A comprehensive method for evaluating kernel quality was established by estimating in detail the kernel quality of 27 pecan cultivars introduced into China and by exploring the major trait differences among the different cultivars of pecan. The contents of crude fat, crude protein, soluble sugar, and tannin; the fatty acid composition; the amino acid composition; and the mineral element composition of 27 pecan cultivars were analyzed and tested using the national standards for principal component analysis (PCA), and orthogonal partial least-squares discriminant analysis (OPLS-DA) was used to comprehensively evaluate the 34 characteristic indicators. The fatty acids in the kernel were dominated by unsaturated fats, with oleic acid having the highest content relative to linoleic acid; the amino acid composition was dominated by medicinal amino acids; and potassium, magnesium, and calcium were the predominant mineral elements. Systematic cluster analysis revealed that the 27 pecan cultivars could be classified into three categories (relatively optimal, general, and poorest kernel quality) and 21 indexes, including oleic, linoleic, linolenic, crude fat, soluble sugars, aspartic acid, and threonine, served as indexes of the differences among the 27 tested cultivars. Combined with principal component analysis and stepwise regression analysis, a kernel quality evaluation model was established and verified, and reliable evaluation results were obtained. In addition, Nos. 9, 65, 66, 72, 8, and 21, which had the best quality, were further ranked using the probability ranking method within the third category of optimal quality cultivars. There were obvious differences in kernel characteristics among the different cultivars of pecan. Six cultivars with potential to be developed into excellent cultivars were preliminarily screened out. It was found that the organic combination of cluster analysis, principal component analysis, and orthogonal partial least-squares discriminant analysis can provide a reliable method for the quality evaluation of pecans.

In the present study, the antimicrobial tests of patchouli oil were studied by using molecular docking technology and antimicrobial test in vitro. Five biological macromolecule enzymes, required by the bacteria in the process of biosynthesis were selected as target molecules. Five antibiotics benzylpenicillin, sulfadiazine, trimethoprim, rifampicin and ciprofloxacin, which are generally acknowledged as antibacterial drugs, were selected as reference compounds. The 3 three-dimensional (3D) structures of the 5 reference compounds and 26 compounds from patchouli oil were established by using surflex-dock software (8.1). And the 3D structures of five biological macromolecule enzymes derived from Protein Data Bank (PDB). Molecular docking was carried out between the 31 chemical compounds (ligands) and the 5 enzymes (receptors) by using surflex-dock function. Furthermore, the antibacterial effects of 31 chemical compounds were investigated by the scoring function after molecular docking was completed. By comparing the scoring result of 26 compounds in patchouli oil with 5 compared components, we inferred antibacterial activity in about 26 compounds in patchouli oil. On the other hand, six frequently-used pathogenic bacteria were selected for antimicrobial test in vitro, patchouli oil and its two major compounds: (-)-patchouli alcohol and pogostone, which their contents exceeded 60% in patchouli oil samples, were selected antibacterial agents. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) were also determined. Molecular docking technology and antimicrobial test in vitro proved that patchouli oil had strong antimicrobial effects. Particularly, pogostone and (-)-patchouli alcohol have potent antimicrobial activity.

As woody oil crop, pecan [Carya illinoinensis (Wangenh.) K. Koch] may be a solution to the shortage of edible oil in the future. In this study, fruit traits, kernel nutrition and fatty acid composition of 10 pecan varieties were determined to assess the potential of pecans for exploitation as edible oil, as well as to further screen varieties that could be used as edible oil resources and to understand their development prospects for cultivation in mountainous hills. The study showed that all the fruit trait indicators measured, including green-fruit weight (mean 28.47 g), nut weight (10.33 g), kernel weight (5.25 g), nut percentage (36.83%) and kernel percentage (50.50%), showed highly significant differences among the 10 varieties. Among the main nutritional indicators of the kernels, the crude fat content was stable (mean 70.01%) with non-significant differences, while protein (67.50 mg·g⁻¹), soluble sugar (10.7 mg·g⁻¹) and tannin (6.07 mg·g⁻¹) showed highly significant differences between varieties. The oil percentage of nuts (kernel percentage * crude fat) averaged 35.36%, with highly significant differences between varieties. The fatty acid composition was dominated by unsaturated fatty acids (mean 91.82%), with unsaturated fatty acids being 11.24 times more abundant than saturated fatty acids. Among the monounsaturated fatty acids, oleic acid was the highest (mean 70.02%), with highly significant differences between varieties, followed by cis-11-eicosanoic acid (0.25%), with non-significant differences between varieties; among the polyunsaturated fatty acids, linoleic acid was the highest (19.58%), followed by linolenic acid (0.97%), both of which showed highly significant differences between varieties; monounsaturated fatty acids were 2.42 times more abundant than polyunsaturated fatty acids. Compared to other oilseed crops, pecan has the potential to produce “nutritious, healthy and stable” edible oil, while its wide habitat and good productivity benefits offer broad prospects for development in the hills and mountains of subtropical China.

It is of great significance to study the nutritional characteristics of plants. Further understanding of plant mineral nutrient dynamics can provide theoretical basis for scientific fertilization to improve fruit quality and yield. In this study, eight mineral elements (N, P, K, Ca, Mg, Mn, Zn, B) were measured at regular intervals in leaves and kernels of the pecan “Mahan” planted in southern China. The study discussed the characteristics of mineral nutrient dynamics of pecan through the indicators of concentration, accumulation and cumulative relative rate, a new first proposed indicator, and focused on critical time, intensity, amount of mineral nutrients required in pecan during the fruit developing period, as well as the transfer information of the elements in leaves and kernels. The results show that the mineral nutrient requirements of the leaves and kernels are not identical, with an upward trend in nutrient accumulation within the kernel. The most abundant mineral nutrients in the leaves and kernels were N, K and Ca with Ca being greater than N in leaves. In particular, the concentration of Mn in pecan ‘Mahan’ is higher than that of other plants, and its Mg content is also higher than that of P in kernels. The dynamic changes of mineral nutrients in walnut showed obvious stages, with a trend of “slow (before mid-July) - fast (mid-July to late August) - slow (late August to late September) - fast (late September to harvest)”. The “critical period” of kernels was before mid-July, during which the cumulative relative rates increased rapidly, indicating that the kernels had a great potential to absorb mineral nutrients. Significant accumulation of mineral nutrients occurred from mid-July to late August and late September to the end.