Studies on General and Specific Combining Ability Effects in Onion Using Male Sterile, Maintainer and Restorer Lines and Hybrids

Abstract

An experiment was conducted on onion variety Hisar-2 in field conditions over two years to identify eight male sterile lines and two maintainer lines using pollen staining test and 24 hybrids obtained from crossing between male sterile and restorer lines. Observations were recorded on five randomly selected plants for height and attributes of bulb yield and quality. Phenotypic coefficient of variation was higher then genotypic coefficient of variation for most of the traits. The line MS 20 was found good general combiner for a greater number of traits. Line MS 34 was found good general combiner (GCA) for number of leaves per plant, average weight of bulb, total bulb yield, marketable yield, moisture content of bulb (%) and dry matter content of bulb (%). Tester Pusa Red figured good general combiner for plant height, diameter of bulb, average weight of bulb, total bulb yield, marketable yield, moisture content of bulb (%), dry matter content of bulb (%) and total soluble solids of bulb (%). Crosses MS 35 x Hisar- 3, MS 37 x Hisar-3, MS 22 x Agrifound Dark Red, MS 40 x Pusa Red and MS 21 x Pusa Red exhibited high Specific Combining Ability (SCA) suggesting the utility of heterosis breeding. Both additive and non-additive gene actions were operative to determine bulb yield and its components and quality parameters, which suggest that selection and heterosis breeding can be practice for improvement of onion.