| Carya dabieshanensis was a nut and woody oil species with high nutrition and health care value. In the study, the phenotypic variation regularity and genetic diversity were reaearched in order to provide a theoretical basis for the germplasm collection, evaluation, genetic improvement and conservation of Carya dabieshanensis. The main results were as follows:The results indicated that the 14 quantitative traits in 5 populations had abundant variations, the genetic variation in the populations were much higher than that among populations, there was no significant genetic differentiation among populations. Although, the variation coefficient of nut length and nut diameter were far below the parietal long, parietal wide and other nutritional traits in the populations, on the population level, the variation coefficient of nut length and nut diameter were much higher, which reached 24.18%, 30.98%. The variance analysis of 5 populations showed that C.dabieshanensishad significant difference(P<0.01)except the leaf axis length, total petiole length in tishuigou population and the Parietal width in the yangliuhepopulation. Among the populations, ten phenotypic traits were significantly different, 17 traits were not significant. The Pearson correlation analysis on 27 characters showed that 33 pairs of characters had significant correlation. The results of principal component analysis showed, the length of petioles, shapes of terminal pinnules base, pubescence on leaves, pubescence on veins, pubescence on petioles, pubescence on columellae, length of terminal pinnules, width of terminal pinnules, and colors of columellae were the main components, which were played important roles in the variation of C. dabieshanensis. The UPGMA cluster analysis showed that the phenotypic traits were quite different among populations, they mixed with each other and could not gather for a class. This meant genetic diversity of C. dabieshanensis were mainly exsited in populations, there was no obvious genetic differentiation among population which may be related to the breeding system of C. dabieshanensis.We analyzed the genetic diversity of 5 population using inter-simple sequence repeat(ISSR) makers. The results were as follows: 14 ISSR Primers amplified 105 DNA fragments, of which 95(89.30%) showed polymorphisms among the populations.The percentage of polymorphic bands at the population level ranged from 53.60% to 62.80%, with an average of 58.31%. Nei’s index and Shannon’s information index at the population level ranged from 0.65 to 0.75, respectively; at the species level, Nei’s index and Shannon’s information index were 0.81 and 1.91, respectively. Genetic identity and genetic distance had great significance to determinate genetic relationship. The genetic identity of Carya dabieshanensis were ranged from 0.48 to 0.78, with an average of 0.54; and the genetic distance were ranged from 0.46 to 0.62, with an average of 0.62.The genetic differentiation coefficient among the populations were 0.1345, the gene flow were 1.61, the high gene flow meant that the genetic differentiation among populations were small. The genetic variation main existed in populations. The UPGMA showed that the yangliuhe and dishuigou populations were the most genetically similar of all the populations, nannigou and yutan populations had the similar Genetic similarity, the two populations which the position nearer could not cluster firstly, it may be had the relationship with pollination by wind and the strong gene flow hindered the genetic drift may another reason. |
