The Morphology and Anatomy of Ovule and Fruit Development in Arachis hypogaea L

The vascular system of the monocarpellary gynoecium with tenwell differentiated traces and a few cross links probably representsa precocious development of the post-fertilization vasculatureof the fruit wall. The restriction of the two integuments ofthe ovule to the micropylar half, and the endothecial natureof the chalazal cells adjoining the embryo sac appear to indicatea pathway of derivation of the unitegmic tenumucellate ovulefrom the bitegmic crassinucellate one. During double fertilization,a dark staining refractive body appears in the nucleolus ofthe egg as well as the fusion product of the polar nuclei. The peg that carries the ovary into the soil after fertilizationgrows by the activity of a rib meristem at the basal solid partof the gynoecium. During sub-soil fruit development, the ovarywall develops a prominent spongy inner zone which finally disappears,and a peripheral zone that forms the mature fruit wall. Theabinitio nuclear endosperm is much reduced and degenerates afterproducing a few cell layers in the chalazal half alone. Seeddevelopment is pachychalazal. The main vascular supply of theseed branches at the chalaza into eight to ten strands in theseed coat. All seeds that have a vascular ramification in theseed coat are probably pachychalazal. In the variety Valencia, diminutive fruits with viable seedmay develop aerially from pegs that fail to grow long enoughto reach the soil from the higher nodes. Arachis hypogaea L., groundnut, fruit development, seed development, carpel vasculature, seed vasculature, pachychalaza     

烟台甜樱桃柱头的可授性、形态特征与坐果率

采用数码照相、电镜扫描、联苯胺-过氧化氢测试及去雄套袋等技术手段, 对烟台甜樱桃(Cerasus avium)花期不同发育阶段柱头的可授性、形态特征和坐果状况进行了观察。结果表明, 烟台甜樱桃在套袋状态下, 柱头可授期从开花前1天开始可持续5–7天。从杯状花期到花瓣平展期, 柱头逐渐有乳突细胞破裂并呈现分泌液, 出现渐强的可授性; 从花瓣平展期到花瓣脱落期, 柱头由暗黄渐变至暗黑, 逐渐萎缩并丧失可授性。去雄套袋及人工授粉实验结果显示, 在大蕾期、杯状花期、花瓣展放期、花瓣平展期和花瓣脱落期进行人工授粉, 烟台甜樱桃的坐果率分别为60.50%、58.33%、62.08%、57.14%和39.13%。在自然条件下烟台甜樱桃的坐果率一般为30%–42%, 传粉成功的最佳期主要发生在杯状花期至花瓣平展期。     

烟台甜樱桃柱头的可授性、形态特征与坐果率

采用数码照相、电镜扫描、联苯胺-过氧化氢测试及去雄套袋等技术手段,对烟台甜樱桃（Cerasus avium）花期不同发育阶段柱头的可授性、形态特征和坐果状况进行了观察。结果表明,烟台甜樱桃在套袋状态下,柱头可授期从开花前1天开始可持续5–7天。从杯状花期到花瓣平展期,柱头逐渐有乳突细胞破裂并呈现分泌液,出现渐强的可授性;从花瓣平展期到花瓣脱落期,柱头由暗黄渐变至暗黑,逐渐萎缩并丧失可授性。去雄套袋及人工授粉实验结果显示,在大蕾期、杯状花期、花瓣展放期、花瓣平展期和花瓣脱落期进行人工授粉,烟台甜樱桃的坐果率分别为60.50%、58.33%、62.08%、57.14%和39.13%。在自然条件下烟台甜樱桃的坐果率一般为30%–42%,传粉成功的最佳期主要发生在杯状花期至花瓣平展期。     

Morphology and Anatomy of the Fern Genus Gymnogrammitis

The anatomy and morphology of Gymnogrammitis Griffith, the genericaffinity of which has been in dispute, is described in detailfor the first time. The diagnostic features are that the stemis protected by peltate scales with both marginal and superficialhairs. Its ground tissue is parenchymatous and is provided withnumerous pits on the cell-walls. Scattered among the parenchymaare a large number of groups of tanniniferous cells. The vascularcylinder is dorsiventral and is dissected into many small subequalmeristeles. The articulation pad, separating the petiole fromthe rhizome is homogeneous and is composed of thin-walled parenchymatouscells. Two large adaxial and two or more smaller abaxial bundlessupply the petiole. The receptacles are seated on the vein andare without any indusia. Spores are bilateral and have no perine;the ektexine is thick and bears many clava- or bacula-like projections.It is argued that the genus is a well-defined taxon and thatit shows affinities with the Davallioid ferns.     

伞形琥珀螺（腹足纲，琥珀螺科）的形态解剖结构

伞形琥珀螺(Succinea daucina),最早由Pfeiffer在1854年报道。本文采用形态解剖学的方法对采自新疆乌鲁木齐南山西白杨沟(43°24.674′N,87°08.620′E,海拔1 785 m)的伞形琥珀螺进行了观察。测量并解剖了贝壳颜色分别为黄棕色和浅黄色的性成熟个体各10只,绘制了内部解剖图,应用电子扫描显微镜对两种壳色各3只个体齿舌、颚片的显微结构进行了观察和拍摄记录。伞形琥珀螺贝壳为长卵圆形,中等大小,壳高10.06~12.90 mm,壳宽6.28~8.56 mm,壳质薄,有3~3.5个螺层。其齿式为16-21:10-13:1:10-13:16-21,中央齿三锥型,侧齿和边缘齿双锥型。软体乳白色,色素点少。储精囊一个,蛋白腺、前列腺大,阴茎管状,约3/4被阴茎鞘包裹。两种壳色标本的齿舌、颚片及内部解剖特征相同,为同一种,即伞形琥珀螺。     

Morphology and Anatomy of Pisum Sativum Somatic Embryos

The morphological and anatomical aspects of direct and indirect somatic embryogenesis in pea were described. Direct embryos were induced from shoot apical meristems of 3 to 5-d-old pea seedlings, embryogenic callus originated from immature pea zygotic embryos or shoot apices. Auxin (picloram, 2,4-dichlorophenoxyacetic acid) was necessary to induce somatic embryos. The developmental stages typical for pea zygotic embryos were detected. Globular and heartshaped somatic embryos were morphologically similar to their zygotic counterparts; in contrast, torpedo and cotyledonary somatic embryos displayed great morphological variation, which affected mainly cotyledons (size, shape, number). Based on anatomical sections, possible ways of somatic embryo formation and localization of initiation sites within primary explant tissue have been proposed. The multicellular origin of somatic embryos is supposed in both systems of pea somatic embryogenesis under investigation.     

Isolation and Characterization of Beneficial Bacteria Associated with Citrus Roots in Florida

Cultivable diversity of bacteria associated with citrus was investigated as part of a larger study to understand the roles of beneficial bacteria and utilize them to increase the productive capacity and sustainability of agro-ecosystems. Citrus roots from Huanglongbing (HLB) diseased symptomatic and asymptomatic citrus were used in this study. A total of 227 and 125 morphologically distinct colonies were isolated and characterized from HLB asymptomatic and symptomatic trees, respectively. We observed that the frequency of bacterial isolates possessing various plant beneficial properties was significantly higher in the asymptomatic samples. A total of 39 bacterial isolates showing a minimum of five beneficial traits related to mineral nutrition [phosphate (P) solubilization, siderophore production, nitrogen (N) fixation], development [indole acetic acid (IAA) synthesis], health [production of antibiotic and lytic enzymes (chitinase)], induction of systemic resistance [salicylic acid (SA) production], stress relief [production of 1-amino-cyclopropane-1-carboxylate deaminase] and production of quorum sensing [N-acyl homoserine lactones] signals were characterized. A bioassay using ethidium monoazide (EMA)-qPCR was developed to select bacteria antagonistic to Candidatus Liberibacter asiaticus. Using the modified EMA-qPCR assay, we found six bacterial isolates showing maximum similarity to Paenibacillus validus, Lysinibacillus fusiformis, Bacillus licheniformis, Pseudomonas putida, Microbacterium oleivorans, and Serratia plymutica could significantly reduce the population of viable Ca. L. asiaticus in HLB symptomatic leaf samples. In conclusion, we have isolated and characterized multiple beneficial bacterial strains from citrus roots which have the potential to enhance plant growth and suppress diseases.     

The Acquisition and Utilization of Carbon in Early Spring by Kiwifruit Shoots

Measurements of net photosynthetic rate (at 1450µ molm^-2s^-1photosynthetically active radiation) of leaves, of leafand stem respiration, and of shoot growth of potentially-fruitinglaterals on kiwifruit (Actinidia deliciosa ) were used to estimateweekly shoot carbon balances over the first 10 weeks of shootgrowth (budburst to anthesis). Consistent differences in therate of shoot elongation, of internode expansion and of increasein basal diameter were found among shoots. Faster-growing (long)shoots acquired carbon by photosynthesis at a faster rate evenin the first few weeks after budburst, but the amount of carbonrequired to sustain this growth resulted in shoot carbon deficitswhich were approx. seven times greater than those of the slower-growing(short) shoots. It was estimated that the transition from shootcarbon deficit to carbon surplus occurred 3–4 weeks afterbudburst, irrespective of shoot growth rate. As a result ofsubsequent rapid increases in shoot photosynthetic rate, longshoots had a shoot carbon surplus of 4.4 g C week^-1in the weekbefore anthesis, approx. three times that of the short shoots.Defoliation (66%) of shoots 1 week after budburst, and subsequentremoval of later-emerging leaves to maintain the level of defoliation,had the effect of slowing shoot growth in the carbon deficitperiod, particularly for the long shoots. However, the durationof shoot expansion in the defoliated shoots was longer, resultingultimately in shoots which were longer than the control shoots.Linkages among early carbon balance dynamics of shoots, shootlength at anthesis, and fruit growth are discussed. Actinidia deliciosa ; kiwifruit; shoot growth; carbon acquisition; respiration; photosynthesis     

药用植物博落回形态与发育解剖学研究

博落回(Macleaya cordata)是罂粟科含有异喹啉生物碱的主要药用植物, 其生物碱提取物具有多种药理活性。目前对博落回的研究主要集中在生物碱的成分、活性和药理等方面, 对与其合成、运输、储藏密切相关的发育解剖结构及生物碱组织化学定位研究还未见报道。该文报道了温室中生长的博落回植株形态特征, 并结合徒手切片和改良碘化铋钾沉淀的方法对主要器官(根、茎、叶)的发育结构和生物碱组织化学染色进行了初步分析。结果表明, 博落回发育基本遵循一般双子叶植物的规律。根中生物碱出现在中柱鞘外的薄壁细胞和导管周围。茎和叶柄中的生物碱主要出现在维管束周围, 偶尔也出现在茎的髓细胞中。总体上, 茎中的生物碱积累量少于根。     

Relationship of Pruning and Growth Morphology with Hormone Ratios in Shoots of Pillar and Standard Peach Trees

Genotype and cultural management determine the shape of peach [Prunus persica (L.) Batch] tree canopies in orchards. Not well understood, however, is the relationship between terminal growth, lateral branching, and shoot hormone levels that can fundamentally affect tree canopy development. In this experiment, two peach cultivars with widely differing growth habits (Pillar, KV930479 and Standard, ‘Harrow Beauty’) were budded on ‘Lovell’ rootstock, planted in the field in 1998, and characterized for shoot morphology and hormone concentrations in 2002 and 2003 (the fourth and fifth leaf, respectively). Auxin (indole-3-acetic acid) and cytokinins (largely trans-zeatin riboside, dihydrozeatin riboside, and isopentenyladenosine) were measured in shoot tips (2002) and current-year shoots (2003) using mass spectrometry. In 2002, Pillar trees had less sylleptic branching, more upright growth, and higher auxin and auxin-to-cytokinin ratios than Standard trees. In Pillar trees in 2003, auxin concentrations and shoot growth were highest in current year shoots; in pruned trees, only auxin levels increased. Peach tree growth habits may be the result of altered hormone metabolism. Growth forms leading to superior production efficiency may be developed by selection based on specific target hormone concentrations and ratios.     

柑橘类果实枯水机理及防治研究进展

对柑橘类果实枯水过程中果皮、果肉的解剖结构和一些生理生化指标的变化,以及导致枯水发生的因素及控制措施的研究进展进行了综述,分析了柑橘枯水的可能机理。     

Characters of Pod Anatomy Associated with Resistance to Pod-Shattering in Soybean

Seven characteristics of pod anatomy were studied for theirassociation with resistance to pod-shattering in 16 soybean[Glycine max (L.) Merrill] varieties and strains. The thicknessand length of the bundle cap on the dorsal side of the pod andpod-wall thickness were found to be significantly negativelycorrelated with the degree of pod-shattering. Further statisticalanalyses confirmed that these three anatomical characters werealmost equally important and could potentially serve as criteriafor the selection of resistance to pod-shattering. The identifiedtraits/sites in the pod represent sclerenchymous structuresand may provide the structural basis of resistance to pod-shatteringin soybean.Copyright 1995, 1999 Academic Press Pod, anatomy, shattering, soybean, Glycine max (L.) Merrill     

Cytological Comparison of Leaves and Stems of Prunus Avium L. Shoots Cultured on a Solid Medium with Agar or Gelrite

An axillary proliferating clone of Prunus avium L. was subcul- tured every four weeks on solid MS medium with agar as the gelling agent. Vitrification (hyperhydricity) of shoots was induced in one four week cycle with the same medium except that agar was replaced by gel- rite. During culture on the vitrifying medium, the water content of the shoots progressively increased with a parallel decrease in chlorophyll content. Cytological differences between the leaves and stems of the vitrified and normal shoots were detected by light and electron (both transmission and scanning) microscopy. Leaves of vitrified shoots were characterized by lower number of chloroplasts in the palisade parenchyma and by a defective cuticle. The stems of vitrified shoots had a less developed and lignified xylem tissue, lacked sclerenchy- matic areas and showed hypertrophy of the cortical parenchyma. More intense vacuolar activity with evagina- tions of the chloroplast envelope into the vacuole was noted in cells of vitrified leaves.     

中国产异蒴藓属（Lyellia）植物形态解剖比较观察

利用扫描电镜法、徒手切片法对中国产的2种异蒴藓进行观察分析。分别观察了孢子大小、颜色、叶片和茎的长度和宽度等。结果表明异蒴藓属植物叶片的一些形态学和解剖学性状表现出了金发藓科植物所共有的特征,异蒴藓属在金发藓科中气孔较明显属于进化性状,而孢壁纹饰则属于原始性状。