Pb胁迫对小麦种子萌发及幼苗生长的影响

Effects of Pb Stress on Seed Germination and Seedlings Growth of Wheat

以小麦品种德抗961为试验材料,设Pb胁迫浓度5、50、200、300、400、500和600 mg/L共7个处理,以清水处理为对照(CK),研究了Pb不同胁迫浓度对小麦种子萌发及幼苗生长的影响。结果表明:Pb胁迫浓度5和50 mg/L处理的小麦种子发芽率、活力指数以及小麦幼苗的芽长和根长均>CK,Pb胁迫浓度≥200 mg/L时会抑制小麦种子萌发以及小麦幼苗芽和根的生长,其中Pb胁迫对小麦幼苗根的抑制作用大于对芽的抑制;Pb胁迫浓度≤400 mg/L处理的小麦种子发芽势和发芽指数均>CK,从而提高小麦种子萌发的整齐度;Pb胁迫浓度5 mg/L处理的小麦幼苗鲜重和干重均>CK,Pb胁迫浓度≥50 mg/L时会抑制小麦幼苗对养分的吸收和干物质的积累;Pb胁迫处理的小麦胚芽鞘长度均≤CK。随着Pb胁迫浓度的增大,Pb对小麦种子发芽、幼苗生长的胚芽鞘的抑制作用增强。

The effects of different concentrations of lead stress on seed germination and seedlings growth of wheat were studied using wheat variety Dekang 961 as test material, it conducted 7 Pb concentrations （ 5, 50, 200, 300, 400, 500 and 600 mg/L ） , and with water as a control. The results showed that seed germination rate and vigor index, seedlings germinal length and root length of wheat under Pb concentration of 5 and 50 mg/L were all higher than that of CK. When Pb stress concentration was more than or equal to 200 rag/L, it could inhibit the seed germination and seedling bud and root growth, of which the inhibitory effect of Pb on root of wheat seedlings was greater than that on bud. Wheat seedling germination potential and germination index were more than that of CK if the concentration of Pb was less than or equal to 400 rag/L, thereby the uniformity of seed germination was increased. The fresh weight and dry weight of seedlings of wheat under the concentration of 5 mg/L were all higher than that of CK, and the nutrient uptake and dry matter accumulation in wheat seedling were inhibited when the concentration of Pb was greater than or equal to 50 mg/L. The coleoptile length of wheat treated with Pb were less than or equal to CK. With the increase of Pb stress concentration, the inhibition effect of Pb on seed germination and seedling growth of wheat was enhanced.