QTLOMICS AND EXPRESSION ANALYSIS OF CANDIDATE GENES OF ToLCV RESISTANCE AND SELECTED FRUIT QUALITY TRAITS AND MARKER ASSISTED BREEDING IN TOMATO (Solanum lycopersicum L.)
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Date
2019-02
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University of Horticultural Sciences, Bagalkot. (College of Horticulture, Bengaluru).
Abstract
The tomato minicore compromising 260 accessions was field evaluated at two
locations for ToLCVD incidence, yield and component traits, firmness and shelf life
besides using contained facility and linked DNA markers. Seven accessions - DARL-
66, EC-538380, F-7012, FLA-7421, INDAM-2103-4, INDAM-2103-6-1 and H-24 were
identified as stable and immune to ToLCVD. Minicore accessions that exhibited
significantly high genetic variability for all the traits tested. A set of 26 accessions for
both Ty1 and Ty3 genes, 39 for Ty1 gene alone, 13 for Ty3 gene alone and 182 for null
alleles of these genes were identified. A set of 49 accessions were found homozygous
for qFiR 2.2 QTL, 104 for qFiR 2.5 QTL and 66 for qFr_Shelf 1 QTL. QTLomics
analyses using GenScan, GenMark and FgeneH revealed one gene in Ty1, three genes in
Ty3, one gene in qFIR 2.2, 34 in qFIR 2.5 and eight in qFr_Shelf 1 as common
candidate genes. Expressional analyses of RETRO, LRR, WIP-1, RdRP for ToLCVD
and AUXIN, bHLH112, PE-1, MYBEFM, DEAD, FtsH6, SNORCS2, UBIQ-RNF4,
GLURP23 and NBS-Mi-1A candidate genes for firmness and shelf life revealed 0.12 to
11.79 and 2.56 to 14.92 fold changes, respectively. PTP down regulated in ToLCVD
manifestation. Ty1 and Ty3 genes from H-24 and EC-538380 resistant sources were
introgressed separately into susceptible three recurrent varieties through Marker
Assisted Backcross (MABC) with fore ground and background selections: TMABC1:
Anagha × EC-538380; TMABC2: Anagha × H-24; TMABC3: DMT-2 × EC-538380;
TMABC4: DMT-2 × H-24; TMABC5: PKM-1 × EC-538380 and TMABC6: PKM-1 ×
H-24. Resulting BC3F2 progenies recorded high levels resistance to ToLCVD.
Similarly, F5 lines derived through MAS involving TMAS1: DMT-2 × H-24 and
TMAS2: DMT-2 × EC-538380 for Ty1 and Ty3 recorded high levels of resistance
coupled with high attributes for yield related traits.