沙埋和水分对3种灌草植物种子萌发及出苗的影响

选取柠条、紫花苜蓿和披碱草3种沙区常见灌草植物进行大田盆栽实验,研究种子在不同沙埋深度和供水条件下的萌发及出苗特性.结果表明：1）柠条和紫花苜蓿种子主要在2.5 ～5.0 mm供水量条件下出苗,柠条种子的最大出苗率为59.00％±7.21％,紫花苜蓿种子出苗率未超过40％,2.5 mm供水量条件下紫花苜蓿幼苗死亡率较大,存在萌发后大量死亡的现象,披碱草种子在5.0～9.0mm供水量条件下出苗较好,最大出苗率为52.67％士10.67％;2）柠条和紫花苜蓿种子的适宜沙埋深度分别为0.5～1 cm和0.5cm,随着埋深的增加,二者的出苗率显著降低,在4.5cm埋深时,柠条种子萌发后未出土幼苗数最多,披碱草种子对沙埋的适应性较好,4.5 am沙埋深度时出苗率最大.

Effects of sand burial and water supply on seed germination and seedling emergence of three psammophytes

This paper aims to study seed germination and seedling emergence of three dominant species （Caragana korshinskii Kom,Medicago sativa Linn and Elymus dahuricus Turcz） in Mu Us sandy land under different water supply regimes and sand burial depths.The results indicate that：1） For C.korshinskii and M.sativa,a relative large number of seeds emerge mostly at 2.5-5.0 mm water supply.The maximum seedling emergence rate of C.korshinskii is 59.00％ ＋7.21％,while that of M.sativa is no more than 40％.The seedling mortality of M.sativa is relatively high at 2.5 mm water supply,which means the death of a lot of seeds after germination.2） For E.dahuricus,seeds emerge well at 5.0-9.0 mm water supply.The maximum seedling emergence rate of E.dahuricus is 52.67％ ＋ 10.67％.3） The most suitable sand burial depths for the seeds of C.korshinskii and M.sativa are 0.5-1 cm and 0.5 cm.As the burial depth increases,the seedling emergence rate of two species,C.korshinskii and M.sativa,decreases significantly.C.korshinskii has the highest rate of non-emergence at 4.5 cm burial depth.4） E.dahuricus adapts well to sand burial,and has the maximum seedling emergence rate at 4.5 cm burial.