| In F1 plants, spike density was intermediate while rachis toughness,
lower internode shape and growth habit were dominant. KAGAWA (1927), KIHARA
(1958), DOSBA & CAUDERON (1972) were also obtained similar results from
various wheat-Aegilops hybrids. The characteristics of the parents
and F1 hybrids are shown in Table 1.
The ears of the hybrid plants looked like mostly Ae. speltoides in
compare with the other parent (Fig. 2). All F1 plants were tested against stripe rust and found as resistant. It was conclude that resistance was dominant. Like other wheat-Aegilops hybrids (OZGEN 1983b, 1984, 1985), these F1 plants also had non dehiscent anther. It has been known that differences in number and structures of chromosomes of parents may be cause of sterility (KIHARA & YAMASHITA 1956). On the other hand, there are also some genes which cause sterility by affecting meiosis or its resulting gametes in the interspesific hybrids (STEBBINS 1958). Thus, only 8 seeds were obtained from 487 spikes of 12 F1 plants. According to this result, back-crossing is necessary to obtain off-springs from T. durum var. hordeiforms x Ae. speltoides hybrid. Meiotic configuration and chromosome pairing of F1 hybrids are given Table 2 and 3. These show that the number of bivalents varied between zero and six, and most of them were of rod type, but there also were some ring types (Fig. 3). Furthermore, a few trivalents and quadrivalents were seen. The percentage of cells with no bivalents was as low as 9.5 per cent. Chromosome pairing in the F1 hybrids of T. durum var. hordeiforme x Ae. speltoides were found to be higher than for T. durum var. hordeiforme x Ae. umbellulata's F1 hybrids (OZGEN 1983b). From the result, thus, it can be inferred that Ae. speltoides is more suitable than Ae. umbellulata in order to transfer gene to T. durum var. hordeiforme. References DOSBA, F. and Y. CAUDERON. 1972. A new interspesific hybrid: Triticum aestivum ssp. vulgare x Aegilops ventricosa. Wheat Inform. Serv. 35: 22-24. DVORAK, J. 1977. Transfer of leaf rust resistance from Aegilops speltoides to Triticum aestivum. Can. J. Genet. Cytol. 19: 133-141. DVORAK, J. and D.R. KNOTT. 1980. Chromosome location of two leaf rust resistance genes transferred from Triticum speltoides to T. aestivum. Can. J. Genet. Cytol. 22: 381-389. DYCK, P.L. and E.R. KERBER. 1970. Inheritance in hexaploid wheat of adult-plant leaf rust resistance derived from Aegilops squarrosa. Can. J. Genet. Cytol. 12: 175-180. FELDMAN, M. and E.R. SEARS. 1981. The wild resources of wheat. Scientific American. 244: 102-112. HIRATSUKA, N. 1955. Reaction of Aegilops and Triticum to Puccinia graminis Pers. and Puccinia glumarum Eriks. and Henn. Wheat Inform. Serv. 2: 5-7. KAGAWA, F. 1927. Cytological studies on Triticum and Aegilops II. On the genus crosses between Triticum and Aegilops. Utsunomiya Agricultural College. 1-25. KIHARA, H. and K. YAMASHITA. 1956. Wheat and its relatives. Wheat Inform. Serv. 4: 16-23. KIHARA, H. 1958. Fertility and morphological variation in the substitution and restoration backcrosses of the hybrids, Triticum vulgare x Aegilops caudata. Xth Int. Congress of Genet. 142-171. LILIENFELD, F.A. and H. KIHARA. 1951. Genome analysis in Triticum and Aegilops. Cytologia. 16: 101- 103. OZGEN, M. 1983a. Hybrid seed in wheat X Aegilops crosses. Wheat Inform. Serv. 56: 9-11. OZGEN, M. 1983b. Morphological characters and meiotic associations in a T. durum Desf. var. hordeiforme Korn. x Ae. umbellulata Zhuk. hybrid. Wheat Inform. Serv. 57: 1-3. OZGEN, M. 1984. Morphological characters and meiotic associations in a T. aestivum L. var. erythroleucon Korn. x Ae. biuncialis Vis. hybrid. Wheat Inform. Serv. 58: 1-3. OZGEN, M. 1985. The meiotic analysis and morphological characters of the hybrid Triticum aestivum L. var. delfii Korn. x Aegilops triaristata Willd. Wheat Inform. Serv. 60: 1-4. SEARS, E.R. 1956. The transfer of leaf rust resistance from Aegilops umbellulata to wheat. Brookhaven Symp. Biol. 9: 1-21. STEBBINS, E.R. 1958. The inviability, weakness and sterility of interspesific hybrids. Advences in Genetics. 2: 147-215. |
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