【作者】 程和禾；

【导师】 张玉星；

【作者基本信息】 河北农业大学 ， 果树学， 2004， 硕士

【摘要】 黄金梨属砂梨系统，果实品质极优，是目前梨树品种结构调整中极具发展潜力的一个品种。本试验以黄金梨为试材，进行了以下研究：(1)从生长动态、果点和石细胞的发育、呼吸强度和乙烯释放、内含物和硬度的变化等方面对果实生长发育特性进行了研究，(2)对果实的贮藏生理特性进行了研究。主要研究结果如下： 1．黄金梨果实的生长动态曲线为“S”型。纵、横径的增长经过了迅速生长期、缓慢生长期、熟前生长期3个阶段，呈“快-慢-快”的趋势；果实鲜重和体积在前期生长缓慢，到花后70天前后增长速度开始加快，直至果实成熟。 2．黄金梨果实细胞分裂的时间进行到花后25天(5月10日)左右；细胞停止分裂后，幼果的增大主要靠细胞体积的增加。 3．黄金梨果实的果点形成经历了气孔期、皮孔期、果点形成和增大期三个阶段，花后15～20天气孔破裂，进入皮孔期，花后45天进入果点形成和增大期；果肉中石细胞发育从花后15天开始，到花后40天时石细胞团直径趋于稳定，随着果实的膨大，石细胞团密度明显下降。 4．在整个生长发育过程中，果实内含物及硬度变化：(1)果实的可溶性总糖含量在幼果期积累较慢，近成熟前增长迅速，增加了近一倍，果实中糖的组分主要有果糖、葡萄糖、蔗糖，其中果糖的含量为最高；(2)果实中可滴定酸含量在果实发育前期较高，随果实生长呈下降的趋势，果实成熟时略有升高；(3)果实淀粉在果实发育的前期以积累为主，后期以降解转化为糖的过程为主；(4)随着果实的成熟，黄金梨果实中可溶性固形物含量逐渐增加，硬度逐渐降低；(5)果实中Vc含量在幼果期较高，从幼果膨大时下降到较低水平，近成熟时又迅速上升。(6)在生长发育前期，果实中木质素含量出现高峰，后期含量一直很低；酚类物质含量在整个生长期呈下降趋势。 5．黄金梨果实成熟和贮藏过程中乙烯峰和呼吸峰先后出现，发生呼吸跃变现象，属于呼吸跃变型果实。 6．常温贮藏条件下，果实的贮藏期只有10～14天，随后果实出现皱缩、腐烂现象，烂果率迅速增加。在此期间，果实的失水率迅速增加；硬度前期下降迅速，后期下降较慢；可溶性固形物含量略有上升；采后2天出现呼吸高峰，之后呼吸速率下降；贮藏后期乙烯释放量增加；LOX活性出现两次高峰，PG活性随硬度下降迅速上升，后缓慢下降，PME活性前期下降较快，后期下降缓慢。 7．5℃低温贮藏可以使黄金梨果实贮藏期延长至100天以上，并长期保持其优良商品特性，主要在以下几方面对果实产生影响：(1)降低黄金梨果实的失水率、防止烂果的发生；(2)延缓果实硬度下降的进程；(3)延迟果实呼吸峰的到来，并使峰值降低；(4)有效抑制黄金梨果实中LOX、PG的活性，从而延缓果实的衰老过程。更多还原

【Abstract】 Golden pear is a new variety from South Korea, which belongs to sandy pear. The fruit is well known by its high quality, so it has a high potential to be developed. In this experiment, the physiological property of golden pear was studied. The main results were as follows:1. The growth curves of golden pear showed an "S" shape. The growth of diameter and length had experienced 3 stages, it showed a trends of "quick-slow-quick"; fresh weight and fruit volume grew slowly at prophase, then their growth was accelerated from 70 days after bloom to fruit ripening.2. Cell division would stop from 25 days after bloom. After that, the fruit grew by the growing of cell volume.3. The development of fruit spot had experienced 3 stages; it could be formed till 45 days after bloom. Stone cell development started from 15 days after bloom; when 40 days after bloom, the diameter of stone cell group would not raise again, and after that the density of stone cell group would dropped apparently.4. The changes of fruit inclusion content and firmness during fruit growth and develop -ment were as follows: (1) In the early stage of fruit development, the changes of the soluble sugar were not obvious; from June 14 to fruit ripening, soluble sugar accumulated rapidly. The main ingredient of sugar in fruit is fructose, glucose and sucrose, and the content of fructose is the highest. (2) The content of titratable acid was high at the beginning. With the development of fruit, titratable acid content decreased, and it increased lightly near fruit ripening. (3) During fruit development, the starch content was raised apparently first, with the fruit growing, most of it changed to sugar, and its content decreased evidently and quickly. (4) With the development of fruit, the content of soluble solid increased and the fruit hardness decreased. (5) The content of Vitamin C dropped in early development stage, and it increased evidently before harvest. (6) In the early stage, there is a peak of lignin content, and after the peak lignin content was reduced; and the content of phenol showed downtrend all through the fruit development.5. Respiratory climacteric came forth during fruit ripening and storage: the maximum value of ethylene production and respiratory rate appeared successively, so golden pearbelonged to climacteric fruit.6. Stored at room temperature, the golden pear would be rotted soon after 10~14 days. During this time, the weight loss ratio increased rapidly; the fruit firmness decreased speedy at storage prophase then slow down; and soluble solid content went up slightly; respiratory rate value arrived to its maximum in 2 days after harvest, then declined; ethylene production grow up when the fruit began to be rotted; LOX activity appeared two peaks, PG activity increased rapidly, then fell down a little, PME activity slow down quickly at first, then slowly.7. Golden pear could keep high quality over 100 days if stored at 5 centigrade, because the low temperature had influenced it in many aspects: (1) Made weight loss ratio lower than normal, and no fruit rot appeared; (2) Keep high fruit firmness all through the storage; (3) Respiratory climacteric came forth later than that which stored at room temperature, and the peak was lower than normal; (4) Activity of LOX and PG were inhibited, so the process of fruit senescence was delayed effectively.更多还原