西藏3种灌木种子萌发特性研究

Seed Germination Characteristics of Three Shrubs in Xizang

西藏灌木在防风固沙、国土绿化中起着重要的作用,然而其种子繁育是大面积推广应用的主要限制因素之一。为了优化西藏灌木种子繁育条件,选择西藏3种灌木(拉萨黄花木、江孜沙棘、云南沙棘)的种子进行萌发特性、百粒重和吸水曲线的研究分析。结果显示:(1)3种灌木种子吸水过程可分为快速吸水(0~2 h)、缓慢吸水(2~24 h)2个阶段,在20 h时基本达到饱和;(2)3种西藏灌木种子在25℃培养条件下相对发芽率最高。(3)在初始常温水、25℃培养条件下测定不同浸种时间对种子发芽影响,发现拉萨黄花木和云南沙棘在不浸种条件下发芽率最高,分别为22.34%和92.79%,而江孜沙棘种子发芽率在浸种48 h后最高,为98.24%。(4)3种灌木在浸种24 h、25℃培养条件下,测定不同浸种温度对种子发芽的影响,发现拉萨黄花木在沸水浸种刺激时发芽率达76.11%。江孜沙棘不同温度处理下整体发芽率均在95.96%以上,云南沙棘在浸种温度30℃和60℃时发芽率均高于91%。(5)后期拉萨黄花木幼苗在叶长、地径、鲜重、干重上均表现出优异特性。

Shrub in Xizang plays an important role in wind prevention and sand fixation and land greening,but its seed breeding is one of the main limiting factors for its widespread application.In order to optimize seed breeding conditions,the germination characteristics,100 grain weight and water absorption curves of the seeds of three Tibetan shrubs,namely Piptanthus concolor,Hippophae gyantsensis and Hippophae rhamnoides subsp.yunnanensis were analyzed.The results showed that:(1)The water absorption process of the three shrub seeds could be divided into two stages:rapid water absorption(0-2 h)and slow water absorption(2-24 h),and the saturation was basically reached at 20 h.(2)The seed germination rate of three shrub in Xizang was the highest under 25℃.The effects of different soaking time on seed germination were measured under normal temperature water and 25℃.(3)It was found that the germination rate of P.concolor and H.rhamnoides was the highest under non-soaking condition,was 22.34%and 92.79%,respectively,while the germination rate of H.gyantsensis was the highest after soaking 48 h,was 98.24%.(4)In addition,the effects of different soaking temperatures on seed germination of the three shrubs were measured under the incubation conditions of sqaking 24 h and 25℃.It was found that the germination rate of P.concolor was 76.11%under the stimulation of boiling water soaking.The whole germination rate of H.gyantsensis was above 95.96%under different temperature treatment,and the germination rate of H.rhamnoides was above 91%under soaking temperature of 30℃and 60℃.(5)The P.concolor saplings showed excellent characteristics in leaf length,ground diameter,fresh weight and dry weight.