Survey Of Cyst-forming Nematodes In Jiangxi And Guangdong Provinces And Field Control Of Cyst-forming Nematodes Using Tea Saponin Granules

In this thesis,through survey of cyst nematodes on major crops in Jiangxi and Guangdong provinces,a new record cyst nematode species in soybean was discovered and identified as Heterodera sojae,and the researches on its host range,pathogenicity and host resistance were conducted.In the survey in Guangdong Province a new species of cyst nematode on rice Heterodera luodingensis n.sp.,was discovered and described.The occurrence and distribution of the Heterodera elachista in Guangdong Province was found for the first time.The control effect of tea saponin granules were conducted in field trials against Heterodera filipjevi and Heterodera glycines.And the appropriate dosage and application method for tea saponin granules were also studied.All of this promote the use of tea saponin as a new plant origin nematicides.During 2015-2017,a survey for the cyst nematode in Jiangxi and Guangdong provinces were carried out,261 samples were collected mainly from rice,soybean,rape,corn,sugar cane.The cyst nematodes were isolated and detected in samples from 14 sites.By morphological and molecular biological identification,wherein 4 cyst samples collected in Luoding and Jiangmen City were identified as a new cyst nematode species Heterodera luodingensis n sp.,The phylogenetic trees based on ITS sequences and D2D3 sequences combined with the morphological characteristics,showed that the H.luodingensis n sp.,H.elachista and Heterodera oryzaecola belonging to Cyperi group,support node 100%.The restriction enzyme fragment diversity analysis(RFLP)of the ITS fragment PCR product of the H.luodingensis n sp.showed that the enzyme digestion map of the H.luodingensis n sp.could be clearly distinguished from the similar species of the cyst nematodes.A cyst nematode population was collected from the soybean of Wuyuan County,Jiangxi Province.It was identified as a new record species of Heterodera sojae by morphology and molecular biology.The method of artificial inoculation was used to measure the pathogenicity of H.sojae to soybean(Louhan soybean)and the host range among leguminous crop species,and 42 domestic soybean cultivars' resistance to Heterodera sojae was identified.8 cysts samples collected in Qingyuan City,Sihui City,Zhaoqing City,Gaoyao City,and Yichun City were found to be Heterodera elachista parasitic on rice.In 2016-2017,the field control trials of tea saponin granules against cereal cyst nematodes showed that 5% and 10% tea saponin granules had good control effects on cereal cyst nematode(Heterodera filipjevi).The control effect was more obvious in the early growth stage of wheat.The investigation results showed,W53,W107 and W105 the nematodes in roots of treatments were significantly less than the control's.At the harvesting stage,both concentrations of tea saponin granules got the lowest cysts reproduction coefficient in the intermediate dose(W54,W107).For the CK treatment,the reproduction coefficient of the cysts reached 4.36 at the harvesting stage,while the best effect treatment W54 was 2.08 and the control effect was 52.3%.The results of wheat production test showed that 5% tea saponin granules 1:5 treatment had the best yield.The output per square meter was significantly higher than that of the control,and the yield increase was 22.5%,higher than Avermectin's 14.6%.In 2015 and 2016,the field control trials of tea sapogenin granules and rapeseed cake powder against soybean cyst nematode(race 4)were conducted in Langfang.The results showed that tea saponin granules had good control effect in low doses of 80-150 g per plot(3.3-6.2 kg per mu),and the efficacy of control was 65%-75%,and the increase in production was 4.3-9.5%.The median dose rapeseed meal of 250 g each test plot(10.4 kg per mu)had the best control effect,reaching 64.6%.However,the lowest dose rapeseed meal of 200 g per plot(8.3 kg per mu)had the best yield increase,which increased production by 4.7%.Field control trials of tea saponin on soybean cyst(race 3)were conducted in Heilongjiang Province in 2017.The results of the investigation showed that the efficacy of tea saponin granules reached 65%-75%,and the lythidathion treatment reached 80%.The effect of the tea saponin compound preparations WS22 is close to lythidathion treat,with control efficiency 73.3%.Field production test were conducted during the soybean harvest period.The results showed that the actual production of the tea saponin preparation was greater than that of the control,and the yield was increased from 12% to 31%,which was higher than that of the lythidathion treatment 7.0%.