药用植物六角莲基因组DNA提取方法

以硅胶干燥的六角莲叶片为试材,对基因组DNA提取方法进行了研究。通过对CTAB法的改良,提取的六角莲总DNA含多糖、蛋白质、色素、RNA等杂质较少,A260/A280=1.86,完全能满足对六角莲进行分子生物学试验的要求。该提取方法同样适用于同属其它3种植物。     

Preparation of board-like moldings from composites of isolated lignins and waste paper II: effect of inorganic salt addition on board performance and evaluation of practical use of MDF

Board-shaped composites with medium density (MDF) were prepared from isolated lignins and waste newspaper, in addition to preparation of the composites with high density (HB). The board properties of both composites concerning bending strength and water resistance were improved by the addition of hardwood acetic acid lignin (HAL). The internal bond strength and water resistance of MDF, in particular the degree of thickness swelling (TS), were also improved by prolonged molding time. Adding inorganic salts contributed to the improvement of TS. The effect depended on the charge of the cation. Considering practical utilization of lignin-based MDF as a structural material, its performance was evaluated by combination of the single-shear test of nailed joints and the modulus of rigidity. As a result, this MDF had sufficient strength to be utilized as an internal shear wall material. Therefore, lignin can be considered as an alternative to conventional adhesives for the production of boards such as HB and MDF.     

Allomorphs of native crystalline cellulose I evaluated by two equatoriald-spacings

The aim of this study was to develop a facile method for categorizing native celluloses as the algal-bacterial type or the cotton-ramie type and for estimating the I_α/I_β (triclinic/monoclinic) ratio of the cellulose samples. We investigated various native celluloses by X-ray diffractometry; and discriminant analysis was carried out using two equatoriald-spacings: 0.59–0.62 nm (d ₁) and 0.52–0.55 nm (d ₂). All of the samples were classified into the two groups without error. The function used to discriminate between the two groups is represented as:Z=1693d₁ — 902d ₂ — 549, whereZ>0 indicates the algal-bacterial (I_α-rich) type andZ<0 indicates the cotton-ramie (I_β-dominant) type. Another X-ray diffraction study of hydrothermally treatedCladophora cellulose revealed the relation between thed-spacings (d ₁,d ₂) and the I_α/I_β ratio. A calibrating equation by which the I_α/I_β ratio was estimated from the two parameters,d ₁ andd ₂, was then prepared. In the case of relatively highly crystalline native celluloses, it was found that the I_α/I_β ratio is easily determined by applying the two parameters in the equation.     

On the detachment of the gelatinous layer in tension wood fiber

The detachment of the gelatinous layer (G-layer), often observed on microtome cross sections, has led some authors to believe that the G-layer cannot act as the driving force of longitudinal shrinkage in tension wood. The aim of this study was to observe the detachment of the G-layer along fibers. Green wood blocks were cut transversely into two samples. One sample was kept in water and the other was oven-dried. With one face being common to both samples, the detachment of the G-layer was studied on the same fibers. Observations were performed after blocking deformation by embedding. This revealed that the detachment of the G-layer is an effect produced by the act of cutting the transverse face of the wood block to be embedded. At distances greater than 100 µm from this primary surface of the sample, no detachment was observed. Drying shrinkage shows little or no effect on this detachment. The result seems to explain well why the detachment of the G-layer occurs during sectioning using conventional sliding microtomy. These observations prove the adhesion of the G-layer in massive wood and confirm the active role of the G-layer in tension wood properties.     

In situ visualization of hardwood microcracks occurring during drying

Microcracks produced in an Acacia hybrid (Acacia mangium × Acacia auriculiformis) and Melia azedarach during drying were visualized in situ using confocal laser scanning microscopy (CLSM); the morphological differences were compared. In the Acacia hybrid, numerous microcracks were found between the wood fiber and ray parenchyma, which propagated toward both the pith and bark. The microcracks closed with further drying, but persisted until the last stage of drying. In Melia azedarach, however, few microcracks formed between the wood fiber and ray parenchyma in the latewood region; they also propagated toward both the pith and bark. Because the microcracks subsequently closed, some could not be detected by CLSM. These morphological characteristics resulted from differences in the wood structure and we conclude that the interface zone between the wood fiber and ray parenchyma is one type of weak point on the transverse surface that is susceptible to checking.     

Black spot disease of alstroemeria caused by <Emphasis Type="Italic">Alternaria alstroemeriae</Emphasis> in Japan

A black spot disease on cultivated alstroemeria was found in Nagano Prefecture, Japan, in January 2008. The causal fungus isolated from the diseased plants was morphologically identified as Alternaria alstroemeriae E.G. Simmons & C.F. Hill. An inoculation test with the isolated fungus demonstrated that the disease is caused by this species. This is the first report of black spot on alstroemeria (kokuhan-byo, in Japanese) caused by A. alstroemeriae in Japan.     

普通小麦中外源异染色质的检测研究进展

小麦近缘植物存在着极为丰富的遗传多样性和可供改良小麦的优异基因,加强小麦与其近缘植物的杂交、外源异染色质的检测和利用研究,必将为小麦生产和育种带来更大的进展。本文概述了形态标记、细胞标记、生化标记和分子标记在小麦外源异染色质检测中的研究进展,并对其作了简要的评价。     

EuCAD 基因小片段 RNAi对烟草木质素合成的影响

【目的】深入研究尾叶桉(Eucalyptus urophylla)肉桂酰乙醇脱氢酶(CAD)基因序列中的关键片段并利用其进行木质素合成调控。【方法】采用生物信息学工具对EuCAD基因进行序列分析,根据编码蛋白保守结构域的分布情况进行筛选,获得一段44 bp关键序列用于构建RNA干扰载体并转化烟草,获得转基因植株并对基因表达水平、木质素含量等表型进行检测。【结果】获得28个转基因株系,转基因植株正常生长发育,与野生型无异,随机挑选3个株系进行检测,发现CAD基因表达水平均较野生型显著降低,以R1株系降幅最大,降至野生型的12.51%。对R1株系进一步检测发现,其茎部直径与野生型无异,但木质部厚度较野生型显著降低,其中第4节处降低11.75%,第6节处降低10.06%,茎部整体木质素含量较野生型降低15.26%。表明该RNAi片段显著抑制烟草中CAD基因表达并影响烟草木质素合成。【结论】通过序列分析筛选出的EuCAD基因小片段,可通过RNA干扰显著影响烟草木质素合成,为尾叶桉木质素合成调控研究提供了技术参考。     

早熟优质陆地棉品种中棉113高产高效栽培技术

中棉113是早熟、优质、适宜机械采收的陆地棉新品种.本文介绍了中棉113的特征特性,结合生产示范推广案例,总结了中棉113在西北内陆早熟棉区种植的关键栽培技术,为中棉113大面积推广应用提供技术支撑.     

海岛棉纤维品质与其种子短绒多寡的相关性分析

【目的】为探讨海岛棉纤维品质与其种子短绒多寡之间的相关关系,提高海岛棉品质育种效率。【方法】以218份海岛棉种质资源为供试材料,通过2年纤维品质指标的检测及短绒多寡的调查与分级,分析短绒各分级间纤维品质指标的差异性及纤维品质与短绒多寡的相关性。【结果】方差分析表明,各级间除马克隆值差异不大外,其他纤维品质指标随着短绒的增加而增高,且差异呈极显著或显著(P0.05或P0.01)水平。Spearman相关系数表明,纤维上半部平均长度、断裂比强度、长度整齐度指数和断裂伸长率分别与短绒级别间呈极显著(P0.01)正相关,马克隆值与级别间呈显著(P0.05)负相关。【结论】海岛棉纤维品质与其种子短绒多寡间有统计学意义的正相关性,短绒多寡可作为海岛棉纤维品质优劣的参照之一。