土壤铬含量对水稻生长发育和产量形成的影响

Effects of soil Cr concentration on growth and development and yield formation of rice

在盆栽土培条件下,以武香粳14号为材料,设置不同土壤铬含量(300、400、600、1 000 mg·kg-1),研究长期铬协迫对水稻生长发育和产量形成的影响。结果表明:①随着土壤铬含量的增加,水稻主茎总叶数变少、植株变矮、抽穗期延迟。在土壤铬处理中,对水稻主茎总叶数、株高和抽穗期有显著影响的土壤起始浓度分别为1 000、600和 300 mg·kg-1;②土壤铬处理的水稻产量低于对照,且随着土壤铬含量的提高,产量降幅显著增大(r=-0．998 ); ③土壤铬处理后水稻减产的主要原因是每穗颖花数减少,其次是千粒重下降,而穗数和结实率无明显变化;④土壤铬处理后每穗颖花数减少主要是由于抽穗期单茎干物重下降所致,而单位干物重形成颖花的能力增加;⑤随着土壤铬含量的增加,水稻生物产量显著下降,经济系数无明显变化。生物产量下降主要与水稻生育前期物质生产能力明显降低有关。

In order to investigate the effects of soil Cr concentration on growth and development and yield formation of rice crops, pot experiment was conducted in 2003, using the japonica cultivar Wuxiangjing 14. Results showed that： ① With the increasing of soil Cr concentration, leaf numbers and plant height were reduced, heading stage was postponed. The initiative soil Cr concentration under conditions in this experiment, that had significant effects on leaf numbers, plant height and heading stage, were 1 000, 600, 300 mg · kg^-1, respectively.② With increasing of soil Cr concentration, grain yield decreased significantly （r=-0. 998^＊＊）. ③ The main reason for the decrease of the yield under Cr treatments was the decrease of spikelet number per panicle and 1 000-grain weight, while no significant changes of panicle number and fulfilled grain percentage were detected. ④ The decrease of spikelet number per panicle due to higher soil Cr concentration was chiefly caused by the decrease of dry matter （DM） weight per stem at heading stage, while the ratio of survived spikelets to DM at heading stage under soil Cr stress was increased. ⑤ Total biomass decreased significantly with increasing of soil Cr concentration, while economic coefficient showed no significant change. The decrease of total biomass due to higher soil Cr concentration was mainly related to the decrease of DM production at early growth stages of rice.