Cadmium (Cd) is a hazardous soil contaminant and causes environmental toxicity when present beyond the allowable limit in soil. It can alter growth and metabolism in both plants and animals even at very low concentration. Being sessile in nature, plants try to evade this harmful effect by adopting various defence mechanisms including activation of antioxidants and other metal homeostasis mechanisms. This study shows the varietal Cd stress tolerance capacity of rice cultivars commonly grown in West Bengal, which is a rice biodiversity region in India. Seven days old rice (Oryza sativa L.) seedlings were treated with 10 μM CdCl2 for another 7days and different physiological and biochemical stress parameters were studied to compare the varietal stress responses. Principle component analysis (PCA) and root tolerance index (RTI) revealed that rice cultivars I.E.T-4786, Jamini and Netiya, Maharaj showed divergent stress responses towards susceptibility and tolerance. Histochemical localization of hydrogen peroxide (H2O2), superoxide (O2˙-) and pot experiment were performed in these four cultivars (I.E.T-4786-Jamini and Netiya-Maharaj) to elucidate the different Cd stress tolerance. Histochemical analysis, agronomic traits and grain Cd content analyses showed that I.E.T-4786 and Jamini were susceptible with no Cd accumulation in grain, whereas cultivars Netiya and Maharaj were stress tolerant and Cd accumulators. In addition, health risk assessment was monitored for dietary intake of Cd through Cd accumulating rice and non Cd accumulating rice genotypes were identified. Thus, the study identified the Cd tolerant and sensitive cultivars grown locally.

中文翻译：

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印度西孟加拉邦当地20种水稻品种/地方品种对镉胁迫的基因型变异。

镉（Cd）是一种有害的土壤污染物，当其含量超出土壤允许的范围时，会导致环境毒性。即使浓度很低，它也可以改变动植物的生长和代谢。植物本质上是固着的，试图通过采取各种防御机制来规避这种有害作用，这些机制包括抗氧化剂的激活和其他金属稳态机制。这项研究表明，在印度稻米生物多样性地区西孟加拉邦普遍种植的水稻品种对镉的胁迫耐受能力。将7天大的水稻（Oryza sativa L.）幼苗再用10μMCdCl2处理7天，并研究了不同的生理和生化胁迫参数，以比较品种的胁迫响应。主成分分析（PCA）和根系耐性指数（RTI）显示，Jamini和Maharaj的Netiya水稻品种IET-4786对敏感性和耐性表现出不同的胁迫反应。在这四个品种（IET-4786-Jamini和Netiya-Maharaj）中进行了过氧化氢（H2O2），超氧化物（O2 +-）的组织化学定位和盆栽实验，以阐明不同的镉胁迫耐受性。组织化学分析，农艺性状和籽粒Cd含量分析表明，IET-4786和Jamini对籽粒中Cd的积累不敏感，而Netiya和Maharaj品种耐胁迫，且Cd的积累。此外，通过镉累积大米对镉的饮食摄入进行了健康风险评估，并确定了非镉累积大米的基因型。从而，