Bottle gourd seed infection by Fusarium oxysporum Schltdl. and its role in disease development.

摘要

Bottle gourd [Lagenaria siceraria (Mol. Standl.)] seeds naturally infected with Fusarium oxysporum was characterized on the basis of symptoms of white crust on seed surface. The infected seeds appeared with or without white crust. The incidence of symptomatic seeds in samples of Rajasthan varied from 1.25-26.75%. But on inoculation, the pathogen was isolated from 33% samples with 1-42% incidence in chlorine pretreated seeds. Location of pathogen was studied in both asymptomatic and symptomatic seeds. Mycelium in asymptomatic seeds was extra-embryonal and confined to seed coat only; but it occurred in seed coat, aleurone layer, cotyledon and embryonal axis of symptomatic seed. The extraembryonal infection resulted in transmission of disease from the inoculum present in seed coat to other part of the seedling; whereas, intraembryonal infection mostly caused pre- and post-emergence losses.