Identification of Weed Hosts of Tomato Yellow Leaf Curl Virus in Field-Grown Tomato in Sudan Savanna, Nigeria

Abstract

This study is aimed to detect weed hosts of Tomato Yellow Leaf Curl Virus (TYLCV) in field-grown tomato (Solanum lycopersicum L.) in Sudan savanna regions (Gombe, Jigawa and Kano states) of Nigeria during 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 TYLCV using Triple Antibody Sandwich Enzyme-linked Immunosorbent Assay (TAS-ELISA). Based on the obtained results, 14 weed species from 12 families were detected as alternative host of TYLCV in all states surveyed but with variation in distribution. Gombe and Kano states had significantly (p ≤ 0.05) the highest number (7) of TYLCV weed hosts while the lowest number (4) of TYLCV weed hosts was recorded in Jigawa state. Cassia obtusifolia Linn., significantly (p ≤ 0.05) showed the highest TYLCV frequency rating of 12.1%. The study reports for the first time 13 weed species naturally occurring as an alternative host of TYLCV in Nigeria. The detection of these weed hosts of TYLCV will give a better understanding of the virus disease epidemiology for its effective management. Exploring more weed hosts of TYLCV and molecular characterization of the virus in these weeds for the possible evolution of novel strain(s) in the region is recommended.