Ecological And Genetic Diversity Studies On Carya Cathayensis And C.dabieshanensis

1 Ecological studies on Carya cathayensis and C.dabieshanensisOn Carya cathayensis: The environmental conditions were obviously different in Carya cathayensis distribution areas.Ecological factors, such as climate, soil, terrain and topography had significant influence on growth ,development,fruit yield and quality of C.cathayensis.Crude fat content in kernel of C.cathayensis elite trees was not closely related with readily available N,P,K and pH value of elite trees' soil, readily available P and pH value had relatively greater influence than the other facters.Crude protein content was evidently related with readily available K,its correlation coefficient was 0.2653.Crude protein content was remarkably related with readily available N and organic matter.their correlation coefficients were respectively 0.4957 and 0.4367.Ca,Mg contents were remarkably related with readily available K,their correlation coefficients were respectively 0.3800 and 0.3358. But K content had markedly negative correlation with readily available K,its correlation coefficient was -0.2367.Na content was remarkably related with pH value.its correlation coefficient was 0.3702.On Carya dabieshanensis: Compared with C.cathayensis, the environmental conditions were more observable different in C.dabieshanensis distribution areas.C.dabieshanensis natural communities were kinds of stable communities.Their species composition,structure characteristics, types and proportions of flora components displayed that the communities had some transitional features to a certain extent.2 Genetic diversity study on Carya cathayensis and C.dabieshan- ensisSampling Strategy: Five populations were selected in C. cathayensis .Three populations were selected in C.dabieshanensis.Thirty individuals were collected in every population,distance between two individuals keep more than 50m.Genomic DNA extraction: Total DNA in leaf tissue of C.cathayensis was extracted by four methods.improved SDS method was regarded as the best suitable one.The genomic DNA samples obtained by this method was fit for RAPD experiment.Reaction system and conditions of PCR amplification: PCRamplification program was denaturation at 94 in advance for 3 min,then followed 38 cycles,every cycle:denaturation at 94 for 30s,anneal at 38 for 30s,extentionat 72 , for 90s.RAPD reaction system(20 1) optimum constitution2.5mg/l template,0.3 mol/1 primer,0.067u/ 1 TagDNA polymer - ase,0.2mmol/l each dNTP,2.5mmol/l Mg2+,10*Buffer 2 l,1.2mg/l BSA and 3.0mg/l TMACI.600 Primers were firstly and secondly secondly selected.At last,20 primers were decided to apply to formal amplification.Studies on genetic diversity: 252 bands were amplified by 20 primers in Carya cathayensis ,168 bands were polymorphic and PPB was 66.7%. 238 bands were amplified by 20 primers in C.dabieshanensis .162 bands were polymorphic and PPB was 68.1%.Total shannon phenotype diversity index of C.cathayensis was 0.4102,average shannon phenotype diversity of 5 popula- tions was 0.2451.The shannon phenotype diversity among and within 5 popula -tions were respectively 39.68% and 60.32%. Nei's total gene diversity was 0.2671, average Nei's gene diversity of 5 populations was 0.1647,gene differentiation coefficient was 0.3845.Total shannon phenotype diversity index of C.dabieshanensis was 0.4761, average shannon diversity of 3 populations was 0.2750.The shannon diversity among and within 3 popula -tions were respectively 41.82% and 58.18%.Nei's total gene diversity was 0.3145,average Nei's gene diversity of 3 populations was 0.1865,gene differentiation coefficient was 0.4063. 3 Study on relationship among species of CaryaThe relationship among 6 species of Carya obtained by RAPD method was basically consistent with the result obtained by traditional classification.Compared with C.dabieshanensis,C.hunanensis had closer relationship with C.cathayensis.