Morphological and Molecular characterization of ToLCV (Ty-2 and Ty-3 genes) resistance in Tomato (Solanum lycopersicum L.)
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Division of Vegetable Science ICAR-Indian Agricultural Research Institute New Delhi
Abstract
Tomato (Solanum lycopersicum L.) is one of the most economical solanaceous vegetable
crops grown throughout the world. Its cultivation is highly affected by tomato leaf curl virus
disease (ToLCV/TYLCV) caused by begomoviruses and transmitted by whitefly (Bemisia
tabaci). In order to identify the potential genotypes having good horticultural traits along with
strong and durable resistance against ToLCV/TYLCV disease of tomato, 30 diverse tomato
genotypes carrying different Ty genes were screened at phenotypic and genotypic level. The
morphological data for various horticultural traits alongwith disease symptoms in terms of per
cent disease incidence (PDI) and disease severity of ToLCV was recorded 3 times, i.e. at 30, 60
and 90 days after transplanting under field condition. On the other hand, validation for Ty-2 and
Ty-3 genes was carried out in the molecular laboratory. Earliest first flowering and 50%
flowering were recorded in DT16 and Pusa Rohini respectively. Two genotypes, namely DT11
and DT27 exhibited high pericarp thickness, i.e. 6mm. The maximum weight of matured fruit
was recorded in genotype DT24 (90 g), while yield/plant was recorded maximum yin DT8 (1556
g). In correlation studies, the yield/plant showed highly significant positive correlations with leaf
length (0.66**) and plant height (0.55**). However, its correlation with fruit equatorial diameter
(0.43*), number of flower per cluster (0.42*) and average fruit weight (0.41*) was significant.
Therefore, these traits play an important role for selection point of view for getting higher tomato
yield. 30 tomato genotypes were grouped into 5 different clusters with most of the susceptible
and resistant genotypes in two different clusters. In phenotyping, DT2, DT8, DT10, DT17, DT20
and DT30 were categorized a resistant. None of the genotype was found as highly resistant. After
analyzing phenotyping and genotyping data together, out of six genotypes which were resistant
in phenotypic screening, only four genotypes, namely DT2, DT10, DT20 and DT30 were found
resistant both in phenotypic as well as genotypic screening, i.e. they showed presence of both
resistant genes Ty-2 and Ty-3 at genotypic level. These promising genotypes will be useful as
parental material to develop lines/hybrids carrying multiple genes against both monopartite and
bipartite viruses for strong and durable resistance against ToLCV disease.
Description
T-10317