不同棉花基因型种子萌发响应铜胁迫的差异

在铜污染耕地种植棉花对提高耕地利用效率和棉农收入具有重要意义,但铜胁迫对棉花种子萌发的影响仍不清楚。以7个陆地棉品种（系）为试验材料,设置0、10、100和2 000μmol/L 4个Cu²⁺浓度处理进行发芽试验,记录10d后棉花种子的发芽率和幼苗的鲜重、根长和芽长。以幼苗鲜重、根长和芽长为指标,采用耐性指数和隶属函数对不同品种（系）种子的耐受性进行综合评价。结果表明,在Cu²⁺浓度10~2 000μmol/L范围内随着浓度的升高,幼苗鲜重、根长和芽长所受抑制增强,且根长的受抑制程度高于芽长。在中低浓度下（10~100μmol/L）能将不同基因型种子萌发对铜胁迫的耐受性较好地区分开来,鄂抗棉10号的耐性指数和隶属函数平均值均居首位,而SGK321均居末位。研究结果初步表明,鄂抗棉10号为铜胁迫钝感基因型,而SGK321为敏感基因型。

The Difference of Seed Germination in Different Cotton Genotypes in Response to Copper Stress

It is of great significance for increasing the usage of cultivated land and the income of cotton producers to grow cotton in the copper-polluted soil, but the effect of copper stress on the germination of cotton seeds remains unclear. Seven cotton varieties (lines) were evaluated to a seed germination experiment where seeds were incubated in the solution with four different Cu²⁺ concentration (0, 10, 100 and 2 000μmol/L). The germination rate, seedling fresh weight, root length and shoot length were recorded on ten days after seed incubation. The tolerance index and subordinate function analyses were applied to assess the difference in tolerance capacity to copper toxicity among seven cotton genotypes. The results showed that seedling fresh weight, root length and shoot length decreased with the increasing of Cu²⁺ concentration over the range of 10 to 2 000μmol/L. The reduction of root length due to copper stress was greater than that of shoot length. The tolerance ability to copper stress of seed germination could be well distinguished at low-middle ion levels among these genotypes. Among the seven cotton varieties (lines), Ekangmian 10 ranked first and SGK321 at the end in the terms of tolerance index and subordinate function value. It has been concluded that Ekangmian 10 is a copper resistant genotype and SGK321 is a sensitive genotype to copper stress.