钙多肽对水稻吸收重金属铅的影响

Effects of calcium polypeptides on adsorption of the heavy metal lead in rice

为了探究钙多肽对水稻吸收重金属铅的影响,以总铅含量分别为100、200、500 mg·kg^(-1)的土壤为研究对象,利用钙多肽为水稻种植肥料,常规复混肥为对照,研究钙多肽对土壤中有效态铅含量、pH以及水稻生长的影响效应,同时研究钙多肽对水稻不同生长时期、不同部位铅含量和钙含量的影响。结果表明:钙多肽可降低土壤中有效态铅含量,提高土壤pH。水稻种植实验中,钙多肽促进水稻生长,使株高提高6.8%~28.9%,千粒重提高6.5%~16.9%;钙多肽提高水稻根部的铅含量,降低水稻茎、叶和糙米中的铅含量,根部铅含量提高10.8%~120.6%,茎部铅含量降低2.2%~28.4%,叶部铅含量降低0.5%~28.6%,糙米铅含量降低13.3%~25.5%;同时钙多肽提高了水稻不同部位的钙含量,使根部钙含量提高1.7%~32.6%,茎部钙含量提高1.6%~17.5%,叶部钙含量提高1.1%~13.4%,糙米钙含量提高12.4%~21.5%。水稻茎、叶和糙米钙含量的增加与其铅含量的减少具有一定的相关性,其钙含量的增加抑制了其对铅的富集。研究还表明钙多肽的作用随时间的延长逐渐下降。

The study compared the effects of calcium polypeptides and conventional compound fertilizer on rice grown in soil containing different concentrations of lead(100,200 mg·kg^(-1),and 500 mg·kg^(-1)).These effects included those associated with the available lead content,pH of soil,and growth of rice.In addition,calcium and lead levels were monitored in selected rice tissues during the different stages of growth.The results revealed that compared with the conventional compound fertilizer,the utilization of calcium polypeptides could reduce the available lead content and increase the pH value of lead-contaminated soil.Moreover,applying calcium polypeptides resulted in the enhancements of plant height(6.8%~28.9%)and 1000-grain weight(6.5%~16.9%).Furthermore,the application of calcium polypeptides contributed to an increase in the lead content of rice roots(10.8%~120.6%),but reductions in the stems(2.2%~28.4%),leaves(0.5%~28.6%),and brown rice(13.3%~25.5%).We also detected increases in the calcium contents of different rice tissues,namely,1.7%~32.6%in roots,1.6%~17.5%in stems,1.1%~13.4%in leaves,and 12.4%~21.5%in brown rice.These results indicate that there is a negative correlation between the contents of calcium and lead in the stems,leaves,and brown rice of rice.However,it was found that the positive effects of calcium polypeptides decreased gradually over time.