Abstract
The effect of water stress during flowering and grain filling on seed longevity was studied in three pearl millet genotypes, ICTP-8202, ICTP-8203 and MBH-110. The seeds were produced by three pollination methods; open pollination, selfing (individual panicles enclosed in paper bags), and cluster bagging (panicles from 3-4 adjacent plants enclosed in a paper bag), stored in air-tight plastic bottles under ambient conditions (20-40 degreesC, 30-80% RH) and germination was tested at 12-month's intervals. The seeds lost germination completely after six years of storage in all treatments. Analysis of variance of the estimates of potential seed longevity (i.e. the seed lot constant K of the seed viability equation) showed significant effects of water stress and pollination method (P < 0.01). The interaction between irrigation treatment and method of pollination control was also significant (P < 0.05). Averaged over genotypes and pollination methods, potential longevity was greatest (K = 2.8) in the irrigated control, and averaged over genotypes and irrigation treatments, it was greatest (K = 3.1) in seeds produced by open pollination. The implications of these results were discussed in relation to germplasm seed production.