伊犁绢蒿种群对不同刈割干扰的生理响应

[目的]以新疆蒿类荒漠草地建群种-伊犁绢蒿为对象,探讨刈割强度对其越冬前后根部碳水化合物(可溶性糖、还原糖、淀粉)及渗透调节物质(可溶性蛋白质、氨基酸、脯氨酸)的影响.[方法]利用常规测定方法对刈割处理后的伊犁绢蒿生理指标进行测定与分析.[结果]与越冬前(2008年11月)相比,越冬后(2009年4月)各处理下伊犁绢蒿根中可溶性糖、还原糖、淀粉、可溶性蛋白、脯氨酸及氨基酸含量均呈明显下降趋势(P＜0.05);同一测定时间下,刈割强度对伊犁绢蒿根部淀粉、可溶蛋白含量的影响不显著(P＞0.05);越冬前C5、C2下伊犁绢蒿可溶性糖显著高于C0,脯氨酸含量则表现为C5显著高于C2、C0,越冬后两者在刈割强度间的差异消失;越冬前还原糖表现为C5、C0显著高于C2,氨基酸含量为C5显著高于C2、C0,而越冬后还原糖、氨基酸含量均表现为C5明显高于C0.[结论]C5有利于伊犁绢蒿根部碳水化合物及渗透调节物质的积累,有利于抵御刈割逆境.     

水杨酸对亚洲百合鳞茎碳水化合物的影响

以亚洲百合“精粹”和“普瑞头”为试材,研究水杨酸浸球处理对百合鳞茎碳水化合物含量的影响。结果表明：5mmol·L^-1水杨酸处理,可以促进百合鳞茎内淀粉、可溶性糖及可溶性蛋白质含量的积累。鳞茎内碳水化合物的积累为鳞茎发育提供物质基础。     

Growth of <Emphasis Type="Italic">Dactylis glomerata</Emphasis> along a light gradient in the central Appalachian region of the eastern USA: II. Mechanisms of leaf dry matter production

Microsite influences development and resource allocation of Dactylis glomerata L. (orchardgrass), a traditional pasture species with potential as an understory crop in silvopasture of humid temperate regions. An experiment using container-grown orchardgrass was conducted under field conditions to determine how open (O), shaded woodland (W) and open-to-shaded woodland transition zone (E _O, E _W) microsites influenced leaf DM production. Plants established in spring (SP) and late summer (LS) were clipped each time mean canopy height reached 20 cm. Dry matter production and allocation among structures differed, as a function of light attenuation. Specific leaf area (SLA) and photosynthetic nitrogen-use efficiency (PNUE) were associated with leaf DM production, whereas leaf N, net assimilation rate and shoot total nonstructural carbohydrates (TNC), were not. Specific leaf area was related to leaf DM of LS plants, whereas PNUE influenced leaf DM of SP plants. Stembase TNC was inversely related to relative regrowth rate (RG_RR) with RG_RR greatest and TNC the least at W. The relationship for RG_RR and TNC for SP plants growing at O and LS plants growing at W was similar. Regardless of how indices of growth are related, SP and LS plantings responded as separate populations (representing young and established plants respectively) that have different leaf DM production efficiencies. Orchardgrass was able to sustain leaf production when subjected to simultaneous stresses of shade and repeated defoliation. The LS plants growing at W respond in a manner similar to SP plants and may require management practices attuned to establishing or immature plants. The US Government’s right to retain a royalty-free, non-exclusive copyright is achnowledged.     

不同类型高粱主要农艺性状与品质性状差异分析

对来自国内外60份不同类型高粱材料的农艺性状、产量性状和品质性状在新疆干旱区的表现进行分析比较,目的是了解不同高粱类型在新疆干旱区的差异表现,为新疆干旱区能源用高粱品种选育提供参考依据.研究发现,供试高粱材料间生育期差异显著(P＜0.05),其中,甜高粱的生育期最长,平均为116.8 d,变幅在100.5～131.5 d之间.农艺性状分析发现,帚高粱的株高最高,平均为275.2 cm,籽粒高粱最矮,平均只有235.6 cm.甜高粱的伸长节间数最多,平均为12.6个,其中,甜高粱X054伸长节间数最多,为15.6个.各高粱类型的产量构成差异较大,籽粒高粱的籽粒产量最高,平均为7.9 t/hm2,而甜高粱和帚高粱的茎秆产量较高,分别为10.3和10.2t/hm2,全株总干物质积累量以甜高粱为最高,平均为25.3 t/hm2,变幅在18.4～31.5 t/hm2之间,其次为帚高粱的23.6 t/hm2,籽粒高粱最低,平均只有20.3 t/hm2.品质性状分析表明,籽粒各组分含量最为稳定,各高粱类型间差异较小,其次为叶片和叶鞘,而不同高粱类型间茎秆的碳水化合物含量和木质素含量差异较大,其中,甜高粱表现出更高的可溶性总糖含量,平均为236.6 g/kg,是籽粒高粱的3倍、帚高粱的2倍之多,而甜高粱的木质纤维素含量明显低于籽粒高粱和帚高粱,特别是纤维素含量,平均要低100 g/kg以上.碳水化合物产量分析发现甜高粱和帚高粱的平均积累量较高,分别为14.2和13.8 t/hm2,各高粱类型中均以纤维素和半纤维的贡献最大,特别是帚高粱材料,平均贡献率达65.9％.综上,相比于籽粒高粱和帚高粱,甜高粱整体表现出更强的能源利用潜力.同时应指出,各类型高粱材料均为宝贵的种质资源,应充分的挖掘利用,以筛选并进一步培育出适合新疆干旱区种植的能源用高粱新品种.     

橡胶树树皮和木质部淀粉和可溶性糖含量测定

提出一种橡胶树树皮和木质部非结构性碳水化合物含量测定方法。取样测定范围为10～200　mg,利用80%乙醇浸提提取可溶性糖,硫酸蒽酮法测定可溶性糖含量,硝酸钙法提取淀粉,I2-KI法测定淀粉含量。本方法优点是：取样量小,对胶树伤害小,取样过程简单,测定结果准确。     

糖分在玫瑰花采后保鲜中的有害作用

花卉在人们生活质量日益提高的今天发挥着越来越来大的作用。如何延长采后花期是当前收获后加工技术中的一个集中研究热题。切花采后花期的长短与植物体内糖分有直接关系。如何控制切花中的糖分是其保鲜技术的重要一环。该文就本人的试验结果进行了分析,并着重论述了糖分的有害作用。先将温室玫瑰(品种：Mercedes)放置水中,然后配备溶液(ABA(No.1012, Sigma, USA)+Al₂(SO₄)₃+16 H₂O+白砂糖)进行试验。采后玫瑰的花瓣和叶子自始至终均用电子天平精确纪录其质量,以示其变化。在整个试验过程中,该玫瑰均在恒温室内进行(温度为22℃,光照为14 h/d,12 μE/s x m^-2)。由于糖分起到了能量补充的作用,适量施加糖分对延长花期有明显的效果。但必须根据花卉的不同种类、品种和条件等来合理使用和控制糖分才能达到应有的效果。ABA关闭叶孔的作用明显,合理使用ABA是花卉保鲜的关键。糖分不宜过量,否则会造成叶细胞间积糖,出现叶面斑点和“黑脖子”现象。     

Amylase and trypsin responses to intake of dietary carbohydrate and protein depend on the developmental stage in sea bass (Dicentrarchus labrax) larvae

Sea bass (Dicentrarchus labrax) larvae were fed from day 15 to day 35 with 4 isoenergetic formulated diets that varied in protein (30, 40, 50, 60%) and carbohydrate (37, 27, 17, 7%) content. The diets were designated as P30, P40, P50 and P60, respectively. Best growth and survival were noted for P50 larvae. Poor growth and survival were observed for P30 larvae. The specific activity of amylase increased in direct relation to the dietary carbohydrate level from day 18 onwards. This increase was the result of extensive amylase synthesis. Trypsin activity was positively correlated with dietary protein level only at day 35. This study shows that the mechanisms involved in amylase regulation are efficient in very young sea bass larvae, while those related to trypsin appear later in ontogeny and thus suggests an age-dependent regulation of enzyme synthesis.     

Resistance of picea abies to ips typographus: tree response to monthly inoculations with ophiostoma polonicum,a beetle transmitted blue‐stain fungus

Fifty pole stage trees were inoculated with O. polonicum at monthly intervals between May and September. Most infection, measured as the area of sapwood blue‐stained, occurred in July and least in May and September. The difference between July, August and September might be explained by the effect of temperature on fungal growth, but in May and June the trees had a higher resistance than expected. Tree resistance was correlated with resinosis. Tree variables not correlated with resistance were DBH, annual ring width, periodic growth, vigor index, or phloem carbohydrate concentration.     

Interactions among cutting frequency, reserve carbohydrates, and post-cutting biomass production in Gliricidia sepium and Leucaena leucocephala

The ability of trees and shrubs to coppice vigorously after being cut or pruned is of great importance in the management of agroforestry systems. In a study conducted in the seasonally dry climate of Ibadan, Nigeria, frequent cutting progressively decreased concentrations of starch and total reserve carbohydrates in Gliricidia sepium (Jacq.) Walp. and Leucaena leucocephala (Lam.) De Wit. In frequently cut trees, starch was severely reduced in the stumps of both species. In contrast, soluble sugar concentrations in roots and stems of both species were consistently maintained at or above the levels in uncut control trees, suggesting that sugar levels were maintained through the hydrolysis of starch reserves. No starch replenishment occurred during the six weeks after cutting. In trees that were cut and then allowed to grow undisturbed during the wet season, replenishment of stem starch began within three months after cutting. Shoot regrowth after cutting decreased starch levels first in stems and, only after additional cuts, in roots. Dry-season cuts had little effect on reserve carbohydrates in G. sepium but quickly reduced stem starch in L. leucocephala. Frequent cutting decreased dry matter production, and this decrease was correlated with reduced levels of reserve carbohydrates.This revised version was published online in November 2005 with corrections to the Cover Date.     

桉木RDH蒸煮过程中木质素与碳水化合物的溶出规律研究

对桉木常规硫酸盐(KP)法和快速置换加热(RDH)硫酸盐法蒸煮过程中，木质素与碳水化合物中各单糖组分(葡萄糖、木糖、甘露糖和阿拉伯糖)的溶出规律进行了研究，分析了常规KP浆和RDH浆在纤维素结晶度和α-纤维素含量上的差异。与常规KP法蒸煮相比，在RDH蒸煮的初期，木质素和碳水化合物各单糖组分就大量溶出，蒸煮时没有表现出明显的初始脱木质素阶段。蒸煮结束后，RDH浆比常规KP浆具有相对较高的葡萄糖(纤维素)含量和相对较低的木糖、阿拉伯糖和甘露糖(半纤维素)含量。RDH纸浆的α-纤维素含量相对较高，但纸浆的纤维素结晶度与常规KP浆相比并没有明显的不同。