抗裂与易裂果西瓜果皮解剖结构及酶活性比较

Comparison of Anatomic Structure and Enzyme Activity of Fruit Rinds in Crack-resistant and Crack-prone Watermelons

以小果型厚皮纯合家系抗裂果‘K2’和小果型薄皮纯合家系‘L1’为试材,比较果实果皮解剖结构与酶活性。于授粉后的21、24、27、30d取样,通过石蜡切片观察果皮结构变化。结果表明:抗裂果果皮中石细胞的大小和形状比易裂果的更小更圆;在抗裂果中观察到一个明显的从小细胞到大细胞转变过程,抗裂果果皮结构的变异程度明显高于易裂果;在小型西瓜成熟的过程中,果实的抗裂性与果皮细胞结构的变化和排列有关;检测授粉后30d果皮酶的活性,表明薄皮易裂果家系中果皮果胶酶、纤维素酶和过氧化物酶的活性要高于厚皮抗裂果果皮;裂果率与果皮果胶酶活性呈显著正相关,果皮厚度和果皮果胶酶活性呈显著负相关;果皮过氧化物酶活性和超氧化物歧化酶活性呈显著负相关。

Taking crack-resistant‘K2＇and crack-susceptible‘L1＇as tested materials,fruit pericarp anatomic structure and enzyme activity in fruit cracking-resistant and cracking-prone mini-watermelons were compared.The fruit pericarps were sampled after self-pollination for 21,24,27,30 days and were observed by paraffin section.The results showed that the stone-cells in the crack-resistant accession were smaller and rounder than those in the crack-susceptible accession.An obvious transition from the small cells to the big cells was observed in the crack-resistant.Variation in the degree of pericarp structure of the crack-resistant was more obvious than of the crack-susceptible late in fruit development.Fruitcracking resistance was associated with the variation and arrangement of pericarp structure in the process of miniwatermelon maturity.At the same time,the fruit pericarps that were sampled after self-pollination after 30 days were observed for enzyme activity.Pectinase activity,cellulose-enzyme activity and activity of peroxidase（POD）in the thin pericarp,crack-susceptible line were higher than those in the thick pericarp crack-resistant line.Cracking tendency and pectinase activity in the pericarp were significantly positively correlated.Pericarp thickness and pectinase activity in the pericarp were significantly negatively correlated.In the pericarp,POD activity and SOD activity were significantly negatively correlated.