Author
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Dunkle, Larry |
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LAPAIRE, C - PURDUE UNIVERSITY |
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Submitted to: Phytopathology
Publication Type: Abstract Only Publication Acceptance Date: 5/1/2002 Publication Date: 6/1/2002 Citation: Dunkle, L.D., Lapaire, C.L. 2002. Production and liberation of secondary conidia by cercospora zeae-maydis. Phytopathology. 92(S):44. Interpretive Summary: Technical Abstract: On a variety of nutrient-deficient substrates, conidia of the maize gray leaf spot pathogen, Cercospora zeae-maydis, germinate and develop secondary conidia (SC) on conidiophores produced from germ tubes or directly from conidial cells. A population of conidia increases its numbers more than 2-fold by 2 days on a water droplet and by 4-fold when primary conidia are attached to trichomes of monocot or dicot leaves. Upon transfer from high humidity to a dry atmosphere, SC and conidiophores gradually dehydrate and collapse. Dehydrated SC can be liberated from the conidiophores by wind speeds about one-third (1.3 m/s) those required to liberate hydrated conidia (3.7 m/s). The dispersed SC are able to rehydrate and germinate normally on water agar. Because this microconidiation cycle (MC) occurs at the expense of endogenous reserves, the ability to produce SC is lost after 4 cycles without an intervening period of growth on nutrient media. The MC process may have epidemiological consequences by maintaining inoculum potential during periods of fluctuating relative humidity when primary conidia fail to establish successful infections. |
