Potential Sources of Resistance to Fusarium Wilt and Powdery Mildew in Melons

Abstract

<jats:p>In total, 139 <jats:italic>Cucumis melo</jats:italic> accessions were evaluated for resistance to races 0, 1, and 2 of <jats:italic>Fusarium oxysporum</jats:italic> fsp. <jats:italic>melonis</jats:italic> and 127 accessions were evaluated for resistance to races 1 and 2 of <jats:italic>Sphaerotheca fuliginea.</jats:italic> In addition, seven <jats:italic>C. melo</jats:italic> wild relatives were also tested. Artificial inoculations were performed and plants were scored for presence or absence of symptoms. The screening revealed that sources of natural resistance to these fungi are limited. However, several sources of resistance were found in <jats:italic>C. melo</jats:italic> accessions. Thus, the accession `CUM-334' from Tajikistan has shown resistance to the three races of <jats:italic>F. oxysporum</jats:italic> fsp. <jats:italic>melonis</jats:italic>, behaving similarly to the melon inbred line `MR1'. Two accessions of <jats:italic>C. melo</jats:italic> var. <jats:italic>conomon</jats:italic>, `CUM-190' and `Shiroubi Okayama', from Japan, were resistant to races 0 and 1 and twelve accessions were resistant to races 0 and 2. Intra-specific variability for resistance to powdery mildew in <jats:italic>C. melo</jats:italic> was found to be poor. Nevertheless, six Spanish cultivars and the accessions `TGR-1551', `CUM-313', and `CUM-129' were resistant to races 1 and 2 of <jats:italic>S. fuliginea.</jats:italic></jats:p>

Mechanical transmission of Tomato leaf curl New Delhi virus to cucurbit germplasm: selection of tolerance sources in Cucumis melo

“…This species has been reported to be resistant to nematodes and soil fungal pathogens, and has potential to be used as rootstock for cucumbers and melons (Á lvarez et al 2005;King et al 2010;Munera et al 2014). The lack of mechanical transmission may suggest a resistant behavior to this new virus.…”

Morphological and molecular characterization of melon accessions resistant to Fusarium wilts

“…The symptoms of Fusarium wilt were observed in the susceptible seedlings as early as 7 days after inoculation, and plants died within 21 days. Furthermore, since a correlation between wilt severity and inoculum concentration has been reported (Douglas 1970), we used spore concentrations (3 9 10 6 spores/ml) three times higher than those used in previous works (1 9 10 6 spores/ml) (Zink and Thomas 1990;Á lvarez et al 2005) and applied an inoculation method that keeps the plant roots in a continuous contact with the inoculum, to ensure a good seedling infection. The AUDPC means, reported in Table 2, pointed out that accessions 'Kogani Nashi Makuwa', 'C-40' and 'C-211', coming from Japan, showed the highest level of resistance to both pathotypes of F.o.m.…”

“…Several screenings for resistance to F.o.m races 0, 1 and 2 have already been made (Zink 1983;Champaco et al 1992;Zuniga and Zitter 1995;Pitrat et al 1996;Á lvarez et al 2005), and the identified resistant accessions belonged to different botanical varieties.…”

“…Nowadays many sources of resistance to F.o.m races 0, 1 and 2 are known (Pitrat et al 1996;Á lvarez et al 2005) but it is not the same for race 1,2; resistance to this race has only been found in some Far Eastern accessions (Messiaen et al 1962;Perchepied and Pitrat 2004) which are organoleptically far from commercialized melon in the western countries. That is why, in the present study a screening was conducted for detecting new melon resistant accessions to race 1,2 within the Cucumis melo germplasm collections maintained in the Vegetable Germplasm Bank of Zaragoza (Spain), and in the ''Estación Experimental La Mayora'', Malaga (Spain).…”

Inheritance of resistance to Fusarium oxysporum f. sp. melonis races 0 and 2 in melon accession Tortuga

“…Resistance to races 0, 1 and 2 of F.o.m. has been found in several accessions belonging to different melon botanical varieties (Zink et al 1983;Champaco et al 1992;Pitrat et al 1996;Á lvarez et al 2005).…”