ISSN 1000-6346
CN 11-2326/S
中华人民共和国农业农村部 主管
中国农业科学院蔬菜花卉研究所 主办
CN 11-2326/S
中华人民共和国农业农村部 主管
中国农业科学院蔬菜花卉研究所 主办
The objective of the current study was to exploit susceptible gene（S-gene）for DM in cucumber，which will be provided as target S-gene for editing and functional analysis，leading to a new way of breeding for durable and broad-spectrum resistance to DM in cucumber. A total of 15 cucumber inbred lines of different genetic background of DM resistance（DMR） was used to identify and clone the homologs of DMR6，a DM S-gene in Arabidopsis，with the analysis of systematic evolutionary tree and major QTLs of cucumber DMR. A highly homologue candidate S-gene CsaDMR6-2 was identified. The alignment of the amino acid sequences and the prediction of secondary and tertiary protein structures between CsaDMR6-2 and Arabidopsis genes DMR6，DLO1 and DLO2 of known functions indicated that one base-pair mutation was found at 856 bp of CDS sequence of CsaDMR6-2 from K15 and K58 of European type with DMR，leading to the change of amino acids from serine（TCA） into alanine（GCA），which resulted in some changes of their protein secondary and tertiary structures.The results also indicated that CsaDMR6-2 and Arabidopsis genes DMR6，DLO1 and DLO2 have very high homologue in sequences. They are in the same group of oxidases，having the same domain and the same mutation location happened in catalytic region from the DMR genotype. The current study provided support to further function analysis of CsaDMR6-2 and the utilization of S gene for durable and broad-spectrum resistance to DM in cucumber.
Twenty-five cruciferous vegetable varieties，including 19 Chinese cabbage varieties，3 cabbage varieties，3 radish varieties，with resistance to clubroot were concentratedly demonstrated in Changyang County Yichang City and Lichuan City of Hubei Province．The results showed that the pathogenicity of Changyang Plasmodiophora brassicae is much stronger than Lichuan Plasmodiophora brassicae．Majority of the Chinese cabbage cultivas were anti-resistant to Changyang Plasmodiophora brassicae，but resistant to Lichuan Plasmodiophora brassicae，only‘Jingchun CR2’and‘Jingchun CR3’were resistant to the both，and their comprehensive economic characters were excellent．They can be extended in Changyang，Lichuan and similar regions，where have the same clubroot pathogenicity．The other Chinese cabbage cultivas with single resistance to clubroot can be extended in Lichuan and similar regions also．Radish variety‘Xuedan No.3’in Changyang was tolerant to this disease and in Lichuan was resistant variety．Its comprehensive economic characters was good．Cabbage variety‘2012070’was tolerant to clubroot in Changyang，but all tested cabbage varieties were not resistant to Lichuan clubroot disease．
This experiment investigated the control effect and mechanism of Zanthoxylum bungeanum seed meal on tomato root-knot nematode via pot expetiment in greenhouse．The results indicated that the concentrations of total nitrogen，total phosphorus，total potassium，available nitrogen，available potassium in soil were significantly increased by biofumigation of Zanthoxylum bungeanum seed meal for 30 days，and the pH value of soil was on the rise tendency，while the content of available phosphorus was decreased．30 days after fix-planting，the tomato root knot index was gradually decreased along with the increase amount of Zanthoxylum bungeanum seed meal．However，the plant height and stem diameter showed the tendency of first increase then reduce．Different concentrations of Zanthoxylum bungeanum seed meal extracts all had inhibitory effects on hatchability of root knot nematode eggs．The GC-MS analysis showed that there were 28 kinds of volatile substances in Zanthoxylum bungeanum seed meal，about 13.53% of which was D-limonene and linalool．Different concentrations of D-limonene and linalool could effectively inhibit the activity of root-knot nematode second-stage juveniles，and showed obvious concentration effect．Therefore，apropriate application of Zanthoxylum bungeanum seed meal could not only improve soil physical and chemical property，promote tomato growth，but also effectively control the occurrence of root-knot nematode disease．The mechanism was due to the abundant D-limonene and linalool contents in Zanthoxylum bungeanum seed meal．
