Organic Agriculture Division, National Academy of Agricultural Science, Suwon 441-707, Korea.
Plant Pathol J. 2013 Mar;29(1):87-92. doi: 10.5423/PPJ.OA.02.2012.0031.
This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension (10(6) sporangia/ml). At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840) showed moderate resistance and two accessions (IT185446 and IT187904) were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.
本研究旨在确定 514 份西瓜种质资源对辣椒疫霉的抗腐病性。在测试的 514 份种质中，约有 46%来自乌兹别克斯坦、土耳其、中国、美国和乌克兰。通过浇淋 5 毫升含 10（6）个游动孢子/毫升游动孢子悬浮液的方法，将辣椒疫霉接种到 45 天大的西瓜幼苗上。接种后 7 天，有 21 份材料未表现出任何病症，而 291 份易感西瓜种质的病斑超过 60.1%。在接种后 35 天，共有 510 份西瓜种质表现出明显的病症，被评为易感至高度易感。高度易感的西瓜种质在病斑上表现出白色真菌菌丝，或出现水渍状和褐变的猝倒症状。一个材料（IT032840）表现出中度抗性，两个材料（IT185446 和 IT187904）对辣椒疫霉表现出抗性。结果表明，这两个抗性种质可以作为砧木，并作为培育抗辣椒疫霉西瓜品种的抗性来源。
