Note: * mean significant different at 0.05 level; ** mean significant
different at 0.01 level.
Principal Component
Analysis
The oil content of seed kernels
and the main fatty acid fractions of 70 A. truncatum samples from nine
populations were subjected to principal component analysis, and two
principal components were extracted by analyzing the degree of
contribution of each index, screening out independent variables with
dominant roles, and using an eigenvalue greater than one as the
principle (the results are shown in Table 7). As can be seen in Table 7,
the cumulative contribution of the first 2 principal components is as
high as 84.29%, which has been able to explain most of the information.
In the 1st principal component, palmitic acid, stearic acid, oleic acid,
linoleic acid, eicosapentaenoic acid, erucic acid, and neuronic acid
contents were more highly correlated with PC1, and the absolute value of
the loading was higher, all of which were greater than 0.8, so the 1st
principal component can be summarized as the fatty acid component
playing a major contributing role; in the 2nd principal component, the
oil content of the seed kernel of A. truncatum had the largest
absolute value of the loading, and thus the 2nd principal component
mainly contained the seed oil content. In summary, the difference
between the oil content of A. truncatum seed kernels and the
major fatty acid fractions was large, which was the same as the results
of the previous analysis of variance, and the contribution of the major
fatty acid fractions was more than that of the oil content of the seed
kernels, indicating that the fatty acid fractions played a major
contributing role in the variation of the seed oil of A.
truncatum .
Table 7. Principal
component analysis of seed kernel oil content and main fatty acid
components in Acer truncatum