Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2001
Publication Date: 6/1/2001
Citation: Bruton, B.D., Brady, J., Mitchell, F., Bextine, B., Wayandande, A., Pair, S.D., Fletcher, J., Melcher, U. 2001. Yellow vine of cucurbits: Pathogenicity of serratia marcescens and transmission by anasa tristis [abstract]. Phytopathology. 91:S11-S12.
Technical Abstract: Cucurbit yellow vine disease (YV), which causes foliar chlorosis, wilting, phloem discoloration and plant collapse, was consistently associated with Serratia marcescens (Sm). Squash seedlings were inoculated at the cotyledon stage with 10(^6) to 10(^10) CFUs Sm via vascular puncture (Phytopathology 85:139), resulting in infection of <10% to 50% of the plants, respectively. After 28 d, symptomatic plants were stunted, slightly chlorotic, had phloem necrosis, and were PCR positive for Sm, but did not wilt or collapse. When squash bug (Anasa tristis) adults, fed on Sm- or broth-infiltrated squash cubes, were confined 8 wk on Reemay-covered squash plants in the field, 15% of plants exposed to Sm-fed A. tristis, but no control plants, displayed the complete array of YV symptoms. Sm cultured from diseased plants was indistinguishable from that of the inoculum in PCR and sequence analysis. These results represent tcompletion of Koch's postulates for Sm and demonstrate that the squash bug is a vector of the bacterium.