地质高背景区镉污染稻田中低累积水稻品种筛选

Screening of low-bioaccumulation rice varieties in cadmium contaminated paddy fields with high geological background

  • 摘要: 【目的】探究地质高背景区镉(Cd)污染稻田水稻对Cd的富集转运特征,筛选适用于稻田安全生产的Cd低累积水稻品种,为该地区的水稻安全生产提供参考。【方法】以贵州开阳县10个主栽水稻品种为材料,采用田间小区试验的方法,测定土壤、水稻不同组织部位Cd含量,对比不同水稻品种对Cd的富集和转运特征,并结合水稻产量和聚类分析,筛选Cd低累积水稻品种。【结果】参试水稻品种的稻田土壤pH为5.88~6.37、全Cd含量为0.89~1.30 mg/kg、有效态Cd含量为0.40~0.58 mg/kg,不同品种间土壤pH及Cd含量无显著差异(P>0.05,下同)。水稻不同组织部位间的Cd含量以茎部和根部积累较高。相对于根际土,Cd在水稻茎、根中呈明显的富集特征,富集系数均超过1.00,但多数品种谷壳、糙米对Cd的富集系数小于1.00。Cd转运系数以糙米/谷壳、茎/根转运系数较高,其中,水稻体内Cd从根向茎、谷壳向糙米的转运能力相对较强,接近或超过1.00。在水稻品种间产量无显著差异的前提下,结合聚类分析可将10个水稻品种划分为三类:第Ⅰ类(较低值类)包括成优1479和天优1177;第Ⅱ类(中间值类)包括C两U华占、黑糯80、川华优320、红优2号、C两优华占和泸香优110;第Ⅲ类(较高值类)包括金优2017和宜香优2115。【结论】10个参试水稻品种中,本地主栽水稻品种各部位相对易于富集Cd,其中,金优2017和宜香优2115糙米Cd含量严重超标,不建议在Cd污染稻田中种植;成优1479和天优1177的糙米Cd含量较低,可作为Cd低累积水稻品种推广种植。

     

    Abstract: 【Objective】A plot study was performed to explore the bioaccumulation and transport of cadmium(Cd) in the paddy fields of a high geological-background area, and to screen low-bioaccumulation rice varieties, providing reference for safe rice production in the area.【Method】Ten rice varieties that spread throughout central Kaiyang of Guizhou were tested by plot experiment. The Cd content of different soil and rice tissues was determined, and the enrichment and transport characteristics of Cd were compared with different rice varieties, and combined with rice yield and cluster analysis to select Cd low accumulation rice varieties.【Result】The soil pH of the tested rice varieties was 5.88 to 6.37, full Cd content was 0.89 to 1.30 mg/kg, and effective Cd content was 0.40-0.58 mg/kg. There was no significant difference in soil pH and Cd content between different varieties(P>0.05, the same below). Cd content in different tissues of rice was high in stem and root. Compared with rhizosphere soil, Cd was obviously enriched in rice stems and roots, and the enrichment coefficient was more than 1.00, but the enrichment coefficient of most varieties of husk and brown rice was less than 1.00. The Cd transport coefficient was high in brown rice/chaff and stem/root transport coefficient, and the capacity of Cd transport from root to stem and chaff to brown rice was relatively strong, close to or over 1.00. On the premise of no significant difference in yield among rice varieties, combined with cluster analysis, 10 rice varieties could be divided into three categories:category Ⅰ(lower value category) including Chengyou 1479 and Tianyou 1177;category II(intermediate value category) including C Liang U Huazhan, Heinuo 80, Chuanhuayou 320, Hongyou 2, C Liang U Huazhan and Luxianyou 110;category Ⅲ(higher value category) including Jinyou 2017 and Yixiangyou 2115.【Conclusion】Among the 10 tested rice varieties, all parts of local main rice varieties are relatively easy to enrich Cd. Among them, the Cd content of Jinyou 2017 and Yixiangyou 2115 brown rice seriously exceeds the standard, so it is not recommended to plant in Cd polluted rice fields. The brown rice of Chengyou 1479 and Tianyou 1177 has low Cd content, which can be populari-zed as rice varieties with low Cd accumulation.

     

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