伯乐树幼苗特性与不同年龄阶段苗木生长规律研究

[目的]研究伯乐树播种育苗过程中幼苗特性与不同年龄阶段的苗木生长规律。[方法]测定种子基本品质特性,种子萌芽阶段生长特性,不同阶段苗木生长规律以及遮阴处理对生长的影响。[结果]①伯乐树种子千粒重为830～1 384 g,含水量52.2%,为无胚乳种子,子叶留土;②伯乐树种子萌芽阶段胚根在第3 d生长很快,上胚轴生长迅速,下胚轴生长很缓慢,这是子叶留土的主要原因;伯乐树幼苗期真叶羽状复叶较短,这可能与树体营养物质贮存有关系;③播种育苗遮阴对苗木生长没有明显影响;④伯乐树一年生苗木高生长呈"S"曲线,6月初和7月初苗圃肥、水管理是促进苗高生长的关键。[结论]多年生苗木高度生长较快,第4年和第5年为苗高生长快速期,而苗木的地径生长较慢,因此在大苗培育过程中除了要加强肥、水、土壤管理外,还要适当增加移植苗木的株行距,以促使地径增粗。

A Study on Characteristics and Growth Laws of Bretschneidara sinensis Hemsi.During Young Seedling Period

[Objective]Study on characteristics and growth laws of Bretschneidara sinensis Hemsi.during young seedling period.[Method]This paper analyzed the quality characteristic of seedling,growth characteristic in the budding stage,growth rhythm of different seedling stage and effects of shading treatments on growth.[Result]①The water content of Bretschneidara sinensis Hemsi.seed is 52.2%;the weight of 1 000 seeds are 830-138 4 g;exalbuminous seed;hypogaeous seedling.②During seed germination,the radicles begin to grow faster in the third date and the speed of growth are very more faster than hypocotyls,which lead to cotyledons remain under soil.However,length of pinnately compound leaves of annual seedlings is more shorter,so we think that it may be related to the nutrients accumulated in the bodies of trees.③Shading has not effects on growth of seedlings.④The curve of height of annual seedlings is a"S"-shaped one,which shows that time of June and July are the key period to promote growth of seedlings by management of water,fertilizer and soil.[Conclusion] In contrast,seedlings of more than 2 years have high speed of growth in the fourth and fifth year of germination,which shows that it is important to have a great row spacing of Bretschneidara sinensis Hemsi.seedlings.