中国生态农业学报2018，Vol.26Issue(7)：1011-1018,8.DOI:10.13930/j.cnki.cjea.171033
模拟干旱和盐碱胁迫对碱蓬、盐地碱蓬种子萌发的影响
Effects of PEG, NaCl and Na2CO3 stresses on Suaeda glauca and Suaeda salsa seed germination
摘要
Abstract
Suaeda glauca and S. salsa are native halophytes in China with a key role in the improvement and restoration of salt marsh ecologies. There is a lot of works on the response of Suaeda plants to salinity, but works are limited about the effects of drought and alkali stress on S. glauca and S. salsa, especially at germination stage. The aim of this study was to evaluate the impacts of PEG, NaCl and Na2CO3 stress on the germination of S. glauca and S. salsa seeds. The in-vitro seed germination test was carried out with various solutions of PEG-6000 (29 mmol·L-1, 38 mmol·L-1, 45 mmol·L-1 and 50 mmol·L-1), NaCl (100 mmol·L-1, 200 mmol·L-1, 300 mmol·L-1 and 400 mmol·L-1) and Na2CO3(70 mmol·L-1, 140 mmol·L-1, 210 mmol·L-1 and 280 mmol·L-1) in iso-osmotic concentrations (-0.46 MPa, -0.92 MPa, -1.38 MPa and -1.84 MPa). We measured the germination rate, germination index, mean germination time, early seedling growth after 7-day treatment and final germination rate after another 7-day recovery. The results showed that with increasing osmotic stress intensity, the germination rates of two species were depressed under PEG, NaCl and Na2CO3 treatments, while -0.46 MPa treatment did not differ significantly from that of the control (fresh water). The negative effect of NaCl on S. glauca seed germination was less than iso-osmotic PEG and Na2CO3 treatments. By contrast, the effects of iso-osmotic PEG, NaCl or Na2CO3 treatments on S. salsa seed germination were not significantly different. The germination rate of S. salsa was positively related to osmotic potential. Recovery study indicated that PEG, NaCl and Na2CO3 stress had no negative effects on the final germinate rate of S. glauca and S. salsa, meaning that the inhibition of PEG, NaCl and Na2CO3 stress on seed germination was due to osmotic pressure rather than ion toxicity. In addition, mild NaCl treatments (-0.46 MPa for S. glauca, and-0.46 and-0.92 MPa for S. salsa) promoted S. glauca and S. salsa seedling elongation, while PEG and Na2CO3 treatments inhibited it. In iso-osmotic conditions, radicle and hypocotyl lengths of S. glauca and S. salsa seedlings under NaCl treatment were greater than those under PEG and Na2CO3 treatments. Compared with S. glauca, S. salsa seedlings grew better under -0.46 MPa and -0.92 MPa NaCl treatments, but worse under-0.46 MPa Na2CO3 treatment. The findings suggested that, 1) S. salsa seeds exhibited strong resistance to PEG, NaCl and Na2CO3 stress, and its resistance to PEG and Na2CO3 stress was greater than that of S. glauca. 2) S. salsa had stronger capacity to establish seedlings under NaCl stress than S. glauca, but its tolerance to mild Na2CO3 stress was weaker than that of S. glauca.关键词
种子萌发/碱蓬/盐地碱蓬/NaCl胁迫/Na2CO3胁迫/PEG胁迫Key words
Seed germination/Suaeda glauca/Suaeda salsa/NaCl stress/Na2CO3 stress/PEG stress分类
农业科技引用本文复制引用
李劲松,郭凯,李晓光,封晓辉,刘小京..模拟干旱和盐碱胁迫对碱蓬、盐地碱蓬种子萌发的影响[J].中国生态农业学报,2018,26(7):1011-1018,8.基金项目
国家重点研发计划课题(2016YFC0501308)和中国科学院科技服务网络计划(KFJ-SW-STS-141-04-1, KFJ-STS-ZDTP-001-03)资助 This study was supported by the National Key Research and Development Program of China (2016YFC0501308) and the Science and Technology Service Network Program of the Chinese Academy of Sciences (KFJ-SW-STS-141-04-1, KFJ-STS-ZDTP-001-03). （2016YFC0501308）
