小盐芥营养器官的结构特点与其盐渍环境的关系研究

利用石蜡切片法研究了盐生植物小盐芥(Thellungiella halophila)营养器官的解剖结构。结果表明：小盐芥根的初生结构中表皮细胞为1层,且细胞大而高度液泡化,根毛数量较少;皮层仅由外皮层和内皮层2层细胞构成,细胞大,排列紧密;根次生维管组织发达。茎的初生结构中外剀维管束8～10束,大小不等,呈一轮排列;髓和髓射线发达;茎次生结构中维管组织也很发达。根和茎的这些结构特点提高了植物体吸收、运输水分的能力,而且根的特殊结构和输导系统将盐分限制在根内,适应于盐渍环境所造成的渗透胁迫和干旱胁迫。小盐芥叶片较小,上、下表皮细胞各1层,细胞大而高度液泡化,叶肉中栅栏组织与海绵组织分化不明显,但叶绿体体积大、数目多,细胞间隙较大,通气性能好,光合效率高。这些特点对其适应干旱盐渍环境有重要意义。小盐芥上述结构特征与典型真盐生植物、旱生植物相去其远,其营养器官内也无盐腺、囊泡等泌盐结构。由此推论,小盐芥更倾向于似盐生植物(拒盐植物)。     

川西高原4种高山海棠的根茎解剖结构特征及其抗旱响应策略分析

采用石蜡制片法对川西高原区4种高山海棠的根、茎解剖结构进行观测分析,明确根茎结构特征与抗旱性的关系,揭示高山海棠的抗旱适应策略。结果表明:(1)4种海棠植物根茎的解剖构造基本相似,根由周皮组织和维管组织构成,茎由周皮组织、皮层薄壁组织、维管组织和髓组成。(2)根茎中均发现特化结构:根系中木射线细胞增宽至6~8列,有利于增强植物根系的水分横向运输;茎中的栓内层厚壁细胞、环髓带中的厚壁细胞以及导管周围的"假薄壁细胞"均是增强水分输导和机械支持的特化结构特征。(3)4种高山海棠植物在响应干旱逆境时采取的策略有所不同,其中,变叶海棠(Malus toringoides)主要通过根茎中发达的输导组织响应干旱逆境,花叶海棠(M.transitoria)根中强壮的韧皮部和茎中发达的髓结构使之能很好地适应干旱环境,山荆子(M.baccata)通过根中孔径较大的导管和茎中强大的韧皮部来响应干旱逆境,湖北海棠(M.hupehensis)根系中发达的栓内层、韧皮部结构和茎中宽广的髓结构使得干旱适应能力增强。     

青藏高原地区刺山柑解剖特征研究

采用石蜡切片法对分布于海拔4 000 m的西藏札达的刺山柑解剖结构进行研究,进一步探讨青藏高原植物独特生理结构及其与环境的适应性。结果表明刺山柑具有适应高山荒漠草原环境的典型结构特征: 次生根周皮发达,具有较厚的木栓层和发达的次生木质部;茎具表皮毛和角质层,皮层较厚,厚角组织发达,髓较小;叶具角质层,气孔密集,栅栏组织多层,为双栅型等面叶;花冠较大,白色花瓣,适于虫媒传粉;侧膜胎座,子房多室,胚珠多数,花粉外壁较厚,具较强的抗腐蚀及抗酸碱性能。刺山柑形成上述结构特征是青藏高原特殊综合生态环境长期作用的结果。同时也是刺山柑对高原环境的高度适应。     

贺兰山10种不同植物的旱生结构研究

对贺兰山10种不同生活型植物的形态解剖研究表明,长期生长在干旱贫瘠环境中植物,均形成适应生境的一些特殊形态结构．叶器官主要表现在：（1）叶表面积与体积之比缩小,表面覆有厚的角质膜,并被有表皮毛,气孔下陷,具孔下室;（2）栅栏薄壁组织细胞明显增多,海绵薄壁组织细胞减少．有叶肉不分化叶、等而叶和异而叶3种结构形式;（3）叶内贮水组织和机械组织增强。轴器官主要表现在：（1）根普遍形成周皮,且木栓层细胞层数增多;（2）机械组织非常发达,在周皮、皮层和韧皮部中有许多厚壁细胞分布。维管组织中的木薄壁细胞的细胞壁也明显木质化加厚;（3）有些植物的根具有异常维管组织。另外,这些植物根、茎、叶中均有粘液细胞和含晶细胞分布。这些结构具有重要的适应干旱生境的意义。     

菰适应湿地环境的解剖和屏障结构特征研究

菰(Zizania latifolia)是一种多年生挺水植物,为了探讨该植物根、茎和叶的解剖结构、组织化学及其质外体屏障的通透性生理。该文利用光学显微镜和荧光显微镜,对菰的根、茎、叶进行了解剖学和组织化学研究。结果表明:(1)菰不定根解剖结构由外而内分别为表皮、外皮层、单层细胞的厚壁机械组织层、皮层、内皮层和维管柱;茎结构由外而内分别为角质层、表皮、周缘厚壁机械组织层、皮层、具维管束的厚壁组织层和髓腔。叶鞘具有表皮和具维管束皮层,叶片具有表皮,叶肉和维管束。(2)不定根具有位于内侧的内皮层及其邻近栓质化细胞和外侧的外皮层组成的屏障结构;茎具内侧厚壁机械组织层,外侧的角质层和周缘厚壁机械组织层组成的屏障结构,屏障结构的细胞壁具凯氏带、木栓质和木质素沉积的组织化学特点,叶表面具有角质层。(3)菰通气组织包括根中通气组织,茎、叶皮层的通气组织和髓腔。(4)菰的屏障结构和解剖结构是其适应湿地环境的重要特征,但其茎周缘厚壁层和厚壁组织层较薄。由此推测,菰适应湿地环境,但在旱生环境中分布有一定的局限性。     

高山红景天解剖学研究

高山红景天(Rhodiola sachalinensis A.Bor.)根、茎、叶中均有发达的通气组织, 根中的通气组织是维管射线细胞破裂形成的。根中任何薄壁组织细胞中均含有固体蛋白质。茎中维管束环外有糊粉层。叶肉细胞中的固体蛋白质多数存在于叶脉周围。植物体内丰富的蛋白质构成了其较强抗冻能力的物质基础。根中木栓十分发达。     

朝鲜越桔的解剖结构及其环境适应性

朝鲜越桔(Vaccinium hirtum Thunb.var.koreanum(Nakai)Kitamura)是辽宁省珍稀濒危保护植物,主要分布于长白山脉南端,生长于中高山顶部光照充足的岩石缝隙及峭壁之上,具有适应山顶部瘠薄、干旱、寒冷以及强风等极端环境的特征。然而,关于朝鲜越桔解剖结构及抗性的研究尚未见报道。本文通过石蜡切片法对朝鲜越桔的根、茎、叶进行解剖结构的观察,揭示其解剖结构与环境适应性之间的关系。结果表明,朝鲜越桔多年生侧根的输导组织发达,毛细根的表皮及皮层细胞体积较大,内皮层细胞中存在着大量的固体状内含物,且毛细根中具有大量的杜鹃花类菌根菌、深色有隔内生菌及丛枝菌根菌,这些特征有利于其根系对于水分和营养物质的吸收。茎部解剖显示,一年生茎的表皮外侧具有较厚的角质层(10.74±0.89)μm,皮层厚壁细胞和髓细胞中具有大量的固状内含物,表皮内侧皮层中具有特殊的气腔结构,其厚度占茎半径的30%,这些特征将提高植株的保水性和耐低温的能力;另外,茎部韧皮组织发达,有利于水分和养分的输送。叶部结构特征显示,叶片上表面及下表面均覆盖了一层较厚角质膜,分别为(2.06±0.75)、(2.04±0.73)μm,叶脉的韧皮组织发达,这将有利于提高其耐旱及吸水性能。综合分析认为,朝鲜越桔的解剖结构反映其具有耐旱、耐寒、抗风及保水的特性,是其能够适生于辽东地区山顶部恶劣生境的重要原因之一。     

30种新疆沙生植物的结构及其对沙漠环境的适应

新疆３０种沙生植物营养器官的解剖学研究表明,它们的形态结构为适应沙漠环境发生相应变化。叶片表面积／体积比普遍小于中生植物;表皮细胞外壁具厚的角质膜,并覆盖毛状体,气孔下陷,具有孔下室;按叶肉结构的差别,３０种沙生植物的叶片可归为正常型、全栅型、环栅型、不规则型、禾草型、退化型等６类。轴器官中普遍具有发达的机械组织,一些植物形成异常结构;根的周皮发达;茎中基本组织／半径比率较大;部分植物形成同化枝,有的茎、叶中存在粘液细胞或结晶。按其适应沙生环境的形态结构特点,可以分为薄叶植物、多浆植物、肉茎植物以及卷叶植物等４类。沙生植物以不同的旱生结构特征和不同的方式适应沙漠环境。     

2种高山海棠营养器官的解剖结构及其生态适应性研究

采用NaOCl法、石蜡切片法对分布于海拔3 000 m的川西高原野生变叶海棠和花叶海棠的叶、茎、根进行了研究,旨在分析2种高山海棠营养器官的解剖构造,并探讨其解剖特征与川西高原干旱贫瘠地区的生态适应关系。结果表明:变叶海棠和花叶海棠的解剖构造极为相似,这可能与二者在起源及地理分布等的密切联系有关:二者叶的上下表皮细胞均具有厚的角质层,且上表皮气孔缺失、下表皮气孔密集,栅栏组织较厚,叶柄中具有分化出栅栏组织和海绵组织的纵棱脊结构;二者茎中的栓内层细胞壁较厚,次生木质部发达,导管周围分布着细胞壁木质化的木薄壁组织细胞,髓的外围有一圈细胞壁增厚的环髓带细胞;2种海棠的细根中已出现典型的次生结构,木质部占有极大的比例,主要以单管孔的形式存在的导管密集,无髓结构。变叶海棠和花叶海棠的上述解剖结构特征体现了二者对川西高原地区干旱环境都具有较强的适应能力。     

濒危植物海南风吹楠营养器官解剖结构特征

该研究采用石蜡切片和光学显微技术,对海南风吹楠营养器官的解剖结构及其对环境的适应性进行了探讨。结果表明:海南风吹楠为典型异面叶,叶片中脉发达,中部分化出髓,上表皮外侧具角质层,内侧具1层内皮层,下表皮外侧无角质层,有气孔器分布,气孔器为双环型,略下陷;栅栏组织3~4层细胞,海绵组织4~6层细胞。茎的初生结构中表皮轻微角质化,维管束为外韧型,8~10个初生维管束围绕髓排列为1轮;茎的次生结构中,表皮外部角质层加厚,维管柱紧密排列连成环状,次生韧皮部和次生木质部发达,形成层细胞3~5层。根的初生结构中表皮细胞外壁加厚,外皮层细胞体积大,形状不规则,内侧具1层形成层,内皮层具凯氏带,初生木质部为多原型,呈辐射状排列。根的次生结构中木栓层细胞5~6层,木栓层内侧具1层木栓形成层,栓内层细胞3层。海南风吹楠营养器官具有一定耐阴和耐旱结构特征,同时与其生活的热带雨林沟谷中高温荫湿的环境相适应。     

Y-chromosome Data and Tribal Affiliations of Allenopithecus and Miopithecus

The phylogeny of Old World monkeys has remained unresolved in part because of a lack of resolution in the Cercopithecinae. Competing morphological hypotheses have had Allen's swamp monkey (Allenopithecus nigroviridis) and the talapoins (Miopithecus spp.) as basal branches of either the tribe Cercopithecini or the tribe Papionini. Previous molecular analyses have not adequately addressed the issue. To better understand the evolutionary history of these primates, we sequenced and subjected to phylogenetic analysis 3.1 kb of 2 loci (TSPY and SRY) from the non-recombining portion of the Y-chromosome. Individuals from the genera Allenopithecus, Miopithecus, Erythrocebus, Chlorocebus, and Cercopithecus were surveyed and their sequences compared with those previously published for the Papionini and Colobinae. The results suggest Allenopithecus and Miopithecus are more closely related to the Cercopithecini than Papionini. Our data also support the hypothesis that within the Cercopithecini, Erythrocebus and Chlorocebus share a close evolutionary relationship, distinct from the other members of the tribe.     

Ovule and seed anatomy ofCistaceae and relatedMalvanae

Ovule and especially seed anatomy of eight species ofCochlospermaceae, Bixaceae, Cistaceae, Monotoideae, Pakaraimaeoideae (two subfamilies ofDipterocarpaceae), andSarcolaenaceae were investigated. All representatives show a bixoid chalazal region in the seed as probable exclusive synapomorphy among angiosperms. The palisade layer of the exotegmen is curved inwards at its proximal end and forms a dome-shaped structure. A plug of hypostase tissue with an annulus/core structure fits into this dome. Moreover, two additional tissue types in the hypostase can be found in some representatives of the group. These and other micromorphological, wood anatomical, and floral morphological characters, indicate that the taxa form a monophyletic group close toMalvales s. str. The form of the starch grains in the endosperm is compared and is described for the first time forPakaraimaea (Dipterocarpaceae) andLeptolaena (Sarcolaenaceae). The position ofDiegodendron close toBixa and the presumably more distant positions ofMuntingia andNeuradaceae are discussed.     

Nystatin and killer toxin sensitivity of free and immobilizedSaccharomyces cerevisiae

The inhibitory effect of nystatin and killer toxin on the growth of free and covalently-immobilizedSaccharomyces cerevisiae cells was studied. The resistance of immobilized cells to both agents was accompanied by increased amounts of phospholipids and sterols. The possible relationship between these changes in the membrane composition and the transduction of a signal across the cytoplasmic membrane is discussed.     

Amino acids and sugars in nectar,and their putative evolutionary significance

Individual amino acids and sugars from flower nectar of 32 plant species with different pollination systems were quantified and compared. Data show that there is no correlation between sugar and amino acid concentration. Furthermore there is no correlation between composition and concentration of amino acids and evolutionary advancement, nor any direct relation with pollination systems. However, higher sugar concentrations are often linked with more advanced morphological characters. Nectars from pierced or damaged flowers or nectars contaminated with pollen exhibit modifications and increases in amino acid composition. The presence of proline probably indicates such pollen contamination. Most pollinating animals depend on flower nectar in their energetic requirements, yet innumerable alternative amino acid and protein sources exist. Future research has to consider the relationship between nutritional requirements of pollinating animals and dependence on flower nectars.Dedicated to Prof. Dr.L. van der Pijl, Den Haag, in honour of his 80th birthday.     

Cyclooxygenase inhibitory and antioxidant cyanidin glycosides in cherries and berries

Anthocyanins from tart cherries, Prunus cerasus L. (Rosaceae) cv. Balaton and Montmorency; sweet cherries, Prunus avium L. (Rosaceae); bilberries, Vaccinum myrtillus L. (Ericaceae); blackberries, Rubus sp. (Rosaceae); blueberries var. Jersey, Vaccinium corymbosum L. (Ericaceae); cranberries var. Early Black, Vaccinium macrocarpon Ait. (Ericaceae); elderberries, Sambucus canadensis (Caprifoliaceae); raspberries, Rubus idaeus (Rosaceae); and strawberries var. Honeoye, Fragaria x ananassa Duch. (Rosaceae), were investigated for cyclooxygenase inhibitory and antioxidant activities. The presence and levels of cyanidin-3-glucosylrutinoside 1 and cyanidin-3-rutinoside 2 were determined in the fruits using HPLC. The antioxidant activity of anthocyanins from cherries was comparable to the commercial antioxidants, tert-butylhydroquinone, butylated hydroxytoluene and butylated hydroxyanisole, and superior to vitamin E, at a test concentration of 125 microg/ml. Anthocyanins from raspberries and sweet cherries demonstrated 45% and 47% cyclooxygenase-I and cyclooxygenase-II inhibitory activities, respectively, when assayed at 125 microg/ml. The cyclooxygenase inhibitory activities of anthocyanins from these fruits were comparable to those of ibuprofen and naproxen at 10 microM concentrations. Anthocyanins 1 and 2 are present in both cherries and raspberry. The yields of pure anthocyanins 1 and 2 in 100 g Balaton and Montmorency tart cherries, sweet cherries and raspberries were 21, 16.5; 11, 5; 4.95, 21; and 4.65, 13.5 mg, respectively. Fresh blackberries and strawberries contained only anthocyanin 2 in yields of 24 and 22.5 mg/100 g, respectively. Anthocyanins 1 and 2 were not found in bilberries, blueberries, cranberries or elderberries.     

Pollen morphology ofSonchus and related genera,and a general discussion

The pollen morphology of the taxa belonging to the generaAetheorhiza Cass.,Launaea Cass.,Reichardia Roth andSonchus L. in the Iberian Peninsula has been studied with light and electron microscopy. The pollen is 3(-4)-zonocolporate and echinolophate (without polar lacunae, but in general with prelacunae), with equatorial ridges and 15–20 lacunae: 3–4 poral, 6–8 abporal and 6–8 paraporal. Small to medium size, P × E = 19–36 × 23–42 µm; sometimes two different sizes have been found. Exine 3–9 µm thick and ornamentation microreticulate and echinate. The results clearly show the relationships between genera. Moreno-Socías, E., Mejías, J. A., Díez, M. J., 1994: Morfología polínica deLactuceae (Asteraceae) en la Península Ibérica, I.Lactuca y géneros relacionados. — Acta Bot. Malacitana.19: 103–113.     

Utilized and potentially utilizable seaweeds on the Namibian coast: biogeography and accessibility

Of the 1500 km coast of Namibia, only 80 km is predominantly rocky, the remaining 1420 km being sandy with only minor rocky outcrops. At present two species are utilized, Gracilaria verrucosa for agar and Laminaria schinzii for human consumption. Other potentially utilizable seaweeds occurring on the coast are Ecklonia maxima for alginates, Suhria vittata for agar, Gigartina radula, G. stiriata and Aeodes orbitosa for carrageenans and Porphyra capensis for human consumption. Laminaria schinzii also can be used for alginate production. Due to the diamond-mining areas around the 80 km rocky area at Luderitz (26° 39 S), only 20 km are accessible; hence, at present the seaweeds are being exploited almost to their full potential. The species currently not being utilized could be used, however, to support the industry that already exists at Luderitz. To increase production, access to the diamond areas would have to be gained or a cultivation program initiated.     

Molecular identification and differentiation of Brevibacterium species and strains

Amplified ribosomal DNA restriction enzyme analysis (ARDRA), pulsed field gel electrophoresis (PFGE) and ribotyping were used to differentiate among 24 strains of Brevibacterium linens, Brevibacterium casei and Brevibacterium epidermidis obtained from type culture collections or isolated from various smear ripened cheeses. ARDRA was applied to the 16S rDNA. B. linens was shown to be a quite heterogenic group with 2 to at least 4 copies of rrn operons per strain with aberrant nucleotide sequences. AccI gave genus specific restriction patterns and was used to separate Brevibacterium from Corynebacterium species. The expected species specificity of TaqI applied to B. linens type culture strains, but not to all strains isolated from cheese. By AvaI restriction, B. casei and B. linens were differentiated from B. epidermidis and the orange pigmented Arthrobacter casei, a new species of coryneform bacteria; by XmnI restriction, B. linens and B. epidermidis were differentiated from B. casei. One of 4 B. linens genotypes could not be distinguished from B. casei by this method. Here, the typical orange B. linens pigments were used for classification, which was confirmed by partial sequencing of the 16S rDNA.     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.     

The hernandez and fernandez genes of Drosophila specify eye and antenna

The formation of different structures in Drosophila depends on the combined activities of selector genes and signaling pathways. For instance, the antenna requires the selector gene homothorax, which distinguishes between the leg and the antenna and can specify distal antenna if expressed ectopically. Similarly, the eye is formed by a group of "eye-specifying" genes, among them eyeless, which can direct eye development ectopically. We report here the characterization of the hernandez and fernandez genes, expressed in the antennal and eye primordia of the eye-antenna imaginal disc. The predicted proteins encoded by these two genes have 27% common amino acids and include a Pipsqueak domain. Reduced expression of either hernandez or fernandez mildly affects antenna and eye development, while the inactivation of both genes partially transforms distal antenna into leg. Ectopic expression of either of the two genes results in two different phenotypes: it can form distal antenna, activating genes like homothorax, spineless, and spalt, and it can promote eye development and activates eyeless. Reciprocally, eyeless can induce hernandez and fernandez expression, and homothorax and spineless can activate both hernandez and fernandez when ectopically expressed. The formation of eye by these genes seems to require Notch signaling, since the induction of ectopic eyes and the activation of eyeless by the hernandez gene are suppressed when the Notch function is compromised. Our results show that the hernandez and fernandez genes are required for antennal and eye development and are also able to specify eye or antenna ectopically.