Development of molecular marker to select resistant lines and to differentiate the races related to powdery mildew in melon (Cucumis meloL.)

Abstract

멜론 흰가루병의 race 분화 및 저항성 계통 선발을 위한 분자마커 개발김회택 ･ 박종인 ･ 石川 友子 ･ 葛谷 真輝 ･ 堀井 学 ･ 八城 和敏 ･ 노일섭 Development of molecular marker to select resistant lines and to differentiate the races related to powdery mildew in melon (Cucumis melo L.) Abstract Powdery mildew (Podosphaera xanthii) commonly occurs in cultivated fields of melon (Cucumis melo L.). It inflicts a lot of damages. Therefore, breeding resistant lines is essential. Development of a resistant line by integrating resistance gene takes a long time. In addition, break down of developed resistance by generating new virulent fungus strains increases disease susceptibility. This phenomenon was related to races of powdery mildew. Therefore, it is important to develop a DNA marker to genetically analyze race-specific resistance genes of melon powdery mildew to breed resistant lines. To date, a total of 28 races of Podosphaera xanthii have been reported in the literature. In Japan, 10 races have been reported in the Ibaraki region. We developed a system to characterize the races of Podosphaera xanthii and confirmed eight out of those 10 races in the Ibaraki region. In Korea, only one race has been characterized to date. However, some different races were detected. Through genetic analysis of resistant lines and susceptible lines of powdery mildew, resistance genes of race1 (Pm-X, PXB, and Pm-R 1), race N1 (PXA), race 2 (Pm-w and Pm-R 2), race 3 (Pm-X3), and race 5 (Pm-X5 and Pm-R5) were identified in melon. These related genes of race 1, 3, N1, 5, and race 1, 2, 5 were located at linkage group II and V, respectively. In race 1, resistance gene was located in the linkage group XII. In addition, each race-specific marker related to specific resistance gene was developed. Using race information and race selection system obtained in this study, resistant line can be bred to develop resistant cultivar for several areas. Furthermore, this will make it more easily and economically to breed resistant lines by using selected markers.

Identification of a New Race and Development of DNA Markers Associated with Powdery Mildew in Melon

“…This interaction table has been developed comparing our screening results with mapping results of Fukino et al (2008) and distribution information of resistant genes in different linkage groups (Kim et al 2015). z) R: resistant, S: susceptible, I: intermediate.…”

“…The genotypes of F2 and backcross populations obtained from the selected parental combinations were also screened against the N5 race. Kim et al (2015) published the resistant genes present in different races of powdery mildew fungus along with their position in three different groups, LG II, LG V, and LG XII. Combining our screening results with the location of resistant genes in relevant LGs (Kim et al 2015), we developed genotypic configuration of different melon lines corresponding with their disease reaction against the N5 race (Table 3).…”

“…The two selected SSR markers (CMBR120, CMN01-38) which were able to separate the resistant and susceptible genotypes against N5 race were located in LG II and LG XII. For different other races, resistant QTL were reported to be located in LG II, LG V, and LG XII (Fukino et al 2008;Izumikawa et al 2009;Kim et al 2015). Comparing our results with that of previous studies it can be commented that the resistant genes for powdery mildew race N5 were located in the same or near the other resistant genes of powdery mildew against other different races, for example: Pm-XII of AR5 and Pm-y of VA435 were located in LG XII (Pitrat 1991;Fukino et al 2008).…”

“…Since numbers of different races of powdery mildew fungi are available therefore to develop a race-specific resistance it is important to use race-specific markers (Kim et al 2015). Thomas and Webb (1982) reported that Pm-1 resistant gene of melon against race 1 fungus had dominant inheritance.…”

Identification of Two New Races of Podosphaera xanthii Causing Powdery Mildew in Melon in South Korea

“…The pattern of inheritance of the powdery mildew genes was reported as dominant inheritance such as resistant Pm-1 gene against race 1 fungus (Thomas and Webb, 1982); Pm-W gene of resistant line WMR29 and PI414723 against race 2 and Pm-X gene against race 1 ( Pitrat, 1991 ). In addition, QTLs for powdery mildew resistance were mapped and molecular markers were developed using differential segregating populations of melon ( Fukino et al, 2008 ; Kim et al, 2015 ; Perin et al, 2002 ).…”