转化酶与甜瓜果实膨大及糖分积累相关研究

【目的】探明厚皮甜瓜果实及叶片转化酶与果实膨大及糖分积累的内在机理,为厚皮甜瓜品质遗传改良提供理论依据。【方法】以丰蜜二号和好运52为材料,对甜瓜果实农艺性状、可溶性糖含量、转化酶及叶片转化酶活性进行测定。【结果】两个厚皮甜瓜在授粉后16d内果实纵径长度、横径宽度及果肉厚增长迅速,还原糖含量迅速增加,果肉和叶片酸性转化酶和中性转化酶活性急剧下降,蔗糖含量低;授粉16d后,蔗糖含量迅速增加,果肉酸性转化酶和中性转化酶的活性下降,但叶片中性转化酶活性呈上升趋势。【结论】两个厚皮甜瓜在授粉后16d内,果实迅速膨大,24d后果实膨大速度缓慢,甜瓜蔗糖积累迅速,果肉转化酶活性降到较低水平;相关分析表明,两个厚皮甜瓜品种的还原糖含量与果肉中性转化酶呈显著负相关;在丰蜜二号中,蔗糖积累与叶片中性转化酶呈显著正相关。

The relationship between invertase activity and sucrose accumulation during the development of fruits in melon

Objective]The present experiment was conducted to elucidate the relationship between invertase activity in fruits and leaves,and sucrose accumulation and development in melon to provide reference for its quality improvement.Method]Some agronomic traits,soluble sugar content in fruits and the activity of invertase enzyme in leaves and fruits were determined at different growing stages of melon varieties Fengmi 2 and Haoyun 52.Result]The fruit of two melon varieties started to developed within 16 d of pollination.At this stage,an increase in reducing sugar content were observed,the activities of acid invertase and neutral invertase in fruits and leaves were decreased sharply.And the sucrose content was very low during this period,however,it increased rapidly after this.The activities of acid invertase and neutral invertase in pulp declined after 16 d of pollination,however,the activity of neutral invertase in leaves showed rising trend.Conclusion]The fruit of two melon varieties developed rapidly within the 16 d after pollination,however,its growth rate slowed down at 24 d after pollination.During this period,the sucrose accumulated rapidly and invertase activity reduced to a lower level.Results revealed a significant negative correlation between the reducing sugar content of melon fruits and activity of neutral invertase in pulp in both varieties.However,the sucrose accumulation and leaf neutral invertase showed a significant positive correlation in leaves of Fengmi 2.