不同栽培条件对水稻籽粒镉含量及主要性状的影响研究

为筛选高效低成本降镉栽培措施,以2份水稻低镉准品种(V1、V2)为试验材料,设空白(A0)、淹水(A1)、喷施锌肥+淹水(A2)、施生石灰+淹水(A3)、喷施锌肥+施生石灰+淹水(A4)5个栽培处理,分析各处理对材料农艺性状和精米镉含量的影响。结果表明,除V2材料晚稻A1和A2处理出现镉超标情况外,其他降镉处理镉含量均合格。V1材料晚稻A3处理对精米率、有效穗数和产量呈负向影响,V2材料晚稻A3处理对长宽比和蛋白质含量呈负向影响,A4处理对垩白粒率、垩白度呈负向影响,其他处理负向效果不显著。综合来看,V1、V2早稻和V1晚稻选用A1处理,V2晚稻选用A3处理,成本相对较低,精米镉含量不超标,对产量、米质影响较小,综合效果最优。V1、V2可在审定后搭配降镉栽培技术在广西中度镉污染稻田推广应用。

镉低积累水稻品种筛选及其在镉超标稻田的表现评价

【目的】筛选镉低积累型水稻品种并开展镉超标稻田表现评价研究,为广西中低度镉污染稻田生产安全稻米提供品种和数据参考。【方法】以114份(V1~V114)水稻低镉品种育种材料为试验对象,从中筛选综合性状优良且籽粒表现为镉低积累的目标材料;对目标材料进行大田试验和盆栽试验验证,测定其在广西不同试验点的农艺性状和精米镉含量。【结果】初步筛选试验的114份参试材料中,除V102的精米镉含量低于最低检测值外,其余113份水稻育种材料的精米镉含量范围在0.01~0.35 mg/kg,平均值为0.10 mg/kg,筛选得到综合性状优良且精米镉含量较低的材料V111(审定后名称为桂育12)。桂育12在中低度镉污染区大田验证种植时,精米镉含量(0.01~0.10 mg/kg)未超出国家标准GB 2762—2017《食品安全国家标准食品中污染物限量》规定的限值(0.20 mg/kg)。盆栽试验结果表明,在pH为5.0,土壤镉含量3.0 mg/kg条件下,桂育12精米镉含量(0.34 mg/kg)有超标风险;各试验中土壤镉含量对桂育12部分农艺性状指标影响显著(P<0.05),但属于品种种植的正常波动范围,对米质和产量的综合影响有限。【结论】从114份水稻材料中筛选出的镉低积累品种桂育12,经多年多点试验验证,在中低度镉污染稻田产出的稻米镉含量不超标,籽粒镉低积累性状较稳定,综合性状表现受土壤镉含量影响较小,可在广西中低度镉污染稻田推广应用。

Effects of Combined Pollution of Pb and Cd on Growth and Yield of Rice

[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 rice 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,1 000-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%. [Conclusion]The study had provided basis for the establishment of rice cultivation system in pollution areas.