低温胁迫下戊唑醇和苯醚甲环唑种子包衣对玉米种子出苗和幼苗的影响

为研究低温胁迫下种子包衣对玉米种子出苗和幼苗生长的影响,以适宜温度(25℃/20℃,白天/晚上,下同)处理为对照,对不同剂量包衣的玉米种子进行低温胁迫。研究结果表明,戊唑醇和苯醚甲环唑种子包衣在适宜温度下对玉米种子出苗具有促进作用,能提高玉米幼苗植株的叶绿素含量,对玉米幼苗的株高和鲜重没有抑制作用。但在17℃/6℃、15℃/0℃、10℃/0℃低温胁迫下,戊唑醇和苯醚甲环唑均能抑制种子出苗和幼苗生长,加剧低温胁迫导致的膜脂质过氧化作用和对叶绿体的分解。但用苯醚甲环唑处理玉米种子比用戊唑醇更安全,前者能抑制低温胁迫导致的叶片细胞内电解质外渗,后者却会加剧电解质的外渗。比较玉米幼苗根系的呼吸作用也可以发现,苯醚甲环唑比戊唑醇更有利于玉米幼苗补偿和修复低温胁迫所致的伤害。

Effects of Seed-coating Tebuconazole and Difenoconazole on Emergence ofMaize Seeds and Response of Seedlings at Chilling Stress

In order to study the effects of seed treatment on the emergence of maize seeds and the growth of maize seedlings at chilling stress,active ingredient coated maize seeds at different dosage were chilling stressed,using optimum temperature (25℃/20℃,day/night) as control.At 25℃/20℃,the seed treatment of tebuconazole and difenoconazole could improve the emergence of maize seeds,increase the contents of chlorophyll in the seedlings.and have no negative effect on seedling height and fresh weight.But at chilling temperature 17℃/6℃,15℃/0℃,10℃/0℃,the seed treatment of tebuconazole and difenoconazole could inhibit the emergence of maize seeds and the development of seedlings.Deterioration of peroxidation to membrain lipids and degradation of chloroplasts induced by chilling stress were observed in seedlings that seed-coated by tebuconazole and difenoconazole.The results showed that treatment of difenoconazole was relatively safer than tebuconazole to maize seeds because difenoconazole could inhibit the leakage of electrolytes from leaves,but tebuconazole worsened the leakage of electrolytes.Moreover,difenoconazole could enhance the respiration of roots which benefit the recovery of chilling stressed seedlings,but tebuconazole inhibited the respiration instead.