铅镉复合污染对水稻生长及产量的影响

[目的]探讨铅镉复合污染对水稻生长、产量及品质的伤害及机理.采用盆栽试验,研究了不同程度的铅镉复合污染对水稻生长发育及产量品质的影响.[结果]铅镉低浓度胁迫能够促进水稻生长,高浓度抑制水稻的株高;铅镉胁迫显著降低了水稻的分蘖数,随着胁迫浓度增加,分蘖数下降幅度增大;铅镉胁迫显著降低了水稻每盆穗数、结实率、千粒重和产量,低浓度胁迫下每穗总粒数显著增加,高浓度胁迫下每穗总粒数显著降低;铅镉低浓度胁迫下糙米绿和精米率显著增加,高浓度胁迫下糙米率和精米率显著降低,整精米率随处理浓度的增加而显著下降;水稻籽粒中铅镉含量与土壤中铅镉浓度成显著正相关,土壤铅镉含量达到中高浓度时,水稻籽粒铅镉含量严重超标,铅镉最高超标达333%和122%.[结论]该研究为污染地区水稻栽培技术体系的建立提供依据. Abstract： [Objective] The aim was to study the damage and the mechanism of combined pollution of Pb and Cd on rice growth,yield and quality of rice.[Method]Effects of combined pollution of Pb and Cd on the growth and yield of rice were studied by pot experiment with cultivating rice. [Result] Pb and Cd could promote dce growth at low concentration while inhibit plant height at high concentration;Pb and Cd stress reduced the number of rice tillers significantly,with the increasing of stress concentration,the decrease amplitude of the number of tillers was greater;the panicle per pot,seed setting rate,1000-grain weight and yield of rice were reduced significantly by Pb and Cd stress,the grain number per panicle decreased significantly under low concentration of Pb and Cd but increased significantly under high concentration;the brown rice rate and milled rice rate increased significantly under low concentration of Pb and Cd while at high concentration of Pb and Cd,the both two reduced significantly,the head milled rice rate reduced significantly with the decreasing of concentration;The Pb and Cd content of grains were significantly positively related to the concentrations of Pb and Cd content in soil,it had excessively exceeded hygienic standard when the concentrations of Pb and Cd in soil were medium-high and the unqualified rate reached 333% and 122%.[Condusion]The study had provided basis for the establishment of rice cultivation system in pollution areas.