Distribution And Identification Of Root Knot Nematodes Of Salvia Miltiorrhiza And The Screening Of Biocontrol Strains

Salvia miltiorrhiza Bunge is the dried root and rhizome of the labiatae family of the plant kingdom.Salvia miltiorrhiza is widely used to treat many diseases and contains many chemical constituents.Plant-parasitic nematodes are one of the most important plant diseases in a variety of crops,resulting in a loss of about 157 billion dollars in production a year?Ste?phane Bellafiore et al.,2015?.Root knot nematodes can do harm to Salvia miltiorrhiza,causing the roots swollen and unable to absorb nutrients normally.By investigating the incidence of root knot nematodes of Salvia miltiorrhiza in Shandong province,the main pathogenic species of root knot nematodes of Salvia miltiorrhiza were identified.The biocontrol strains of Salvia miltiorrhiza were isolated and the effect of biocontrol was verified by pot experiment.The main results were as follows:?1?Sampling the diseased plants of Salvia miltiorrhiza in Shandong province,the analysis of the relationship between root knot nematode and geographical location was carried out.It was concluded that the distribution of root knot nematode of Salvia miltiorrhiza has no direct relation with geographical location.?2?Three species of root knot nematodes of Salvia miltiorrhiza were identified by identification of root-knot nematodes in the above areas.That is,Meloidogyne incognita,M.arenaria and M.javanica.Among them,Meloidogyne incognita is most widely distributed.?3?The distribution of root knot nematodes was not uniform in the planting area of Salvia miltiorrhiza.The most harmful areas is Changqing,and the density of insects reached 178ind·g^-1 soil.In the less harmful areas,such as Gangcheng,the population density was 6.5 ind g^-1 soil.?4?The occurrence of root knot nematodes reduced to some extent by rotation in the planting area of Salvia miltiorrhiza.In which Danshen participated in the rotation of cereal crops,the density of root knot nematodes of Salvia miltiorrhiza was low.The harm of root knot nematodes to Salvia miltiorrhiza reduced.?5?According to the dynamic results of root-knot nematode during the planting period of Salvia miltiorrhiza,the root knot nematodes in September were most abundant and most harmful.Root knot nematodes were harmful to Salvia miltiorrhiza.To prevent root knot nematodes from Salvia miltiorrhiza,we should do well in soil nematode removal before planting.?6?The samples of root knot nematodes of Salvia miltiorrhiza were diluted and the biocontrol bacteria were passed the contact test with root knot nemarode.Two strains of biocontrol bacteria were obtained.After cultured for 48 hours in shake flask and treated with root knot nematodes for 12 h,the corrected mortality of strain B1 was 81.88%and B30 was71.34%.?7?The morphological observation,physiological and biochemical tests as well as molecular biology identification of strain B1 were all carried out.This strain was identified as Bacillus sporothermodurans.?8?The data of 35 days'experiment showed that the control effect of the treatment group on root-knot nematodes was 57.22%.Strain B1 had a good growth promoting effect on tomato plants.Biocontrol bacteria B1 has ideal insecticidal potential for root knot nematodes and can play a role in biological control of root knot nematodes of Salvia miltiorrhiza in the future.