Two Turfgrasses Nematode’s Isolation,Community Characteristic Analysis And The Indoor Bioassay Of Beijingarea

In this paper,the nematode isolation was performed by using Baermann funnel method.The results showed that the separation efficiency of the nematode was better than that of the other two media,the temperature,25 ~ 35 for the optimal temperature of the separation of nematodes,but with several ℃ ℃other selected test temperature difference is not;separation time of 24 h when the largest number of nematodes isolated;different volumes the number of samples was proportional to the number of isolated nematodes.When the sample volume was 200 mL,the number of nematodes was the largest.The conditions of nematode isolation were screened out,which provided the basis for the isolation of nematodes in subsequent experiments.The number and structure of the soil nematodes in the rhizosphere soil of the tall fescue turfgrass in Shunyi District of Beijing were measured for one year.The changes of the vegetative groups of the turfgrass nematodes in different periods of the year were clarified.The results showed that the number of plant nematodes accounted for the highest proportion of total nematodes in March,close to 50%.The number of nematodes in the third quarter is the largest,and the third quarter of each year may be the most important stage of nematode control.The population structure of the rhizosphere soil nematode was analyzed in the virescence region of 6 districts in Beijing,China.There was no significant difference between the 6 regions involved in the nematode trophic groups,the morphological identification indicated that plant phytophage nematode were classified into 6 genera in 5 families of 2 orders and beneficial nematodes(non PPNs)were classified into 12 genera in 5 families of 3 orders.The population density of nematodes was from 250 to 950 individuals per 100 g soil.The PPNs accounted for 24.7% to 71.6% of the total number of nematodes identified from 6 areas.At the same time,the most dominant taxa and main dominant groups in six areas of Beijing were identified,among them,Helicotylenchus crenacauda was the most dominant group,and Pratylenchus scribneri was the dominant group.To improve the soil ecological environment and reduce the damage of chemical pesticides on the soil,Five biological agents were used to evaluate the killing effects to the nemotods in the genera Helicotylenchμs crenacauda.The results showed that the five nematicides had remarkable killing effect to Helicotylenchμs crenacauda nematodes,respectively,and the killing effect is significant.Among them,abamectin has the best effect on the killing effect of Helicotylenchus crenacauda,can be used as an alternative killer agent for further study.