The difference of soluble sugar contents and starch synthetic key enzyme activities between high and low starch cultivar of cassava

The difference of soluble sugar contents and starch synthetic key enzyme activities between high starch cultivar and low starch cultivar were studied in this experiment, of which FuXuan01, GR891, SC124, and SC201 were used as materials. The results showed that the contents of reducing sugar in root tube of low starch cultivars were higher than those of high starch cultivars in all growth periods, the contents of sucrose in root tube of high starch cultivar were higher than those of low starch cultivars in the early growth period, but, lower in the late growth period, and there were almost no difference in the contents of soluble sugar in root tube between high starch cultivar and low starch cultivar in the early growth period, but notable difference in the late growth period and the soluble sugar contents of low starch cultivars were higher than those of high starch cultivars. It also-showed that the activities of ADPGPpase, SSS, and SBE （starch branching enzyme） of high starch cultivars were higher than those of low starch cultivars. It was evident that there were close correlations between the content of sucrose, reducing sugar and soluble sugar in root tube, and the activities of ADPGPpase, SSS, SBE, and the starch accumulation in the root tubers of cassava. It was quite evident in this experiment that the soluble sugar and starch synthetic key enzyme were main factors controlling starch accumulation in root tubers. These results provided important indication for physiological controlling in high starch cultivation and gene engineering breeding of high starch cultivar of cassava.

木薯交联羧甲基淀粉吸附铅离子的试验研究

采用搅拌球磨机对木薯淀粉机械活化,以活化60min的木薯淀粉为原料,干法合成交联羧甲基淀粉吸附剂。考察了交联羧甲基淀粉的取代度、溶液pH、Pb2+初始质量浓度、吸附时间、用量等因素对交联羧甲基淀粉吸附Pb2+的影响。结果表明:交联羧甲基淀粉对Pb2+有很好的吸附作用;用取代度为0.763的交联羧甲基淀粉吸附溶液中的Pb2+,在Pb2+初始质量浓度40mg/L、pH=7.0、交联羧甲基淀粉用量0.10g、吸附时间40min条件下,吸附容量为18.6mg/g,吸附率为93.1%。