禾本科植物HKT基因家族研究进展

HKT基因家族在维持植物K+、Na+平衡中发挥着重要作用。文中对禾本科植物HKT基因家族的研究进展进行了综述,并对其未来发展进行了展望。     

甘肃禾本科饲用植物11个属的牧草质量分析(简报)

甘肃禾本科饲用植物资源丰富,据初步统计,共有74属301种,是构成甘肃天然草地植被的重要成分。本研究利用灰色关联分析法,对甘肃禾本科饲用植物11个属的7项营养指标进行了综合分析,选出了优质种类。综合评价结果表明,各属营养成分灰色关联度为臭草属(Melica)(0.6887)>隐子草属(Cleistogenes)(0.6605)>早熟禾属(Poa)(0.6271)>剪股颖属(Agrostis)(0.5889)>羊茅属(Festuca)(0.5762)>雀麦属(Bromus)(0.5616)>披碱草属(Elymus)(0.5508)>针茅属(Stipa)(0.5095)>异燕麦属(Helictotrichon)(0.5082)>芨芨草属(Ach-natherum)(0.4577)>鹅观草属(Roegneria)(0.4333)。     

龙眼果实采收成熟度与耐贮性关系研究

以'石硖'和'古山二号'龙眼Dimocarpus longan Lour. cv.Shixia and Gushan No.2为试材,对果实成熟度与耐贮性之间的关系进行了研究. 结果表明:在果实成熟期间,品质指标可溶性固形物(TSS)和糖含量及内果皮褐变指数在果实完全成熟前后或过熟后都发生了阶段性变化,提出以比熟度作为量化衡量果实成熟度的重要参考指标. '石硖'和'古山二号'龙眼果实最适贮藏的采收成熟度均为完熟前8.5～9.0成熟度(10为完全成熟),约为花后90～95 d;随着成熟度的提高,果实质量损失率下降,贮藏后好果率也下降,与'古山二号'龙眼相比,'石硖' 龙眼的质量损失率较低,耐贮性较高. 不同成熟度果皮细胞显微结构研究表明,随着成熟度的增加,果皮结构由致密逐渐变得疏松,细胞结构变得模糊,细胞间隙逐渐增大,组织趋向分解,其变化与果实衰老、耐贮性降低的变化一致,'古山二号'龙眼耐贮性较低,这与其果皮组织结构比'石硖'疏松有关.     

不同禾本科牧草与组合秸秆混合饲料的营养特性及利用效率研究

利用体外产气技术研究了青贮玉米秸秆与稻秆组合(50∶50)与7种禾本科牧草二次组合时体外发酵特性。结果表明,不同比例组合产气量、理论最大产气量、产气速率及产气延滞时间变化趋势不同;青稻与皇竹草或黑麦草按25∶75的比例组合时的组合效应明显好于其他组合;粗蛋白及中性洗涤可溶物与产气量及产气速率间极显著(P<0.001)正相关,而中性洗涤纤维及酸性洗涤纤维则与之呈极显著(P<0.001)的负相关关系。生产实践中应针对低质粗饲料营养特性,适当添补易发酵或高蛋白牧草,提高粗饲料利用效率。     

Tillage intensity effects on soil properties and crop yields in a long-term trial on morainic loam soil in southeast Norway

Many tillage studies focus primarily on grain crops, whereas other important agricultural crops receive little attention. This paper presents yield results for various crops grown in the tenth to sixteenth year of a long-term tillage trial on loam soil in southeast Norway. Traditional plough tillage was compared with deep and shallow tine cultivation and with minimum tillage, and the residual effects of tillage were measured in the seventeenth and eighteenth years. Soil bulk density, air permeability and other soil conditions were found to be favourable for crop growth on all treatments in the tenth year. The yield levels of cereals (Hordeum vulgare L., Triticum aestivum L. and Avena sativa L.) and potatoes (Solanum tuberosum L.) showed consistent increases of 2–8% with declining tillage intensity, whereas yields of fodder beet (Beta vulgaris L.) were highest after plough tillage. The latter result was thought to be due to lower soil temperatures under reduced tillage. Yields of brassica crops were greatly affected by tillage intensity, owing to a marked reduction of clubroot (Plasmodiophora brassicae Wor.) infection with reduced tillage. Average yields for these crops were 23%, 52% and 59% higher with deep tine cultivation, shallow tine cultivation and minimum tillage, respectively, than with plough tillage. The effects were particularly dramatic in the case of fodder rape (Brassica napus L. ssp. oleifera Sinsk. f. biennis Reichb.) and cabbage (Brassica oleracea L. var. capita L.). Liming raised the yields of some brassica crops but did not influence the effect of tillage.

Soil acidity was measured twice during the trial period and again in the second residual year, and showed values which were 0.1–0.3 pH units lower with reduced tillage than with plough tillage. This rules out the conclusion that the effect of tillage on clubroot was associated directly with acidity. Positive residual effects of reduced tillage systems were found on the yields of both brassicaceous and gramineous crops. Reduced tillage intensity may thus be recommended for all crops studied, with the exception of fodder beet, on morainic loam soils of southeast Norway.     

Are Vavilov's law of homologous series and synteny related?

Summary Synteny, the co-linear arrangement of genes in related taxa, shows parallelity to Vavilov's law of homologous series and possibly provides a molecular approach for the explanation of this law.     

青海禾本科植物的生物多样性分析

对青海省禾本科植物种类多样性、植物区系多样性、外部形态特征多样性以及植被类型多样性四个方面进行了分析研究。结果表明：野生禾本科植物有55属，246种，31变种或亚种；青海特有种10种2变种，区系组成有7个分布类型和5个变型，禾本科植物的根、茎、叶、花、果实都表现出多种多样的形态特性。以禾本科植物为建群种或优势种的植被类型有17个，在这些植被类型中伴生有其它多种禾本科植物。     

A technique for identifying polyploid sectors in grass inflorescences

Summary A simple technique for counting mitotic chromosome numbers in ovaries of inflorescences has been developed and applied to grasses. The uses, as outlined, include isolating polyploid inflorescences for hybridization, and as an alternative method to root-tip squashes for chromosome morphology and banding studies.     

气温和降雨量对高寒草甸不同功能群植物产草量的影响

[目的]研究气温和降雨量对高寒草甸不同功能群植物产草量的影响。[方法]选择典型的高寒草甸为研究对象，通过对1995~2004年气温和降雨量变化的分析，对不同功能群产草量的影响进行了研究。[结果]气温和降雨量对禾本科功能群植物的产草量的影响较大，相关性均达到极显著水平；降雨量对莎草科产草量影响较大且相关性达到显著水平。[结论]不同植物个体对气温和降雨量的反应不同。该研究结果可为草地生态学研究提供理论依据。     

贺兰山禾本科植物的生态地理分布及区系特征

通过对贺兰山禾本科植物的采集调查和分析研究，发现本区有野生禾本科植物４１属、１１２种、６变种。从垂直分布来看，随着海拔由低到高的变化，种类的分布和数量都有明显的改变，其中在山地荒漠带（海拔１４００－１６００米）有３３种左右。占本区禾草总数的２８％，在山地疏林草原带（海拔１６００－２０００米）有３０种左右，占２５．４％；在山地针叶林带（海拔２０００－３０００米）约有３８种，占３２．２％；而在山地灌丛草甸带（海拔３１００－３５５６米）仅有８种左右，占６．８％。在水平分布方面，本区南部几乎包含了整个山体分布的所有禾草，而在北部分布的种类则不超过４０种。从属的分布类型来看，本区汇集了８个分布类型，其中温带分布类型有２７属，占全部禾草属数的６５．７％；热带分布类型有１０属，占２４．４％。另外本区系的禾本科植物还具有如下几个特点：（１）种类丰富，种属比值居上，是贺兰山种子植物区系中的第一大科；（２）种的地理成分混杂；（３）分布广泛，建群种和优势种较多。