硒酸盐和亚硒酸盐对7种不同基因型小麦种子萌发和幼苗生长的影响

Phytotoxicity Differences Among 7 Winter Wheat Genotypes in China when Amended Selenate and Selenite

选择全国7个主栽小麦品种,通过培养试验研究了外源添加硒酸盐以及亚硒酸盐对小麦的生物毒害作用,旨在确定小麦发芽阶段硒敏感指标并且为耐硒小麦品种的筛选提供依据。结果表明:添加低浓度外源硒(硒酸盐<8 mg·L-1,亚硒酸盐<20 mg·L-1)能够促进发芽阶段小麦的生长,高浓度硒(硒酸盐≥8 mg·L-1,亚硒酸盐≥20 mg·L-1)则表现为显著的抑制作用;同等硒浓度条件下(10mg·L-1),硒酸盐对小麦种子的毒害作用显著高于亚硒酸盐(P<0.05)。指标综合相关性模型与Bartlett球形检验结果表明,小麦的芽长抑制率可作为亚硒酸盐态硒生物毒性的敏感指标,而根长抑制率可作为硒酸盐态硒的敏感指标。不同基因型小麦对硒的耐受程度不一,以西农979、小偃22和鲁麦23的耐受性较强,适宜于富硒粮食的推广;鄂麦20、烟农19对亚硒酸盐耐受性较高,对硒酸盐耐受性较弱,可以作为土壤硒环境的指示品种;陕麦159、蒿优2018则对硒的耐受能力相对较差,可以作为富硒土壤指示的敏感品种。

The culture experiments were conducted to study the effects of exogenous selenite and selenate on seed emergence and seedling grouth of 7 main winter wheat genotypes, in order to select the most sensitive indicator and provide the basis of Se-resistant wheat genotypes selection. The result showed that low concentration of Se（selenate〈8 mg L-1, selenite〈20 mg L-1） could promote the growth of wheat; and while higher concentration could inhibit the growth. The toxic effects of selenate were significantly higher than selenite on wheat at the same concentration（ 10 mg L-1 ）. The statistic analysis showed that the inhibition of shoot height and root length could be regarded as the sensitive indicators of selenite and selenate, respectively. Different wheat genotypes varieties had different tolerance：Xinong979, Xiaoyan22, and Lumai23 had high tolerations and could be extended as Se-rich wheat; Shaanmai159, Shongyou2018 have low tolerance and could be used as the sensitive species of Se pollution in soil.