The Study On The AMF Populations In Roots And Rhizosphere Of Potato Samples Collected Form The Middle Region Of Inner Mongolia

Potato is one of the world's fourth largest food crops and the main food crop in Inner Mongolia.In this study,we used the samples of potato root and rhizosphere soil samples collected from different locations of Inner Mongolia Autonomous Region,such as Damaoqi Dajing Village,Liangcheng Xumayao village,and Chayouhouqi,Honggeertu village,and the root and rhizosphere soil sample sof different developmental stages of potato collected from Damaoqi Dajing Village to study the AMF population variation.The DNA libary of Arbuscular mycorrhizal fungi(AMF)were constructed by using DNA samples isolated from samples described above.To study the structure and composition of the AMF population,25 clones selected randomly from different libraries were sequenced and constructed the genetic tree.By using microscopy,the infection rate was quantified by trypan staining,the results listed as follows:1.Among three locations,the samples from Honggeertu village showed the highest AMF diversity in both roots and rhizosphere soil samples,followed by samples from Dajing village and samples from Xumayao village.2.The diversity of AMF population in root and rhizosphere of three different sampling points showed that the diversity of AMF in rhizosphere soil samples was higher than that of root system.Rhizophagus group appears only in the root system and has the highest proportion among all AMF species;Glomus group B and Glomus group C have a certain distribution in rhizosphere soil and root samples in three different locations.3.Compared the AMF population diversity among samples collected from three different developmental stages,the populations from potato seedling showed the highest level,followed by samples from flowering and tuber development stage.Also the AMF diversity in rhizosphere soil samples was higher than that of roots at different developmental stages,among them,Rhizophagus group is only distributed in root samples and showed the highest population,whereas,Glomus group B and Glomus group C are only found in rhizosphere samples.4.We also compared the effects of rotation on the AMF population and results showed that succession cropping of potato will decrese the AMF communities in Rhizosphere soil,however it does not have obvious effects on the AMF population in potato root system.5.The infection and colonization rate of AMF were investigated by trapping experiments.Our results showed that infection rates are generally lower than colonization rates in root.Meanwhile,the infection rate of hyphae is higher than that of arbuscular and vesicules.Among three locations,the infection rate of AMF in Honggeertu village sample is the highest,followed by Dajing village and Xunmayao samples,meanwhile,the colonization rate of arbuscular is also higher than that of hyphae.The total AMF colonization rate is higher than the other two sites.There has positive correlation between infection rate/colonization rate and AMF diversity in potato soil.