Genetic Variation of Ditylenchus destructor and Its Association with Ecological Factors

Ditylenchus destructor is a quarantine plant-parasitic nematode that distributed worldly.The genetic variation of D.destructor may be modified with the change of ecological environment.The effect of ecological factor on the genetic structure may be induced by the genetic variation of different population of Ditylenchus destructor.The genetic diversity and genetic differentiation of D.destructor were analyzed with inter-simple sequence repeat(ISSR) molecular marker in this study.The effect of ecological factor on genetic diversity of D.destructor was analyzed with SPSS software.Results showed that genetic diversity was relative high in D.destructor.At the population level,the higest genetic diversity existed in the Taihe population of Anhui Province,the lowest genetic diversity existed in the Changli population of Hebei Province.At the group level,the genetic diversity of five groups was arranged as AnhuiShandongJiangsuHebeiBeijing.Relativey low genetic differentiation and high gene flow were existed in five groups with which coefficient of genetic differentiation(Gst) was 0.0725 and gene flow(Nm) was 6.3933.Correlation analysis showed a positive relationship between Shannon genetic diversity and altitude,longitude,latitude and annual precipitation,while a negative relativeship existed between Shannon genetic diversity and average temperature,maximum temperature and minimum temperature.A positive relationship also existed between genetic distance and geographical distance.The results imply that D.destructor adapts to low temperature and it will be suitable to propagate in northern China.The management of seedling and seedtuber of sweet potato(Solanum tuberosum) shall be reinforced to prevent it's distribution and spreading in northern China.