Studies On The Inheritance Of The Cucumber Bitterness And AFLP Molecular Marker

Cucumber is one of the main vegetable in the world. We have the largest cucumber planting area. In the recent years the problem of bitterness of cucumber fruits has become more and more serious in dependent territory which caused economic losses. Therefore it is of significant importance to study the inheritance mode about bitterness. Molecular markers are considered to be one of the most useful tools to assist in the selection of nonbitter plant during the period of seedling and then shortening breeding process. One aim of this research is to ascertain the genetic regulation of bi and Bt and their interaction by studying three F2 population of three inbred lines(the genotype is BiBiBtBt,BiEJibtbt and bibibtbt respectively). Another aim is to find AFLP markers linked to the bitter gene using a F2 population. The main results are as follows:l.Bi/bi segregation ratio is 3:1 that abstained by tasting the vegetative and fruit was 1 vegetative bitter :2 vegetative and fruit bitter:! nonbitter when the bt gene was not segregating in the F2 progeny.When the genotype is Bibi,not only the vegetative is bitter but also the fruit is bitter.2.The Bt/bt was inherited as a single gene when bi was not segregating in the cross. The genetic information was also abstained by tasting F2 population. The F2 progeny segregation frequency fit a ratio of 3 vegetative:! nonbitter fruit.3.The genetic segregation is comprehensive when bi and Bt gene were in the same genetic background. The interaction mode is epistatic that has not been reported previously.The two genes was inherited in a ratio 11:1:4.4.Two AFLP markers were identified to be linked with the bitter gene and nonbitter gene by screening 192 pair of primers. The genetic distance with the bitter gene was 15.0cM and with the nonbitter gene was 18.8cM respectively.Graduate: Guo Yanmei Major: Olericulture Supervisor: Prof.Yu Guangjian...