DETECTION OF WEED SPECIES INFECTED BY Tomato ringspot virus IN FIELDGROWN TOMATO IN SUDAN SAVANNA, NIGERIA.

Abstract

Field study was conducted to determine the occurrence and distribution of weed hosts of Tomato ringspot virus (ToRSV) in field-grown tomato in Gombe, Jigawa and Kano States in the Sudan savanna regions of Nigeria during the 2017 and 2018 dry and wet seasons. Three farms each from three Local Government Areas (LGAs) of each state were surveyed. Ten symptomatic and asymptomatic weed samples within and around each farm (n=1080) were randomly collected and assayed against ToRSV using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The results showed that 19 weeds species from 11 families were established as alternative host of ToRSV in all States surveyed but with variation in distribution. Kano States had significantly (p ≤ 0.05) higher number (12) of weed hosts (12) of ToRSV compared to five weed species each in Gombe and Jigawa States. Solanum nigrum L. significantly (p ≤ 0.05) had the highest frequency rating (10.3 %) of ToRSV. From available literature, this is the first report of ToRSV naturally infecting the 19 weed species in Nigeria. The findings of the present study point to a better understanding of ToRSV disease epidemiology for its effective management. It is recommended that similar studies be carried in others adjoining states to identify potential weed hosts of ToRSV. Molecular characterization of the virus isolates of the virus should be conducted for the possible existence of new strain(s) in the region.