Mapping of fruit length related QTLs in interspecific cross (Capsicum annuum L. x Capsicum galapagoense Hunz.) of chilli

Fruit length in chilli is quantitatively inherited trait and selection based on phenotypic performance is tedious and time consuming. To detect QTLs determining fruit length in Capsicum spp., an interspecific F-2 mapping population was developed from the cross of C. annuum L. cv. 'FL 201' with C. galapagoense Hunz. accession 'TC 07245'. Fruit length in this cross showed a quantitative inheritance with the population depicting a symmetric distribution in histogram. To map quantitative trait loci (QTLs) for fruit length 400 SSR markers were surveyed on the parental genotypes but only 28 markers were observed to be polymorphic indicating less genetic diversity between the two Capsicum species. Polymorphic markers were then analyzed in F-2 population consisting of 210 plants and 24 of these markers were mapped on to three linkage groups (LGs): LG 1, LG 2 and LG 3. Two fruit length determining QTLs designated as paufl2.1 and paufl2.2 were identified and both the QTLs were mapped on to LG 2. The two QTLs together explained 21.78 per cent of the phenotypic variation. Apart from the two QTLs, positive alleles were detected in the small fruited parent 'TC 07245' which might be of potential use in chilli breeding programs.