The Establishment Of SSR System And The Analysis Of Genetic Diversity Of Aphid-Resistant Alfalfa

Nine different aphid-resistant alfalfas and four cross bred F1 were used in this experiment to investigate better dosage in SSR technique system and to seek the best combination among factors.At last,the best SSR technique system was established. The Taq DNA polymerase was 0.2μL(5U/μL),the 10×Buffer(Mg2+Plus)was 2.5μL , the dNTP Mixture was 2μL ( 2.5mmol/L) , the primer was 1.5μL (10μmol/L),the template DNA was 1μL,the ddH2O was 16.3μL ,and the whole system was 25μL.The amplification bands were clear and standard by using this system. SSR markers were used to investgate the Genetic diversity of the nine different aphid-resistant alfalfa,the four cross bred F1 and their parents.The conclusions were: aphid-resistant alfalfa M8 and HA-3 were near relatives ,their similar coefficient was 0.8550.The S7 and X2 had the smallest similar coefficient that was 0.5362.The similar coefficient between high-resistant aphid alfalfa HA-3 and low-resistant aphid alfalfa Hunter River was 0.7391,they had large genetic differences of their background.Besides this,the genetic distance between Golden Kaiserin(♂)and G3(♀)was 0.5108,and the genetic distance between X2(♂)and G(3♀)was 0.7156, the genetic diversity between male parent and female parent was large comparatively.The similar coefficient between cross bred F1 and their parents was from 0.3556 to 0.6333,they had some genetic differences with their parents.