| Torreya grandis ‘Merrillii’, a dry fruit species, is high in both economic and nutritional value,Male Torreya grandis as a paternal parent plays an important role in the production of T. grandis‘Merrillii’. However, due to a high economic value of T. grandis ‘Merrillii’, male Torreya grandistrees have not attracted enough attention. This paper studied phenotypic parameters and nutritentsof seeds hybridized between T. grandis ‘Merrillii’ and male T. grandis and analyzed geneticsimilarity of maternal parents and five populations in T. grandis ‘Merrillii’ from the mainproducing areas of Zhejiang with SRAP markers. The results were as follows:1. Maternal parents most significantly affected the young fruit setting rate （p＜0.01）andmale T. grandis trees and their interaction with the maternal parents significantly affected theyoung fruit setting rate in T. grandis ‘merrillii’（p＜0.05）, but all this could not explain theinfluence on the final fruit setting rate.2. The maternal parents and their interaction with the male T. grandis trees most significantlyaffected the weight, vertical diameter and transverse diameter of seeds with and without aril, theshape index of seeds with and without aril, and the weight percentage of seeds without aril tothose with ari（lp＜0.01）. The male T. grandis trees most significantly affected the weight, verticaldiameter and transverse diameter of seeds with and without aril and the shape index of seedswithout aril（p＜0.01）, and significantly influenced the shape index of seeds with ari（lp＜0.05）,but didn’t have effects on the weight percentage of seeds without aril to those with aril.3. The maternal parents and their interaction with the male T. grandis trees most significantlyaffected the fat content, protein content and starch content of hybrid seeds in T. grandis ‘merrillii’（p＜0.01）. In terms of fat content in seeds, there were four male trees significantly differentfrom each other; on the average,♀7was the highest and not significantly difference from♀1,and♀4as well as♀9was the lowest and not significantly difference from♀2,♀3,♀5and♀6; and male T. grandis trees varied more than the maternal parents. In terms of starch contentand protein content in seeds, there were some variations among seeds from different maternalparents.4. Polymorphic loci in maternal T. grandis ‘Merrillii’ accounted for12.69%based on analysiswith SRAP markers. The coefficient of genetic similarity ranged from0.911to0.980among ten maternal parents, out of which8maternal trees had a coefficient of the genetic similarity higherthan0.95and that of other two maternal parents also exceeded0.91. There was differentiationamong maternal parents, but at a low level less than10%.5. Polymorphic loci accounted for65.83%based on analysis with SRAP markers inpopulations of old T. grandis ‘Merrillii’ trees with the number of observed alleles (Na) being1.6538, the number of effective alleles (Ne) being1.2713, a Nei’s genetic diversity index (H) of0.1696, a Shannon’s Information index (I) of0.2664, and a total genetic diversity (Ht) of0.1694.15.27%of the total variation existed among populations, and84.73%within a population, whichindicated that genetic diversity was mainly distributed within populations of T. grandis ‘Merrillii’,but there was gene flow among populations. It was suggested that the source of scion in T. grandis‘Merrillii’ was more than one, though T. grandis ‘Merrillii’ was mostly propagated throughgrafting, and T. grandis ‘Merrillii’ was a category of cultivated trees.6. Controlled hybridization showed that the maternal parents significantly affected the heightof hybrid seedlings（p＜0.05）, and mostly significantly affected the basal diameter of hybridseedlings（p＜0.01）. The male T. grandis trees had no significant effect on the height of hybridseedlings, but significantly affected the basal diameter of hybrid seedlings（p＜0.05）. Interactionbetween the maternal parents and the male T. grandis trees had no significant effect on growth ofhybrid seedlings. |
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