| I. Research Notes Cytological investigations in hexaploid Triticale A.J SHAH, N.M. SHAHANI and N.N. ANSARI Department of Plant Breeding & Genetics, Sind Agriculture University, Tandojam, Pakistan Comprehensive work on the cytological behaviour of hexaploid Triticale has been carried out during last two decades, which have been verified and supplemented by many workers (KROLOW 1969a, b, MERKER 1973, TSUCHIYA 1974, WEIMARCK 1974, 1975, HAFIZ et al. 1982, HAFIZ & LARIK 1984). Present studies were also carried out to investigate the cytological behaviour of five hexaploid Triticale lines developed at the Department of Plant Breeding and Genetics, Agricultural University of Norway. Materials and Methods Five hexaploid Triticale lines namely Beaver-arm, Bacum, Beagle, ITYN78,21 (Beagle) and Mapache were obtained through the kind courtesy of Dr. K. AA STVIET, Professor of Plant Breeding and Genetics, Agriculture University of Norway. The crosses were made between Beaver-arm x Beagle, Beaver-arm x Bacum, Bacum x Beaver-arm, Beagle x Bacum, ITYN78,21 (Beagle) x Beaver-arm. The seeds of F1 hybrids, thus obtained, were sown in the field alongwith their parental lines. Ten plants from each of the cross and parental line were selected at random for the study of quantitative characters. For cytological studies, the young bud spikes were collected and fixed in a fresh Carnoy's solution (a mixture of alcohal and glacial acetic acid in a ratio of 3 : 1) at room temperature. After 24 hours, the Carnoy's solution was replaced by 70% alcohal and was stored at 4C. The meiotic observations were made on squash preparations of pollen mother cells using orecien acetic acid stain according to DARLINGTON and LACOUR 1969. Cytological studies of parental lines and F1 populations were done for all the stages of Meiosis-I and II. A sample of 100 cells per plant for each stage was studied. The chromosomal irregularities for univalents, multivalents, laggards, micronuclei and bridges were recorded in terms of frequencies of irregularities on single cell basis. |
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