基于ITS2序列的17种外来入侵 植物分子鉴定

中国入侵植物种类繁多、危害严重,对入侵物种的准确鉴定是开展各项研究的基础。本研究采用植物DNA条形码序列ITS2片段来探讨其在入侵植物中的鉴定能力。结果表明,ITS2序列在入侵物种及其近缘物种间存在明显的遗传差异,种间变异大于种内变异,在17种常见入侵植物与36种近缘物种的300份样品鉴定中成功率达95.5%。构建的NJ树可以很好地显示各不同入侵植物物种的聚类。此外,ITS2的二级结构也具有一定的系统学及分类学意义。因此,ITS2条形码序列能够作为入侵植物分子鉴定的有力工具,具有重要的应用价值。     

On the Variability of Harvest Indices

The harvest index Z is defined, for example for cereals, as the ratio between grain yield X and biological yield Y: Z = X/Y. For many purposes the variance of Z is of major interest. In this paper several approximations for this variance are derived and their accuracy was investigated. These explicit formulae depend on some characteristics (means, variances or coefficients of variation, covariances or correlations) of the component variables grain yield X and biological yield Y. It is shown that for most practical applications the approximation v²z = v²x + v²y - 2rv_xv_y provides a sufficient accuracy for numerical calculations (v_x v_y and v_z are the coefficients of variation for grain yield X, biological yield Y and harvest index Z and r denotes the correlation coefficient between X and Y). Some conclusions on the relations between v_x, v_y and v_z are derived.
Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter-rapeseed data.     

河南鸡公山引栽鹅掌楸属树种生长规律的初步研究

本文报道了鹅掌楸属树种的生物学特性、年生长发育过程及其生长规律,为制定其栽培措施提供了依据。     

茶多酚生物学活性的研究进展

研究表明,茶叶含有大量的生物活性成分,其中茶多酚是最重要有效成分之一。本文结合近20年来有关茶多酚最新研究成果,阐述了茶多酚生物学活性及研究进展。     

Effect of Water Stress on the Yield of Cowpea (Vigna unguiculata L. Walp.) Genotypes in the Delmarva Region of the United States

Drought is an important yield-reducing factor for corn and soya bean which are the two major crops in the Delaware, Maryland and Virginia (Delmarva) region of the United States. Cowpea (Vigna unguiculata L. Walp.) is primarily grown in drier regions of the world where it is one of the most drought-resistant food legumes. Field experiments were conducted in which 10 genetically diverse cowpea genotypes were evaluated for adaptability to the Delmarva area. The cowpea genotypes were grown in rain-out shelters under non-water-stressed and water-stressed conditions. The results showed that under non-water-stressed conditions cowpea genotypes California Blackeye 5, Champion and Mississippi Silver gave higher seed yields, while genotypes White Acre, Six Week Browneye and Texas Cream 8 provided lower seed yields. Genotypes California Blackeye 5 and Champion gave comparatively better seed yields under water-stressed conditions. California Blackeye 5 was the highest seed-yielding genotype under both water-stressed and non-water-stressed conditions. The highest biological yield under non-water-stressed conditions was given by genotypes Two Crop Brown, White Acre and Elite, whereas under the water-stressed condition genotypes Texas Cream 8, California Blackeye 5, and Mississippi Silver gave higher biological yield. Genotypes Quickpick Pinkeye and Elite were identified as early maturing genotypes. The harvest index (HI) varied significantly among genotypes, with Texas Cream 8 having the lowest HI. Cowpea genotypes which gave higher seed yield under water-stressed conditions could play an important role in sustaining crop production in the Delmarva region.     

甘肃羌活资源特征及开发利用

在多点、多次实地考察和查阅大量文献资料的基础上,对羌活Notopterygium incisum生物学特性、品种分类以及在甘肃的资源分布状况作了较系统的介绍,并对其开发利用进行了探讨.     

外引高羊茅草种的生物学特性研究

以39个美国高羊茅草坪草品种为供试材料,于1998年9月在福建农林大学试验教学农场进行试验。通过对景观品质、密度、质地、颜色、耐践踏性、弹性、日生长速度、覆盖率、成坪速度、叶面积指数和分蘖数等11个主要性状的观察表明,该种草坪具有景观品质优、耐践踏、弹性强、颜色大都较为浓绿等多种优点,是一个有极具开发潜力的草坪草种。以11个主要性状为依据,对39个品种进行聚类分析,定阈值为5.4为分类标准,初步将所有品种分为五大类。     

高羊茅生物学性状分析在草坪品种选育中的应用

通过对高羊茅品种１０个生物学性状的聚类分析，选出不同类型的代表亲本与轮回选择得到的品系Ｓｙｎ－Ⅱ进行杂交。调查了交后代分蘖数、株高，叶宽等主要草坪学性状的遗传增益。讨论从这些杂交后代得的品系中选育适于北京地区的草坪型高羊茅品种的可能性。     

阿拉尔地区野生鸡腿蘑菇菌丝体生理特性初探

阿拉尔地区野生鸡腿蘑茹的菌丝体可用一般食用菌的培养方法进行培养、繁殖、其菌丝体生长所需的温度范围为10°—30℃,最佳温度为25℃左右,PH值范围为5—10最佳PH值为7是一种怕光,需氧生长的菌丝体。     

乳铁蛋白的生物学功能及其基因工程研究进展

乳铁蛋白是一种具有多种生物活性的糖蛋白。本文主要就乳铁蛋白的生物学功能及其基因工程研究进展作一综述。