| Table 2 presents the days to flower and number
of effective tillers in recipient wheat varieties and also in the male sterile
analogues obtained from the three sources. The table shows that Ae. ovata
and Ae. caudata cytoplasms, though confer great vigour as exhibited
by their profuse tillering capacity, are late in maturity which is an undesirable
character under our conditions. There was a considerable increase in ear length of the Ae. ovata analogues. However, Ae. ovata and Ae. caudata analogues due to their late maturity and with the onset of hot winds at the time of maturity developed highly shrivelled seeds. On the other hand, T. timopheevi analogues possessed excellent agronomic and yield abilities without having any undesirable side effect. Keeping in view these facts much emphasis was laid on T. timopheevi male sterile and fertility restorer analogues. Thus, male fertility restorer analogues were produced from the T. timopheevi source only. Production of male fertility restorer analogues: Restorer DIRK (T. timopheevi), a promising male fertility restorer line, was crossed with all the above mentioned ten wheat varieties. F1's were crossed with a male sterile line-M.S. Sonora-64 (T. timopheevi) to test whether the F1's carried R gene(s). Besides, backcrosses were also made with the respective varieties. The tester x the ten F1's seeds were sown and on selfing it was observed that the F1's restored to male fertility very effectively. This indicated that R gene (s) have been tranferred. In further backcross generations selection was practiced and only those single plants that carried fertility restoring gene (s) and also resembled morphologically with the recurrent parent variety, were selected and used in advancing the backcross programme. In addition to the production of male fertility restorer analogues in Indian wheat varieties we also explored the possibility of locating male fertility restoring genes in several wheat varieties per-se. Besides three Indian hexaploid wheat varieties i.e., N.P. 839, N.P. 883 and N.P. 880 reported by MIRI, AMAWATE and JAIN (1970) to possess R genes, some twenty four Indian and exotic wheat varieties (N.P. 52, N.P. 165, N.P. 720, N.P. 758, N.P. 761, N.P. 770, N.P. 775, N.P. 792, N.P. 799, N.P. 805, N.P. 818, N.P. 823, N.P. 829, N.P. 852, N.P. 858, N.P. 862, N.P. 865, N.P. 891, NAPO-63, Ciano F-67, GA-BO, INIA-66 and Norin-59) were crosed with male sterile Sonora-64 (T. timopheevi). None of the above mentioned varieties, including those reported by MIRI and his associates could restore the male fertility. Literature cited FUKASWA, H. 1959. Nucleus substitution and restoration by means of successive backcrosses in wheat and its related genus Aegilops. Jap. J. Botany 17 (1): 55-91. KIHARA, H. 1951. Substitution of nucleus and its effects on genome manifestations. cytologia 16: 177-193. MIRI, R. K., J. S.AMAWATE and H. K. JAIN. 1970. N. P. 839, N. P. 883 and N. P. 880: new sources of fertility restoration in male sterile. Wheat Inform. Serv. Kyoto 31: 9-11. (Received April 10, 1973) |
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