Early Identification Method Of Melon Male Sterile Seedling Stage

Melon(Cucumis melo L.)has obvious heterosis which is an important cash crop of Cucurbit,in the past few years,researchers and breeders have cultivated large quantities of fine hybrid seeds of melon all around the world,which Created great economic benefits.However,at present,the hybrid seed production still uses the measures of removing female male flowers by hand,artificial pollination,bagging and so on,the processes are complicated,the workload is big and the cost is high,these measures can easily cause damage to flower organs,resulting in a decline in production.Utilization of male sterility can reduce breeding cost,but only after the plants have blossomed can they be identified,therefore,it is one of the ways to reduce the breeding cost and increase the economic benefit to find the identification method of male sterility in melon at seedling stages.Therefore,the study maked hybrid combination of genetic male sterility ms-5and HM1-1 of the thin skin melon strain in Heilongjiang Province and get F1,F2 and backcross population,and analyzed the genetic regularity of the male sterility.The study also searched for molecular markers linked to male Sterility in Melon by SLAF-Seq-BSA.In addition,it found the identification method of male sterility at seedling stages by molecular marker assisted selection breeding and used 34 kinds of common materials in melon to make seedling identification by using molecular markers linked to male Sterility,and it explored the accuracy of identification methods for male sterility at seedling stages combining with field phenotypic traits.The results are as follows.In this study,the F1 population was obtained by using 30 ms-5 and 30 HM1-1 plants of melon as parent combinations,and 650 F2 segregated population,172 BC1P1 and 70 BC1P2 plants were investigated.A fertility survey and chi-square test revealed that genetic development of male sterility ms-5 accorded with Mendel's genetic law,the male sterile gene was controlled by a single nuclear recessive gene.Through SLAF-Seq-BSA,it designed 127 pairs of CAPS primers from 4,304,282 to6,053,037(gene position)on 9th chromosome in melon,after screening in parents,F1 plants and F2 plants,29 pairs of CAPS markers which had better polymorphism were obtained,Polymorphic rate 22.83%.It found two molecular markers linked with ms-5 by screening CAPS molecular markers: BSA3-3 and BSA16,the linkage distance to male sterility of melon was 0.1cm and 0.2 cm respectively.Two molecular markers,BSA3-3 and BSA16,were identified by molecular markers with ms-5,HM1-1,F1 and 34 melon materials respectively.the results of fertility detected by molecular markers were compared with the results of field seedling testing by using Carmine acetate staining to check pollen fertility and artificial pollination to check the fertility of all female inbred lines of melon,the detection accuracy of this molecular marker was as high as97%.The results showed that BSA3-3 and BSA16 polymorphic markers were closely linked to the male sterility gene in muskmelon,it can be used to identify melon varieties at seedling stages.This experiment provides a method of indoor seedling identification for field breeders and shortens the breeding time,it also provides scientific basis for cloning male sterility gene in muskmelon in the future and establishes the foundation for scientific research of molecular breeding in melon.