Genetic Diversity Of Chinese Wild Apple Stocks

SSR and ITS genetic diversity analysis of Malus hupehensis(Pamp.) Rehd. accessions which were collected from different populations of China from North to Southwest was carried using 10 SSR markers, including 17 of Chinese wild apple rootstocks wild species and 7 of foreign rootstock varieties and five domestic cultivars in a total about 53 samples, coming from different regions of China. Combined with the study of the Malus rootstocks graft compatibility previously by predecessors, the linking between wild rootstock kinship and hybrid rootstocks affinity was explored.1. Exploring the methods of extraction genome DNA of Malus, which containes much polysaccharides and phenol substances, and high purity of genomic DNA was gathered.2. 55 of Malus genome samples were amplified with 10 pairs of SSR primers, 149 pairs of alleles were obtained, the allelic points were from 9-25, between 80 bp-800 bp fragments. According to the results of the different primers which performing different polymorphisms rate, the population distribution between 90.1%-99.6%.This showed polymorphism between Malus.3. By SSR markers and nr DNA ITS sequence analysis, and using mapping software to draw clustering analyze program showing, there is a definite link between malus wild rootstock kinship and hybrid rootstocks affinity,however, it is usually affecting by the environment and the impact of variability. The experimental results confirm that Sect. Gymnomeles has a close relationship with common apple cultivarieties. It also explains why the plants of the Sect. Gymnomeles become the most widely used apple rootstock at present.