温度、PEG和NaCl对3种胡枝子种子萌发和幼苗生长的影响

选用陇东达乌里胡枝子(Lespedeza davurica cv.Longdong)、科尔沁尖叶胡枝子(L.hedysaroides cv.Keerqin)和阿拉善牛枝子(L.potaninii)3种胡枝子种子为试验材料,研究了温度、PEG和NaCl对其发芽率、发芽指数、胚根和幼苗生长的影响,并综合比较3种胡枝子的抗旱、耐盐能力。结果表明,温度变化对种子发芽率影响不大,而种子发芽指数大小与温度变化密切相关,20/30℃变温条件下3种胡枝子的发芽指数最高;PEG变化对胡枝子种子发芽指数和幼苗长度影响最大。隶属值综合分析显示阿拉善牛枝子和陇东达乌里胡枝子在种子萌发期的抗旱能力较强;不同浓度NaCl溶液对胡枝子种子的发芽指数、胚根和幼苗生长均有显著的抑制作用(P0.05),隶属值综合分析显示阿拉善牛枝子在种子萌发期耐盐能力较强;综合PEG、NaCl处理结果显示,在3种供试胡枝子中阿拉善牛枝子抗旱、耐盐性最强,本研究结果为胡枝子栽培驯化和遗传选育提供了理论依据。

Effects of temperature,PEG and NaCl treatments on seed germination and seedling growth of three Lespedeza species

The seed germination percentage,germination index,radical length and seedling length of Lespedeza davurica cv.Longdong,L.hedysaroides cv.Keerqin and L.potanimii were measured under treatments with temperature,PEG and NaCl stress.The results showed that 20/30 ℃ was the most suitable temperature for the three Lespedeza species.PEG stress had great influence on seed germination index and seedling length.L. davurica cv.Longdong and L.potanimii had the better performance under drought tolerance stress.The ger-mination index,radical length and seedling length of these three species seeds significantly decreasing under NaCl stress treatment.L.potanimii showed the best performance under NaCl stress treatment.L.potanimii Vass.was selected as the best accession with drought and salt stress tolerance by comprehensive evaluation, which will provide the insight for germplasm cultivation and genetic breeding for new varieties.