杂交水稻不同器官重金属铅浓度与累积量

以生长于盆钵中的两系杂交稻和三系杂交稻共6个组合为试验材料,设置土壤铅(Pb)浓度为500mg/kg和不加Pb土壤(对照)两个处理,测定水稻植株不同器官Pb的浓度和累积量。结果表明,Pb处理降低了两优培九、103S/郑粳2号、丰优香占和汕优63的产量,主要是每穗粒数减少,对其余组合的产量无显著影响;不同基因型水稻植株对Pb吸收与积累存在差异,以103S/郑粳2号和两优培九累积量最多,K优818累积量最少;水稻植株不同器官Pb的浓度和累积量的大小顺序为根>茎鞘>叶片。籽粒不同部位Pb的浓度大小顺序为糠层>颖壳>精米,精米中Pb累积量仅为谷粒的25%左右,精米中Pb的浓度以103S/郑粳2号最高,K优818最低;在抽穗期和成熟期,同一器官Pb浓度与累积量呈显著或极显著正相关,但不同器官之间的相关不显著。对不同杂交稻组合植株中Pb浓度和累积量差异的原因进行了讨论。

Concentration and Accumulation of Lead in Different Organs of Hybrid Rice

The concentration and accumulation of Pb in different rice plant organs were measured in a pot culture experiment at soil lead concentrations of 0 mg/kg(CK) and 500 mg/kg with six hybrid rice as materials. The results showed that Pb addition significantly reduced the grain yield of Liangyoupeijiu, 103S/Zhengjing 2, Fengyouxiangzhan and Shanyou 63 due to the reduction of spikelet number per panicle. There was no significant effect on grain yield for other hybrid rice combinations. Significant differences in uptake and accumulation of Pb were observed among the six combinations, with 103S/Zhengjing 2 and Liangyoupeijiu having the highest and K you 818 the lowest Pb accumulation in plants. Concentration or accumulation of Pb in various plant organs followed the order of root> culm and sheath> leaf, and Pb concentration in grains followed the order of bran> hull>milled rice. Pb in milled rice accounted for 25% of the total amount of Pb accumulated in grains. The concentration and accumulation of Pb in the same organ at heading and maturity stages were positively and significantly correlated, but the correlation was not significant between different organs. Among the six hybrids, Yangliangyou 6 contained the highest, and K you 818 the lowest Pb concentration in milled rice. The reasons for variations of Pb concentration and accumulation in plants among the hybrids were also discussed.