PEG胁迫下新疆地区狗牙根种子的萌发特性

Germination characteristics of Cynodon dactylon seed in Xinjiang under PEG stress

为了解狗牙根(Cynodon dactylon)种质芽期抗旱性强弱,并筛选出适宜鉴定抗旱性的PEG浓度,分别对6份狗牙根种子在0、7.5%、15.0%、22.5%、30.0%PEG(质量比)胁迫下的发芽率、发芽势、发芽指数、胚芽长、胚根长、根芽比、苗重进行测定,并采用隶属函数法对其抗旱性进行了综合评价。结果表明,随着干旱胁迫的增加,狗牙根种质的发芽势、发芽率、发芽指数均显著降低(P<0.05),且不同指标出现显著降低的PEG浓度并不一致;高浓度PEG抑制了狗牙根种质的胚芽长、胚根长、根芽比、幼苗重(P<0.05),而低浓度对其影响不显著(P>0.05);15%的PEG可作为狗牙根芽期抗旱鉴定的最适处理浓度;隶属函数综合分析认为,6份狗牙根的抗旱性由强到弱依次为Cd016>Cd043>Cd047>Cd002>Cd034>Cd013。

In order to understand drought resistance of 6 Bermuda grass germplasm at germinating stage and select suitable PEG concentrations for drought resistance selection,the seed germination rate,germination energy,germination index,radicle length,plumule length,ration of radicle to plumule and seedling weight were measured under 0%,7. 5%,15. 0%,22. 5%,30. 0% PEG（ polyethylene glycol） stress and the drought resistance ability of these germplasm was determined using subordinate function method. The results showed that the seed germination percentage,germination energy,germination index of Bermuda grass significantly decreased（P〈0. 05） with the increase of drought stress,and the significant reduction of different indices did not appear in the same PEG concentration. Higher PEG concentration stress reduced seed radicle length,plumule length,ration of radicle to plumule and seedling weight. The optimal concentration to evaluate drought tolerance of Bermuda grass was 15% PEG. According to subordinate function analysis,the drought resistance of 6 Bermuda grass from strong to weak was Cd016,Cd043,Cd047,Cd002,Cd034,Cd013.