fs3.1:a major fruit shape QTL conserved inCapsicum

Abstract

fs3.1 is a major fruit shape (defined as the ratio of fruit length to fruit width) quantitative trait locus (QTL) originally detected in an intraspecific cross of Capsicum annuum between the blocky and elongated-fruited inbreds 'Maor' and 'Perennial', respectively. In addition to increasing fruit shape index, the 'Perennial' allele at fs3.1 increased fruit elongation and decreased fruit width and pericarp thickness. We verified the effect of fs3.1 in backcross inbred lines (BILs) derived from crossing 'Perennial' with 'Maor' and with a second blocky-type inbred line of C. annuum. To determine the effect of the fs3.1 region in additional Capsicum species, we constructed an advanced backcross population from the cross of 'Maor' and the oval-fruited Capsicum frutescens BG 2816 and an F2 of the introgression line IL 152 that contains an introgression of the fs3.1 region from Capsicum chinense PI 152225. QTLs for fruit shape, fruit width, and pericarp thickness, but not for fruit length, were detected in both crosses, indicating the conservation of the fs3.1 region as a QTL affecting fruit shape in pepper. We also tested tomato (Lycopersicon spp.) introgression lines containing the corresponding fs3.1 region from L. pennellii and L. hirsutum, but we did not detect a significant fruit shape QTL in these lines. The effect of fs3.1 on the growth of fruit dimensions varied with the genetic background. By measuring the length and width of ovaries and fruits of near-isogenic C. annuum lines that differ in fs3.1 during fruit development, we determined that fs3.1 controls shape predominantly by increasing the growth rate of the longitudinal axis in the first 2 weeks after pollination. However, in the crosses of C. annuum with C. frutescens and C. chinense, fs3.1 predominantly exerted its effect on the width dimension.

Linkage of the A locus for the presence of anthocyanin and fs10.1, a major fruit-shape QTL in pepper

“…In a second cross between blocky and oval-fruited parents the same genomic region of fs3.1 had the most effect on fruit shape, while no QTL effect was detected in the genomic region of fs10.1 (Rao et al 2003). The effect of fs3.1 was further studied and verified in additional genetic backgrounds by Ben Chaim et al (2002).…”

“…We recently performed genetic and molecular analyses of fruit shape in pepper and mapped several quantitative trait loci (QTLs) controlling fruit shape in different Capsicum species (Ben Chaim et al 2001, 2002Rao et al 2003). The objectives of the present study were: (1) to localize the genes that control the presence of anthocyanins in various plant organs on the genetic linkage map of pepper, (2) to determine their allelic relationships, and (3) to examine the linkage between these genes and fruit-shape QTLs.…”

An integrated view of quantitative trait variation using tomato interspecific introgression lines

“…IL populations are now available for many wild tomato species [39][40][41][42][43]. Similarly, the power of the IL approach is now being realized in other model systems, including major food and biofuel crops such as pepper [44], rice [45], barley [46], wheat [47], maize [48 ], soybean [49] and Arabidopsis [50 ]. These populations are being phenotyped widely, but only a small fraction of the raw data finds its way to existing databases.…”

Selecting a set of wild barley introgression lines and verification of QTL effects for resistance to powdery mildew and leaf rust

“…But here, the coverage of the donor genome was not complete and/or the lines contained multiple exotic introgressions simultaneously. Examples for these lines can be found for instance for cabbage (Ramsay et al 1996), coffee (Prakash et al 2002), cotton (Percy et al 2006), lettuce (Jeuken and Lindhout 2004), peanut (Garcia et al 1995), pepper (Ben Chaim et al 2003), rapeseed (Howell et al 1996), and soybean (Concibido et al 2003). For spring barley, Brown et al (1988) primarily generated a set of 84 backcross lines, each carrying a single homozygous isozyme marker-defined segment of an Hsp accession.…”