Gametophytic competition in pearl millet, Pennisetum typhoides (Stapf et Hubb.)

Abstract
Factors affecting reproductive strategies of pearl millet, which is currently classified as a predominantly allogamous species, were investigated. Gametophytic competition as well as the effect of growth temperature on this phenomenon were studied by means of the pollen mixture technique. The relative competitive ability of pollen from five different genetic stocks (Ligui, Massue, "Chinese," Thiotandé, 23d2B) was assessed by isozyme electrophoresis (esterase, alcohol dehydrogenase) of progeny plants. Gametophytic competition with a polygenic inheritance trend for pollen competitive ability is reported. A better competitive ability of autopollen on various types of allopollen was systematically found for the Ligui genotype. Temperature stress enhanced this trend. Hypotheses on the role of gametophytic competition in the evolution of the primary genetic pool of P. typhoides are discussed.Key words: pearl millet, pollen, competitive ability, segregation distortions.