| Seed setting and germination in crosses of AB-genome
monosomic lines of Pb C 591 x Bijaga Yellow and their back cross generations
in wheat* R.R. HANCHINAL and J.V. GOUD Department of Agricultural Botany, University of Agricultural Sciences, Dharwad campus, Karnataka, India Seed setting is a major problem in interspecific crosses. Variation in chromosome numbers in the two species used for crossing may be one of the reasons, which leads to the failure in fertilization, because of the imbalance of the chromosomes in the female and male gametophytes. Sometimes, though there is fertilization, the embryo abortion during the development stages is observed. Even if there is seed set, seeds are weak and shrivelled. Such seeds lack the proper development of embryo and endosperm. When such seeds are germinated, drastic reduction in germination is noticed. WATKINS (1927), BOYES & THOMPSON (1937) and THOMPSON & CAMERON (1928) etc. studied the seed setting and germination in interspecific crosses between hexaploid wheat and tetraploid wheat. But the present investigation includes the seed setting and germination of crosses between AB-genome monosomic lines of Pb C 591 (Triticum aestivum) and Bijaga Yellow (T. durum) and their back cross generations. Material and Methods The first fourteen monosomic lines of hexaploid wheat variety Pb C 591 (monosomic for A or B genome) were crossed as female parents with T. durum cv Bijaga Yellow. In F0 generation, both crossability and germination percentage was worked out. In F1 generation, only the plants with 13"+8' were selected in all the 14A and B genome lines and back crossed to Bijaga Yellow. Then crossability and germination percentage was worked out. In the first back cross generation, though the chromosome number was varying from 30 to 34, only such plants with 30 chromosomes (13"+2') were selected and again back crossed to Bijaga Yellow. In second back cross generation, plants with 27 chromosomes (13"+1') were selected and back crossed to Bijaga Yellow. In all these generations crossability as well as germination percentage was worked out. Results and Discussion As there was much variation in the seed setting and germination, in different generations, the subject is discussed generations wise. |
| * Part of the Ph. D. thesis submitted by the first author to the University of Agricultural sciences, Bangalore-1980. |
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