瓜果腐霉游动孢子对番茄和秋海棠侵染过程的研究

ON THE INFECTION PROCESS OF ZOOSPORES OF PYTHIUM APHANIDERMATUM TO TOMATO AND BEGONIA

作者研究了瓜果腐霉游动孢子的附着特性和侵染过程。游动孢子主要附着在番茄苗根的根毛区和根冠上,休止孢子萌发的芽管在侵入根毛之前,能形成附着孢或前侵染丝;而游动孢子对秋海棠的附着主要集中在茎部和叶尖、叶缘处,芽管直接侵入茎、叶的表皮细胞及须根。

The pathogenic Pythium species were isolated and identified from tomatoand begonia,and the pathogenicity test was done.The characteristics atta-ching of zoospores of Pythium aphanidermatum and their infection mechanismwere studied and observed.The zoospores of P.aphanidermatum aggregatedmainly at the region of root hair and root cap,whill a few in the elongationarea of the tomato roots.Before penetrating the root hair,the germ tubesof cystospores at first formed appressoria and infection peg or prepenetra-tion hyphae.But the germ tubes penetrated directly through the cuticle cellsof the root cap,the root elongation region and the base of root hair.Thezoospores adhered mainly to the stem,leaf tip and leaf edge and a few inthe fibrous root of the begonia seedlings.The germ tubes of cystospores didnot form appressoria or prepenetration hyphae but penetrated directly thro-ugh the surface of the stem,leaf and fibrous root.