ISHS Acta Horticulturae 108: International Cashew Symposium
STUDY OF MICROSPOROGENESIS IN CASHEW |
| Authors: | P.K. THANKAMMA PILLAI, M.C. NAMBIAR |
| Abstract:
Six cashew trees growing at the C.P.C.R.I. Kasaragod campus were selected for this study. For meiotic studies, the flower buds were fixed in freshly prepared Carnoy's solution (6:3:1 alcohol: chloroform: acetic acid) between 2 and 3 p.m. and refrigerated for 24 hrs and then transferred to 70 per cent alcohol after treating the buds with ferric acetate. Squash preparations of anthers, with acetocarmine were made for the study of microsporogenesis. Pollen stainability was determined by using 1:1 acetocarmine: glycerine. The meiotic behaviour was found to be uniform in all the six trees examined. At metaphase I, 63 to 68 per cent of the cells showed 21 bivalents. The mean chiasmata per cell and the between cell variance (within plant variation) have been analysed. In cashew, the frequency of chiasmata ranged from 39 to 42 per cell and the cell variance within a tree ranged from 0.25 to 1.1. Most of the cells showed 19 ring bivalents and 2 rod bivalents, and two of the bivalents consistently showed unterminalised chiasmata at metaphase I. Out of the 223 cells observed at metaphase I, 144 were found to be normal possessing 21 bivalents. The rest showed irregularities like chromosome mosaics, suggesting premeiotic irregularities and stickiness of | |
