红色砂梨2个品种着色过程中的外观变化及其解剖学结构观察

A study of the visual changes of the skin color and fruit transection structure of two Chinese red skinned pear cultivars during fruit coloring process

以红色砂梨(Pyrus pyrifolia Nakai)品种美人酥和云红梨1号为试材,以套袋处理(果袋类型、去袋方式和去袋时间组合成10个不同的套袋处理)为手段研究了果实着色过程中外观和解剖结构的变化。结果表明,红色砂梨的着色需要有高强度的光照。生长过程中套有不透光袋的果实临近成熟时,只有完全曝光才能大量合成花青苷,而且在很短的时间内(大约2周)果实着色面积、着色程度即可优于对照(不套袋处理)。红色砂梨着色是从果实向阳的一侧先开始,且以果点为中心呈放射状向四周扩展,至采收时果实阳面红色能够均匀分布,但整个果面色泽很难一致。解剖结构分析表明果面呈红色是因为果皮中紧邻表皮层的3～4层细胞存在红色细胞(含有花青苷),在果实着色过程中这些红色细胞数目不断增多,同时细胞内色素浓度不断增大。云红梨1号合成花青苷的能力明显优于美人酥,果实着色更鲜艳。解剖学观察发现云红梨1号的表皮细胞层也含有红色细胞。

Two red skinned Chinese sand pear cuhivars （Pyrus pyrifolia Nakai ev. Meirensu and Yunhongli No. 1） were used as material for studying the effects of bagging on the visual changes of skin eolor and fruit trans-seetion structure during eoloring proeess. The effects of 10 fruit bagging treatments, combining with the bag types, bag removal patterns and hag removal dates on the changes of the skin color were studied. Results showed that the synthesis of anthocyanin in these 2 red skinned Chinese pears was a highly-light-dependent proeess and the fruit bagged with light-impermeable bags could accumulate the largest amount of anthocyanin only when the bag was removed totally before harvest and the fruit appearance could be more attractive than that of the control during about 2 weeks after bag removal. Fruit began eoloring around fruit dots of exposed side and then red color was radially scattered. Although the color became even-distributed on the exposed side, the whole fruit surface was diffieuh to be even-distributed when the fruit was harvested. Anatomical strueture observation showed that the pattern of anthoeyanin distribution in red skinned Chinese pear euhivars involved 3 to 4 layers of subpidermal cells containing anthoeyanin. Both numbers of red cells and cell pigment concentrations increased with coloring proeess. Yunhongli No.1 eultivar showed greater potential in anthocyanin formation than that in Meirensu and red cells even existed in the epidermal layer of Yunhongli No. 1.