Identification of watermelon chromosome translocation lines using oligo-nucleotide probes and their application

XU Binghua; ZHAO Qinzheng; GU Yan; HUANG Dayue; CHENG Rui; LIU Xin; ZHANG Chaoyang; XU Wenzhao; SUN Yudong

doi:10.16861/j.cnki.zggc.2024.0467

Abstract：In order to further study the chromosomal translocation lines of watermelon,and facilitate the identification.G59 which was a watermelon chromosome translocation line obtained by using independent selection was used as the test material in this study.A total of 20 350 oligonucleotide probes were developed based on the G42 watermelon genome,with an average density of 0.42-2.86 oligos/kb on 11 chromosomes.This set of probes were used to identify the chromo-some translocation of G59.The non-denaturing in situ hybridization(ND-FISH)results showed that there was an exchange translocation of chromosomes 6 and 10.The pollen morphology by Alexander's staining solution under micro-scope was observed and the number of seeds in single watermelon was investigated.The pollen of G59 was normal mor-phology,and the percentage of sterile pollen was about 4.28％,and the number of seeds in single watermelon was about 212.33.There was no significant difference between G59 and common self-inbreeding lines G33,G37 and G42.The percentage of sterile or deformed pollen in the hybrid combinations Shengjia No.1,Sumeng No.15,Sumeng No.17 were 54.17％,46.52％,and 43.66％,respectively,which were extremely significantly higher than both parents.The number of single fruit seeds of Shengjia No.1,Sumeng No.15,Sumeng No.17 was about 65-80,extremely significantly less than that of both parents and normal hybrid generation varieties such as Sumeng 5.The oligonucleotide probe developed in this study can be used for the identification of chromosomal translocation lines in watermelon,and the chromosomal trans-location inbred line G59 can be used for the breeding of translocated watermelon varieties with few seeds.