| Melon (Cucumis melo L.) belongs to the Cucumis genus, Cucurbitaceae family, annual creeping herbaceous plants, is one of the important horticultural crops in the world and who has the most of diverse species in this genus. Wild melon has many good characteristics which cultivated species are lack in, such as high female flowers rate, high fruit-baring rate, strong disease resistance and adversity resistance. It will be important significance in raising the adversity resistance, the yield-production and improving the quality of melon if these beneficial genes of wild melon were transferred into cultivation species. Meanwhile, the development and utilization of the wild germplasm resources is an important source to develop the genetic resources of melon, which has cause more and more the attention of experts and scholars in the world.In this study, the wild melon LCW-01was crossed as male parent with the cultivatied melon X09-18.The two parents and the hybrid progenies as material, observing the genetic expression of the20main characteristics of hybrid progeny, such as branch number, fruit-baring rate, single fruit weight, etc. Then, using ADM model to genetic analysis, study the wild hybrid progeny genetic regularity, estimate the genetic parameter on, and construct a genetic map with SSR molecular markers and phenotype makers were adopted to build up a genetic linkage map for QTL localization. The main results were as follows:1) No matter positive or negative hybrid, hybrid F1of wild melon basically were tend to the cultivated parent, and the fruit length, single fruit weight and fresh thickness and so on had a great improvement space. However, the different results of positive and negative hybrid F1showed that there existed maternal effects.2) The separation of fruit characteriscs of the wild hybrid F2was obvious, which had a great choice of potential. Among these characteristics, placenta color and fresh bitter taste were complied with Mendelism and controlled by one or two pair of dominant genes, respectively, while to placenta orange color as fresh bitter taste to not bitter was dominant characteristics, and the bitter genes existed superior effect, the separation ratio was3:1and9:7, respectively. Fresh color and acidity were quality characteristics, but which did not conform to the separation law, controlled by dominat genes. While the other characteristics such as single fruit weight and branch number, etc. variated continuously and conformed to the distribution of normal distribution were quantitative characteristicss. The genetic variance components and genetic force size is different as different characters.3) In this research,313pairs of SSR primers for two parents, and after the145F2plants of group validation,10SSR markers associated with gynoecia’s in melon were found, which involved in the genetic map construction of5linkage groups without the fresh acidity marker. The total length of the genetic map was190.3cM, whose average distance between markers is13.5cM, The longest linkage group is97.2cM (LG3), and the shortest linkage group is5.0cM (LG4). Maximum distance and minimum distance between two markers are49.8cM and5.0cM respectively.4) Three QTLs were preliminary detected when using Windows QTL Cartographer V2.5software with CIM in this genetic map to analysis QTL loci. They were QTL1, QTL2, QTL3and linked with single fruit weight, branches length, leave width, respectively. These QTLs were mapped in linkage group1,2,3, respectively. Their LOD value varied among2.53-3.91. QTL2which located in the2nd linkage group explained the highest phenotypic variation was16.23%. The three closed linkage markers (SSR12833、MU7586、CMAGN73) can be used in fine mapping of fruit weight, branches length and leave width, respectively, which provides important reference anchors to the QTL in the future. |
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