Genetic and chemical characterization of avocado commercial cultivars avocado of Risaralda Colombia

Abstract This research aimed at performing the molecular characterization of commercial Papelillo avocado (Persea americana cv Lorena) cultivars from the municipality of Marsella (Risaralda, Colombia), as well as the physicochemical analysis and antioxidant activity assessment of the pulp and seed. An evaluation of 50 individuals among commercial varieties and possible patterns was performed using 17 microsatellite markers. Proximate analysis of the pulp was performed, and the fatty acid profile of oils, the antioxidant activity by the DPPH and FRAP methods, and the total phenolic content were evaluated. From the cluster analysis, Dice index, and Principal Coordinates Analysis, it became evident that all the individuals showed a tendency to group by populations. In addition, the pulp revealed high fiber contents (4.96–20.64%) and moisture (80.75–82.96%); however, it showed low oil content (5.97–6.56%). The fatty acid found in the highest proportion in seed oil is linoleic acid and that in pulp oil is oleic acid. The antioxidant activity by the DPPH method for seed oil (87.87 to 91.04%) presented a greater inhibition concerning to the pulp oil (20.34% and 24.43%), this same trend was observed by the FRAP method. Concerning the content of total phenols, the seed oil (31.94–76.30 mg GAE g-1) has a higher value than the pulp (30.18–54.30 mg GAE g-1). The set of samples was characterized as a significant source of genetic variability; thanks to the excellent alternatives they provide as rootstocks for commercial varieties such as the ‘Lorena’ cultivars. The chemical classification carried out in this study is of great importance, due to the lack of information about the oil of the ‘Papelillo’ avocado cultivated in different regions of Colombia.

摘要 本研究旨在对哥伦比亚里萨拉尔达省马塞利亚市的商业帕佩利略鳄梨（Persea americana cv Lorena，即鳄梨栽培品种洛雷娜）开展分子鉴定，并对其果肉与种子进行理化分析及抗氧化活性评估。研究利用17个微卫星标记(microsatellite markers)，对商业品种及潜在类群中的50个个体进行了遗传评估。对果肉开展了常规营养组分分析，并检测了油脂的脂肪酸组成、采用DPPH与FRAP法测定的抗氧化活性以及总酚含量。通过聚类分析、Dice指数(Dice index)及主坐标分析(Principal Coordinates Analysis)结果可见，所有供试个体均呈现出按类群聚类的趋势。此外，果肉的膳食纤维含量（4.96%~20.64%）与水分含量（80.75%~82.96%）较高，但油脂含量较低（5.97%~6.56%）。种子油中占比最高的脂肪酸为亚油酸(linoleic acid)，果肉油中占比最高的脂肪酸则为油酸(oleic acid)。采用DPPH法测定的抗氧化活性结果显示，种子油的自由基清除率为87.87%~91.04%，显著高于果肉油的20.34%与24.43%；FRAP法测定结果亦呈现相同趋势。总酚含量方面，种子油的总酚含量为31.94~76.30 mg GAE·g⁻¹，高于果肉油的30.18~54.30 mg GAE·g⁻¹。本研究供试样本群体具有丰富的遗传变异多样性，其作为‘洛雷娜’等商业品种的嫁接砧木具备优异应用前景。鉴于目前哥伦比亚不同产区栽培的‘帕佩利略’鳄梨油脂相关信息较为匮乏，本研究开展的化学组分分析工作具有重要意义。