In memoriam

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In memoriam

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In memoriam Karl Escherich

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In memoriam Prof. Dr. Oldwig Jancke

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In memoriam Zum Tode von Prof. Dr. Martin Schwartz

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Julius Speer zum 70. Geburtstag

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Grinnerungen an fchwere Zeiten forftlicher Roth

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疣枝桦播种育苗技术

疣枝桦（Betula pendula Roth．），又名垂枝桦，系新疆阿尔泰山及天山特有物种，属落叶阔叶乔木。其树皮白色，树体高大，冠幅圆满，枝叶繁茂，翠绿葱郁。其树叶在入秋经霜打之后，金黄灿亮；在落叶之后，其白色树干也自成一片风景，是良好的植树造林及城市庭院绿化树种，最适宜种植成片林。由于其种子颗粒小、种皮坚硬、发芽时间长，且苗期生长慢，管理要求细致。因此，疣枝桦播种育苗需要掌握以下技术。     

Autotetraploid plants from callus cultures of Betula pendula Roth

Autotetraploid plants with 2n = 56 chromosomes were found in a population of plants derived from callus cultures of stem internodes of silver birch (Betula pendula Roth) with 2n = 28 chromosomes. These plants were readily identified by their twisted, pubescent foliage and slow rate of growth, and by cytological examination. The frequency of autotetraploidy varied with the auxin used in the culture medium. When indole-3-butyric acid was used, autotetraploids accounted for 3.8% of the total study population, whereas when naphthaleneacetic acid was used, the frequency of autotetraploidy increased to 11.0%. The remainder of the plants in the study population were morphologically normal with 2n = 28 chromosomes. The autotetraploids have potential value as breeding material for the production of triploid birches (2n = 42), which are known to be fast growing, through crosses with diploid silver birch.     

庞桦桦的构造及性质研究

对新疆阿尔泰哈巴河林区的疣林区的疣枝桦木进行了宏观和微观构造及木材纤维长度，宽度的观察和测量。同时，对该木材的物理力学性能进行了测试和比较。结果表明，疣枝花为散孔材，属中等密度，大部分力学强度指标属中学，冲击韧性较高，适于做建筑用材。     

Analysis of EST-SSRs in silver birch(Betula pendula Roth.)

Simple sequence repeats(SSRs) defined as sequence repeat units between 1 and 6 bp occur abundantly in both coding and non-coding regions in eukaryotic genomes and these repeats can affect gene expression. In this study, ESTs(expressed sequence tags) of Betula pendula(silver birch) were analyzed for in silico mining of ESTSSRs, protein annotation, open reading frames(ORFs),designing primers, and identifying codon repetitions. In B.pendula, the frequency of ESTs containing SSRs was 7.8 %with an average of 1SSR/4. 78 kb of EST sequences. A total of 188 SSRs was identified by using MISA software and dinucleotide SSR motifs(65.9 %) were found to be the most abundant type of repeat motif followed by tri-(27.1 %),tetra-(4.8 %), and penta-(2.2 %) motifs. Based on ORF analysis, 175 of 178 sequences were predicted as ORFs and the most frequent SSRs were detected in 50 UTR(58.43 %),followed by in ORF(31.46 %) and in 30UTR(8.43 %). 102 of 178 ESTs were annotated as ribosomal protein, transport protein, membrane protein, carrier protein, binding protein,and transferase protein. For a total of 102 SSRs(57.3 %)with significant matches, a set of 102 primers(100 %) with forward and reverse strands was designed by using Primer 3 software. Serine(Ser, 19.6 %) was predominant in putative encoded amino acids and most of amino acids showed nonpolar(35.3 %) nature. Our data provide resources for B.pendula and can be useful for in silico comparative analyses of Betulaceae species, including SSR mining.     

Micropropagation of a mature colchicine-polyploid and irradiation-mutant of Betula pendula Roth

Tetraploid plantlets were regenerated from cultured apical and axillary buds of a 23-year-old colchicine-polyploid and irradiation-mutant Betula pendula Roth tree. Bud explants were grown on modified Murashige and Skoog medium supplemented with 2.0 mg l(-1) benzylaminopurine (BAP) and 0.01 mg l(-1) 1-naphthaleneacetic acid (NAA). The medium allowed both induction of adventitious buds and development of shoots. The cut ends of new shoots produced new buds and shoots during a 4-week culture period. The micropropagated shoots were rooted on modified Murashige and Skoog medium containing 0.1 mg l(-1) NAA as the sole growth regulator. Plantlets were transferred to a peat/soil mixture (1:1) in the greenhouse, acclimated and then transplanted to a cold frame. The regenerated plantlets had a tetraploid chromosome set (4n = 56) and an altered leaf morphology typical of colchicine-polyploid birches. The leaves were hypertrophied and asymmetrical, with curly leaf margins. The mutant nature of the parent tree was also evident in the light-green color of the leaves of the plantlets.     

Prof. Dr. Abdulgafur Acatay in memoriam

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