Hete rosis and combining ability studies in hybrid rice

摘要

Hybrid rise, though commercially popularized in China, receiv d a serious setbackin India, in the initial stages due t introduction of exotic, unacceptable Chinese CMS lines which became susceptible to tropical pesis and diseases. Hybrid rice programme initiated all over India with the help of UNDP-ICAR funds aims to develop stable, local CMS lines and identification of effective restorer lines. As the process of CMS line conversiou is under way, research program was reinitiated with IRRI bred CMS lines which are fairly well stable and suitableto the tropics with good out crossing per cent (Virmani et al., 1991 ). Rice cultivation in the coastal regions is highly specific to seasons and nitrogen levels. Rice varieties cultivated in the dry season (DS) are highly responsive to nitrogen fertlisation upto 120 kg N/ha. The present study was conducted to explore the potentiality of heterotic rice hybrids at two N levels in DS (60 and 120 kgN/ha) and selection of parents with high GCA.