沙冬青种子萌发及幼苗生长特性  

SEED GERMINATION AND SEEDLING PERFORMANCE OF AMMOPIPTANTHUS MONGOLICUS

作　　者：丁琼[1] 王华[1] 贾桂霞[1] 郝玉光[2] 

机构地区：[1]北京林业大学园林学院,北京100083 [2]中国林业科学研究院沙漠林业实验中心,内蒙古自治区磴口县015200

出　　处：《植物生态学报》2006年第4期633-639,共7页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(30271075)

摘　　要：沙冬青(Ammopiptanthusmongolicus)是亚洲中部荒漠特有种,由于其分布的环境条件特殊,现存植被天然更新困难,人工育苗、造林存在一定问题。为改善种皮透水性,获得整齐一致的发芽,分别用21.5(室温)、40、60、80和90℃的温水浸种5min。结果表明:60℃温水浸种效果最好,与对照相比,显著地提高了种子发芽势,并有效地降低硬实率。对比分析了15、20、25、30、35和40℃环境温度下种子萌发的特性,种子发芽最适温度是30℃,而胚根及下胚轴伸长最快的温度为25～30℃。较低温度下种子发芽延续时间较长,并且种子萌发后下胚轴和胚根伸长缓慢,易形成畸形(胚根严重扭曲、缢裂)幼苗。15℃时畸形幼苗占发芽种子数的28.1%,而30～40℃时仅占5.2%～8.6%。温度过高不利于种子萌发及幼苗生长,40℃时,吸胀种子绝大部分丧失活力,发芽种子在35℃以上温度下生长2～3d,胚根胚轴组织呈水渍状坏死。另外,催芽后的种子播种在河沙中子叶出土最快,出土率可达63%,显著高于在粘质壤土中出土率(11%)。不同粒径的种子播种后幼苗生长特性表现出一定的差异,粒径5mm以下小粒种子播种后幼苗长势弱,苗期成活率低,生长70d后幼苗成活率仅为35.4%,而粒径5mm以上种子同期幼苗成活率达56.2%。据上述试验结果,结合自然分布区内环境条件的资料,分析了沙冬青濒危原因,并为植被恢复育苗措施提出建议。Background and Aims Ammopiptanthus monglicus, endemic to the semi-arid desert region of central Asia, is an endangered evergreen leguminous shrub. Having difficulties to recruit into its original habitat, A. mongolicus population is experiencing difficulties in regeneration, and the area it ever possessed is shrinking. It is included in the China Red Data Book of Endangered Plant as the third-class protected plant. Despite the importance of seed germination characteristics in developing an adequate understanding of both primary and secondary colonization processes, there still not a few previous studies on the germination of A. mongolicus. To get a comprehensive understanding about the germination characteristics and seedling performance of A. mongolicus, experiments were, therefore, conducted to define the optimum environmental condition for germination. Further, the seed size effects on the seedling performance is also investigated here. Methods In order to find out optimal temperature for soaking, Seeds were soaked in water of 21.5 （ room temperature）, 40, 60, 80, 90 ℃ for 5 minutes respectively. Treated seeds were placed on moistened filter papers in 11 cm diameter Petri dishes, then, transferred into a laboratory incubator at 28 ℃. To test the germination response of the seed to the environmental temperature, seeds presoaked in 60 ℃ hot water were put into incubator under 15, 20, 25, 30, 35, 40 ℃ for germination, respectively. In the case of container seedling culture, presoaked seed were sowed with different cultural media, sandy soil, clay loam, mixed soil （sand soil mixed with clay loam at the ratio of 1 ： 1 ）. Attempt to answer the question that whether the seeds with different size will differ in seedling performance, seeds were categorized into three groups according to the their diameter, those less than 5 mm, those between 5 and 6 mm, and those that of more than 6 mm. Pretreated seeds of its respective size were sowed into the raised seedbed separately. Observations on the seedlin

关 键 词：沙冬青 浸种 温度 粒径 发芽率 幼苗出土 

分 类 号：S793.9[农业科学—林木遗传育种]