木霉对月季幼苗生长的影响

为了研制促进月季生长的木霉生防菌肥，采用本实验室分离鉴定的哈茨木霉T6施于月季盆栽土壤中，分析木霉菌对"十姐妹"月季硬枝扦插发芽、幼苗生长、防御酶活性和内源激素水平的影响。结果表明：施用哈茨木霉T6的月季硬枝出芽率和幼苗枝条长度分别是对照的1.4和1.82倍；并且枝条和叶的干重、枝条和叶的含水率均显著增加。此外显著提高了叶中3种防御酶SOD、POD、CAT的活性及6种内源激素IAA、GA₃、ZT、ABA、SA和JA的水平。说明木霉T6具有促进月季生长和提高其抗性的作用，研究结果为研制促进月季生长的生物菌肥提供理论依据。     

Social structure,habitat use and breeding biology of hedgerow Dunnocks Prunella modularis

A population of Dunnocks Prunella modularis inhabiting hedgerows was studied over a period of four years in order to examine the habitat structure of breeding territories and to attempt to determine how the constraints imposed by the linear structure of hedgerows might influence the mating combinations and breeding success. Eleven monogamous and 14 polyandrous territories were observed. No examples of polygyny or polygynandry were recorded. Polyandrous territories were significantly larger than monogamous territories but contained significantly more grassland, which is of little value for Dunnock foraging. Overgrown hedgerows formed the largest component of territories, and young and overgrazed hedgerow types constituted only a small area. All territories supported large patches of Nettle Urtica dioica and Bramble Rubus fruticosus/Dog Rose Rosa canina, the latter supporting most Dunnock nests. Clutch sizes, nestling weights and numbers of young fledged did not differ significantly between monogamous and polyandrous systems, but sample sizes were small. It is suggested that the restricted availability of mature overgrown hedgerows, the relatively low breeding density and the linear shape of hedgerows contributed towards the less complex mating system. The preference for overgrown hedgerows with basal outgrowths of Nettle and Bramble/Rose is discussed in the light of the recent decline of the Dunnock on farmland.     

Aeciospore-surface structures of Phragmidium species parasitic on roses

Aeciospore-surface structures of Phragmidium species parasitic on roses were investigated by scanning electron microscopy. Seven kinds of structures were distinguished according to gross shape of ornamentations and their distribution on the aeciospore wall. The seven different structures were categorized into three major types: echinulate, annulate, and verrucose. The echinulate type was further classified into five types and designated in a numerical series, echinulate types 1–5. Application of the aeciospore-surface structures in the classification of Phragmidium species is discussed. Received: November 13, 2001 / Accepted: January 12, 2002     

The effect of polyamines on leaf senescence in two diverse rose species

Polyamines (PAs) retarded the senescence of leaf discs of two diverse speciesof rose viz., Rosa bourboniana andRosa damascena, while polyamine biosynthetic inhibitorsdifluoromethylornithine (DFMO), difluoromethylarginine (DFMA), methylglyoxal-bis(guanylhydrazone) (MGBG) and abscisic acid (ABA) promoted senescence. Sperminewas significantly the most effective polyamine in retarding senescence inR. bourboniana while MGBG and DFMA were more prominent inaccelerating senescence in R. damascena and R.bourboniana respectively. Protein and RNA content were significantlyhigher in polyamine treated leaf discs compared to those treated with polyaminebiosynthetic inhibitors and ABA. Total and reducing sugars decreased under alltreatments while the starch content increased significantly only in polyaminetreated leaf discs. Peroxidase and cellulase activities were retarded bypolyamine treatments and accelerated by polyamine biosynthetic inhibitors andABA. The role of PAs is discussed in relation to senescence.     

Kinetics of efflux of K+ from cultured rose cells treated with ultraviolet light

Irradiation of cultured rose ( Rosa damascena Mill. cv. Gloire de Guilan) cells with ultraviolet light caused of loss of K⁺, which occurred with sigmoid kinetics. The kinetics of loss of K⁺ were not changed when the extracellular concentration of K⁺ was held constant during the period of efflux. Furthermore, the rate of loss of K⁺ was approximately the same even though the K⁺ concentration in the medium was increased from 0.1 to 10 m M . The kinetics of uptake of the lipophilic methyltriphenylphosphonium cation, an indicator of the plasma membrane potential, were linear throughout the period of K⁺ efflux, suggesting that the starting and stopping of K⁺ efflux do not reflect a passive response to changes in the membrane potential of the cells. The results are interpreted in terms of activation and inactivation of an efflux channel or pump for K⁺.     

Rose leaf elasticity changes in response to mycorrhizal colonization and drought acclimation

Tissue elasticity can affect plant response to drought, in terms of turgor maintenance and water uptake from drying soils. The purpose of this study was to determine the effect of mycorrhizal colonization and drought acclimation on rose ( Rosa hybrida L. cv. Samantha) leaf elasticity. Bulk elasticity was characterized by the pressurevolume method using plots of the elastic modulus as a function of leaf turgor pressure, total water potential and relative water content. The treatments, arranged in a 2 × 3 factorial design, included acclimated and unacclimated plants, and either Glomus irararadices Schenck and Smith, Glomus deserticola Trappe, Bloss and Menge, or a non-mycorrhizal control. Plants with root mycorrhizal colonization showed reduced leaf elasticity (i.e. higher elastic moduli) over a broad range of leaf waler potential and water content. Both mycorrbizal colonization and acclimation facilitated the maintenance of positive values of turgor and elasticity at lower leaf water potential and water content than in controls. Mycorrhizal infections may aid plants in acclimating to water deficits through effects on leaf tissue elasticity.     

The Development of Activity of Cell Wall Bound β-Fructofuranosidase with Ripening and Senescence of Tomato Fruit

Optically active trisubstituted and tetrasubstituted cyclopentanes, with proper functional groups of proper stereochemistry as precursors for chiral synthesis of brefeldin A and prostaglandins, were prepared stereoselectively from carbohydrate.