybrids were generated and evaluated in the preliminary yield trial (PYT) during the 2000 wet season (WS) and 2001 dry season (DS). Low frequency of commercially usuable 2-line hybrids were generally observed in both trials. Only 5 hybrid combinations out of the 53 hybrids evaluated were found commercially usuable with 1.0-1.5 t/ha yield advantage over the highest yielding check variety. All the hybrids evaluated were early maturing with the intermediate plant height and tiller number. The commonly observed negative traits associated with the two-line hybrids evaluated are the overly exposed panicles, weak straw and low seed yield. This negative traits could be accountable to lack of TGMS lines with improved plant type and good combining ability. And since all the hybrids evaluated were from indica by indica crosses, it is also suspected that low frequency of heterotic hybrids could be due to lack of genetic diversity in the parental materials
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