Studies On Root Knot Nematodes Of Aquilaria Sinensis Seedlings

Aquilaria sinensis is one of the tropical native species of Hainan Province,which contains resin wood-eaglewood;is China's top natural spices,but also China's unique and valuable medicinal herbs.Hainan Province is an important producing area of China's eaglewood,Aquilaria sinensis in Hainan is called "green gold",Aquilaria sinensis cultivation has become an important source of Hainan local farmers'economic income.Root-knot nematode is the main disease of the Aquilaria sinensis seedling,the sick Aquilaria sinensis 1 year old seedlings or 2-year-old large bags of seedlings appear small plants,leaves yellowing loss of green,slow growth,serious seedling growth stagnation,leaf litter,withered phenomenon,and sick seedlings susceptible to other leaf disease,part of the Aquilaria sinensis nursery mortality rate of 40%to 60%.In this paper,the pathogenesis of root-knot nematode disease was described in detail,and the root-knot nematode pathogens were identified.The occurrence and dynamics of the second instar larvae of the root-knot nematode were studied,and carried out the treatment experiment of root-knot nematode disease,and carried out.Below are key research findings.(1)Symptoms and pathogen identification of Root-knot nematode disease in the seedlingofAquilaria sinensis.The sequences of the rDNA-ITS region of the tested samples were analyzed by universal primers V5367 and 26S,and the results were compared with those of the second instar larvae,females and perineal patterns.The samples collected from the four townships were identified as(Meloidogyne enterolobii Yang&Eisenback).This is the first time combined with morphological methods and rDNA-ITS-PCR technology to identify the root-knot nematode of the Aquilaria sinensis seedlings,and for the first time in the Chengmai County,Hainan Province,The study of nematode disease laid the foundation for further study.(2)Study on occurrence regularity of root-knot nematode disease in the seedlingof Aquilaria sinensis.The occurrence of the second instar larvae of the root-knot nematode in the Aquilaria sinensis nursery was increasing with the increase of the soil layer.The number of root-knot nematodes in the soil was 63.38%,and the distribution of root-knot nematodes in the soil layer in contact with the basal bag was 25.96%.Therefore,the incidence of root-knot nematode mainly in the matrix bag,in addition to a part of the distribution in contact with the matrix bag shallow soil.There was no significant difference in the incidence of root-knot nematodes from different levels of position,that is,the incidence of root-knot nematodes in the soil was serious in a serious nursery.The second instar larvae of the root-knot nematode can occur throughout the year,especially in the middle of March to mid-April,and from mid-November to mid-December.In addition,the second instar larvae of the root-knot nematode in the nursery soil Occurrence of the impact of extreme weather,especially strong typhoon,continuous heavy rain,continuous extreme hot weather.(3)Study on the control of root-knot nematode disease in the seedlingof Aquilaria sinensis.The results showed that 3.2%high chloromethyl chloride microemulsion,5.2%Avi high chlorine EC,40%phoxim EC,0.5%matrine water,3.2%avermectin EC has a good control effect to the number of larvae of the second instar larvae.Further analysis showed that 5.2%Ave high-chlorine EC had no significant growth after 90 days,and the incidence of yellowing and deciduous leaves was increased.Therefore,3.2%high chloromethyl fluoride microemulsion,40%phoxim EC,0.5%matrine water,3.2%abamectin EC treatment can reduce the amount of secondary larvae in the nursery soil while promoting disease Aquilaria sinensis seedlings to restore growth,to a certain extent,to achieve the purpose of treatment of Aquilaria sinensis seedlings root knot nematode disease.