小麦萌发期对镉胁迫的响应及腐胺的缓解效应

Response to cadmium stress and alleviating effect of putrescine in wheat germination

本文旨在探讨腐胺对镉胁迫下小麦萌发及幼苗生长的影响。以9个小麦品种(系)为试验材料,使用不同浓度(0、40、80、120、160、200 mg·L^(-1))镉进行萌发试验,根据种子萌发指标和幼苗生长指标筛选镉胁迫浓度并鉴定镉高敏感型和高耐受型品种(系)。筛选所得材料分别于6个腐胺处理(0、0.05、0.1、0.2、0.4、0.8 mmol·L^(-1))下浸种,以筛选的镉浓度进行萌发试验,研究不同浓度腐胺对镉胁迫下小麦种子萌发及幼苗生长的影响。结果表明,80 mg·L^(-1)镉处理为小麦耐镉性筛选的鉴定浓度,运麦399为镉高敏感型品系,98-6188为镉高耐受型品系。80 mg·L^(-1)镉胁迫下,适宜浓度的腐胺可缓解镉胁迫对小麦种子萌发和幼苗生长的抑制效应,但品系间存在差异。多指标综合评价分析发现,镉胁迫下,0.1~0.2 mmol·L^(-1)(T2~T3)腐胺对两个品系小麦的种子萌发和幼苗生长均有明显的促进作用;0.4~0.8 mmol·L^(-1)(T4~T5)腐胺对镉高耐受型品系有促生作用,而对镉高敏感型品系存在抑制作用。综上,镉胁迫下,0.1~0.2 mmol·L^(-1)腐胺可以有效缓解镉对小麦萌发和幼苗生长的抑制作用,提高了小麦的抗镉性。本研究为腐胺在大田生产中的应用提供了一定的理论参考。

This study aims to investigate the effects of putrescines on wheat germination and seedling growth under cadmium stress.Nine wheat varieties(lines)were used as experimental materials,and ger-mination experiments with different cadmium concentrations(0,40,80,120,160 and 200 mg·L^(-1))were carried out to screen suitable cadmium stress concentration and identify cadmium highly sensitive or tol-erant varieties(lines)according to seed germination indexes and seedling growth indexes.Then,the se-lected lines were used as materials to study the effects of different concentrations(0,0.05,0.1,0.2,0.4 and 0.8 mmol·L^(-1))of putrescine on seed germination and seedling growth of wheat under cadmium stress.The results showed that 80 mgL-1 cadmium treatment can be used to screen and identify cadmium tolerance in wheat,Yunmai 399 was a cadmium high sensitive line,and 98-6188 was a cadmium high tolerance line.Under 80 mg·L^(-1)cadmium stress,the appropriate concentration of putrescine could alleviate the inhibitory effect of cadmium stress on wheat seed germination and seedling growth,but there were differences among varieties(lines).The results of multi-index comprehensive evaluation and analysis showed that under cadmium stress,0.1-0.2 mmol·L^(-1)(T2-T3)putrescine had a significant effect on seed germination and seedling growth of the two wheat lines,0.4-0.8 mmol·L^(-1)(T4-T5)putrescine had a growth-promoting effect on cadmium-tolerant line,but inhibitory effect on cadmium-sensitive line.In summary,under cadmium stress,0.1-0.2 mmol·L^(-1)putrescine can effectively alleviate the inhibitory effect of cadmium on wheat germination and seedling growth,and improve the cadmium resistance of wheat.This research provides a theoretical reference for the application of putrescine in field production.