曲柳和豌豆染色体核型分析及比较

用常规染色体研究技术研究曲柳的体细胞染色体 ,并将其核型同豌豆的核型进行了比较分析。结果表明 ,曲柳和豌豆之间亲缘关系较近 ,曲柳的染色体长度大于豌豆 ,但宽度和体积均小于豌豆。曲柳的核型公式为K( 2n) =10m +4m (SAT) ,为“1A”类型 ;染色体相对长度组成 :2n=14=8M2 +6M1。

曲柳和荷兰豆的染色体核型分析与比较

对豌豆属植物曲柳(PisumstivaL)和荷兰豆(PisumsativumL)细胞染色体作了计数,并讨论了有关细胞学和分类学问题.实验表明,曲柳的核型公式为K(2n)=14=6m+6sm+2st,属于"2A"型,相对长度组成为2n=14=2L+4M2+8M1;荷兰豆的核型公式为K(2n)=14=8m+2m(SAT)+2sm+2st,属于"2A"型,相对长度组成为2n=14=8M2+6M1.同时还计算了两种植物染色体的体积,研究了它们的相对长度变异幅度、臂比变异幅度等.

荷兰设计师用曲柳实木打造减震单车

荷兰阿姆斯特丹的设计师paul Timmer设计制作了一款曲柳实木打造、保存了木质的最原始美感的单速越野赛车。这是一款质量轻、工艺感强的自行车。整车质量仅为11kg，凭借其木质材料的特性，这款车堪称是减震能手，能消除一切的震动感，为车手提供一种非常舒适的骑行体验。车子的前叉结构设计非同寻常，不像其他车子的设计从车架中穿过，取而代之的是在车架的前端结合，从外部轴承固定。

仿真水曲柳板制作工艺

仿真水曲柳板是在万能装饰板的基础上加以改进而成的一种新型装饰板材,它可与水曲柳三、五合板相媲美。其仿真性强。强度、韧性、纹路、手感均与水曲柳板类似,并具有防火、融热、隔潮、不变形、耐腐蚀、使用寿命长等特点,尤其低廉的加工成本(每平方米6元),使其在目前我国木材资源贫乏而板材又十分走俏,市场需求量急剧增大的情况下,实属高档家具制作,室内外墙体、吊顶及门面装饰的替代产品。木板在制作上有机械化制作和手工制作两种加工工艺,现介绍手工制作:

人造防火水曲柳板研制成功

一种人造新型防火水曲柳板生产技术,近日由河南省郑州市华杰科技实业司研制成功,并通过省级质量检测。

水曲柳硬枝扦插技术

水曲柳硬枝扦插技术据黑龙江林科所朴楚炳等研究试验，水曲柳采用硬枝扦插，配合生根剂处理，扦插生根率可达８５％－８６．７％。扦插方法：（１）插穗采自１年生实生超级苗，扦插时间５月１－５日。从剪取插穗到扦插不超过３６小时，扦插深度５ｃｍ。（２）池状低床，床...

水曲柳原生质体分离初探

[目的]通过优化限制因素,探索水曲柳原生质体制备的最佳方法。[方法]采用酶解法,对影响原生质体分离的影响因素,设计正交实验,通过显微镜观察计数比较原生质体的分离效果。[结果]在M7和M9的酶液组合对原生质体分离效果最好,产量分别为6.61×105个/g和5.76×105个/g,活力分别为97.57%和97.07%。在11%的渗透压中原生质体产量最高。pH 5.2时产量最高,pH值增加不利于原生质体产量增加。酶解时间对原生质体产量差异显著,虽然14 h产量最高,但6 h、8 h、12 h、14 h之间产量差异不显著。[结论]采用酶解法初步获得了水曲柳原生质体分离的最适条件,在预处理3 h,渗透压为11%,在1.5%纤维素酶+0.8%离析酶+0.4%半纤维素酶中,pH值为5.2,黑暗条件下酶解14h。

春光一曲柳千条

“春来柳先知”。当春姑娘姗姗而来时，柳树已展露碧翠的身姿，将那点点芽黄抽成万缕丝条，婆娑婀娜，风情万种，恰如古诗所云：“春光一曲柳千条”，令人心旷神怡。

甘肃柳属一新种

甘肃柳属一新种⒇孙学刚（甘肃农业大学林学院，兰州７３００７０）关键词柳属；舟曲柳；甘肃ＡＮＥＷＳＰＥＣＩＥＳＯＦＳＡＬＩＸＦＲＯＭＧＡＮＳＵＳｕｎＸｕｅ－ｇａｎｇ（ＣｏｌｅｇｅｏｆＦｏｒｅｓｔｒｙ，ＧａｎｓｕＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖｅｒｓｉｔ...

Influence of main site factors on Fraxinus mandshurica (Oleaceae) plantation

the investigation was carried out on 10-year-old plantation of Fraxinus mandshurica in Mao抏r Mountain Experimental Station of Northeast Forest University. Tree height (H), diameter at breast height (D1.3) and the increment of tree height in 5 years (H5), the thickness of humus layer, as well as the soil moisture were measured for the plantation and the growth indexes (H, D1.3, H5) for different site conditions were analyzed. The results showed that main site factors influencing the growth of Fraxinus mandshurica were soil moisture, gradient and location of slope in order. The growth of Fraxinus mandshurica was better on the middle- or up-slope site than on the down-slope site. Soil moisture and late frost caused by terrain are the main reasons that limit the growth of Fraxinus mandshurica plantation.

Enzyme Solutions and H_2O_2 on Somatic Embryogenesis of Fraxinus mandshurica Rupr. (Oleaceae)

[Objective] This study aimed to explore the effects of treatments with three types of exogenous oxidase solutions and H2O2.solution on the somatic embryogenesis of Fraxinus mandshurica Rupr. （Oleaceae）. [Method] The immature zygotic cotyledons were treated with PPQ （polyphenol oxidase） solution, GQD （glucose oxidase） solution, SOD （superoxide dismutase） solution and H202 （hydrogen peroxide） at different concentrations to explore the effects on the growth, browning and somatic embryogenesis on cotyledon explants in the somatic embryogenesis of F. mandshurica. Through comparative analysis on the effects of different treatments on somatic embryogenesis of F. mandshurica, the relationship between explants browning and somatic embryogenesis was uncovered during the somatic embryogenesis of F. mandshurica. [Result] H2O2 treatment not only advanced the explants browning, but also inhibited the growth and somatic embryogenesis of explants; different concentrations of PPQ promoted the growth and browning of explants, as well as improving the incidence of somatic embryogenesis; both GOD and SOD treatment could raise the explants browning rate; when somatic embryogenesis of explants treated with enzyme solutions advanced, the incidence of somatic embryogenesis was low; however, when the disparity of the incidence of somatic embryogenesis between 30 and 60 d treatments reached its peak, the incidence of somatic embryogenesis was also high. [Conclusion] The results of this study provide basis for raising the incidence and improving the status of somatic embryogenesis of F. mandshurica, as well as optimizing the somatic embryogenesis system of F. mandshurica.

The variation of nutrient concentration in the rhizosphere of larch and ash in mixed and monoculture stands

Soil samples were taken from rhizosphere zone and off-rhizosphere zone of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) in mixed and monoculture stands, and the nutrient concentration of N, P, and K was analyzed to study the effect of nutrients variation on yield improvement in the mixed stand. The result showed that: 1) The stand level total soil N concentration and available N in the mixed stand was similar to that in the monoculture stand of ash, but higher than that in monoculture stand of larch. The total N and available N concentration in rhizosphere soil of ash in the mixed stand was similar to that in the monoculture stand of ash, but the available N concentration in rhizosphere of larch in mixed stand was much higher than in its monoculture. 2) The stand level total P, total K concentration in the mixed stand was similar to that in monocul-ture stands of both species, but available P and K was more concentrated in the mixed stand than in the monoculture stands of ash. The rhizosphere available P and K of ash in the mixed stand was 44.1% and 13.5% (for the 9-yr-old stands) and 79.6% and 25.6% (for the 21-yr-old stands) higher than that in its monoculture. The improvement of soil P and K availability in the mixed stand is concluded.

Spatial distribution of fine roots of larch and ash in the mixed plantation stand

The spatial distribution of standing fine roots in tree rows of different species in a 12-year-old mixed stand of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) was studied by soil core sampling in early spring, 2001. It is found that ash and larch differ greatly in their belowground biomass distribution. Ash has much higher fine root biomass density in the soil than larch at stand level (with the max value of 4442.3 vs. 2234.9 gm-3). Both tree species deployed more fine roots in their neighboring zone, suggesting a less intensive competition between roots of the two species. Both fine root biomass density and root length density of ash in the zone between larch tree rows are greater than that of larch in zone between ash tree rows, indicating that ash is more powerful than larch in belowground competition. The spatial distribution feature of roots favors the growth of ash in the mixed stand.

文苑拾趣(二则)

一 唐刘禹锡诗云:春江一曲柳千条,二十年前旧板桥;曾与美人桥上别,恨无消息到今朝。 清代郑燮幼贫,习书画曾受邻嗤笑。成名后,亲邻一反旧态,纷乞书画,连早年所弃之画稿,也视为至宝。燮感于此,刻“二十年前旧板桥”印一方,讽刺世态。后干脆自号“郑板桥”这真是:世态炎凉实堪嗟,徒重势利弃才华。

刘禹锡改削白居易

刘禹锡改削白居易诗一事,对人颇有启迪。白居易的《板桥路》一诗写得不够出色,经刘禹锡“稍加删削,改易数字,便觉精采动人。”(《唐绝句史》107页)白诗如下:

壮乡行

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