Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2021
Publication Date: N/A
Interpretive Summary: Fusarium wilt is a cotton disease caused by the fungal pathogen, Fusarium oxysporum f. sp. vasinfectum. One particular form of the pathogen, known as FOV4, causes severe root rot and wilt, and eventual plant death. FOV4 was initially detected and confined to cotton fields in California, but has recently been detected in several cotton fields in West Texas and New Mexico. Small amounts of cotton seed harvested from these fields are infected with the FOV4 pathogen, but the mechanism by which seed become infected is unclear. In this report, we show that stink bugs, which commonly feed on developing seeds within cotton bolls, can acquire and transmit the FOV4 pathogen. Consequently, our findings suggest that stink bugs may play a significant role in the transmission and spread of FOV4 from plant to plant and field to field.
Technical Abstract: Fusarium oxysporum f. sp. vasinfectum VCG 0114 (race 4) (i.e., FOV4) is an emerging pathogen that causes severe root rot and wilt of cotton. FOV4 is seed-borne, but the mode of seed invasion is uncertain. In an initial study, seeds in bolls that were puncture-inoculated with FOV4 conidia when 25- or 30-d-old became infested but remained viable. Because stink bugs can ingest and introduce bacterial and yeast pathogens into cotton bolls, we hypothesized that stink bugs may ingest and transmit FOV4. Southern green stink bugs and brown stink bugs were exposed to PDA cultures of FOV4 and subsequently caged with cotton bolls to assess transmission potential. Both species fed on the cultures and acquired FOV4, and brown stink bugs transmitted FOV4 to cotton bolls. Thus, management of FOV4 may require management of stink bugs to mitigate the spread of the disease in cotton.