不同淀粉型木薯品种采后块根变质生理特性的比较

Comparison on the physiological characteristics of tuberous roots of cassava varieties with different starch content during post-harvest deterioration

为探明不同淀粉型木薯品种采后块根变质的生理特性,以淀粉含量较高的木薯品种‘辐选01’(RS01)和淀粉含量较低的木薯品种‘华南124’(SC124)为试材,测定采后贮藏0、5、10、15和20d的块根生理指标。结果表明:随着贮藏时间的延长,块根褐化程度逐渐加深,干物质含量和CAT酶活性变化趋势为先下降后上升,淀粉含量为先上升后下降,MDA含量和SOD酶活性为先上升后下降再上升,POD酶活性则表现为持续上升趋势。RS01贮藏过程中块根褐化程度较严重,贮藏第5天褐化面积达30%,而SC124贮藏第20天才开始出现褐化。淀粉含量较高的木薯品种块根干物质含量较高且变化大,失水速率较快,MDA含量较高,SOD、POD和CAT酶活性均较高。可见,块根采后抗变质能力与淀粉含量有密切关系,淀粉含量越高的木薯品种采后块根越容易发生变质。

The aim of this study was to investigate the physiological characteristics of post-harvest deterioration in cassava tuberous roots with different starch content.The physiological indexes of tuberous roots of different cassava varieties with higher starch content (RS01) and lower starch content (SC124) were measured at 0,5,10,15 and 20 days post harvest.The results showed that:With the storage duration,the browning degree of tuberous roots was gradually deepened,dry matter content and CAT enzymatic activities were firstly decreased and then increased,starch content was firstly increased and then decreased.Meanwhile,MDA content and SOD enzymatic activities were firstly increased and then decreased,lastly increased,and the POD enzymatic activities was continue increased.RS01's browning degree was more serious,it reached 30% in 5 d post harvest,and browning was discovered on SC124 20d postharvest.In the roots of cassava varieties with higher starch,its dry matter content was richer and more changeable,water was lost faster,MDA content was richer.The SOD,POD and CAT enzymatic activities all were stronger during the storage process.In conclusion,there were significantly correlation of storability with starch content that the storability of cassava varieties with low starch is stronger than those with high starch.