唐菖蒲周年供花研究初报

本文报道唐菖蒲花期调节试验的结果,表明采用自然栽培、控制栽培及促成栽培等综合措施是实现唐菖蒲周年供花的有效途径     

唐菖蒲赤霉素受体基因克隆及表达分析

以唐菖蒲子球为材料,采用RT PCR技术,克隆了1个赤霉素（GA）受体基因,命名为GhGID1a（GenBank登录号为KU525107）。其开放阅读框为1 032 bp,编码343个氨基酸。序列比对结果表明,GhGID1a推导氨基酸序列与百子莲、油棕和海枣等植物的GID1的氨基酸序列相似性较高,分别为82%、78%和77%。50 mg/L GA₃对子球萌发具有促进作用,150 mg/L GA₃会抑制其萌发。实时荧光定量PCR结果显示,GA3处理对GhGID1a基因表达具有反馈抑制作用,GhGID1a表达量随着子球休眠解除而逐渐降低,推测唐菖蒲子球休眠解除可能与GA及其受体基因有关,GA及其受体基因GhGID1a可能参与了调控唐菖蒲的子球休眠与萌发过程。     

微波法和超声波法提取绿穗苋多糖响应面优化研究

绿穗苋是一种药食兼用作物,其中多糖成份具有很高的药食价值。本研究以绿穗苋地上部分为材料,以微波和超声波两种方法对绿穗苋多糖进行提取,并通过响应面分析法对提取进行优化,确定最佳工艺,通过水提醇沉的方法得到绿穗苋粗多糖。综合比较两种提取工艺,提取效果最佳工艺为微波提取法。其条件为:提取时间41.42 min,提取功率211.65 W,料液比1:33.338 (g/mL),实际得率为13.25%。该研究结果促进绿穗苋资源的有效利用,为绿穗苋多糖的提取工艺及产品的开发利用提供理论依据。     

A phenological scale for the development of Gladiolus

A staging system for development of gladiola (Gladiolus × grandiflorus) that relies on simple, visual, non‐destructive criteria is proposed. Four field trials were conducted during the spring 2010, autumn/winter 2011 and winter 2011 at Santa Maria, RS, Brazil, with different gladiola cultivars, in order to observe the developmental stages of the above‐ground parts and their dry matter. The developmental cycle, which starts at dormant corm and ends with plant senescence, is divided into four developmental phases: dormancy phase, sprouting phase (from filiform roots appearance to sheaths appearance), vegetative phase (from emergence of the first leaf tip to emergence of the final leaf tip on the stem) and reproductive phase (from heading to plant senescence). The developmental stages that were identified during the dormancy phase and during the sprouting phases are coded as S stages: S0 = dormant corm, S1 = appearance of roots, S2.1 = first sheath, S2.2 = second sheath and S2.3 = third sheath. Vegetative phase is coded as V stages: VE = emergence of the sheaths above ground, V1 = first leaf, V2 = second leaf, Vn = nth leaf and VF = flag leaf. Leaf tip is the marker for V1–VF. The developmental stages during the reproductive phases are coded as R stages: R1 = heading, R2 = blooming, R3 = onset of flowering, R4 = end of anthesis, R5 = end of florets senescence and R6 = plant senescence (leaves and floret axis are brown). Sub‐stages have also been assigned between R1 and R2 and between R3 and R4. Illustrations (photographs) of each developmental stage taken from field pot‐grown plants are provided and the proposed scale was tested with field observations. These criteria are straight forward and allow for quick determination of development stage. This system can be used by both farmers and for experimental trials.     

Explaining disparities in species richness between Mediterranean floristic regions: a case study in Gladiolus (Iridaceae)

Aim The causes of geographical variation in species richness in clades that do not follow the latitudinal diversity gradient have rarely been investigated. Here, we examine spatial asymmetries of diversity in Gladiolus (Iridaceae), a large genus (> 260 species) that is present in two mediterranean climate biomes: the Cape of southern Africa (106 species) and the Mediterranean Basin (7 species). Despite convergence of climatic conditions between the two regions, the species density of Gladiolus is over one order of magnitude higher in the Cape than in the Mediterranean Basin. We investigate whether the diversity disparities observed in the genus are better explained by recent colonization of species‐poor areas (temporal hypothesis) or by differential rates of diversification (evolutionary hypothesis). Location Africa, Madagascar and Eurasia Methods We employ a recently developed Bayesian method for the estimation of diversification rates and a biogeographical optimization approach within a phylogenetic framework. Results In Gladiolus, the ‘diversity anomaly’ between the two Mediterranean climate regions cannot be explained solely by the time available for speciation in the Cape, but is also due to locally reduced rates of diversification in the Mediterranean Basin. Furthermore, high overall diversity in southern Africa stems from an ancient origin in the Cape allied with high rates of diversification in the summer‐rainfall region of the subcontinent. Main conclusions Both evolutionary and temporal hypotheses must be taken into account in order to explain the diversity anomaly between the Mediterranean Basin and the Cape. Our results suggest that regions at comparable latitudes and/or with similar climate may not converge in diversity levels due to heterogeneity of diversification rates and contrasting biogeographical histories.     

A mathematical model describing the combined effect of exposure time and temperature of hot-water treatments on survival of gladiolus cormels

Gladiolus cormels of five cultivars were given hot-water treatments at 50.0°C, 52.5°C, 55.0°C or 57.5°C for different exposure times. Survival of cormels was determined. A mathematical model to describe the combined effect of exposure time and temperature on cormel death is presented. Consequences of these relationships for the practical application of hot-water treatments to control cormel-borne Fusarium oxysporum f.sp. gladioli are discussed.     

Effectiveness of Petasites hybridus preparations in the prophylaxis of migraine: A systematic review

The objective of this review was to evaluate the strength of evidence of effectiveness for Petasites hybridus in the prophylaxis of migraine. Several databases and other sources were searched to identify randomised-controlled trials investigating P. hybridus preparations. Two trials totalling 293 patients (60 and 233 patients) were included in this review. Both trials investigated the proprietary Petasites root extract Petadolex^®. The trials were described in narrative way, taking into consideration methodological quality scores. Pooling of data was not carried out due to the heterogeneity of the results. The extract at higher dose (150 mg) showed a greater decreased frequency of migraine attacks and a greater number of responders (improvement >50%) after treatment over 3–4 months than the extract at lower dose (100 mg) and placebo. Moderate evidence of effectiveness is, thus, available for a higher than the recommended dose of the proprietary Petasites root extract Petadolex^® in the prophylaxis of migraine. Further rigorous studies are required to confirm effectiveness and safety in long-term use before treatment with Petasites root extract can be recommended as an alternative option in the treatment schedule for the prophylaxis of migraine.     

Fluorescence Microscopic Observations on Actin Filament Distribution in Corn Pollen and Gladiolus Pollen Protoplasts

Actin filament (AF) distribution in Zea mays pollen and Gladiolus gandavensis pollen protoplasts was localized by FITC conjugated phalloidin fluorescence microprobe. The pollen was incubated in Brewbaker and Kwack (BK) medium, and the pollen protoplasts were isolated enzymatically and cultured in K3 medium containing various supplements by a previously reported method. Samples were fixed for 30 min with 1.5% paraformaldehyde dissolved in 0.1 mol/1 phosphate buffer (pH 7), half strength of BK elements, 1 mol/1 EGTA and sucrose, stained for 30–60 min with 1 μg/ml FITC-phalloidin in the buffer solution, and observed by a fluorescence microscopy. In hydrated corn pollen grains, the AFs constituted an irregular network. Prior to germination a part of the pollen grains showed polarized pattern of Afs. At the opposite pole to the germ pore, there was a center from which AF bundles radiated and converged toward the pore, often making a spindle-shaped configuration. In just isolated gladiolus pollen protoplasts, the AFs appeared as irregular fine network. After 4–7h of culture, the AF distribution coincided in some cases with the unevenly regenerated new wall area as exhibited by FITC-phalloidin and Calcofluor White ST double staining, indicating a possible involvement of AF in wall synthesis. After 17–18 h of culture, a part of the pollen protoplasts went on germination. The AFs became polarized in such protoplasts and converged into the tubes produced, and ran longitudinally along the tubes just like in the tubes germinated from pollen grains. However, in ungerminated pollen protoplasts, the AFs behaved abnormalty, showing various irregular arrangements. When protoplasts bursted, the actin aggregates often located at the protrusion site from which the protoplasts would burst, and were discharged into the medium. In neither corn pollen nor gladiolus pollen protoplasts AFs were observed within the generative or sperm cells.     

Fitness effects of a photosynthetic mutation across contrasting environments

To test the hypothesis that variation in photosynthesis can cause differences in fitness, we compared wild‐type (WT) Amaranthus hybridus genotypes to those having a single‐gene mutation (R) that affects photosynthetic rate. By using light and water treatments, we generated a range of differences between WT and R genotypes in photosynthetic rate, growth and reproduction at three developmental stages. In two cases photosynthetic differences were in the expected direction (WT > R), they did not differ in others, and in one case the R genotype had a higher rate than the WT. Across light and water treatments, higher rates of photosynthesis were related to increases in specific leaf area, leaf nitrogen content and stomatal conductance relative to the other genotype. Differences between genotypes in growth and allocation paralleled those in photosynthesis; in treatments where photosynthetic rate differed between the genotypes (high light), growth and reproduction did as well. In high light, the effects of genotype on fitness were indirect with high‐water availability, but were direct with low‐water availability. When photosynthetic rate did not differ between genotypes (low light), neither did growth and reproduction. These results demonstrate that variation in photosynthesis can cause differences in growth and reproduction. Furthermore, resource availability can moderate the ways in which selection operates on photosynthetic traits.     

Callus induction and plant regeneration from gladiolus

A method for the initiation of callus capable of plant regeneration from in vivo grown cormels of gladiolus (Gladiolus x grandiflorus Hort.) is described. Sliced cormels of the large-flowering hybrid, Peter Pears were cultured in vitro on a modified Murashige and Skoog medium, supplemented with various auxins. Yellow callus, which was either friable or compact, could be induced on all media tested. Callus induced on media with naphthaleneacetic acid failed to proliferate. Callus induced on media with 9 mM 2,4-dichlorophenoxyacetic acid showed the best growth. Addition of micro-elements and vitamins increased the induction and growth of callus capable of plant regeneration. Explants taken from the middle part of the cormels had the highest competence for callus initiation. Callus was induced on several gladiolus hybrids and the South African species G. garnierii Klatt. Callus induction was genotype dependent and among the cultivars tested, Peter Pears and White Prosperity were superior with respect to callus production on the media with either 2,4-dichlorophenoxyacetic acid or picloram. Plants were regenerated from yellow compact callus of all genotypes on media containing zeatin and benzyladenine in various concentrations.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - MS Murashige and Skoog basal salt and vitamins (1962) - CI callus induction medium - NAA -naphthaleneacetic acid - BA 6-benzyladenine - picloram 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid - zeatin 6-[4-hydroxy-3-methylbut-2-enylamino]purine