龙眼果实采收成熟度与耐贮性关系研究

Studies on Relationship Between the Harvest Maturity and Storability of Longan Fruits

以‘石硖’和‘古山二号’龙眼Dimocarpus longan Lout. cv. Shixia and Gushan No. 2为试材，对果实成熟度与耐贮性之间的关系进行了研究．结果表明：在果实成熟期间，品质指标可溶性固形物（TSS）和糖含量及内果皮褐变指数在果实完全成熟前后或过熟后都发生了阶段性变化，提出以比熟度作为量化衡量果实成熟度的重要参考指标．‘石硖’和‘古山二号’龙眼果实最适贮藏的采收成熟度均为完熟前8．5～9．0成熟度（10为完全成熟），约为花后90～95d；随着成熟度的提高，果实质量损失率下降，贮藏后好果率也下降，与‘古山二号’龙眼相比，‘石硖’龙眼的质量损失率较低，耐贮性较高．不同成熟度果皮细胞显微结构研究表明，随着成熟度的增加，果皮结构由致密逐渐变得疏松，细胞结构变得模糊，细胞间隙逐渐增大，组织趋向分解，其变化与果实衰老、耐贮性降低的变化一致，‘古山二号’龙眼耐贮性较低，这与其果皮组织结构比‘石硖’疏松有关．

The relationships between harvest maturity and storability of ‘ Shixia＇ and ‘ Gushan No. 2＇ longan fruits were studied. The results showed that as the maturity increased, the content of TSS and sugar, the browning index all changed during stage of fruits fully ripened or over ripened . The relative maturity was used to evaluate the fruit maturity as an important quantitized index. The optimum harvest maturity for storability for both ‘ Shixia＇ and ‘Gushan No. 2＇ longan fruits is between 8.5 - 9.0 maturity （ 10 for full ripening）, about 90 -95 d after anthesis; higher maturity at harvest led to lower mass loss of fruits and lower good fruit rate during the storage, with ‘ Shixia＇ longan fruits being lower in mass loss and better in storability than ‘ Gushan No. 2＇. Microstructure study on the pericarp at various stages of maturity showed that with the increase of maturity, the tissue of the pericarp gradually became loose, the cell structure got fuzzy, intercellular space expanded and the tissue tended to get decomposed. The changes in the structure of the pericarp were consistent with the changes of fruits＇ senescence process and weakening storability. It was related to its loose structure of the pericarp that the storability of ‘ Gushan No. 2＇ was lower than ‘ Shixia＇.