Genetic Linkage Map Construct And QTL Analysis For Agriculture Traits In Bitter Gourd (Momordica Charantia L.)

Bitter gourd (Momordica charantia. L) has2n=22chromosomes, as a vegetable of the cucurbitacea family, growing in temperate and tropical regions of Africa, Asia, the Caribbean, and South America. Asian bitter gourd originated from tropical Africa. Areas of eastern India and southern China where some wild genotype bitter gourd were existed in, proposed for its original place of domestication. To date, the genetic diversity of bitter gourd, just as genetic diversity in its Chinese or Indian populations, has been preliminarily studied by using a variety of DNA markers.A molecular linkage map was constructed using F2progenies with one line Z-1-4(gynoecy line type) and the other line189-4-1(normal inbreds line) as parents.The EST-SSRs, SSRs, AFLPs and SRAPs were employed to screen for polymorphisms. At the base of this genetic map, through two years, two areas, three cultivar periods and two cultivar types cultivar trails,20agriculture trails were anynasized.The results were as following:In theory that EST-SSR markers not only have related-species transferability, but also can transferred in cross-species, so we developed7EST-SSRs from cucumber,9EST-SSRs from melon in cucurbitaceae, and10EST-SSRs from Chinese cabbage and leaf mustard in brassicaceae were transferred into bitter gourd for genetic map construction, and selected some SSRs to construct the map, too. More than one linkage group to bitter gourd chromosome pairs, and this map contain twelve linkage maps.The parameters of this map are the below:total maker number194, total length1009.5cM, total mean interval5.2cM; the range of mean interval for perlinkage group4.1-6.1cM,84.1cM per linkage group, and ranging from22.5cM (Lgl1) to151.7cM (Lg1).Association with the development of bitter gourd breeding program and vegetable markers consumer trends, in this study the experiment material including two parents and144F2progenies of bitter gourd are cultivared in greenhouse in early spring in2009and2010in Wuhan Huazhong agriculture research base and open field in Huangshi in summer of2009. At the basedata of the22quantitave agriculture traits of F2group in bitter gourd in two years, two areas, and three cultivar periods. QTL were analysized, and the results were as following:QTLs affecting20quantitave agriculture traits of22were detected, including the traits of female blossom node(FBN), female blossom time(FBT), female blossom height(FBH), male blossom node(MBN), male blossom time(MBT), male blossom height(MBH), female node percentage(FNP), first fruit node(FFN), first fruit height(FFH), yield per plant(YPP), fruit per plant(FPP), fruit length(FL), fruit diameter(FD), fruit shape(FS), fruit weight(FW), fruit pedicel length(FPL), fruit fresh diameter(FFD), fruit pedicel ratio(FPR), internode length(IL), step diameter(SD). The QTLs affecting first fruit weight and mature period were not detected, and totol of63QTL were detected among total20traits in defferent enviroments, and average QTL per trait is3.0. Nine QTLs were simultaneously detected in concurrent three environments, and two QTLs were associated with the male blossom height or male blossom node were detected, respectively; and one QTIL was associated with female blossom node as same as two QTL for female node percentage were detected; the remant of two QTL affecting yield per plant were detected, too. At the same time, twenty-four major QTLs in two defferent environments and thirty special QTLs in any one environment were detected.9QTL which were detected in three deffrent environements were counted as the major and stable QTL, should be used to clone the important QTL.The hot QTL regions on the Lg1,4and5were proved, and these regions contain more than one major or stable QTLs checked affecting of some traits, such as the region of Lgl ranged about52.0cM from molecular markers cs50to cm53, contains6molecular markers, checked out8QTLs, and five of them tightly were related to male or female blossom height, and another three QTLs related to fruit length, fruit diameter and fruit fresh diameter. The interval of the QTLs checked in this region affecting of female blossom node, male blossom node, female blossom height, male blossom height and female node percentage was closed, so we inferred to these five traits were tightly related to flower bud differentiation mechanism, and the hot QTL regions existed in one gene more effects.This study is the first time to report the QTL analysis of more than20quantitave traits in bitter gourd with the two different cultivared types of two years, two areas and three cultivar periods. The quantitave traits contains yield, maturaty, fruit shape and important agriculture traits, and the results previously located some regions which should be easy to clone some intersing trait.Not only the developed EST-SSRs and SSRs, but also the genetic map, or lots of QTs checked in this study should improve bitter gourd genetic research and bitter gourd moleculer breeding.