Warm Dry Storage and Application of Gibberellins in The Lipid Profile of Chincuya Seeds (Annona purpurea Moc. & Sessé ex Dunal)

Abstract

By virtue of the knowledge of the beneficial effect of the warm and dry storage, for the growth of the chincuya seed embryo, defined as morphological dormancy. The effect of the same type of storage was studied for the seed viability and germination by soaking gibberellic acid. Also, fatty acids and their kinetics were identified during the warm and dry storage. The following treatments were evaluated: storage time (0, 3, 6, 9 and 12 months), seed soaking in gibberellic acid at 350 mg L-1, and for the control, imbibition in distilled water, both for 72 h. The seed viability was evaluated through the stain test with tetrazolium chloride. The embedded seeds were germinated on absorbent paper towels and incubated at different temperatures of 30 ° C during the day and 25 ° C at night and 12 hours of photoperiod. The lipid profile was developed by gas chromatography. Seeds were held at constant temperature of 25 ± 3 ° C, in darkness, during the storage time. Results demon-strated that the high initial viability was maintained until the ninth month, when it decreases and is statisti-cally different from the other treatments. The smaller germination percentage (26.1 %) was observed in the freshly harvested seeds and, the higher one corresponded to the six months (65.6 %), with these differences being statistically significant. Regarding the identified fatty acids and their average content, it was found that 33.41 % corresponded to palmitic acid, 7.72 % to stearic acid; the arachidic acid with 1.30 %, making a total of saturated fatty acids of 42.44 %. The detected unsaturated fatty acids were: palmitoleic acid 1.52 %, oleic acid 43.37 % and linoleic acid 7.24 %, in total, 52.15 %. No significative changes were observed in the fatty acids content that are the largest part of the total seed reserves; although the higher concentrations matched with the longest germination (three months), with an average of 92.84 % total fatty acids. Specified regressions indi-cated with statistical robustness that palmitoleic and palmitic acids increased while the oleic acid decreased during the dry storage. The arachidic acid showed a slightly downward trend. Also, the concentrations of fat-ty acids were significatively different between unstored and unincubated seeds (intact) and unstored and in-cubated, but without germinating seeds (dormant), in the latter, the total fatty acids content was significantly lower. Given that the application of gibberellic acid and warm dry storage favored germination, as well as the change in fatty acid content during warm dry storage, added to the results already reported on morphological changes and embryonic growth as an effect of the same type of storage, it is established that Annona purpurea seeds present morphophysiological dormancy, also this is the first identification report of arachidic and pal-mitoleic acids in chincuya seeds and the higher germination percentage reported (65.6 %).