引发对种子萌发和幼苗生长特性的影响

以紫花苜蓿(Medicago sativa)种子为材料,以水、PEG-6000溶液(-0.6 MPa)、KNO3溶液(2%)、GA3溶液(100μmol·L-1)和CaCl2溶液(2%)为引发剂,研究各引发处理后的种子在不同温度、盐分和水分胁迫下的萌发和幼苗生长特性。结果表明,1)除引发显著提高低水势下以及KNO3引发显著促进高盐下的萌发率外(P0.05),引发对紫花苜蓿在所有温度、盐分和水势下的萌发率均没有显著影响(P0.05)。2)除CaCl2引发在10和15℃及PEG引发在高盐胁迫下的平均萌发时间没有影响外(P0.05),引发均显著缩短了紫花苜蓿的平均萌发时间(P0.05)。3)引发对紫花苜蓿在不同温度、盐分和水势胁迫下的根和苗生长的影响不同:水引发显著促进紫花苜蓿在10℃下根的生长,但在其它条件下对根的生长无显著作用。水引发显著促进了紫花苜蓿在10℃和高盐胁迫下苗的生长。但除水引发外,所有引发处理均显著促进了紫花苜蓿在低水势下苗的生长,其中以KNO3引发效果最好(P0.05)。

Effect of priming on seed germination and seedling growth

Germination and seedling growth of Medicago sativa seeds primed with H2 O,PEG-6000 (-0.6 MPa),KNO3 (2%),GA3 (100 mol?L-1 )and CaCl2 (2%)were determined under different temperature,salt and water stress.The results showed that:1 )All priming treatments significantly increased germination per-centage at low water potential but not under the other conditions except for a significant increase at severe salt stress condition by KNO3 priming.2)Priming significantly decreased the average germination time except for at 10 and 15 ℃ after CaCl2 priming,or at high salt stress after PEG priming.3)Effects of priming on seedling radicle and shoot growth varied with priming treatments,varieties and test conditions.For example,hydro-priming significantly increased radicle growth at 10 ℃,but showed no effect under the other conditions.Hy-dropriming significantly increased shoot growth at 10 ℃ or under severe salt stress condition.In addition to hy-dropriming,all priming treatment significantly promoted alfalfa shoot growth under low water potential,a-mong which KNO3 priming exhibited the optimal effect.