糯米糍荔枝果实内源激素与落果的关系

Endogenous Hormones in the Fruit of Litichi chinensis cv. Nuomici Relating to Furit Abscission

以糯米糍荔枝生理落果期的田间调查和胚胎发育研究为基础,探讨了内源激素与生理落果的关系.结果表明,糯米糍生理落果高峰的主要原因是:第1次因授粉受精不良导致的生长促进类激素尤其是CTK水平过低;第2次与胚乳为胚的发育所利用而消失、IAA和GAs急剧降低有关;第3次与胚的败育造成CTK、GAs和IAA的全面下降有关;第4次发生在假种皮(果肉)迅速生长期,与种皮和假种皮ABA升至高水平有关.此外,还探讨了ABA /(IAA+GAs+CTK)与生理落果的相关性,以及胚囊、珠被和假种皮等果实内部组分内源激素的变化特点.

The relationship between fruit endogenous hormones and the physiological fruit drop was studied. Results showed that the four abscission peaks during fruit setting of seed aborted cultivar 'Nuomici' were closely correlated with the hormone fluctuation characteristic in the certain stage of fruit development respectively. The first peak was caused by under pollination and under fertilization resulting to the GAs and CTK deficiency in abscinding fruit. The second revealed in the same period of endosperm disintegration accompanied with the decrease of IAA and GAs in embryo sac. The third occurred in the initial stage of embryo abortion with the obvious decrease of IAA, GAs, and CTK. The fourth peak was correlated with the fast growth of aril by the obvious increase of ABA in integument and aril. The ABA/(IAA+GAs+CTK) as related to fruit drop and changes of endogenous hormone characteristic of compositional parts of fruit (embryo sac, integument and aril) were also discussed.