甜瓜种质资源对疫病的抗性鉴定研究

旨在通过苗期人工接种鉴定，筛选高抗疫病的甜瓜材料，为甜瓜抗病育种以及抗疫病遗传学研究奠定基础。本研究采用灌根接种法，向植株根茎部土壤注入浓度为1×106个/mL的游动孢子悬浮液，对收集到的166份甜瓜材料进行了抗性鉴定，这些材料中有薄皮类型甜瓜41份，厚皮类型甜瓜104份，野生材料15份，近缘种6份。最终筛选到4份免疫材料，25份高抗材料。在供试的厚皮类型甜瓜中有66%的材料抗性水平在中抗及以上，而薄皮类型中有98%的抗性水平是感病或高感。通过相关性分析，发现厚皮类型甜瓜对疫病的抗性要显著高于薄皮类型甜瓜。通过对不同材料的果实性状进行调查，发现在免疫和高抗材料中有14份单瓜重达到1 kg以上，有8份果实可溶性固形物含量在10%以上。这些兼具高抗、高产和高可溶性固形物的材料，可用于抗病基因的定位、克隆等遗传学研究，也可作为育种亲本将抗病基因转移到农艺性状优良但抗性差的甜瓜品种中。

Resistance Identification of Melon Germplasms to Phytophthora Rot

This study aimed at screening the melon germplasms, which were high-resistant to Phytophthora capsici by artificial inoculation. The resistant germplasms would lay a foundation for melon disease resistance breeding and inheritance research of resistance to Phytophthora capsici. Using the root-irrigating method, the resistance of 166 melon accessions were identified by releasing 1 mL zoospore suspension into the soil of each plant with the concentration of 1×106 zoospores per mL. Among the 166 tested accessions, 41 belonged to Cucumis melo L.subsp. agrestis, 104 belonged to Cucumis melo L.subsp. melo, 15 belonged to Cucumis melo L.agrestis and 6 belonged to Cucumis zayherii. It turned out that 4 accessions were immune and 25 accessions were high resistant to P. capsici. 66 percent of the tested Cucumis melo L.subsp. melo were at least at a middle resistant level. While, 98 percent of the tested Cucumis melo L.subsp. agrestis were susceptible or highly susceptible to P. capsici. Further correlation?analysis revealed that the resistance level of Cucumis melo L.subsp. melo was significantly higher than that of Cucumis melo L.subsp. agrestis. The survey of fruit phenotypes showed that the single-fruit weight of 14 accessions was more than 1 kg. and the central soluble solid content of 8 accessions was more than 10%. The resistant germplasms with high-yield or high soluble solid content could be used for genetic research like gene mapping or cloning, and could also be used as parent lines to transfer the resistance gene(s) into the lines which owned good agronomic characters but with poor resistance.