不同种类重金属胁迫对两种小麦产量及构成因素的影响

以当前农业研究的热点领域——重金属污染为切入点，研究了大田Cd、Pb、As、Hg、Cr5种重金属胁迫对小麦（郑麦9023、小偃22）籽粒产量及构成因素的影响。结果表明重金属胁迫下，cd、Pb、As、№、cr重金属对产量三要素中单位面积群体穗数的影响最大，其次为穗粒数，对千粒重的影响最小；单位面积群体穗数对重金属Cr、Pb最为敏感，在旱田偏碱性的土壤上，Cr、Pb胁迫对小麦单位面积的群体穗数影响的临界含量分别约为187．5mg·kg^-1和175mg·kg^-1。对两个小麦品种的籽粒产量影响不同，郑麦9023籽粒产量依次为Cr2〈Crl〈CK〈Cd2〈Hgl〈As2〈Asl〈Hg2〈Pbl〈Cdl〈Pb2；小偃22籽粒产量依次为Cr2〈Crl〈CK〈Hgl〈As2〈Hg2〈Cdl〈Cd2〈Pb2〈Asl〈Pb1。重金属Cr对小麦的产量表现为抑制效应，Cd、Hg、Pb、As对小麦产量的影响表现为增产效应；不同种类重金属胁迫对小麦产量影响作用依次为Hg〈Cd〈As〈Pb〈Cr。

Effects of Varieties Heavy Metals Stress on Wheat Grain Yields of Two Genotypes and the Main Ingredients

In this article, effects of 5 heavy metals（Cd, Pb, As, Hg, Cr） stress on wheat（Zhengmai9023, Xiaoyan22 ） yields and ingredient in farmlands were analyzed. The results showed that 5 heavy metals greatly influenced on spikes per hectare, then followed kernels per spikes and weight of 1 000 kernels; and spikes per hectare was sensitive to Cr and Pb, which the critical values of Cr and Pb to spikes per hectare were 187.5 mg. kg^-1, 1.75 mg·kg-1, respectively, in glebe and alkaline soils. Furthermore, the grain yields of two wheat genotypes were also af- fected by Cd, Pb, As, Hg, and Cr compared with CK treatment; and the grain yield order of Zhengmai9023, Xiaoyan22 under 5 heavy metals stress were Cr2〈Crl 〈CK〈Cd2〈Hgl 〈As2〈As 1 〈Hg2〈Pb 1 〈Cd 1 〈Pb2 and Cr2〈Crl 〈CK〈Hgl 〈As2〈Hg2〈Cdl 〈Cd2〈Pb2〈As 1 〈Pb 1, respec- tively. In addition, the results also indicated that the increasing trends of wheat under Cd, Pb, As, and Hg stress, and the decreasing trends of wheat under Cr stress. Finally, the order of 5 heavy metals effects on wheat is Hg〈Cd〈As〈Pb〈Cr.