The Effect of Temperature upon the Local Lesion Response of Cowpea Inoculated with Cucumber Virus I

Abstract

The use of cowpea, Vigna sinensis Savi, as a local lesion, semiquantitative assay host for cucumber virus I was described in some detail in an earlier paper.2 Sometime before this Price3 described the cowpea local lesion response. It was felt that additional work concerning the effect of temperature upon the development of local lesions might reveal greater consistent differences than those reported previously.2 With this in view, cowpeas, var. Black, were grown at 160, 200, 240, and 280 C under winter light conditions, using the same standard conditions for growth, age of plants, inoculation techniques, choice of inoculum, and strain as described by Sill and Walker.2 All plants were started at 200 C and then were moved to the critical temperatures one week prior to inoculation. Five trials were completed, lesion averages per trial being based upon 40 primary leaves on 20 plants. The work was done in part at the University of Wisconsin, Madison, and was completed at Kansas State College, Manhattan.