GENETIC AND ENVIRONMENTAL VARIATION IN ANTHER, POLLEN AND PISTIL DIMENSIONS IN SESAME

Measurements of anther (length, width, depth), pollen grain (percent f ertility, polar diameter, equatorial diameter, polar diameter/equatori al diameter ratio, volume) and pistil (stigma length, style length, ov ary length, total pistil length, stigma width, style width, ovary widt h) were taken on 12 diverse sesame (Seasamum indicum L.) genotypes on each of four collection dates in 1994. Highly significant differences among genotype means were obtained for all characters except polar dia meter. Highly significant differences among environment (collection da te) means were found for ten of the 15 characters measured. Highly sig nificant genotype x environment interactions were obtained for all cha racters except anther length. For the anther characters measured, rela tively high repeatability values were found, ranging from 99.8% for le ngth to 87.6% for depth. For the pollen grain characters measured, the repeatability values ranged from 67.6% for percent fertility to 23.1% for polar diameter. For the pistil characters measured, the repeatabi lity values ranged from 94.0% for style width to 49.6% for total pisti l length. These results indicate that genotype and environment influen ce anther, pollen grain and pistil characters. Variation in some of th ese morphological aspects could influence the consistency and interpre tation of male transmission studies on both the applied and evolutiona ry levels.