The length, width, thickness, length/width ratio and 100-seed weight of Magnolia officinalis seeds from 15 natural distribution regions in China were measured and their germination rates were tested. The results showed that there were significant differences among seeds from different region in seed characters and 100-seed weight. Correlation analysis between seed characters and geographical climatic factors showed that the main variation was of geographical locations. The annual mean temperature, annual precipitation and frost-free period were the leading ecological factors restricting the seed variation. The results of test showed that there were significant differences in germination rates among different seed sources. The seeds from Ningqiang had the highest germination rate, while that from Kaixian the minimum. The seeds from Jingning, Wuyishan and Longsheng had high germination potential. According to cluster analysis on 5 trait-location mean values including seed size and quality and geographical climatic factors, the Magnolia officinalis from 15 natural distribution regions could be divided into 2 provenance regions, i.e. south-east M. officinalis provenance region and north-west provenance region.

The experiment on four exotic alder including Alnus glutinosa, A. rubra, A. nitida and A. incana growing under four different concentrations of nitrogen was conducted in a greenhouse in order to research the alder’s responses under different nitrogen concentrations and stresses. The results showed that the growing parameters of alder on the survival percent of transplanting, plant height, ground diameter, biomass, root-top ratio, relative content of chlorophyll (SPAD) and rooting parameters (length, superficial area, volume and tips of root) were significant among different materials and different nitrogen concentrations, the different level of nitrogen significantly affected the growth of alder. Specifically, the survival percent of transplanting went down with the going up of nitrogen concentration, and the plant height, ground diameter, relative content of chlorophyll and rooting parameters went up when nitrogen varied from 0 to 1/2 normal nitrogen, yet went down at one or two times of normal nitrogen (E. G. Bollard formula). The relative content of chlorophyll went up with the concentration of nitrogen increasing from 0 to 2 normal nitrogen, and its trend during one year period showed rising firstly and then descending. The relationship between the value of SPAD and biomass did not appear positive correlation. The appropriate concentration for growing on alder was 1/2 normal nitrogen. The order of performance of growth among the four alder was Alnus glutinosa, A. rubra, A. nitida and A. incana. So, A. glutinosa and A. rubra potentially could be used as plantation trees of ecological protection and short-rotation lumber in the beach and low hills of middle and lower reaches of Yangtze River.

[目的] 基于转录组数据开发适用于桤木属树种的SSR标记，揭示其在转录组序列中的分布类型及特征，为桤木属树种分子标记辅助育种提供有利工具。[方法] 利用MicroSAtellite（MISA）软件对所有转录组序列进行SSRs搜索，并对SSR位点的数量、分布特征进行统计分析。设计100对SSR引物，采用琼脂糖凝胶电泳和毛细管电泳分离检测方法对3种不同倍性桤木属植物（12份材料）进行遗传多样性检测，确定引物多态性及通用性。[结果] 85 769条Unigenes序列中发现8 678个SSR位点，分布在8 298条Unigenes中发生频率为9.67%，转录组序列中平均每14.04 kb长度就有一个SSR位点分布。其中，二核苷酸重复类型数量最多，占65.87%。根据转录组Unigenes序列，利用Primer 3软件共设计出4 531对符合要求的引物，挑选出的100对SSR引物中，获得18对多态性高、稳定性好的SSR引物。[结论] 本研究可扩增出多态性位点的引物重复单元以二、三核苷酸重复为主。基于桤木属转录组序列的SSR标记开发是可行的，开发的引物为桤木属遗传多样性分析、分子育种、遗传图谱构建和功能基因的挖掘提供了丰富的候选分子标记。