Evaluation of resistance to melon yellow spot virus in a cucumber germplasm collection

Abstract

Melon yellow spot virus (MYSV), a member of the genus Tospovirus, is a serious thrips-transmitted virus of cucurbits in Japan. Resistant cultivars provide an effective means for reducing the impact of the disease; however, no MYSV-resistant cucumber has been reported. Susceptibilities of 398 cucumber accessions originating from 26 countries were evaluated by mechanical inoculation of MYSV. Thirteen accessions from South Asia, South East Asia and unknown origin had low disease severity indices (DSIs), and 10 of them showed no necrotic lesions on inoculated leaves. No or little positive reaction was detected by DAS-ELISA analysis of inoculated leaves of these accessions. 27028930 showed resistance to a melon isolate (MYSV-S) of MYSV, and ÔYamakyuri-1Õ showed moderate resistance to a cucumber isolate (FuCu05P).

Effect of temperature on symptom expression and viral spread of Melon yellow spot virus in resistant cucumber accessions

“…Accession 27028930, originating from Thailand, has resistance to MYSV-S; while Yamakyuri-1, of unknown origin, has moderate resistance to MYSV-FuCu05P (Sugiyama et al 2009). …”

“…Systemically infected leaves were stored at -80°C for later use as inocula. Two MYSV isolates, MYSV-S and MYSV-FuCu05P, used in this study were originally isolated from a melon in Shizuoka Prefecture (Kato et al 2000) and from a cucumber in Fukuoka Prefecture (Sugiyama et al 2009), respectively.…”

“…Recently, we evaluated 398 cucumber accessions for resistance to melon (S) and cucumber (FuCu05P) isolates of MYSV and found no immune or highly resistant accessions to these isolates (Sugiyama et al 2009). However, disease severity was lower on accessions originating from South Asia, and in particular Southeast Asia, especially against MYSV-S. Cucumber accession 27028930 [preservation number of the National Institute of Agrobiological Sciences (NIAS) GeneBank in Japan] had the lowest percentage of infected plants and no necrotic spots on MYSV-S-inoculated leaves compared with susceptible cucumber.…”

“…Nor was any virus accumulation detected in a double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) of MYSV-S-inoculated leaves. The resistance to MYSV of 27028930 is isolate-specific because all plants of 27028930 were systemically infected by MYSV-FuCu05P (Sugiyama et al 2009). Melon yellow spot virus -S and FuCu05P were originally isolated from a melon and a cucumber, respectively, and the host range in cucurbits differs among isolates (Kato et al 1999;Takeuchi et al 2001).…”

The Present Status of Breeding and Germplasm Collection for Resistance to Viral Diseases of Cucurbits in Japan

“…Melon thrips (Thrips palmi Karny) transmit MYSV in a persistent manner, but MYSV is not transmitted via soil contamination, or seeds (Kato et al, 1999). Sugiyama et al (2009a) reported that cucumber accessions originating from South Asia, and particularly Southeast Asia, had intermediate resistance to MYSV. The cucumber accessions 27028930 ( Fig.…”