Keinath A P, Hassell R L
Clemson University, Coastal Research and Education Center, Charleston, SC 29414.
Plant Dis. 2014 Feb;98(2):255-266. doi: 10.1094/PDIS-01-13-0100-RE.
Grafting watermelon (Citrullus lanatus var. lanatus) onto rootstocks of interspecific hybrid squash (Cucurbita moschata × C. maxima), bottle gourd (Lagenaria siceraria), or citron (Citrullus lanatus var. citroides) has been used in Asia and Israel to mange Fusarium wilt of watermelon caused by Fusarium oxysporum f. sp. niveum. The objectives of this study were to determine the frequency of infection of six rootstocks by F. oxysporum f. sp. niveum races 1 and 2 and the field performance of grafted rootstocks in Charleston, SC. Grafted and nongrafted watermelon and rootstock plants were inoculated in the greenhouse with race 1, race 2, or water (the control treatment). With both races, the frequency of recovery of F. oxysporum from scion and rootstock portions of inoculated watermelon plants grafted onto 'Ojakkyo' citron was greater than from watermelon plants grafted onto 'Shintosa Camel' and 'Strong Tosa' interspecific hybrid squash, and from plants grafted onto 'Emphasis', 'Macis', and 'WMXP 3945' bottlegourd. For nongrafted plants inoculated with race 1, percent recovery also was greater from Ojakkyo than from interspecific hybrid squash and bottlegourd. For nongrafted plants inoculated with race 2, F. oxysporum was recovered from the base of ≥79% of all inoculated plants. More than two-thirds (15) of 21 isolates recovered from the tops or scions of inoculated plants were pathogenic on watermelon. In spring 2010 and 2011, the six rootstocks were grafted with seedless watermelon 'Tri-X 313', which is susceptible to both races, and transplanted in a field infested with races 1 and 2 of F. oxysporum f. sp. niveum. Disease incidence for nongrafted and self-grafted Tri-X 313 (the control treatments) and Tri-X 313 grafted onto Ojakkyo citron did not differ significantly. Grafted watermelon plants produced greater weights and numbers of fruit than plants of the two control treatments. Nonpathogenic isolates of F. oxysporum and isolates of F. oxysporum f. sp. niveum colonized interspecific hybrid squash, bottlegourd, and grafted watermelon. The rootstocks evaluated, however, restricted movement of F. oxysporum f. sp. niveum into the watermelon scion, suppressed wilt symptoms, and increased fruit yields in an infested field.
在亚洲和以色列，将西瓜（西瓜栽培变种）嫁接到种间杂交南瓜（南瓜×笋瓜）、葫芦（葫芦）或香瓜（西瓜栽培变种）砧木上，用于防治由尖孢镰刀菌西瓜专化型引起的西瓜枯萎病。本研究的目的是确定六种砧木被尖孢镰刀菌西瓜专化型1号和2号小种感染的频率，以及在南卡罗来纳州查尔斯顿嫁接砧木的田间表现。将嫁接和未嫁接的西瓜及砧木植株在温室中用1号小种、2号小种或水（对照处理）接种。对于这两个小种，从嫁接到‘Ojakkyo’香瓜上的接种西瓜植株的接穗和砧木部分回收尖孢镰刀菌的频率，高于嫁接到‘Shintosa Camel’和‘Strong Tosa’种间杂交南瓜以及嫁接到‘Emphasis’、‘Macis’和‘WMXP 3945’葫芦上的西瓜植株。对于用1号小种接种的未嫁接植株，从Ojakkyo回收的尖孢镰刀菌频率也高于种间杂交南瓜和葫芦。对于用2号小种接种的未嫁接植株，从所有接种植株基部回收尖孢镰刀菌的比例≥79%。从接种植株顶部或接穗回收的21个分离物中，超过三分之二（15个）对西瓜致病。在2010年和2011年春季，将六种砧木与对这两个小种均易感的无籽西瓜‘Tri-X 313’嫁接，并移植到一块被尖孢镰刀菌西瓜专化型1号和2号小种侵染的田地里。未嫁接和自嫁接的Tri-X 313（对照处理）以及嫁接到Ojakkyo香瓜上的Tri-X 313的发病率没有显著差异。嫁接的西瓜植株比两种对照处理的植株结出的果实重量更大、数量更多。尖孢镰刀菌的非致病分离物以及尖孢镰刀菌西瓜专化型的分离物定殖于种间杂交南瓜、葫芦和嫁接的西瓜中。然而，所评估的砧木限制了尖孢镰刀菌西瓜专化型向西瓜接穗的移动，抑制了枯萎症状，并在受侵染的田地里提高了果实产量。
