Soil borne Fusarium solani exhibited pathogenic effect on tomato cultivars in Nigeria

Abstract

The pathogenicity of soil borne fungi Fusarium solani on tomato cultivars was relatively unclear in Nigeria. This study thus investigates the pathogenic effect of F. solani on seed germination, seedling growth and fruit of two of the most commonly consumed tomato cultivars (UC82B and Ibadan Local - IL) in Nigeria. Fusarium species were isolated from the rhizospheric soil samples of tomato cultivars and their pathogenicity was assessed using blotter and soil inoculation techniques. Out of the 26 Fusarium species isolated, 6 (23%) were morphologically (with the aid of microscope) identified as F. solani (FS1, FS9, FS10, FS17, FS21 and FS26), among which the strains FS17, FS21 and FS26 significantly inhibited (p < 0.05) germination of UC82B seed, while only FS21 was responsible for poor seed germination in IL. At the same time, FS17, FS21 and FS26 significantly reduced (p < 0.05) plumule and radicle length more in UC82B, compared to IL. At seedling stage, only FS21 manifested visible pathogenicity. Leaves and stems of UC82B were demarcated with distinct rotting and browning; wherein such symptoms were merely visible in IL. However, the fruit of both the cultivars showed variation in their respective pathogenicity range of F. solani; FS21 expressing higher level of disease severity on UC82B fruit (66.50%) compared to IL fruit (55.05%). In general, F. solani (FS21) exhibits considerable potential, both to inhibit germination of tomato seeds as well as cause diseases on seedling and fruit of tomato cultivars in Nigeria.