Study On Seed Phenotypic Traits And Seed Oil Traits In Natural Populations Of Acer Truncatum

Acer truncatum also known as ingot maple,purpleblow maple,shantung maple that is a unique woody oil tree species in China.In order to better understand,protect and exploit the germplasm resources of A.truncatum,the species of natural populations in the main distribution areas of A.truncatum were used as materials to test and analyze the fruit and seed characteristics,seed oil content and fatty acid composition.We analyzed the variation on phenotypic traits and seed oil traits in natural populations of A.truncatum from different populations.The main findings are as follows:1.We used nested variation,coefficient of variation,multi-comparison,correlation analysis and UPGMA cluster analysis to analyze 13 phenotypic traits for 150 individuals in 15 populations of A.truncatum.The results showed that there were extremely significant differences among and within populations.The mean coefficient of phenotypic differentiation between populations was 19.87%,which was lower than that within populations(80.13%),indicating that the variance within population was the main source of the phenotypic variation of the species.The coefficient of variance(CV)of the 13 traits was 8.98%~21.45%,with an average of 13.34%.The CV of seeds among populations(11.46%)was lower than that of wing fruits(14.52%),which means that the seeds have higher stability than the fruits.Principal component analysis(PCA)showed that the main variation source of A.truncatum came from the fruits.Correlation among traits showed that the larger the fruits,the larger the seeds.The angle of the fruits was independent of the fruits and seed sizes.The fruit morphology mainly presented longitudinal variations,while the seeds had no significant variation patterns.The 15 populations of A.truncatum could be clustered into three groups according to the UPGMA cluster analysis,which reflected the obvious difference of geographical longitude.2.Nuclear magnetic resonance was applied to determine the crude fat content from 14 regions of A.truncatum natural distribution.The fatty acid composition was analyzed by gas chromatography and quantified with an internal standard method.The results showed that:There were significant differences in the seed oils from different regions,which from populations of Daiqintala(32.47%)and Yongshou(32.09%)were obviously higher than other populations.Seed oil content accounted for 17.81%~36.56%,and the average content was28.57%.There was the trend that the seed oil content increases with latitude and altitude.The results revealed that the seed oil was rich in unsaturated fatty acids(91.47%),including linoleic acid(32.97%),oleic acid(25.19%),erucic acid(16.49%),a peanut acid(7.90%),nervonic acid(5.76%),linolenic acid(2.76%).And the highest content of nervonic acid(a kind of functional fatty acid)was 7.85%,the lowest was only 3.90%,and the coefficient of variation was 12.62%.There was significant variance in nervonic acid concentration from different populations which from populations of Jiyuan(6.54%)and Pingquan(6.29%)were obviously higher than other populations in which it has basis for screening of specific germplasm resources with high nevonic acid.Various fatty acid variations and genetic diversities were presented among populations,which were higher in Nanjing,Linfen and Yongji.Phenotypic differentiation coefficients among populations for 13 traits ranged from16.74% to 62.19%,emphasizing the importance of differences both among populations and among individuals within populations for screening of oil germplasm resources.Correlation analysis indicated the higher the seed oil,the higher unsaturated fatty acid content and the lower saturated fatty acid content.According to the correlation analysis of phenotypic traits,The larger and the more full the fruit,the more conducive to the improvement of seed oil quality,which can be used as a basis for earlier selection of oil germplasm resources.The correlation analysis between the test index and the geography-ecological factors showed that the seed oil traits had a variety of geographical variation trends,and the altitude and temperature factors had the greatest effect on the seed oil traits.There are abundant variations in the phenotypic traits and seed oil traits in different populations,which provide a theoretical basis for the screening of the excellent germplasm resources of A.truncatum and help to speed up the process of cultivating the A.truncatum.The multiple variations among and within populations provided insights and guidelines for genetic conservation and utilization of A.truncatum germplasm resources.