QTL mapping for important horticultural traits in pepper (Capsicum annuum L.)

Quantitative trait loci (QTLs) for plant height (PHT) and other yield-related traits including number of fruits per plant (NFP), ten fruits weight (TFW), fruit length (FL), fruit width (FW), total fruit weight (ToFW) and pericarp thickness (PT) were mapped in intraspecific advanced recombinant inbred line (RIL) populations of pepper. The RILs were evaluated for 2 years (F8 and F9) for plant height and seven other yield-related traits. Three types of molecular markers; simple sequence repeat (SSR), sequenced characterized amplified region (SCAR) and random amplified polymorphic DNA (RAPD)—were used to generate linkage maps. A total of 10 QTLs for yield-related traits were mapped on four linkage groups (LG). QTLs for plant height were mapped on LG5. The phenotypic contribution of these QTLs ranged from 8 % to 51 % in mean over environments. Out of 10 QTLs detected, nine were stable in both environments except the QTL for fruit length (Qfl.iivr.3.4) on LG3. The five QTLs; Qfw.iivr-2.1, Qtfw.iivr-2.1, Qtofw.iivr-2.1, Qnfp.iivr-2.1 and Qpt.iivr-2.1 were on the same marker interval on LG2 and one QTL, Qtofw.iivr-3.1 were tightly linked on LG3, which suggests that these genomic regions play an important role in enhancing pepper production. The genomic regions of all stable QTLs identified may serve as potential target regions for fine mapping and development of molecular markers for manipulation of yield and morphological traits in pepper.