One of the best options to improve rice production is by exploiting hybrid vigour as proven in China. While considering yield, two-line hybrids have a yield advantage of 30 %. Thermosensitive genic male sterility (TGMS) is a type of environment-sensitive genic male sterility (EGMS) where the plant becomes male sterile above its critical sterility temperature (CST) and male fertile below the CST temperatures. For a tropical region like Kerala, TGMS is ideal and the prerequisite is to develop male sterile lines with stable sterility. With respect to Kerala conditions, TGMS system is more adaptable as the state has significant temperature variation between seasons and between altitudes. Hence this study was conducted as an attempt to develop a TGMS line in red rice background. The study was conducted at the College of Agriculture, Vellayani and the Regional Agricultural Research Station (RARS), Ambalavayal. Crossing was carried out at the College of Agriculture, Vellayani and seed multiplication was done at RARS, Ambalavayal, Wayanad (a high-altitude zone). Seeds of rice varieties Uma, Jyothi and a TGMS line from International Rice Research Institute (IRRI) (EC 720903) were used as parents for crossing. F1 seeds obtained were collected and self-pollinated to obtain F2 seeds. The F2 seeds were bulked, sown and evaluated for male sterility. F2 plants found to be sterile under Vellayani conditions were transferred to RARS Ambalavayal. Plants that produced seed were observed to have red-coloured F3 seeds. The F3 plants were male sterile at Vellayani condition with pollen free anthers. This finding also indicates the suitability of TGMS lines for selection towards crop improvement in rice and climate resilience in the future.
Neethu et al. (Mon,) studied this question.