Cytomorphological studies of trisomics isolated from desynaptic mutants in barley (Hordeum vulgare L.).

From the selfed progency of three desynaptic mutants, 38 primary trisomic plants were isolated. These trisomic plants were classified into seven types based on their identifiable morphological traits. Pollen sterility ranged from 35–90 per cent and ovule sterility ranged from 56–97 per cent. They showed different types of chromosome associations at MI which were trivalent, bivalent and univalent. Range of univalents was 2–13 while, the range of bivalents was 1–6 per cell. Average number of trivalents/cell was 0.09 to 0.43, average number of bivalents/cell was 3.3–4.16 and average number of univalents/cell was 5.93–7.41 in these trisomies. Different types of AI separations such as 9–6 and 8–7 were observed and the average number of laggards/cell was 0.96–1.4. Lagging of chromosomes and formation of bridges at A II and presence of micronuclei in spores were also observed in these trisomics.