Influence of soil conditions, spore densities and nematode age on Pasteuria penetrans attachment to Meloidogyne incognita

摘要

Several soil variables as soil texture, moisture and temperature, Pasteuria penetrans spore densities and nematode age were tested in the laboratory for their effects on spore attachment to Meloidogyne incognita juveniles. Percentage of juveniles with endospores attached and number of spores per juvenile increased with concentration of spores applied to soil. In a clay-loam soil, hundred-percent attachments were reached at densities of 5 X 10~5 spores per g of soil and above. Attachment was greaterin loamy-sand than in sandy-loam and clay-loam soils, but lower when soil moisture was under 10 percent than when it was over 25 percent. Numbers of juveniles with spores attached were greater when soil temperatures were 25 deg C and 35 deg C than at 15deg C and lower in 7-30 days old juveniles than in 0-6 days old juveniles. All factors that favored nematode mobility in soil increased Pasteuria spore attachment to M. incognita juveniles.