土壤盐分、预湿处理对Artemisia monosperma(菊科)种子传播和萌发的影响

Artemisia monosperma是分布于西奈半岛以及以色列地中海沿岸许多活动沙丘及固定沙丘上的建群种植物，在固定沙丘上，雨后的蓝细菌结皮上能产生径流水，A.monosperma的种子在径流水上漂浮并被传播到低洼处或土壤缝隙中，实验表明，有一半的种子在蒸馏水上漂浮3d，而在各种浓度的盐溶液上则能漂浮更长时间，低浓度的盐溶液对种子的萌发无影响而高浓度的盐分抑制种子的萌发，NO3^-可能是影响种子在沙质蓝细菌结皮上萌发的因素，低浓度的NO2＿促进种子萌发而高浓度则抑制。预湿处理的实验表明，在自然生境中，暴露地表或埋在浅表层的种子经受每晚的露水以及小量雨水的反复湿,春萌发力有可能通过强人作用而提高。

Influences of soil salinity and pre-hydration on seed dispersal and germination of Artemisia monosperma(Asteraceae)

Artemisia monosperma\% is a dominant desert small shrub occurring in active sand dunes and stabilized sand fields. A cyanobacterial crust develops on stabilized sand and, as a result, runoff water may occur after rains. The mucilaginous seeds may float on the runoff water and disperse into depressions or cracks. In these experiments, almost half of the seeds remained afloat on distilled water for 3 days and on different concentrations of salt solutions, more seeds remained afloat for longer. Lower concentrations of salt do not influence seed germination while high concentrations have the inhibition effect. NO\ -\-3 may influence seed germination on cyanobacterial sand crust, low concentrations of NO\ -\-3 accelerate while high concentrations inhibit germination. It was indicated from the pre-hydration experiment that in natural habitats seeds located on or near the sand surface may be exposed to repeated wetting by dew or amounts of water smaller than cause germination.The germinabilty of such seeds may be raised by the priming effect.