An AFLP marker linked to the Pm-1 gene that confers resistance to Podosphaera xanthii race 1 in Cucumis melo

Abstract

Brazil produced 330,000 metric tons of melons in 2005, principally in the Northeast region where one of the most important melon pathogens is the powdery mildew fungus Podosphaera xanthii. The disease is controlled mainly by incorporating single dominant resistance genes into commercial hybrids. We report on linkage analysis of the Pm-1 resistance gene, introgressed from the AF125Pm-1 Cantalupensis Charentais-type breeding line into the yellowfleshed melon (Group Inodorus) breeding line AF426-S by backcrossing to produce the resistant line AF426-R, and the amplified fragment length polymorphism (AFLP) marker M75/H35_155 reported to be polymorphic between AF426-S and AF426-R. Segregation analysis of M75/H35_155 using a backcross population of 143 plants derived from [AF426-R x AF426-S] x AF426-S and screened for resistance to P. xanthii race 1 produced a recombination frequency of 4.9%, indicating close linkage between M75/H35_155 and Pm-1. Using the same segregating population, the M75/H35_155 marker had previously been reported to be distantly linked to Prv 1 , a gene conferring resistance to papaya ringspot virus-type W. Since M75/H35_155 is linked to Prv 1 at a distance of 40.9 cM it is possible that Pm-1 and Prv 1 are also linked.

Mapping of resistance genes to races 1, 3 and 5 of Podosphaera xanthii in melon PI 414723

“…xanthii resistance genes from other melon genotypes were located in linkage groups distinct from the one where the resistance genes from PI 414723 have been located in this study. These include Pm-1 from PI 78374 (race 1) in linkage group IX (Teixeira et al 2008), Pm-w from WMR-29 (race 2-French) in LG V, and Pm-y from VA-435 (race 2-French) in LG XII (Pitrat 1991. Besides, resistance QTL were also mapped in LGs II (races 1, 3, and N1), V (1, 2, and 5), and XII (races 1, 5, and N1) (Perchepied et al 2005, Fukino et al 2008, Yuste-Lisbona et al 2011b).…”

“…To date, 12 major genes have been described (Pitrat 2006, Liu et al 2010), but only four have been mapped (Pitrat 1991, Teixeira et al 2008). …”

Fungal species that cause powdery mildew in greenhouse-grown cucumber and melon in Paraná State, Brazil

“…In the absence of chemical or biological control (ISHIDA et al, 2001;KUROZAWA et al, 2005;ZATARIN et al, 2005) or the use of resistant varieties (TEIXEIRA et al, 2008), the disease can significantly reduce yield and quality of the crop.…”

Mapeamento de genes de resistência a três raças de Podosphaera xanthii em meloeiro (Cucumis melo L.)

“…De acordo com Gilbert et al (1994) MARKARIAN, 1968a;YUSTE-LISBONA et al, 2010). Até o momento, 12 genes de resistência a diversas raças de P. xanthii foram descritos (Pm-1, Pm-2, (PITRAT, 2006;LIU et al, 2010) e, dentre estes, quatro foram mapeados: Pm-1 de PI 78374 (raça 1) no grupo de ligação (GL) IX (TEIXEIRA; SILVA-BARRETO; CAMARGO, 2008); Pm-w de WMR 29 (raça 2) no GL V; Pm-x de PI 414723 (raça 2) no GL II e Pm-y de VA 435 (raça 2) no GL XII (PITRAT, 1991;PÉRIN et al, 2002). Locos quantitativos (QTL) também foram mapeados.…”

“…O resultado corrobora estudos anteriores que relatam este mesmo tipo de controle em genótipos de meloeiro (COHEN;COHEN, 1986;EPINAT;BERTRAND, 1993;COHEN, 1989COHEN, , 1992PERCHEPIED et al, 2005;PITRAT, 1991;SILVA-BARRETO;CAMARGO, 2008 (PERCHEPIED et al, 2005). Apesar da conhecida resistência de PI 414723 às raças 3 e 5, ainda não havia sido elucidado seu modo de herança a elas.…”