Seedlings of Yujinxiang melon were used to investigate the effect and inhibitive mechanism of sodium silicate and nanosized silicon oxide on powdery mildew. The results showed that the severity of powdery mildew on me...Seedlings of Yujinxiang melon were used to investigate the effect and inhibitive mechanism of sodium silicate and nanosized silicon oxide on powdery mildew. The results showed that the severity of powdery mildew on melon seedlings was lowered significantly by treatment with either of the two silicon compounds, although the effect of sodium silicate was more powerful than silicon oxide. Application of sodium silicate to the seedlings caused significant increases in the activity of peroxidase (POD) and of β-1,3-glucosidase (GLU), both enzymes are known to be associated with the disease defence systems of plants. SEM-EDX analysis of sodium silicate-treated leaves of the melon seedlings showed an elevated level of silicon deposit at stomata and epidermis. Treatment with nanosized silicon oxide also resulted in a similar increase in silicon deposit, but the treatment did not cause a significant increase in POD activity.展开更多
Melon(Cucumis melo L.)production is often restricted by a plethora of pests and diseases,including powdery mildew and downy mildew caused respectively by the fungal species Podosphaera xanthii/Golovinomyces orontii an...Melon(Cucumis melo L.)production is often restricted by a plethora of pests and diseases,including powdery mildew and downy mildew caused respectively by the fungal species Podosphaera xanthii/Golovinomyces orontii and oomycete species Pseudoperonospora cubensis.Many efforts have been directed on identification of resistant sources by screening(wild)melon germplasm.In the current review,we summarized such efforts from various publications of the last 50 plus years.Resistance to powdery mildew has been identified in 239 melon accessions and downy mildew resistance in 452 accessions of both C.melo and the wild relative species C.figarei.Among the resistance sources,C.melo var.cantalupensis accessions PMR 45,PMR 5,PMR 6,and WMR 29 as well as C.melo var.momordica accessions PI 124111,PI 124112,and PI 414723 have been considered as the most valuable germplasm because multiple resistance genes have been identified from these accessions and are widely used in melon resistance breeding.Further genetic mapping in a number of resistant sources has enabled identification of 25 dominant genes,two recessive genes and seven QTLs conferring powdery mildew resistance,as well as eight dominant genes and 11 QTLs for downy mildew resistances.Based on the reported sequences of associated markers,we anchored physically(many of)these genes and QTLs to chromosomes of the melon cv.DHL92 genome.In addition to presenting a comprehensive overview on powdery mildew and downy mildew resistance in(wild)melon germplasm,we suggest strategies aiming at breeding melon with durable and broad-spectrum resistance to pathogens and pests.展开更多
[Objective] The paper was to measure and analyze pathogen of 18S rDNA sequence of the pathogen of melon powdery mildew from lands overlaid with sands. [Method]The melon powdery mildew was isolated from infected plants...[Objective] The paper was to measure and analyze pathogen of 18S rDNA sequence of the pathogen of melon powdery mildew from lands overlaid with sands. [Method]The melon powdery mildew was isolated from infected plants of ＂Yujinxiang＂, a major melon variety cultivated in lands overlaid with sands in the middle arid area of Ningxia. Genome DNA was extracted from its conidia using Chelex-100 method. 18S rDNA sequence was amplified by PCR, which was analyzed by Blast after sequencing, and the phylogenetic tree was constructed. [Result] 18S rDNA sequence analysis showed that the pathogen of melon powdery mildew belonged to Podosphaera. [Conclusion] The study provided reference for biocontrol and disease-resistance breeding against melon powdery mildew.展开更多
以东北和华东地区118份薄皮甜瓜种质资源为试材,采用重测序方法,研究了全基因组关联分析(genome-wide association study, GWAS)策略在薄皮甜瓜白粉病抗性基础理论研究上的可行性,以期为丰富薄皮甜瓜白粉病抗性育种材料提供参考依据。...以东北和华东地区118份薄皮甜瓜种质资源为试材,采用重测序方法,研究了全基因组关联分析(genome-wide association study, GWAS)策略在薄皮甜瓜白粉病抗性基础理论研究上的可行性,以期为丰富薄皮甜瓜白粉病抗性育种材料提供参考依据。结果表明:共获得高质量SNP位点4 460 133个,2种模型筛选与白粉病相关优异等位基因61个。结合功能注释,预测为DPH3抗体蛋白、PPR蛋白、黄酮醇合酶、类甲基酯酶和类DMR6加氧酶蛋白等。主要参与生物合成、氨基酸代谢、信号通路传导、RNA降解和DNA修复等代谢过程。其中,7号染色体上的CsTLP基因在黄瓜霜霉病抗性中起到至关重要的作用;1号染色体上的EFM1可作为逆境响应机制研究及抗逆育种的优良候选基因。展开更多
Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examin...Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examined in cultivar and wild species by leaf inoculation. The wild germplasms showed resistance to powdery mildew Race1. Cloning and sequence analysis of the Cm MLO2 gene identified an 85 bp difference between the wild and cultivated species. The Cm MLO2 gene was expressed in the wild germplasm after fluorescence-labeled Agrobacterium-mediated transformation. A positive transgenic plant showed successful invasion by powdery mildew Race1. These results suggested that the wild species might have failed to encode the MLO protein, thereby resulting in the MLO-negative regulation of powdery mildew, which in turn resulted in the broad-spectrum resistance of the wild species to powdery mildew.展开更多
文摘Seedlings of Yujinxiang melon were used to investigate the effect and inhibitive mechanism of sodium silicate and nanosized silicon oxide on powdery mildew. The results showed that the severity of powdery mildew on melon seedlings was lowered significantly by treatment with either of the two silicon compounds, although the effect of sodium silicate was more powerful than silicon oxide. Application of sodium silicate to the seedlings caused significant increases in the activity of peroxidase (POD) and of β-1,3-glucosidase (GLU), both enzymes are known to be associated with the disease defence systems of plants. SEM-EDX analysis of sodium silicate-treated leaves of the melon seedlings showed an elevated level of silicon deposit at stomata and epidermis. Treatment with nanosized silicon oxide also resulted in a similar increase in silicon deposit, but the treatment did not cause a significant increase in POD activity.
基金funded by a fellowship from the China Scholarship Council(Grant No.201908140029)。
文摘Melon(Cucumis melo L.)production is often restricted by a plethora of pests and diseases,including powdery mildew and downy mildew caused respectively by the fungal species Podosphaera xanthii/Golovinomyces orontii and oomycete species Pseudoperonospora cubensis.Many efforts have been directed on identification of resistant sources by screening(wild)melon germplasm.In the current review,we summarized such efforts from various publications of the last 50 plus years.Resistance to powdery mildew has been identified in 239 melon accessions and downy mildew resistance in 452 accessions of both C.melo and the wild relative species C.figarei.Among the resistance sources,C.melo var.cantalupensis accessions PMR 45,PMR 5,PMR 6,and WMR 29 as well as C.melo var.momordica accessions PI 124111,PI 124112,and PI 414723 have been considered as the most valuable germplasm because multiple resistance genes have been identified from these accessions and are widely used in melon resistance breeding.Further genetic mapping in a number of resistant sources has enabled identification of 25 dominant genes,two recessive genes and seven QTLs conferring powdery mildew resistance,as well as eight dominant genes and 11 QTLs for downy mildew resistances.Based on the reported sequences of associated markers,we anchored physically(many of)these genes and QTLs to chromosomes of the melon cv.DHL92 genome.In addition to presenting a comprehensive overview on powdery mildew and downy mildew resistance in(wild)melon germplasm,we suggest strategies aiming at breeding melon with durable and broad-spectrum resistance to pathogens and pests.
基金Supported by Natural Science Foundation of Ningxia Hui Autonomous Region(NZ0958)
文摘[Objective] The paper was to measure and analyze pathogen of 18S rDNA sequence of the pathogen of melon powdery mildew from lands overlaid with sands. [Method]The melon powdery mildew was isolated from infected plants of ＂Yujinxiang＂, a major melon variety cultivated in lands overlaid with sands in the middle arid area of Ningxia. Genome DNA was extracted from its conidia using Chelex-100 method. 18S rDNA sequence was amplified by PCR, which was analyzed by Blast after sequencing, and the phylogenetic tree was constructed. [Result] 18S rDNA sequence analysis showed that the pathogen of melon powdery mildew belonged to Podosphaera. [Conclusion] The study provided reference for biocontrol and disease-resistance breeding against melon powdery mildew.
基金The National Natural Science Foundation of China(3136043431471896+1 种基金31301795)Innovation Project Team of the Gansu Academy of Agricultural Science(2015GAAS01)supported this study
文摘Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examined in cultivar and wild species by leaf inoculation. The wild germplasms showed resistance to powdery mildew Race1. Cloning and sequence analysis of the Cm MLO2 gene identified an 85 bp difference between the wild and cultivated species. The Cm MLO2 gene was expressed in the wild germplasm after fluorescence-labeled Agrobacterium-mediated transformation. A positive transgenic plant showed successful invasion by powdery mildew Race1. These results suggested that the wild species might have failed to encode the MLO protein, thereby resulting in the MLO-negative regulation of powdery mildew, which in turn resulted in the broad-spectrum resistance of the wild species to powdery mildew.
