盐分、干旱及其交互胁迫对黑果枸杞发芽的影响

Salt and Drought Stress Effect and Their Interaction on Germination of Lycium ruthenicum Murr.

为了研究土壤盐分和水分对黑果枸杞(Lycium ruthenicum Murr.)萌发的影响,通过单因素等渗试验测定了PEG处理和Na Cl处理对发芽率的影响。结果表明:黑果枸杞种子在水分胁迫下的临界值和极限值分别为-0.39MPa和-0.75 MPa,而在盐分胁迫下分别为-0.46 MPa和-0.8 MPa。以水分胁迫、Na Cl胁迫和发芽温度为试验因子,以种子萌发率为响应值,运用中心组合试验设计(CCD)法,进行3因素5水平的响应面(RSM)分析试验。结果表明:3个因素对黑果枸杞种子发芽率的影响为:PEG>Na Cl>温度。试验结果表明:黑果枸杞在盐分和干旱双重胁迫下,极限耐受值范围为干旱胁迫-0.3^-0.5 MPa,盐分胁迫-0.6^-0.7 MPa。

Seed germination period is the weakest link of resistance in life cycle of plant, which determines some plants survive in the drought, saline environment or not. In arid and semiarid regions, soil salinization has stress effect on seed germination, temperature and moisture was two key ecological factors affecting the seed germination additionally. To study the influences of salt concentration and moisture content in the soil profile on seeds germina- tion of Lycium ruthenicum Murr. , the germination of seeds was measured under iso-osmotic potentials of NaC1 and PEG processing. The regression equation and result showed that the seed critical value was -0.39 MPa and maxi- mum value was - 0.75 MPa under PEG treatment, while they were - 0.46 MPa and - 0.8 MPa under NaC1 treat- ment. Based on central composite design response surface methodology, germination percentage was investigated with respect to PEG, NaC1 solution and temperature, and a quadratic polynomial model was established. According to the results, the influence on germination from strong to inferior is PEG, NaC1 and temperature. Comprehensive re- sult show that seeds of Lycium rutherticum Murr. under salt and drought stress, the limited parameters were water stress, - 0.3- - 0.5 MPa, and NaCl stress, - 0.6-- - 0.7 MPa. Comparing the seed germination response of sin- gle stress and double stress, discussing the adaptive strategy of Lycium ruthenicum Murr. , will provide a scientific basis for vegetation restoration and reconstruction in desert region.