Heterosis for Growth and Development Characteristics in Rice

  • B. K. Joshi Agriculture Botany Division, NARC, Khumaltar, Lalitpur
  • L. P. Subedi Institute of Agriculture and Animal Sciences, Tribhuvan University Rampur, Chitwan


Knowledge of the degree and direction of hybrid vigor is essential for its commercial exploitation. Heterosis,heterobeltiosis and standard heterosis were studied in 14 crosses of rice (Oryza sativa L.) cultivars with three wild aborted male sterile lines. These crosses showed marked variations in the expression of heterosis, heterobeltiosis and standard heterosis for plant height, days to flowering, days to maturity straw and grain yield. Heterosis ranging from -8.7 to 5.5% for days to flowering, -3.8 to 86.6% for plant height and 7.7 to 178.4% for straw yield, and -54.99 to 139.2% for grain yield was observed. Four hybrids showed negative significant heterobeltiosis for days to flowering, 11 hybrids were shorter in height than male parents and 13 hybrids expressed heterobeltiosis for straw yield. Most of the hybrids matured earlier and yielded higher grain and straw than the Masuli cultivar with appropriate choice of parental lines, it possible to develop F1 rice hybrid possessing desired plant height, growth duration, straw, and grain yield.