Headspace solid-phase microextraction combined with gas chromatography/mass spectrometry is one of the strongest tools for comprehensive analysis of volatile compounds and has been used to analyze aromatic components of mango and investigate its varietal characteristics. In this study, profiling of aroma compounds in 17 mango cultivars, grown in the same green house to exclude the effect of environmental factors, was conducted and the patterns were subjected to principal component analysis (PCA) to identify the relationship between the aroma components and cultivars. Fifty-nine different volatile constituents were detected from the blends of these 17 mango cultivars. The cultivars were divided into 4 clusters using PCA based on the volatile components determined in the study. Aiko was found to mainly contain δ-3-carene and showed a composition more similar to its pollen parent, Irwin, than to its seed parent, Chiin Hwang No. 1.

マンゴー ‘愛紅’ は ‘アーウィン’ と比べて隔年結果性が強く，大果性の晩生品種である．本研究では，カンキツの栽培に適用されている隔年交互結実栽培法をマンゴー ‘愛紅’ に応用し，その有効性を検討した．交互結実処理には主枝別交互結実区と樹別交互結実区の2処理区を設け，慣行法の対照区と比較した．花穂発生率に対照区と処理区間で有意な差はみられなかったが，ON-branchおよびON-treeの花穂発生率は安定して高く，ほぼすべての枝から花穂が発生した．両交互結実処理区の収量は対照区と有意差がなかったが，平均果実重は対照区より軽くなり，小玉果の割合が高くなった．作業効率に関し，両交互結実処理区ではせん定時間が短縮され省力化が可能であることが示唆された．一方，MiFT遺伝子の発現量は ‘愛紅’ の隔年結果性と関連があることが示され，開花数の予測に利用可能であることが示唆された．マンゴー ‘愛紅’ において，隔年交互結実栽培は慣行法と同程度の果実品質と収量を維持しながら，生産量の変動制御と省力化を可能にする有効な方法であると考えられた．

近年，日本のマンゴー栽培は様々な地域に広まっているが，栽培品種が‘アーウィン’1品種に偏っているため品種構成の多様化が望まれている．近畿大学で育種した‘愛紅’は，‘アーウィン’と比べ，大果で果肉繊維が少ないのが特徴であり，収穫期は2週間〜1ヶ月程度遅い中晩生品種であるが，隔年結果性が強い．そのため‘愛紅’を連年にわたって安定生産するには，着花・結実特性を明らかにした上で，‘愛紅’に適した栽培管理法を確立することが求められる．本研究では，‘愛紅’について前年の結実の有無や剪定後の新梢伸長回数が花穂発生率に及ぼす影響を隔年結果性が弱い‘アーウィン’と比較調査するとともに，冬季のMiFT遺伝子の発現解析を行った．その結果，品種間および前年結実の有無による影響が認められ，‘愛紅’は‘アーウィン’と比べ花穂発生率が低い特性を持つこと，また，前年度における結実の有無が花穂発生率に強く影響することが示された．さらに両品種とも剪定後の新梢伸長回数は結実枝より不結実枝で多く，不結実枝では‘愛紅’の伸長回数が‘アーウィン’と比べ多いことが示された．また‘アーウィン’では伸長回数に関わらず高い花穂発生率を示したのに対し，‘愛紅’では伸長回数の多い枝で高くなる傾向がみられた．着果負担の多寡によるMiFT発現量への影響はほとんどみられず，また，‘愛紅’におけるMiFT発現量は‘アーウィン’と比較して低く，このことが‘愛紅’の花穂発生率が低くなる要因である可能性が示唆された．‘愛紅’では，結果母枝として剪定後に3回以上伸長した枝を確保することが生産の安定化に重要であることから，生産と遊休を明確に区別する隔年交互結実栽培法の有効性が示唆された．

The skin color of mature mango (Mangifera indica L.) fruit varies from green to red depending on cultivars. Red coloration of mango fruit skin is due to anthocyanin accumulation and is known to be induced by light exposure as in some other fruit crops. Recently, several investigations on the genes involved in anthocyanin biosynthesis in mango fruit skin have been conducted, to understand the molecular mechanism underlying red coloration of the mango fruit. In the present study, we investigated the characteristics of four R2R3-MYB transcription factors (TF) including MiMYB1, which is assumed to be the MYB TF regulating anthocyanin biosynthesis in mangoes. The deduced amino acid sequence of MiMYB1 showed a high degree of similarity with the anthocyanin-related R2R3-MYB TFs from other plant species and contained two conserved motifs defining the anthocyanin-related MYB TFs. Expression analysis in the mango fruit skin under different light conditions showed that the expression of MiMYB1 increased as the intensity of light exposure increased, parallel to anthocyanin accumulation and the expression of some structural genes of the anthocyanin biosynthetic pathway. In addition, a transient expression assay of tobacco leaves showed that co-infiltration of MiMYB1 and MibHLH2, which is a bHLH TF of mango, induced anthocyanin accumulation in tobacco leaves. These results suggest that MiMYB1 acts as the key regulator for anthocyanin biosynthesis in mango fruit skin, and that light-dependent red coloration of mango fruit skin is regulated by MiMYB1 in transcript levels.

In this study, we aimed to identify the utility of pruned mango (Mangifera indica ‘Irwin’) leaves as a resource for ingredients with antioxidant activity. Firstly, we examined the antioxidant activity of extracts obtained from the pericarps, flesh, flowers, barks, seeds, young dark reddish brown leaves (YDL-ext), young yellow leaves (YYL-ext), and pruned old dark green leaves (OML-ext) obtained from ‘Irwin’ mango. Among them, methanolic extract of flower and OML-ext showed the most potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activity. The flesh extract showed weak DPPH radical scavenging activity, but did not show SOD-like activity. Secondly, we investigated the relationship between the maturation of leaves and their antioxidant activity by considering the contents of their two active polyphenolic components, 3-C-β-D-glucosyl-2,4,4’,6-tetrahydroxybenzophenone (1) and mangiferin (2), in addition to chlorophyll (3) and anthocyanins represented by cyanidin-3-O-glucoside (4). The DPPH radical scavenging activity of YDL-ext, YYL-ext and OML-ext were mainly attributable to 1, 2 and 3, whereas their SOD-like activity was partly attributable to 2. The DPPH radical scavenging and SOD-like activities of YDL-ext and YYL-ext were attributable to 1 and 2. These activities were also due to anthocyanins whose content is highest in YDL-ext. Considering the amounts of leaves obtained from pruning, old dark green leaves may be a reasonable natural resource for preparing cosmetics and/or supplemental ingredients with health-enhancing properties, antioxidant activity and inhibitory effect on AGEs formation and pancreatic lipase.

As a part of our ongoing research to find novel functions in mango leaves, we have reported that the methanolic extract of pruned old dark green mango leaf (Mangifera indica ‘Irwin’) exhibited inhibitory effects on the formation of advanced glycation end products (AGEs) in nonenzymatic glycation of albumin. The purpose of this study was to find other mango cultivars with more potent activity in this regard. We examined the inhibitory effect of seventeen mango (Mangifera indica) cultivar leaf extracts on AGEs formation. We also investigated the relationship between the inhibitory activity of the extracts and the contents of their active components, 3-C-β-D-glucosyl-2,4,4’,6-tetrahydroxybenzophenone (1), mangiferin (2) and chlorophyll (3). On the basis of the evaluation of the inhibitory activity of mango cultivar leaf extracts, the HPLC determination of the contents of 1 and 2, and the spectrophotometric determination of 3, it was found that almost all extract showed a significant activity, and the content of 2 and 3 detected in each was similar. In contrast, AGEs formation inhibition tended to be higher as the content of 1 in the leaf extracts increased. This is the first report of phytochemical analysis of compounds 1, 2 and 3 in various cultivars of mango leaf. From the phytochemical point of view, these results suggest that the pruned leaves of any cultivar of Mangifera indica except ‘Chiin Hwang No. 1’ and ‘Kyo Savoy’ may be useful for the preparation of natural ingredients with inhibitory activity of AGEs formation.

Red mangos (Mangifera indica L.) accumulate appreciable amounts of cyanidin-based anthocyanins in the skin, and previous studies showed that these anthocyanins contain galactose as a sugar moiety. To date, two UDP:flavonoid 3-O-glycosyltransferase (UFGT)-like genes named MiUFGT1 and MiUFGT3 (MiUFGalT3) have been isolated from mango `Irwin' peel as anthocyanin-related UFGT genes, but the function of the proteins of the genes have not yet been elucidated. In this study, we characterized recombinant MiUFGT1 and MiUFGalT3 expressed in Escherichia coli. In the presence of quercetin as an acceptor, rMiUFGT1 showed marginal glucosylation activity, while rMiUFGalT3 exhibited significant galactosylation activity 20-fold higher than its glucosylation activity. Specificity analysis using purified MiUFGalT3 found that rMiUFGalT3 almost equally accepts anthocyanidins and flavonols. The anthocyanins extracted from the `Irwin' skins were cyanidin 3-O-galactoside and 7-O-methylcyanidin 3-O-galactoside by instrumental analyses, which is consistent with previous results obtained for other red mango cultivars. The results suggest that MiUFGalT3 is responsible for the red coloration of `Irwin' mango fruit skins.

The red coloration of the mango 'Irwin' skin is an important factor determining its value in the Japanese domestic luxury fruit market. In the present study, to investigate the molecular mechanism underlying anthocyanin biosynthesis of mango fruit skin, UFGT-like genes were isolated and the expression profile of anthocyanin-related genes was determined. Several UFGT-like genes were identified in transcriptome data of red 'Irwin' mango skin and two genes, MiUFGT1 and MiUFGT3, were considered to be involved in mango skin coloration. Deduced amino acid sequences of these genes exhibited high similarity to other plant UFGTs and contained the conserved PSPG box common to the glycosyltransferase family. The presence of a glutamine and a histidine residue at the C-terminus end of the PSPG box in MiUFGT1 and MiUFGT3, respectively, implied that MiUFGT1 and MiUFGT3 use glucose and galactose, respectively, as a sugar donor; however, the actual function and sugar donor preference of these enzymes remain to be elucidated. Expression analysis of anthocyanin-related genes during skin coloration suggested that MiCHS and MiANS, as well as MiUFGT1 and MiUFGT3, play important roles in the anthocyanin biosynthesis of mango fruit skin and that the expression of these genes is regulated by the MYB transcription factor, as reported in other plant species.

The purpose of this study was to examine an inhibitory effect of mango leaf extracts on advanced glycation end products (AGEs) formation and to identify these active ingredients, and also to investigate a relationship between leaves maturation and the inhibitory activity. A methanolic extract of old dark green mango leaf extract (OML-ext) exhibited an inhibitory activity of AGEs formation in nonenzymatic glycation of albumin. The inhibitory activity of OML-ext was attributable to 3-C-β-D-glucosyl-2,4,4’,6-tetrahydroxybenzophenone (1), mangiferin (2) and chlorophyll. Inhibitory effect of young dark reddish brown mango leaf extract (YDL-ext) on AGEs formation was similar to that of OML-ext. The inhibitory activity of YDL-ext was attributable to 1 and 2, in addition, a part of the the activity of YDL-ext due to anthocyanins whose content is highest in young dark reddish brown mango leaves. Considering the amounts of leaves obtained from pruning, old dark green leaves may be a reasonable natural resource for the preparation of ingredients with inhibitory activity of AGEs formation.

Mango (Mangifera indica L.) is one of the most important evergreen fruit trees, but it has a high tendency of biennial bearing because of irregular flowering. In this study, a FLOWERING LOCUS T-like (FT-like) gene was isolated from mango (MiFT) and characterized. The deduced amino acid sequence of MiFT showed high identity of the gene to other plant FT-like genes, and further, MiFT expression increased only in the leaves under floral-inductive conditions. Comparison of heavy crop load (HC) and no crop load (NC) mango trees showed that MiFT expression strongly increased only in NC trees under cool temperature. In NC trees, almost all the apical buds formed panicles, whereas in HC trees, only a few panicles were produced in the next season of fruit set. Further. HC trees had lower starch content in the shoots than NC trees. Furthermore, application of 250-ppm gibberellin 3 (GA(3)) completely inhibited flowering and MiFT expression in both HC and NC trees. GA metabolism genes were also isolated from mango and their expression patterns were investigated. Gibberellin-3-oxidase (GA3-ox) controls the final step of biosynthesis of active GA, and its gene expression surged only in HC trees under cool temperature. In conclusion, MiFT is considered a key factor in mango flowering, and regulation of MiFT expression through GA metabolism was discussed. (C) 2012 Elsevier B.V. All rights reserved.

近年、日本でもマンゴーのハウス栽培が盛んになりつつあるが、その害虫や訪花昆虫についてはあまり調べられていない。そこで、本研究ではマンゴーハウスに出現する害虫、訪花昆虫を調べ、効果的な防除法と受粉法について検討した。以下3種類の調査を近畿大学附属湯浅農場の2つの温室で行った。訪花昆虫調査では、全部で6目27科40種以上の訪花昆虫が確認された。中でも個体数が最も多かった昆虫は双翅目であった。本農場では受粉効率を上げるためセイヨウミツバチを放飼しているが、着果率はあまり良くない。今後、さらなる着果率向上を目指しミツバチと双翅目の併用を検討する必要があると考えられた。アザミウマ等の害虫調査では、粘着テープを温室内に設置し、付着した昆虫を調べた。その結果、7目21科26種以上が確認された。中でも重要害虫のアザミウマはチャノキイロアザミウマが最も多かった。また、アザミウマの捕獲個体密度は農薬散布区よりも無農薬区の方が圧倒的に多かった。被害果実も無農薬区では非常に多くなり、農薬散布は現在のところ不可欠であると思われた。吸蛾類調査では、全部で9科34種以上の蛾の温室への飛来が確認された。その中で口吻を果実に突き刺し果汁を吸っているところが確認された蛾はヤガ科の3種であった。これらヤガ科による果実への被害を未然に防ぐ必要があると思われた。