Impact of Alternaria solani (Early blight) on cultivated tomato (Solanum lycopersicum L.) in North-eastern region of India and identification of early blight disease resistant tomato genotypes

Abstract

The present investigation was carried out to screen genotypes for resistance to Early blight disease of tomato (Solanum lycopersicum L.) of North Eastern region of India. Field trial was conducted in the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during the years 2012-13 and 2013-14 consecutively. The disease severity of tomato genotypes was assessed by 0-5 points scale, percent Disease Incidence (PDI). Of the total materials screened, Sel-35 (TLBRH-6 X Konbilahi) and Sel-19 (TLBRH-6 X Konbilahi) were highly resistant, 7 were resistant, 14 were moderately resistant, 16 were susceptible and 6 were highly susceptible under field condition after inoculation during both years. The genotype having high yield and resistant to early blight was 10/TOLCVRES-3. The genotypes resistant to early blight but having low yield (Sel-35, Sel-19, Sel-9 and Sel-16) may be utilized in future breeding programme for improving yield through selection for higher fruit weight and fruit diameter. Alternatively, they may be used as parents in hybridization or backcrossing programme in order to transfer the gene for resistance to early blight to already adapted high yield varieties.