Seed Morphology and Polyphenolic Compounds of Longan

Abstract

Seed morphology and polyphenolic compounds of the different longan cultivars from germplasm collection plot of Hari Phun Chai Longan Development and Research Station were investigated at the fruit mature stage in July 2013. Comparative studies were considered in two groups of longan cultivars; 1) totally 8 cultivars planting in the north of Thailand and other regions, and 2) totally 17 cultivars of ‘Daw’ cultivars group. Seed characteristic and polyphenolic compounds content in their seed extracts by high performance liquid chromatography were determined. The results showed that seed characteristics of cv. ‘Phetyala’, ‘Thao’, and ‘Vietnam’ had seed size bigger than the cultivars planting in the north. Seeds of cv. ‘Phuangthong’ showed the smallest seed size in all traits. Shape of seed in some cultivars could be used as characteristic of their cultivars. Analysis of polyphenolic compounds in seed found that the gallic acid was accumulated less concentration than ellagic acid. Especially, the accumulation of both acids in cv. ‘Thao’ seed gave the least concentration when compared with all cultivars. Comparative characteristic between ‘Daw’ cultivars group revealed that there was a large seed size of cv. ‘Daw Auntasunuk’ but it had the least concentration of polyphenolic compounds. However, the high quantity of gallic acid and ellagic acid in seed of cv. ‘Daw Kaankhaeng’ were 1.21 ±0.14 and 2.22 ±0.14 mg/g, respectively.