沙地云杉种子萌发及育苗试验

Seed Germination and Seedling Culture of Picea mongolica

沙地云杉是沙地造林的首选树种之一。通过对其种子萌发机理的研究,为沙地云杉在干旱区的推广及林地幼苗更新提供理论依据。在试验室和室外花盆内对沙地云杉的种子进行处理,测定种子含水率及吸胀速率,研究不同温度、不同覆土厚度、不同浓度盐溶液、不同种子处理方式对沙地云杉种子萌发及出苗的影响。结果表明:(1)沙地云杉种子发芽的适宜温度为15～25℃,当温度低于5℃时种子将不能萌发,高于35℃萌发率较高,但会严重影响幼苗生长;(2)种子在吸胀初期,吸水量急剧增加,但随着时间的延长,绝对吸水量逐渐减小,达到一定时间后,种子含水量相对不变,即达饱和状态;(3)种子耐盐性较差,当NaCl溶液浓度高于0.6%时,会严重影响种子萌发,显著降低种子发芽率;(4)种子育苗适宜的覆沙厚度为0.5～0.75cm,大于1.0cm会显著降低发芽出苗率;(5)沙地云杉种子经3种方式处理播种后,以沙藏处理的种子发芽出苗率最高,自来水处理次之,60℃恒温处理最差。在人工对沙地云杉进行繁育时,种子宜先沙藏处理,萌发适宜温度15～25℃,土壤含盐量不宜高于0.6%,不覆土或覆土太厚均不利于种子的萌发。

In order to provide theoretical basis for extension in arid area and seedling regeneration in plantation of Picea mongolica that as one of the first choice for afforestation in sandy area,the author produced experimental study about germination mechanism of seeds of Picea mongolica.Seed germination characteristics of Picea mongolica were examined from aspects including temperature,seed-covered sand thickness,NaCl stress,seed imbibitions and treating methods.The results indicated that：（1） The optimal temperature for the seeds to germinate was 15-25℃.The temperature was lower 5℃,the seeds could not germinate,and the germination rate was higher when the temperature was over 35℃,but seedling length had been strongly bad influenced;（2） Salt tolerance of seed was lower,when the NaCl solution density exceeded 0.6 %,germination rate would decreased;（3） At the start of imbibitions,the water content of seed increased fast,and relative amount decreased gradually with the time passed,at a certain time,the water content of seed was stable;（4） The optimal seed-covered sand thickness was 0.5-0.75 cm,but when the seed-covered sand thickness was more than 1 cm seedling emergence from the seeds was inhibited;（5） Seed of Picea mongolica was planted after three methods disposed,the result showed that germination rate of stratification treatment onthe seed germination was most,water treatment was medium,and 60℃ water treatment was weak.In a word,the artificial breeding was suitable by dealing with sand on seeds,temperature in 15-25℃ and salinity of soil less than 0.6%,without covering soil and rather covering thick soil both went against for germination of seeds of Picea mongolica.