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以荒漠严酷环境下植物种子适应性为科学问题,运用生理生态学原理,以采自不同生境的5个梭梭种群的种子为试材,在实验室模拟基础上,研究了梭梭种子萌发对干旱和盐分胁迫的响应规律。结果表明:在PEG溶液和盐溶液中,来自不同生境梭梭种群的种子其萌发率均随水势的降低而下降,分别到-2.26MPa和-4.15MPa时,所有种群梭梭种子萌发率均接近于零。在水势相等的情况下,所有种子的萌发均受到NaCl和等渗PEG溶液的抑制,并且等渗NaCl溶液对梭梭种子萌发的抑制程度要显著小于PEG溶液,说明渗透胁迫是影响梭梭种子萌发的主要因素。当解除盐胁迫后,梭梭种子恢复萌发率较高,表现出一定程度的高盐诱导休眠现象。水势相等条件下,PEG溶液中恢复萌发率低于NaCl溶液中恢复萌发率,表明离子效应对梭梭种子的影响要小于渗透胁迫。可见,梭梭种子萌发对盐分和干旱胁迫适应性强,是该种群恢复和保育的基础。
Taking the adaptability of plant seeds under the harsh environment as a scientific issue, the seeds of five Haloxylon ammodendron populations collected from different habitats were used as materials to study the germination of Haloxylon ammodendron based on the laboratory simulation. Response of drought and salt stress. The results showed that the seed germination rates of Haloxylon ammodendron populations from different habitats decreased with the decrease of water potential in both PEG solution and saline solution. The seed germination rates of Haloxylon ammodendron seed were all close to -2.26 MPa and -4.15 MPa, respectively At zero. Under the same water potential, the germination of all seeds was inhibited by NaCl and isotonic PEG solution, and the inhibitory effect of isotonic NaCl solution on the seed germination of Haloxylon ammodendron was significantly less than that of PEG solution, indicating that osmotic stress affects the seed germination of Haloxylon ammodendron The main factor. When salt stress was relieved, Haloxylon ammodendron seed germination rate was higher, indicating some degree of salt-induced dormancy. Under the condition of equal water potential, the recovery germination rate in PEG solution was lower than that in NaCl solution, indicating that the effect of ion on the seed of Haloxylon ammodendron was less than that of osmotic stress. It can be seen that the seed germination of Haloxylon ammodendron is very adaptable to salinity and drought stress and is the basis for the restoration and conservation of this population.