Melon breeding for resistance to Fusarium wilt using molecular markers and dihaploidization.

摘要

In this breeding program aimed at developing resistant varieties to Fusarium wilt in Turkish melon type, molecular markers and dihaploidization techniques were used. Cum334 was used as the donor parent in a backcross program and the haploid plants were obtained via pollination with the irradiated pollen from the BC3 population to shorten the breeding period. Four different embryo rescue methods were tested to extract haploid embryos. According to the results, the best methods were found to be "inspecting seeds on the light" and "sowing seeds directly to nutrient media", and a total of the 122 haploid plants were obtained. The haploid plants were screened by molecular markers for fom1 and fom2 genes. A Simple Sequence Repeat (SSR) and a Randomly Amplified Polymorphic DNA (RAPD) marker were used for fom2 gene and a Cleaved Amplified Polymorphic Sequences (CAPS) and three Sequence Characterized Amplified Region (SCAR) markers were used for fom1 gene. While SSR (SSR180) did not segregate the haploid plants the RAPD marker (OPG17) segregated those haploid plants for fom2 gene. Haploid plants were screened for fom1 by a SCAR marker (SB17). Among the tested haploids, 41% of plants were found to be resistant and the rest of 59% were susceptible to the Fusarium wilt races 0 and 2. On the other hand while 34% of plants were resistant 66% were susceptible to the races 0 and 1 of the Fusarium oxysporum f.sp. melonis.