II. 39 Meiotic behaviour and spike fertility in autotetraploid Notch-2 barley.
S.P. Tiwari, Division of Genetics, I.A.R.I. N. Delhi-12. (Present address: C.P.R.I., Lower Lab., Simla-l, H.P.).
Correlations between bivalent frequency, pollen fertility, anaphase-l distribution of chromosomes and spike fertility were worked out in C2, C3, and C4 generations of autotetraploid Notch-2 strain which has been reported to possess high seed protein (Tiwari et al., 1976). No association was found between mean bivalents per cell and spike fertility in all the three generations studied (Table 1). Pollen fertility and spike fertility showed a weak correlation in C2 and no correlation in C4 generation. Mean bivalents per cell and pollen fertility were also found to have no correlation. A high degree of positive correlation (r = 0.852, significant at 0.01 level) was found between normal anaphase-l distribution of chromosomes (14-14) and per cent spike fertility in C4 generation.
Average spike fertility of autotetraploids was 29.37 + 2.94% in C2, 17.16 + 2.16% in C3 and 46.48 + 1.63% in C4 generation. Higher fertility in C4 autotetraploids was obtained by early sowing (on 10th October instead of usually first week of November in Delhi conditions). Aneuploids, which invariably exhibited shorter stature than autotetraploids, gave lower fertility than autotetraploids. In the autotetraploid progeny (ranging from 2n = 26 to 2n = 30) lower spike fertility was attributable to the occurrence of aneuploid plants at population level and due to irregular distribution of chromosomes at anaphase-l at the level of individual plant.
Reference:
Tiwari, S.P., H.C. Bansal, and R.A. Pai. 1976. Protein estimation in induced autotetraploids of Notch-2, a high protein-high lysine mutant of barley. Barley Genetics Newsletter 6:75-76.
