Molecular identification of Mango, Mangifera indica L.var. totupura

Mango (>Mangifera indica) belonging to Anacardiaceae family is a fruit that grows in tropical regions. It is considered as the King of fruits. The present work was taken up to identify a tool in identifying the mango species at the molecular level. The chloroplast trnL-F region was amplified from extracted total genomic DNA using the polymerase chain reaction (PCR) and sequenced. Sequence of the dominant DGGE band revealed that Mangifera indica in tested leaves was Mangifera indica (100% similarity to the ITS sequences of Mangifera indica). This sequence was deposited in NCBI with the accession no. GQ927757. ABBREVIATIONS: AFLP - Amplified fragment length polymorphism , cpDNA - Chloroplast DNA, DDGE - Denaturing gradient gel electrophoresis, DNA - Deoxyribo nucleic acid, EDTA - Ethylenediamine tetraacetic acid, HCl - Hydrochloric acid, ISSR - Inter simple sequence repeats, ITS - Internal transcribed spacer, MATAB - Methyl Ammonium Bromide, Na(2)SO(3) - Sodium sulphite, NaCl - Sodium chloride, NCBI - National Centre for Biotechnology Information, PCR - Polymerase chain reaction, PEG - Polyethylene glycol, RAPD - Randomly amplified polymorphic DNA, trnL-F - Transfer RNA genes start codon- termination codon.     

芒果子叶切段不定根形成的影响因素分析

分别用不同成熟时间、不同取材部位、不同品种、不同大小的芒果子叶切段为外植体进行不定根的诱导,以探讨影响芒果子叶切段不定根形成能力的原因.结果表明,芒果子叶切段的生根能力随着芒果成熟度的增加而逐渐提高,花后50和60 d的2.0 cm长子叶切段都无不定根形成,从花后70 d开始有不定根形成,此时生根率为28.6%,之后其生根能力迅速提高,在花后90 d生根率达到76.7%,之后生根率稳定保持直到110 d果实成熟.成熟芒果的子叶切段长度(2.0、1.0、0.5和0.2 cm)对不定根的形成有显著影响,0.2 cm的子叶切段上无不定根形成,另外3个长度的切段都有不定根形成,且生根能力随着长度的增大而逐渐提高.取材位置(靠近或远离胚轴)则对生根影响不大,且紫花芒、红芒、青皮芒等几种常见芒果品种的不定根形成能力基本相同.     

芒果花药发育的细胞化学研究

芒果花药发育中,花药药壁体细胞中淀粉粒多糖和脂滴类物质一直很少,仅药室内壁细胞中有零星淀粉粒分布.到二胞花粉早期,花粉营养细胞中的大液泡消失,开始积累淀粉粒.芒果成熟花粉中储存营养物质主要是淀粉粒,而脂类物质一直很少.     

Analysing growth and development of plants jointly using developmental growth stages

Background and Aims Plant growth, the increase of organ dimensions over time, and development, the change in plant structure, are often studied as two separate processes. However, there is structural and functional evidence that these two processes are strongly related. The aim of this study was to investigate the co-ordination between growth and development using mango trees, which have well-defined developmental stages.Methods Developmental stages, determined in an expert way, and organ sizes, determined from objective measurements, were collected during the vegetative growth and flowering phases of two cultivars of mango, Mangifera indica. For a given cultivar and growth unit type (either vegetative or flowering), a multistage model based on absolute growth rate sequences deduced from the measurements was first built, and then growth stages deduced from the model were compared with developmental stages.Key Results Strong matches were obtained between growth stages and developmental stages, leading to a consistent definition of integrative developmental growth stages. The growth stages highlighted growth asynchronisms between two topologically connected organs, namely the vegetative axis and its leaves.Conclusions Integrative developmental growth stages emphasize that developmental stages are closely related to organ growth rates. The results are discussed in terms of the possible physiological processes underlying these stages, including plant hydraulics, biomechanics and carbohydrate partitioning.     

The antagonistic effect and mechanisms of Bacillus amyloliquefaciens DGA14 against anthracnose in mango cv. ‘Carabao’

Bacillus amyloliquefaciens strain DGA14 was tested for in vitro antagonism towards Colletotrichum gloeosporioides, a causal pathogen of anthracnose in mango cv. ‘Carabao’. DGA14 produced extracellular metabolites in solid and liquid media that suppressed the growth of C. gloeosporioides. The cells of DGA14 were often observed adjacent to the pathogen so affecting its spore germination and mycelium development. DGA14 colonised mango fruit 48 h after artificial inoculation and persisted 14 days after storage at 18–20°C. On fruit surfaces, DGA14 attached and produced dents to spores of C. gloeosporioides. Dipping mangoes in aqueous cell suspension (10⁸ mL L^?1) of DGA14 significantly decreased the incidence of anthracnose as compared to untreated fruit.     

芒果叶化学成分研究 II

为探讨芒果(Mangifera indica L.)的化学成分,从芒果叶的70%乙醇提取物中分离鉴定了13个化合物,经波谱分析,分别鉴定为:(–)-secoisolariciresinol-9′-O-D-glucopyranoside(1)、7S,8R-erythro-4,7,9-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan-9′-O-β-D-glucopyranoside(2)、7R,8R-threo-4,7,9-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan-9′-O-β-D-glucopyranoside(3)、(7R/S,8R)-7,8-dihydro-9′-hydroxyl-3′-methoxyl-8-hydroxymethyl-7-(4-hydroxy-3-methoxyphenyl)-1′-benzofuranpropanol 9′-O-β-D-glucopyranoside(4)、citrusin D(5)、丁香苷(6)、2,6-二甲氧基-4-羟基苯基-1-O-β-D-葡萄糖苷(7)、原儿茶酸(8)、没食子酸(9)、没食子酸甲酯(10)、没食子酸乙酯(11)、4,5-二羟基-3-甲氧基苯甲酸(12)、β-胡萝卜苷(13)。其中化合物1～7和12为首次从芒果属植物中分离得到。     

Assessing allometric models to predict vegetative growth of mango (Mangifera indica; Anacardiaceae) at the current-year branch scale

? Premise of the study: Accurate and reliable predictive models are necessary to estimate nondestructively key variables for plant growth studies such as leaf area and leaf, stem, and total biomass. Predictive models are lacking at the current-year branch scale despite the importance of this scale in plant science. ? Methods: We calibrated allometric models to estimate leaf area and stem and branch (leaves + stem) mass of current-year branches, i.e., branches several months old studied at the end of the vegetative growth season, of four mango cultivars on the basis of their basal cross-sectional area. The effects of year, site, and cultivar were tested. Models were validated with independent data and prediction accuracy was evaluated with the appropriate statistics. ? Key results: Models revealed a positive allometry between dependent and independent variables, whose y-intercept but not the slope, was affected by the cultivar. The effects of year and site were negligible. For each branch characteristic, cultivar-specific models were more accurate than common models built with pooled data from the four cultivars. Prediction quality was satisfactory but with data dispersion around the models, particularly for large values. ? Conclusions: Leaf area and stem and branch mass of mango current-year branches could be satisfactorily estimated on the basis of branch basal cross-sectional area with cultivar-specific allometric models. The results suggested that, in addition to the heteroscedastic behavior of the variables studied, model accuracy was probably related to the functional plasticity of branches in relation to the light environment and/or to the number of growth units composing the branches.     

Analysis of diversity and relationships among mango cultivars using Start Codon Targeted (SCoT) markers

Genetic variation and relationships among 47 mango germplasm and 3 relative species from Guangxi province in China, were analyzed using Start Codon Targeted (SCoT) markers. Using 33 selected SCoT primers 273 bands were generated with an average of 8.27 bands per primer among the 50 accessions, of which 208 (76.19%) were polymorphic. Genetic relationships estimated using the SM similarity coefficient generated values between different pairs of accessions that varied from 0.531 to 0.923 with an average of 0.782. These coefficients were utilized to construct a dendrogram using the UPGMA. All 50 accessions were basically classified into six clusters and correspond well with their recorded pedigrees. The results will provide much more useful information for the management of germplasm and will also be useful to improve the current breeding strategies. The results also demonstrate that the SCoT marker system is useful for identification and genetic diversity analysis of mango cultivars.     

Effects of hot water treatments and storage temperatures on the ripening and the use of electrical impedance as an index for assessing post-harvest changes in mango fruits

The effects of hot water treatment and storage temperature (4°C, 13°C or 22°C) on the quality and impedance of outer and inner mesocarp of mango were assessed in two experiments during storage, impedance being a potential non‐destructive measure of tissue damage following heat treatment. Fruits were subjected to equivalent heat units at 36.5°C for 60 min plus 46.5°C for 43 min or 46.5°C for 90 min by hot water treatments (hwt) on the assumption of cumulative heat effects and a base temperature of 12–13°C. Fruit reflectance decreased whereas chroma and hue angle increased over storage time and also with increase in storage temperature. The yellow colour increased with a rise in storage temperature in hot water treated mangoes. Soluble solids content of mangoes held at 22°C was highest at 5 days of storage but decreased subsequently over storage time. Impedance of all fruits decreased with increase in frequency, storage temperature and time in store. The impedance of hwt mangoes was lower than that of non‐hwt fruits 8 h after immersion, but recovered almost to control levels on day 5 at 4°C or 13°C, but decreased gradually after 5 days at 13°C. Impedance of all mangoes stored at 22°C decreased continuously during storage. Impedance was higher in the inner mesocarp than outer pulp. Impedance of hwt fruits was poorly correlated with soluble solid content and chroma but well correlated with reflectance of fruit pulp at 22°C. Changes in impedance of mangoes are discussed in relation to physiological and biochemical changes that occur during heat treatment and storage.     

Temporal effect of 2,4-D on induction of embryogenic nuclellar cultures and somatic embryo development of ‘Carabao’ mango

Summary Embryogenic nucellar cultures were established on B5 major salts, MS minor salts and organics, 400 mg/l⁻¹ glutamine, 60 g/l⁻¹ sucrose, 2 g/l⁻¹ gellan gum, and 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D). There was no clear relationship between developmental age of the nucellar explants and induction of embryogenic cultures. The temporal requirements for culture initiation and for induction of embryogenic competence from nucellar explants were determined by pulsing the cultures for 0, 7, 14, 21, 28, 35, 42, 49, 56, and 63 d. Culture initiation required a minimum 7–14 d pulse with 2,4-D, and was maximum after a 56-d pulse; however, embryogenic competence was optimum after a minimum of 28 d exposure to 2,4-D. Somatic embryogenesis occurred directly from the nucellar explants at low frequencies. Somatic embryo maturation only occurred following plating of suspensions onto semisolid medium, and was stimulated by 2.4–4.8 μM kinetin and 4.4 μM 6-benzyladenine.