| 镉胁迫下不同小麦品种对镉的积累特性 |
| 摘要点击 3068 全文点击 1080 投稿时间：2021-05-03 修订日期：2021-08-22 |
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| 中文关键词 土壤镉污染 小麦 镉胁迫 低积累 富集 转运 |
| 英文关键词 soil cadmium pollution wheat cadmium stresses low accumulation enrichment transshipment |
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| 中文摘要 |
| 通过盆栽试验筛选籽粒Cd低积累型小麦品种，为重金属污染耕地安全利用提供技术支撑.试验研究了119个小麦品种植株各部位分别在1.5 mg·kg-1（低含量）和4.0 mg·kg-1（高含量）Cd污染土壤条件下对Cd的富集和转运特性，并探讨了小麦不同器官Cd含量的相关性和土壤Cd含量与小麦吸收Cd的关系.结果表明：①供试小麦品种根、茎、叶和籽粒积累和转运Cd的能力存在显著差异（P<0.05）.在Cd低含量条件下小麦植株各部位富集Cd能力为：叶>茎≈根>籽粒，在高含量胁迫条件下小麦植株各部位富集Cd能力为：叶>根>茎>籽粒，不同含量条件下小麦植株各部位转运Cd能力均为：叶>茎>籽粒.小麦地上部Cd含量与土壤Cd全量和离子交换态Cd含量均呈极显著正相关关系（P<0.01），且与盆栽试验条件下较强的蒸腾作用密切相关.②小麦根、茎、叶和籽粒BCFCd与对应土壤Cd含量相关系数r为-0.267~-0.645，呈极显著负相关关系（P<0.01），表明随着土壤Cd含量的增高，小麦植株各器官对Cd的迁移积累程度呈下降趋势，且茎部BCFCd与土壤Cd含量的负相关性明显高于根、叶和籽粒，说明小麦植株对Cd的富集很大程度上取决于茎部的积累和运输.③低含量组和高含量组小麦根与茎、根与叶、根与籽粒、茎与叶、茎与籽粒和叶与籽粒Cd含量相关系数r为0.450~0.763，呈极显著正相关关系（P<0.01），表明小麦各器官之间存在密切的转运关系，且根向茎和茎向叶转运的程度高于茎向籽粒和叶向籽粒的转运程度.④采用聚类分析与富集和转运系数排序对照优选法，在土壤ω（Cd）1.5 mg·kg-1和4.0 mg·kg-1条件下，分别筛选出16个和11个Cd低积累小麦品种，其中洛旱7号可作为低中高含量下Cd低积累优选小麦品种. |
| 英文摘要 |
| In order to provide technical support for the safe utilization of heavy metal-polluted farmland, we screened wheat varieties with a low accumulation of Cd in grain via a pot experiment. For this purpose, we respectively investigated the enrichment and transport characteristics of Cd in various plant parts of 119 wheat varieties under the conditions of 1.5 mg·kg-1 (low content) and 4.0 mg·kg-1 (high content) Cd-contaminated soil and explored the correlation between the Cd content of different organs of wheat and the relationship between Cd content in soil and the uptake of Cd by wheat. The results showed that:① there were significant differences in the ability to accumulate and transport Cd in roots, stems, leaves, and grains of tested wheat varieties (P<0.05). Under the condition of low Cd content, the Cd enrichment ability of each part of the wheat plant was as follows:leaf>stem ≈root>grain; under high-content stress conditions, the Cd enrichment ability of each part of the wheat plant was:leaf>root>stem>grain; under different content conditions, the Cd transport ability of each part of the wheat plant was:leaf>stem>grain. Cd content in the wheat shoot was positively correlated with total Cd content and ion-exchangeable Cd content in soil (P<0.01) and was closely related to strong transpiration under the pot experiment. ② The correlation coefficient r of BCFCd of wheat roots, stems, leaves, and grain was -0.267 to -0.645, showing a very significant negative correlation (P<0.01), indicating that with the increase in soil Cd content, the migration and accumulation degree of Cd in wheat plant organs showed a downward trend. Moreover, the negative correlation between BCFCd and soil Cd content in stems was significantly higher than that in roots, leaves, and grains, indicating that the enrichment of Cd in wheat plants largely depended on the accumulation and transportation of stems. ③ The correlation coefficient r of Cd content between the root and stem, root and leaf, root and grain, stem and leaf, stem and grain, and leaf and grain in low-and high-content groups was 0.450-0.763, showing a very significant positive correlation (P<0.01), indicating that there was a close transport relationship among the wheat organs, and the degree of translocation from the root to stem and stem to leaf was higher than that from the stem to grain and leaf to grain. ④ Using cluster analysis and enrichment and translocation coefficient sequencing, this study screened 16 and 11 wheat varieties with low Cd accumulation under the soil cadmium content of 1.5 mg·kg-1and 4.0 mg·kg-1, respectively. Among them, Luohan 7 could be used as the optimal wheat variety with low Cd accumulation under the conditions of low-, medium-, and high-Cd content. |
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