Breeding melon for resistance to Fusarium wilt: recent developments

A Oumouloud,H Chikh-Rouhou,A Garcés Claver,R González Torres,R Perl-Treves,M El-Otmani,J M Álvarez

doi:10.1007/s10681-013-0904-4

Abstract

AbstractMelon Fusarium wilt (MFW), caused byFusarium oxysporumf. sp.melonis(Fom), is one of the most destructive diseases of melon (Cucumis meloL.). The development and deployment of resistant cultivars is generally considered to be the best approach to control MFW. Based on the host resistance genes associated with variants of this pathogen,Fomisolates were classified into four physiological races designated 0, 1, 2, and 1,2. Two dominant resistance genes,Fom-1andFom-2, control resistance to races 0 and 2, and 0 and 1, respectively.Fomisolates classified as race 1,2 are able to induce disease in melon lines carrying the above resistance genes. Many sources of resistance toFomraces 0, 1, and 2 have been reported. Partial resistance to race 1,2 controlled by polygenic recessive genes was only detected in a few Far Eastern melon accessions, except for the breeding line BIZ where complete resistance was described. Identification of DNA markers tightly linked to genes conferring resistance toFomhas immediate application in MFW resistance breeding programs. TheFom-2gene has been cloned, and it encodes a protein with a nucleotide binding site (NBS) and leucine-rich repeats domain (LRR). Based on the sequence of this domain, some molecular markers linked to this gene were developed. Several DNA markers linked toFom-1have also been described. However, the usefulness of these markers was variety-dependent. Therefore, their combined use would be very useful in marker assisted selection for introducing resistance toFomraces 0 and 2 in melon. Recently, these markers were used for the positional cloning of this gene, which encoded a protein with a NBS–LRR domains that shows similarity to the toll and interleukin-1 receptores (TIR). RegardingFomrace 1,2, nine QTL were detected on five linkage groups by composite interval mapping. In this paper we review the current knowledge of MFW disease, and focus on genetic resistance toFomand marker-assisted selection for resistance.

Highlights

Melon (Cucumis melo L.) is an important horticultural fruit crop in tropical and subtropical regions, but it is grown extensively in temperate zone countries
In this paper we review the current knowledge of Melon Fusarium wilt (MFW) disease, and focus on genetic resistance to Fom and marker-assisted selection for resistance
Fusarium wilt is caused by a soil-borne pathogen, Fusarium oxysporum Schlechtend: Fr. f. sp. melonis

Summary

Introduction

Melon (Cucumis melo L.) is an important horticultural fruit crop in tropical and subtropical regions, but it is grown extensively in temperate zone countries. World production of cantaloupes and other melons in 2009 was about 26 million tons (www.fao.org). Melon is susceptible to numerous foliar and root fungal pathogens that induce disease and reduce yield and fruit quality. Fusarium wilt is caused by a soil-borne pathogen, Fusarium oxysporum Schlechtend: Fr. f. Melonis (H.N. Hansen) W.C. Snyder & H.N. Hans (Fom). This fungus survives in the soil as chlamydospores, and is capable of colonizing crop residues and roots of most crops grown in rotation with melon (Gordon et al 1989). Crop rotation has only provided limited protection against melon Fusarium wilt (MFW) disease (Crino et al 2007)

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