Identification of tomato yellow leaf curl viurs resistant tomato genotypes

Abstract

Tomato germplasm is a rich source of diversity for different biotic and abiotic stresses. Tomato plant faces number of biotic and abiotic stresses during its growing season. Tomato yellow leaf curl virus is one of the important diseases among biotic stresses.  Keeping in view the importance of the crop to the economy, made it necessary to collect and characterize available commercial varieties from Pakistan and accessions from TGRC (Tomato Genetic Resource Centre) and beyond as a first step to its improvement. 50 tomato accessions were assessed for morphological traits using the IPGRI’s descriptor list. The experimental design was a randomized complete block design with two replications. Data were collected on following morphological parameters; days to maturity, no of fruits per plant, fruit weight and yield per plant for all 50 accessions. In experiment we identified the symptoms & viral load for the identification of resistant genotypes against TYLCV in tomato. Secondly identified tomato genotypes with good potential for high economic traits & adaptability of accessions were evaluated. In this experiment reported SSR primers were used on 20 tomato genotypes that produced polymorphic bands. Disease scoring was done on visual observation bases in the field condition. Disease resistant was measured using detached leaf and whole plant assays. Out of 400 plants 0.24% moderately susceptible, 0.23% high susceptible, 0.21% less susceptible, 0.20% were found with no symptoms on plant, whereas only 0.13% plants were found with extremely high symptoms of TYLCV on plants and leaves. The response of whole plant to TYLCV was similar in all cases. All this work is of considerable interest for tomato breeder as well as for basic research especially in Pakistan.