Biotechnological advances in mango (Mangifera indica L.) and their future implication in crop improvement: a review

Biotechnology can complement conventional breeding and expedite the mango improvement programmes. Studies involving in vitro culture and selection, micropropagation, embryo rescue, genetic transformation, marker-assisted characterization and DNA fingerprinting, etc. are underway at different centers worldwide. In vitro culture and somatic embryogenesis of several different genotypes have been achieved. The nucellus excised from immature fruitlets is the appropriate explant for induction of embryogenic cultures. High frequency somatic embryogenesis has been achieved in some genotypes; however, some abnormalities can occur during somatic embryo germination. Embryo rescue from young and dropped fruitlets can improve the hybridization success in a limited flowering season. Protocols for protoplast culture and regeneration have also been developed. In vitro selections for antibiotic tolerance and fungal toxin resistance have been very promising for germplasm screening. Genetic transformation using Agrobacterium tumefaciens has been reported. Genes that are involved with fruit ripening have been cloned and there have been attempts to deliver these genes into plants. DNA fingerprinting and studies on genetic diversity of mango cultivars and Mangifera species are also being conducted at several research stations. The purpose of this review is to focus upon contemporary information on biotechnological advances made in mango. It also describes some ways of overcoming the problems encountered during in vitro propagation of mango.     

Somatic embryogenesis and plantlet regeneration in mango (Mangifera indica L.)

Summary The ‘Carabao’ or ‘Manila Super’ mango (Mangifera indica L.), a virtually neglected fruit before the advent of KNO₃ flower induction in the early 1970s, is now the third leading Philippine export fruit after banana and pineapple. To apply biotechnology for improvement, a reliable embryogenesis and regeneration protocol is required. We have developed a protocol for somatic embryogenesis and plantlet regeneration in mango: eight strains of ‘Carabao’ and two unidentified varieties, PHL 12384 and PHL 12378. Over 40 batches of nucellar explants from immature fruis (0.75–5.0 cm long) were cultured in vitro from April 1999 to April 2000. Two media were used, MMSE. Mango Medium for Somatic Embryo Induction, Proliferation and Germination and MMPR, Mango Medium for Plantlet Regeneration. These are now routinely used. The protocol is reproducible in 14 other varieties of mango. Shifting the base medium from Gamborg's B5 medium to our own formulation. BP medium (Barba and Pate?a's formulation) effectively controlled browning. Browning has limited the successful in vitro culture of many woody species including the mango. Crop Science Society of the Philippines (CSSP) 2001 Best Paper Award, Asian Agriculture Congress, Westin Philippine Plaza, Manila, Philippines, April 24–27, 2001 and Philippine Fruit Association 2000 Best Poster Award, 8th National Symposium. PCARRD, Los Ba?os, Laguna, Philippines, November 14–16, 2000.     

Nutrient levels in malformed and healthy tissues of mango (Mangifera indica L.)

Samples of malformed and healthy panicles of mango (Mangifera indica L.) as well as leaves and shoots bearing them were collected at different stages of development (fully swollen buds, bud inception, fully grown panicles prior to full bloom and at full bloom) over two consecutive years and were analysed for their macro- and micronutrient status. In addition, malformed and healthy seedlings were collected and analysed. Malformed panicles were found to be significantly higher in N at all the developmental stages except at bud inception. Phosphorus and K also tended to accumulate in malformed panicles at later stages of their development. In general, malformed panicles exhibited lower levels of P, K and Ca than healthy panicles. The differences in levels of Mg and S in malformed and healthy panicles were not significant. All micronutrients were in much lower concentrations in malformed panicles except for Mn which appears to accumulate in malformed panicles particularly at the early stages of development. The leaves on the shoots bearing malformed panicles also showed a tendency to accumulate N, while P, Mg and S were always higher in leaves on shoots bearing healthy panicles. The leaves on shoots bearing healthy panicles had lower levels of Fe, Cu and Mn, whereas levels of Zn and B tended to be higher in leaves on shoots bearing malformed panicles. The nutrient concentration differences between the two kinds of shoots were generally nonsignificant (P=0.05), except for K and S which were significantly lower in shoots bearing malformed panicles. The shoots bearing malformed panicles showed significantly (P=0.05) higher levels of almost all nutrients compared with shoots bearing healthy panicles. Vegetative malformation was found to be associated significantly (p=0.05) with higher amounts of all nutrients except Ca which was significantly higher in healthy seedlings. The present study, therefore, seems to point to lower Ca as one of the pre-disposing factors causing malformation in mango.A part of Ph.D. thesis of the senior author.A part of Ph.D. thesis of the senior author.     

Plant regeneration from protoplasts of mango (Mangifera indica L.) through somatic embryogenesis

 This report describes a protocol for the regeneration of plants from protoplasts isolated from proembryogenic masses (PEMs) in a suspension culture derived from the nucellar callus of mango (Mangifera indica L. cv 'Amrapali'). The maximum yield (24.6±1.1×10⁶), with 81.04±4.1% viable protoplasts per gram PEMs, was obtained with an enzyme mixture containing 1.2% cellulase, 1.0% hemicellulase and 0.6% pectinase. An optimum density of 5×10⁴ cultured protoplasts per milliliter culture medium was required for the highest frequency (88.89±5.40%) of division. Dividing protoplasts developed into microcalli that proliferated on medium supplemented with growth regulators (auxins or kinetin alone, or auxins with kinetin) and produced somatic embryos after transfer to a growth regulator-free medium. The protocallus on 2,4-D-containing medium produced the maximum number (102.50±6.93) of somatic embryos. Maturation of somatic embryos depended upon the presence, and the nature and combination of growth regulators in the medium during proliferation of the callus. The mature somatic embryos germinated and developed into plants that were transferred to soil. Received: 1 April 1999 / Revision received: 27 July 1999 / Accepted: 23 August 1999     

Structural and rheological properties of polysaccharides from mango (Mangifera indica L.) pulp

The structure and rheological properties of water-soluble polysaccharides from industrialized mango pulp were investigated. Soluble fraction (SF) 2 was heterogeneous on high performance size exclusion chromatography, giving two peaks as determined by multi-angle laser light scattering and refractive index detectors. The presence of starch in SF2 was demonstrated by a positive iodine reaction and by 13C nuclear magnetic resonance (NMR) spectroscopy. The presence of pectic polysaccharides was shown by a calorimetric method, 13C-NMR spectroscopy and carboxyl reduction. The main pectic polysaccharide was polygalacturonic acid; type I rhamnogalacturonan was also detected. Analysis of the rheological properties of SF2 showed a pseudoplastic behavior up to 3 g x l(-1). 'Creep and recovery' tests and analysis performed under a dynamic state revealed a weak gel character for solutions at concentrations of 15, 20 and 30 g x l(-1).     

Death and decay in the trees of Mango (Mangifera indica L.)

Death and decay of trees of Mango (Mangifera indica L.) var. Kesar due to fungal infection was studied histologically. Fungal infection in the trees was observed due to various reasons like mechanical injuries in the stem, pruning of the branches, through the inflorescences, attack of Ambrosia beetle and termites. In the initial stage, fungal spores get settled on the flowers due to presence of nectar, followed by their germination and entry of the hypha into peduncle, which gradually spreads into younger branches. The inflorescences were first attacked by Fusarium moniliformis followed by other fungi like Alternaria, Chetomium sp., Aspregillus ellipticus, Aspregillus niger, etc. Fungal mycelia gradually invade the xylem tissues from the top of the branches and spread basipetally ultimately causing death of the infected branches. During monsoon, the crevices on the surface of bark of the healthy plants supported the growth of fungi like Pleurotus, Auricularia, Xyleria, Daldinia sp., and Polyporous sp. The removal of bark from such infected trees revealed minute holes on the surface of the woody cylinder made by Ambrosia beetles. During wet season fungal mycelia makes an easy entry into the xylem through the wounded portion of the stem or pruned branches. Initial entry of the hyphae into xylem was seen through the ray cells. Then the hyphae enter into the lumen of axial elements lining the ray cells through pits and intracellular spaces. The vessel elements located in the xylem (transition zone) between healthy and infected portion were filled with tyloses while axial and ray parenchyma showed heavy accumulation of tannin contents. On the other hand, the infected xylem was also found devoid of reserve metabolites while in normal trees, axial and ray parenchyma showed heavy accumulation of starch grains.     

Transcriptome analysis of flowering genes in mango (Mangifera indica L.) in relation to floral malformation

Journal of Plant Biochemistry and Biotechnology - Flowering is a complicated developmental process of physiological and morphological stages under the control of a number of external signals and...     

Germination and plantlet regeneration from encapsulated somatic embryos of mango (Mangifera indica L.)

 Cotyledonary-stage somatic embryos (3–5 mm in length) originating from nucellar explants of Mangifera indica L. cv. Amrapali were encapsulated individually in 2% alginate gel. The encapsulated somatic embryos (ESEs) germinated successfully on 0.6% agar-gelled medium containing B5 macrosalts (half strength), Murashige and Skoog microsalts (full strength), 3% sucrose and 2.9 μM gibberellic acid. The percentage of germination of ESEs was higher than that of naked somatic embryos of the same size on the same medium. The germinability of ESEs was increased (73.61±7.08%) when the medium was supplemented with full-strength B5 macrosalts. Of the germinating ESEs, 45.83±3.40% developed into plantlets. Abscisic acid at 0.004 and 0.02 μM had no significant influence on germination and plantlet development, but caused a 3-week delay in germination. Well-developed plantlets regenerated from ESEs have been successfully established in soil. Received: 9 February 1998 / Accepted: 22 March 1999     

Ethanolic extract of mango (Mangifera indica L.) malformed inflorescence as effective antifungal agent

Mango (Mangifera indica L.) suffers from floral and vegetative malformation and crop production is seriously affected. The anti-fungal activity of ethanolic extract of malformed mango inflorescence was observed at different concentrations (1000, 2000, 3000, 4000 and 5000 μl/ml) against 10 fungi, viz., Ustilago cynodontis, Cercospora cajani, Sphaerotheca sp., Cercospora sp., Alternaria solani, Bipolaris sp., Helminthosporium sp., Curvularia sp., Fusarium udum and Alternaria cajani. Spore germination of most of the fungi was inhibited at 5000 μg/ml. Some of them were also susceptible at 3000 or 4000 μg/ml concentration. Analysis of phenolic acids by high performance liquid chromatography (HPLC) showed 18 peaks in the extract, but only four could be identified, viz., capachin, gallic, benzoic and cinnamic acids. Because of the high efficacy of ethanolic extract of malformed mango inflorescence, its use under field conditions to control some plant diseases has been suggested.     

Detection of unusual carotenoid esters in fresh mango (Mangifera indica L. cv. 'Kent')

The carotenoid pattern of mango cv. 'Kent' was investigated by LC-(APcI)MS analyses. In solvent extracts from the mesocarp an unusual carotenoid ester was identified as violaxanthin dibutyrate. For unequivocal identification of butyric acid by an independent method, total lipids were isolated by solvent extraction from the fruit flesh and analyzed by GC after saponification and subsequent methylation. Thus, evidence of butyric acid (1.6 area%) was provided. To the best of our knowledge, this is the first report on a xanthophyll dibutyrate in plants. Additionally, further carotenoid peaks were tentatively assigned to 9-cis-violaxanthin and neochrom or luteoxanthin, respectively, by their UV/vis and MS data of the saponified extracts.     

Production and Characterization of Wine from Mango Fruit (Mangifera indica L)

Summary Mango (Mangifera indica L) is the most popular and the choicest fruit of India. A major portion (nearly 60–70%) of the total quantity produced is locally consumed and a sizable portion is exported to other countries. In the present study, six varieties of mango, which are abundantly available in the region were selected for wine production and the conditions for juice extraction were optimized. It was found that the mango juices were similar to grape juice in terms of sugar and acidity. After fermentation, the ethanol concentration was 7–8.5% w/v, the methanol concentration was slightly higher than that of grape wines and other volatile compounds were present in comparable amounts. From the physicochemical characteristics of the mango wine produced, it was observed that aromatic components were comparable in concentration to those of grape wine.     

芒果DNA提取方法比较及ISSR反应体系的优化

为从芒果幼叶中提取高质量的核总DNA,比较了5种DNA提取方法提取芒果叶片核DNA的效果,结果表明:改良CTAB法1提取的DNA A260/A280值最好,ISSR-PCR扩增效果最佳,是有效提取芒果基因组DNA的方法。为得到最佳的芒果ISSR-PCR反应体系,以(ATG)6为引物,采用单因素实验法,优化了ISSR-PCR反应体系:在总体积25μl的反应体系中,含1×反应缓冲液,0.20mmol.L-1dNTPs,0.20μmol.L-1引物,0.60 UTaqDNA聚合酶,30-50 ng DNA模板,不足体积用无菌超纯水补足。     

Inhibitory spectra and modes of antimicrobial action of gallotannins from mango kernels (Mangifera indica L.)

This study investigated the antimicrobial activities and modes of action of penta-, hexa-, hepta-, octa-, nona-, and deca-O-galloylglucose (gallotannins) isolated from mango kernels. The MICs and minimum bactericidal concentrations (MBCs) against food-borne bacteria and fungi were determined using a critical dilution assay. Gram-positive bacteria were generally more susceptible to gallotannins than were Gram-negative bacteria. The MICs of gallotannins against Bacillus subtilis, Bacillus cereus, Clostridium botulinum, Campylobacter jejuni, Listeria monocytogenes, and Staphylococcus aureus were 0.2 g liter(-1) or less; enterotoxigenic Escherichia coli and Salmonella enterica were inhibited by 0.5 to 1 g liter(-1), and lactic acid bacteria were resistant. The use of lipopolysaccharide mutants of S. enterica indicated that the outer membrane confers resistance toward gallotannins. Supplementation of LB medium with iron eliminated the inhibitory activity of gallotannins against Staphylococcus aureus, and siderophore-deficient mutants of S. enterica were less resistant toward gallotannins than was the wild-type strain. Hepta-O-galloylglucose sensitized Lactobacillus plantarum TMW1.460 to hop extract, indicating inactivation of hop resistance mechanisms, e.g., the multidrug resistance (MDR) transporter HorA. Carbohydrate metabolism of Lactococcus lactis MG1363, a conditionally respiring organism, was influenced by hepta-O-galloylglucose when grown under aerobic conditions and in the presence of heme but not under anaerobic conditions, indicating that gallotannins influence the respiratory chain. In conclusion, the inhibitory activities of gallotannins are attributable to their strong affinity for iron and likely additionally relate to the inactivation of membrane-bound proteins.     

Correction to: Transcriptome analysis of flowering genes in mango (Mangifera indica L.) in relation to floral malformation

Journal of Plant Biochemistry and Biotechnology - Correction to: Journal of Plant Biochemistry and Biotechnology     

An overnight chill induces a delayed inhibition of photosynthesis at midday in mango (Mangifera indica L.)

The effect of a cold night on photosynthesis in herbaceous chilling-sensitive crops, like tomato, has been extensively studied and is well characterized. This investigation examined the behaviour of the sub-tropical fruit tree, mango, to enable comparison with these well-studied systems. Unlike tomato, chilling between 5 degrees C and 7 degrees C overnight produced no significant inhibition of light-saturated CO(2) assimilation (A:) during the first hours following rewarming, measured either under controlled environment conditions or in the field. By midday, however, there was a substantial decline in A:, which could not be attributed to photoinhibition of PSII, but rather was associated with an increase in stomatal limitation of A: and lower Rubisco activity. Overnight chilling of tomato can cause severe disruption in the circadian regulation of key photosynthetic enzymes and is considered to be a major factor underlying the dysfunction of photosynthesis in chilling-sensitive herbaceous plants. Examination of the gas exchange of mango leaves maintained under constant conditions for 2 d, demonstrated that large depressions in A: during the subjective night were primarily the result of stomatal closure. Chilling did not disrupt the ability of mango leaves to produce a circadian rhythm in stomatal conductance. Rather, the midday increase in stomatal limitation of A: appeared to be the result of altered guard cell sensitivity to CO(2) following the dark chill.     

Hormonal Changes Associated with Vegetative Malformation of Mango (Mangifera indica L.)

Malformed seedlings of mango showed lower mean content of indole-3-acetic acid, gibberellic acid and a higher mean content of zeatin, abscisic acid and ethylene than healthy seedlings.