Pathogenicity of Pyricularia and Cochliobolus Conidia Compressed by Hydrostatic Pressure
Effects of Physical Factors upon the Plant Diseases V
1972 Volume 38 Issue 2 Pages 95-99
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1972 Volume 38 Issue 2 Pages 95-99
When conidia of Pyricularia oryzae were compressed at 0, 500, 1, 000, 1, 500, and 1, 800kg/cm2 for 10 minutes, the germination was reduced from 97% to 16%. The infectivity of these conidia to rice leaves was correspondingly reduced. At 0-1, 000kg/cm2 the number of conidia with appressoria exceeded those with ordinary germ tubes, whereas at 1, 500 and 1, 800kg/cm2 conidia with appressoria were less than those with germ tubes. With increasing pressures (0-1, 800kg/cm2) the number of susceptible type lesions decreased from 7.5 to 0.5/10cm of rice leaf, whereas the number of resistant type lesions remained approximately constant at 1/10cm.
When conidia of Cochliobolus miyabeanus were exposed to increasing pressures as above, the germination and infection were reduced, but not as much as with P. oryzae. Conidia exposed to pressures above 1, 500kg/cm2 formed smaller lesions on rice leaves than those exposed to lower pressures.
