Abstract:

In this study, we selected paddy fields contaminated with arsenic (As), cadmium (Cd), lead (Pb), and chromium (Cr) in Luxi County, Yunnan Province, as the experimental site. Twenty-six japonica rice varieties provided by the Food Crops Research Institute of the Yunnan Academy of Agricultural Sciences were used as test materials. At the mature stage of rice, the heavy metal contents in the soil, as well as in the stems-leaves and brown rice, were determined. The bioconcentration factors (BCFs) and translocation factors (TFs) were subsequently calculated. Principal component analysis (PCA) was employed to reduce the dimensionality of multiple evaluation indicators. Combined with the membership function method, a comprehensive evaluation value (D-value) was constructed to systematically assess the accumulation and translocation capacities of different japonica varieties regarding the four heavy metals. varieties with low comprehensive heavy metal accumulation were preliminarily screened, and a stepwise regression model was established to simplify the evaluation indicators. The results indicated that varieties differences significantly affected heavy metal contents in various plant parts, with a greater impact observed in stems-leaves than in brown rice. Furthermore, varieties variations influenced the translocation capacity of different heavy metals, exerting the greatest effect on Pb translocation and the minimal effect on Cd translocation. Correlation analysis revealed that the accumulation processes of the four heavy metals in the tested japonica plants were relatively independent; notably, heavy metal content in brown rice primarily depended on the translocation capacity from stems-leaves to brown rice. Based on the comprehensive evaluation results and yield performance, Jinyou 331 was recommended as the suitable japonica rice cultivar for planting in the multi-metal contaminated soils of Luxi County.

Key words: japonica rice varieties, heavy metals accumulation, principal component analysis, membership function method

摘要：

本研究以云南省泸西县砷（As）、镉（Cd）、铅（Pb）、铬（Cr）复合污染稻田为试验区域，以云南省农业科学院粮食作物研究所提供的26个粳稻品种为供试材料，在水稻成熟期测定土壤及水稻茎叶、糙米中的重金属含量，并计算富集系数（BCF）与转运系数（TF）。采用主成分分析对多项评价指标进行降维处理，结合隶属函数法构建综合评价值（D值），系统综合评价不同粳稻品种对4种重金属的积累与转运能力，初步筛选出重金属综合低积累粳稻品种，并建立逐步回归模型以简化评价指标。结果表明，粳稻品种差异显著影响植株各部位重金属含量，且对茎叶的影响大于糙米；同时，品种差异也影响不同重金属的转运能力，其中对Pb转运能力的影响最大，对Cd转运能力的影响最小。相关性分析显示，供试粳稻植株对4种重金属元素的积累过程相对独立，糙米中重金属含量主要取决于茎叶中重金属元素向糙米的转移能力。基于综合评价结果，结合产量指标，本研究推荐锦优331为适宜在泸西县复合污染土壤中种植的粳稻品种。

关键词: 粳稻品种, 重金属富集, 主成分分析, 隶属函数法