65 Identifcation of maintainer and restorer lines for development of wheat hybrids Aruna Devi Ahirwar, Niharika Shukla, RS Shukla and SK Singh 1 * Jawahar Lal Nehru Krishi Vishavidhalaya Jabalpur 482 004, India Abstract Hybrid wheat development is an attractive approach for enhancing productivity of wheat. For an effcient hybrid development programme through CMS approach, a stable CMS line, its suitable maintainer line and restorer lines for high pollen and spikelet fertility is needed. An experiment was conducted to identify suitable maintainer and restorer line among 13 high yielding wheat genotype based on spikelet and pollen fertility in the hybrid combinations using 10 CMS lines. Range of complete sterility to complete fertility was observed among 130 hybrid combinations. All the genotypes DBW 17, GW 273, GW 322, GW 366, HI 1531, HI 1544, JW 3020, JW 3173, JW 3211, JW 3269, Lok 1, PBW 343 and WH 147 were good fertility restorers for either of the CMS lines. On the other hand, only seven genotypes, HI 1531, JW 3020, JW 3211, JW 3269, PBW 343, GW 366 and GW 273 were identifed as maintainers for any of the six CMS lines, namely JWH 4, JWH 8, JWH 14, JWH 16, JWH 17 and JWH 20. Other wheat genotypes were not able to maintain male sterility in the CMS lines. Keywords: Wheat hybrid, maintainers, restorers, cytoplasmic genetic male sterility Introduction Wheat is a major staple food of world population and occupies about 21.8 per cent to total cultivated area accounting for 35.5 percent of total food grain production at global level. India is maintaining its second position in total wheat production since 2000 AD and recorded wheat production of 94.9 m tons during 2011-12, whereas the wheat production during 2012-13 was 92.46m tons from 29.65 million hectare area with productivity of 3.12 t ha -1 (Anonymous, 2013). Similarly Madhya Pradesh has produced 13.13 million ton wheat from 5.30 mha area with average productivity of 2.48 t ha -1 . To keep pace with increasing population, the estimated wheat requirement in India is about 109 million tons by 2020. To meet this target, annual increase in productivity level of ~2 per cent is required. Since area under cultivation is gradually decreasing or stable, the projected demand of wheat production can be met only with increased in productivity level at >3.8 t ha -1 within a stipulated period. In recent years, the enhanced production is due to enhanced wheat area under cultivation and no quantum jump in productivity of wheat genotypes was observed. Further, global climatic changes are also major oncern for enhancing productivity levels. Among some promising wheat improvement approaches, hybrid wheat is an attractive option for realizing hybrid vigour and, therefore, enhanced yield levels. Wheat is a self pollinated species, therefore, hybrids can be produced manually but this is commercially unviable option. Therefore, making wheat as cross pollinated species, there is a need to change in the foral biology i.e. to allow cross fertilization between two parental lines. Success in hybrid wheat has already been reported in USA, France, Australia, South Africa, UK, China and India. A number of male sterility or pollination control systems are available in wheat, i.e., cytoplasmic genetic male sterility, nuclear genetic male sterility, transgenic male sterility, photoperiod sensitive-genetic male sterility, temperature sensitive-genetic male sterility and male sterility induced through chemical hybridizing agents (Virmani and Edwards, 1983; Singh et al., 2010). Each of the pollination system in wheat has merits and demerits depending on the practical feasibility but the Triticum timopheevii based cytoplasmic male sterility system (Wilson & Ross, 1962) has been widely utilized. Some of the basic and fundamental components for a successful development of hybrid wheat are stable male sterile line (A line with widely opened glumes/ angle), a good agronomic base of maintainer (B line with large anther size, long style) and perfect fertility restorer (R line with large anthers having high pollen number). There are several problems in hybrid wheat development and among them, lack of genetic diversity among parents for harnessing heterosis, out-crossing/natural crossing potential, complete fertility restoration and efficient and cost effective hybrid seed production technology are notable. To achieve hybrid vigour, it is necessary to identify, suitable parents for conversion into either cytolasmic male sterile or fertility restorer lines. Keeping in view these facts, an experiment was conducted to identify the maintainers and restorers for F1 hybrids of wheat. Materials and methods The experimental material consisted of 130 F 1 wheat hybrids from 10 cytoplasmic genetic male sterile (CMS) lines namely, J. Wheat Res. 5 (2) : 65-68 Received: 13 December 2013/ Accepted: 18 December 2013 @ Society for Advancement of Wheat Research 1 Current address: Directorate of Wheat Research, Karnal-132001 * Corresponding author's email: sksingh.dwr@gmail.com