Stigmatic constriction in pearl millet following infection by Claviceps fusiformis

摘要: Abstract Infection of pearl millet by Claviceps fusiformis under field conditions occurred through fresh receptive stigmas. Microconidia and macroconidia germinated only on the parts stigma protruding from floret. Subsequent penetration passage hyphae down stylodia closely followed path taken normally pollen. Thirty-six hours after inoculation concurrent with hyphal invasion upper ovary wall, a constricted region located in fused stylodia, consisting collar collapsed parenchymatous cells, became apparent. This response is same as stigatic constriction which occurs to pollination. Stigmas then withered abscissed, effectively isolating Colonization fungus proceeded predominantly abaxial wall towards vascular trace supplying ovary. Hyphae remained intercellular throughout colonization Honeydew exudation florets marked establishment sphacelium 4–5 days inoculation.