不同玉米品种萌发期耐芘胁迫的响应差异

为了评定不同玉米品种对芘的耐性强弱,确定合适的筛选指标和筛选浓度,以0mg·L-（1T0,对照）、0.5mg·L-（1T1）、1.0mg·L-（1T2）和2.0mg·L-（1T3）4个芘处理浓度,采用毒理学试验方法系统评价了14个玉米品种萌发期耐芘胁迫的差异。结果表明,不同品种玉米根干重、芽干重、根长和芽长都受到芘的影响,且这种影响的程度随着芘处理浓度不同而不同,不同品种玉米萌发对不同芘处理浓度的响应也不同,其中2.0mg·L-1的浓度处理适合进行玉米耐芘品种的筛选与鉴定。以根干重、芽干重、总干重、根长和芽长的性状相对值（处理测定值/对照测定值×100%）作为幼苗耐性指数（tolerance indices,TI）适合作为筛选指标。基于耐性指数对各玉米品种耐性进行聚类分析,将14个玉米品种聚为耐性、较耐性、较敏感和敏感4类。

Responsing Differences of Germinating of Maize Cultivars to Pyrene Contamination

In order to evaluate the tolerance of maize germinating to pyrene stress and identify proper screening indices and concentration,the effects of pyrene contamination on germinating of maize seeds were studied,and fourteen cultivars of maize were chosen.The concentrations of pyrene were set in 0,0.5,1.0 and 2.0 mg·L-1.The dry weight of root and shoot,root length and shoot height of different maize cultivars at germinative stage were measured.Results showed that all parameters,dry weight of root and shoot,root length and shoot height,at this stage were impacted under pyrene contamination.The extents of the impact of different treatments of pyrene were different,and the responses of germinating of these different cultivars to different concentrations of pyrene were also different.The high concentration of 2.0 mg·L-1 of pyrene used might be adopted to evaluate the impact of pyrene contamination to those cultivars.Some characteristic parameters were used,such as tolerance indices（TI）to measure the impact of different treatments,including pyrene concentration and cultivars.Result of cluster analysis with TI of each treatment showed that,the fourteen cultivars could be clusted into four groups,which are group Ⅰ to be high sensitive to pyrene contamination（including Heizuanzi,Meibainuo 1 and Huabao 1）,group Ⅱ to be relatively sensitive（including Huabao 8,Sui 1,Shixiang 1,Guangnuo 1 and Guangtian 1）,group Ⅲ to be tolerantive（including Gannuo 1,Zhutian 1,Suitian 2,Jiamei 2 and Fengtian 1） and group Ⅳ to be strong tolerantive（including Guangtian 3）.