苦瓜亚种间遗传图谱构建及果实相关性状QTL定位

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Abstract： Bitter gourd（Momordica charantia L.）is a traditional melon vegetablein China，but its cultivated varieties suffer from a narrow genetic background，necessitating the expansion of genetic diversity through distance hybridization with wild germplasm.In this study，an F2 population was generated from across between the smal-fruited wild subspecies inbred line NJ and the common subspecies inbred line Tan.QTL mapping was performed for five fruit-related traits （fruit length，fruit diameter，fruit shape index，fruit shape， and fruit weight）using a bin marker genetic map through genotyping-by-sequencing，with the MQM（MultipleQTL model） method. Significant correlations were observed among most traits，except between fruit diameter and fruit shape，as well as between fruit shape index and fruit weight.1563 of 1921 bin markers were integrated into an inter-subspecies genetic map，spanning 1556.91 cM across 11 chromosomes，with an average genetic interval of 1.00cM .Comparative analysis between the genetic and physical maps revealed approximately 11Mb （204号 inversion on chromosome MC08 between the two subspecies.A total of seven QTL exceeding the LOD threshold were identified，including two for fruit length（qFL5.1，qFL7.1），two for fruit shape index （qFSI1.1， qFSI4.1），two for fruit weight（qFW5.1，qFW6.1），and one for fruit shape （qFS5.I） .Notably，qFL5.1，qFS5.1 and qFW5.1 were mapped to a consensus major-effect QTL interval.The findings of this study contribute to our understanding ofthe genomic variation between the two subspecies of bitter gourd and provide the foundation for inter-subspecies germplasm innovation and gene mining of fruit-related traits.

Keywords：bitter gourd subspecies;genetic map;fruit-related traits;QTL

苦瓜（MomordicacharantiaL.）属于葫芦科一年生攀援草本植物，是我国夏季重要的瓜类蔬菜。（剩余16152字）