Metabolite profiling in Mango (Mangifera indica L.) pollen grains in relation to viability

Mango productivity is affected mainly by irregular flowering, proportion of bisexual flowers, poor pollination and fertilization and fruit drop. Poor fruit set in some of the varieties may be associated with the lower pollen viability. The present experiment was initiated to assess the viability of pollen grains and their metabolites in three mango cultivars Amrapali, Alphonso and Totapuri which are differing in their fruit set intensity. The profiling of sugars, amino acids and some of the phytohormones were analysed using Liquid Chromatography-Mass Spectrometry (LC-MS/MS). Assessment of pollen grains in three mango cultivars indicated that free sugars such as fructose and glucose, and available amino acids including serine, proline, lysine, phenylalanine, alanine and glutamic acid were predominantly higher in all the cultivars. Phytohormones like IAA, IBA, ABA, GA,zeatin, jasmonic acid and salicylic acid were significantly different in low fruit setting cultivars Alphonso and Totapuri compared to high fruit setting cultivar Amrapali. In cv. Alphonso all the metabolites were higher at anthesis but later decreased drastically compared to cvs. Totapuri and Amrapali. Pollen viability percentage was significantly higher in cv. Amrapali than in cvs. Totapuri, Alphonso. Among all the cultivars, Amrapali maintained better chemical composition at anthesis and also at two hours after anthesis compared to cvs. Totapuri and Alphonso

Determining Composition of Volatiles in Couroupita guianensis Aubl. Through Headspace-Solid Phase Micro-Extraction (HS-SPME)

Composition of volatile components in Couroupita guianensis Aubl. flowers was analyzed using headspace-solid phase micro-extraction (HS-SPME), followed by capillary gas chromatography and mass spectrometry (GC-MS) separation and identification. In all, 75 compounds were identified accounting for 96.32% of the total volatiles present. The major groups of compounds present were oxygenated terpenoids (35.66%), alcohols (26.92%), esters (17.36%), mono-and sesqui-terpenoids (8.64%), aldehydes and ketones (4.71%), hydrocarbons (1.68%), phenols (0.18%), acids (0.754%) and heterocyclic compounds (0.42%) constituted a small proportion of the volatile profile. The most abundant individual constituent was eugenol (18.95%) followed by nerol (13.49%), (E,E) farnesol (12.88%), (E,E)-farnesyl acetate (6.68%), trans ocimene (6.02%), nootkatone (4.64%), geraniol (2.94%), 2-isopropenyl-5- methyl-4-hexenyl acetate (2.69%), cedr-8-en-13-ol (2.58%), (E,Z)-farnesyl acetate (2.40%) and methyl (11E)-11- hexadecenoate (2.041%). Analytical comparison of composition of volatiles in the flowers, obtained by different methods of extraction, viz., solvent extraction, micro-simultaneous extraction and headspace-solid phase microextraction, revealed specific variations in relative concentrations of the constituent chemicals. Linalool was the major chemical (21.5% and 14.9%) in solvent extract and micro-simultaneous extract, respectively, but appeared in negligible quantity (0.16%) in head-space analysis

Molecular Mechanisms Involved in Biosynthesis and Regulation of Carotenoids in Plants

Carotenoids are coloured compounds beneficial to plants and humans. Some of the major health benefits carotenoids provide include Vitamin A precursors and, antioxidants besides being involved in several physiological functions. Even though several carotenoids are synthesised by plants, only a few like beta/ alpha carotenes and cryptoxanthin serve as Vitamin A precursors. The rest are useful as antioxidants. To draw maximum benefits from carotenoids, we need to incorporate these in crop improvement programmes for enhancing available Vitamin A precursor carotenoids. Therefore, it is essential to study biosynthesis of carotenoids, their genetics and their control. In this review, we focus on factors regulating carotenoid biosynthesis, metabolism and storage in plastids. Transcriptional and genetic control of carotenoid production in plants is discussed in the review using several mutants too. Further, environmental regulation of carotenoid biosynthesis is also highlighted. Carotenoid-rich fruits and vegetables have greater economic value owing to their health-promoting effects. Besides,carotenoids have several industrial applications. Therefore, knowledge of regulation mechanism in carotenoid production in plants can help develop crop varieties or technologies, thus generating carotene-rich fruits and vegetables

Antioxidant capacity, radical scavenging ability, total phenols and flavonoids in three types of betelvine (Piper betle L.)

Betelvine (Piper betle L.) leaves from female (Bengaluru local), male (Madras type) and meeta paan (sweet type) were analysed for antioxidant capacity (FRAP) and radical scavenging ability (DPPH) using acidic methanol extracts. FRAP and DPPH values were higher in the leaves of Bengaluru local followed by Madras type and were lowest in sweet type of betelvine. However, chlorophyll was higher in female and sweet betelvine when compared to Madras type. Bengaluru local also recorded higher total phenols and flavonoids followed by Madras type and sweet betelvine recorded lowest phenols and flavonoids. Higher antioxidant and radical scavenging capacities of female and male types was mainly due to the higher phenols and flavonoids and not due to total chlorophyll content. The study indicated that the total phenol content of betelvine is comparable with that of tea powder. &nbsp

Genotypic Variability in Tomato for Total Carotenoids and Lycopene Content during Summer and Response to Post Harvest Temperature

Lycopene is the major carotenoid responsible for fruit colour in tomato (Lycopersicon esculentum Mill.). However, colour of the fruit is greatly affected by high temperature prevailing during fruit growth in the summer crop. To select a genotype suitable for summer conditions that can maintain colour better, a set of 52 tomato genotypes were evaluated for lycopene, total carotenoids and for TSS during summer in Bengaluru. Among the genotypes screened, IIHR 2892 recorded very high lycopene content (328.4mg/100g dry weight) and IIHR 2866 recorded very low lycopene content (25.2mg/100g dry weight). TSS values ranged from 2.6° Brix in cv. Vybhav to 7.0° Brix in IIHR 2866. In addition, study was carried out to determine the effect of postharvest temperature on biosynthesis of lycopene in five selected tomato cultivars (Arka Rakshak, Arka Samrat, Arka Ananya, Lakshmi and Abhinava). Tomatoes harvested at breaker stage were stored at 27° C, 35° C and 40° C for ripening. High temperature reduced lycopene content in tomato fruits. Lycopene synthesis in fruits was completely inhibited above 35°C. In this study, mean lycopene content in tomatoes stored at 27° C was 3-4 times higher than that in tomatoes stored at 40° C. This indicates that in tomatoes, temperature at which the fruits are stored after harvest, is a more important factor for colour development

Seasonal influence on volatile aroma constituents of two banana cultivars (Grand Naine and Nendran) under Kerala conditions

Banana is a tropical fruit with a pleasant flavour, widely consumed throughout the world. Volatile aroma compounds are responsible for olfactory flavor of banana. However, the development of aroma flavors is affected by the atmospheric temperatures during fruit growth period. In order to get good quality fruits in terms of aroma it is essential to understand the optimum temperature for maximum aroma production. The approach used in this study was to alter the dates of harvest to understand the optimum temperature required for maximum production of volatile compounds under Kerala conditions. The results revealed that with increased temperature volatile aroma compounds decreased in cvs. Grand Naine and Nendran. Total volatile compounds were higher in cv. Grand Naine compared to cv. Nendran. Cultivar Nendran recorded increased concentrations of esters, alcohols and decreased aldehydes, ketones, hydrocarbons and acids at high temperatures. Phenols and other constituents did not show much variation with respect to the temperature variation in both the cultivars. Among esters, Isoamyl butanoate and 3-Methylbutyl-3-methylbutyrate esters were the most abundant in both the cultivars. Ketones, especially 4-Methyl-1-penten-3-one was higher in cv. Nendran whereas esters were lower compared to cv. Grand Naine. Total area of aroma constituents in cultivars Grand Naine and Nendran were high in October followed by February with mean atmospheric temperature of 30.5ºC and 32.6ºC respectively. In case of cv. Nendran, total area of esters and alcohols were maximum at high temperature (34.5ºC) but in cv. Grand Naine, esters and alcohols decreased with high temperature. Results indicated that fruits harvested in October were better in terms of volatile aroma quantity in both the cultivars due to lower atmospheric temperature. Seasonal variations affected the two cultivars differentially in terms of percentage of groups of volatile compounds

Antioxidant capacity, radical scavenging ability, total phenols and flavonoids in three types of betelvine (Piper betle L.)

Betelvine (Piper betle L.) leaves from female (Bengaluru local), male (Madras type) and meeta paan (sweet type) were analysed for antioxidant capacity (FRAP) and radical scavenging ability (DPPH) using acidic methanol extracts. FRAP and DPPH values were higher in the leaves of Bengaluru local followed by Madras type and were lowest in sweet type of betelvine. However, chlorophyll was higher in female and sweet betelvine when compared to Madras type. Bengaluru local also recorded higher total phenols and flavonoids followed by Madras type and sweet betelvine recorded lowest phenols and flavonoids. Higher antioxidant and radical scavenging capacities of female and male types was mainly due to the higher phenols and flavonoids and not due to total chlorophyll content. The study indicated that the total phenol content of betelvine is comparable with that of tea powder. &nbsp

Changes in Fruit Quality and Carotenoid Profile in Tomato (Solanum lycopersicon L.) Genotypes under Elevated Temperature

Tomato (Solanum lycopersicon L.) is a rich source of carotenoids, especially lycopene, and is affected severely by high temperatures under tropical conditions. To study the effect of elevated temperature on lycopene content and other quality parameters, five tomato genotypes, viz., RF4A, Abhinava, Arka Saurabh, IIHR 2195 and Arka Vikas, were grown in a temperature gradient tunnel (TGT) facility under 33.4 and 35.4°C temperature conditions. Fruits were analyzed for total carotenoids, total phenols, total flavonoids, total sugars, TSS, acidity, Vitamin C besides carotenoids profile (β-carotene, lycopene, phytoene and luteoxanthin content). Results revealed that all the quality parameters studied were superior at 33.4°C, compared to 35.4°C in all the genotypes. 'IIHR 2195' recorded highest total phenols (479.28mg/100g dw), total flavonoids (70.27mg/100g dw), ferric reducing antioxidant potential (FRAP) (310.53mg/100g dw), diphenyl picryl hydrazyl (DPPH) radical (487.89mg/100g dw), Vitamin C content (292.25mg/ 100g dw) and total sugars (606.88mg/g dw) at 33.4°C and at 35.4°C. 'RF4A' and 'Arka Vikas' were found to have better total carotenoids content and lycopene at higher temperature than other genotypes. 'Arka Vikas' recorded highest total soluble solids (TSS) (8.9°Brix) and acidity (0.80%) at 35.4°C. Higher TSS and acidity were recorded at 35.4°C than at 33.4°C in all the five genotypes. Genotypic variation was observed in the above stated biochemical parameters in response to elevated temperatures

Metabolite Profiling for Six 'B' Vitamins Using LC-MS in Tomato Genotypes at Different Stages of Fruit Maturity

Vitamins are essential nutrients in food crucial for maintaining good health. Tomato, being a widely consumed vegetable, provides a good quantity of vitamins. Metabolite profiling of vitamins at different stages of fruit maturity in a crop helps identify the right stage for better quality. Based on preliminary screening for quality parameters, tomato lines rich in TSS, antioxidants, lycopene and beta-carotene were selected for the present study. Eight genotypes and a wild species were profiled for 'B' vitamins at three different stages of fruit maturity, viz., green, breaker and ripe stage. A simple and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for simultaneous determination of six 'B' vitamins was developed and validated by us. Among the genotypes studied, IIHR-249-1 recorded higher niacin, pantothenic acid and biotin content. Pyridoxine content was higher in the hybrid, Arka Rakshak. The wild species, LA-1777(Solanum habrochaites) was found to be rich in pantothenic acid, riboflavin and thiamine. Content of most of the vitamins increased with ripening of the fruit. IIHR-249-1 and LA-1777 were found to be rich in 'B' vitamins, earlier reported to be also rich in antioxidants and lycopene. These genotypes can be used for improving the nutritive value of tomato under crop improvement programmes, through conventional breeding or biotechnological approaches

Breeding tomato (Solanum lycopersicum L.) for resistance to biotic and abiotic stresses

Tomato (Solanum lycopersicum L.) is an important vegetable crop cultivated in the tropical and sub-tropical regions of the world. Low productivity in India is due to occurrence of both biotic and abiotic stresses. Among the biotic stresses, tomato leaf curl disease, bacterial wilt, early blight and Groundnut Bud Necrosis Virus disease have become serious production constraints causing considerable yield loss in the major tomato growing areas of the country. Adoption of multiple disease resistant varieties or F1 hybrids would be the most appropriate way to address these diseases. At ICAR-IIHR, Bengaluru systematic breeding strategies were employed to pyramid genes for resistance to early blight, bacterial wilt and tomato leaf curl diseases and to develop advanced breeding lines& F1 hybrids with triple disease resistance. Stable source of resistance to early blight and bi-partite begomo-virus (Tomato Leaf Curl New Delhi Virus) has been identified in Solanum habrochaites LA-1777. Validation with molecular markers linked to tomato leaf curl virus resistance revealed that LA-1777 carryTy2 and other putative resistant genes. Several high yielding dual purpose hybrids were also developed for fresh market and processing with high level of resistance to multiple diseases. Cherry tomato lines have also been bred for high TSS, total carotenoids, total phenols, flavonoids, vitamin C, acidity and lycopene content. IIHR-249-1, IIHR-2101 (Solanum habrochaites LA-1777), IIHR- 2866 and IIHR-2864 recorded high values for quality parameters like total carotenoids, lycopene, vitamin C, total phenols, flavonoids and TSS. Drought tolerant root stock has been developed by an interspecific cross between S. habrochaites LA-1777 and S. lycopersicum (15 SB SB). Resistant sources have also been identified against Tuta absoluta, a serious insect pest reported from major tomato growing areas in the country in recent time. High temperature tolerant breeding lines are in pipe line