Journal of Horticultural Sciences

M. R. Dinesh ¹, K. V. Ravishankar ¹, Donald Sangma ¹

Affiliations
1 Division of Fruit Crops, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru – 560 089, IN

Abstract

The mango (Mangifera indica L.) is one of the most important tropical fruits of India in which improvement has been attempted since the early 20^th Century. The species, M. indica, having originated in India, has a large diversity within the country. Extensive surveys have located several wild species of importance, many of them figuring in the IUCN Red List. Conservation and evaluation of these species, as well as the large seedling diversity, needs attention as these could be a source for important traits. Strategies of in situ, ex situ and 'onfarm' conservation should from a priority at this juncture. Hybridization has resulted in several hybrids. Widening of genetic base in polyembryonic varieties and identification of zygotic embryos through markers is the need of the hour for utilization in breeding programmes. Although several of these have not become popular, they can be very well used as pre-breeding lines. Use of molecular markers for selection will greatly reduce time taken for developing improved varieties. Strategies other than hybridization, viz., selection among open-pollinated progenies, should be adopted for identifying better recombinants, as, a large number of progenies are available in this method.

Keywords

Mango, Mangifera india L., Breeding, Polyembryonic, Monoembryonic.

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C. Kanupriya ¹, D. Manmohan Kumar ¹, P. Nischita ¹, M. Gayathri ¹, K. V. Ravishankar ¹, P. Sampath Kumar ²

Affiliations
1 Division of Biotechnology, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru, 560089, IN
2 Division of Fruit Crops, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru, 560089, Karnataka, IN

Abstract

Pomegranate genotypes have been characterized mainly on the basis of morphological traits; but, these traits are affected to a large extent by environmental and cultivation conditions, resulting in their ambiguous discrimination. Molecular markers are more suited for accurate discrimination of genotypes and cultivars. Sequence-Related Amplified Polymorphism (SRAP) markers were used in the present study to analyze polymorphism among the important pomegranate genotypes grown in India. The total number of bands generated by 30 SRAP primers for 12 genotypes was 1448, with an average of 48.3 bands per primer. Polymorphism varied from 2.7 to 73.9, with an average of 40.95%. Similarity-value based on Jaccard's Coefficient ranged from 0.63 (between cvs. Naina and Amlidana) to 0.95 (between cvs. Kabul Yellow and Jalore Seedless). UPGMA (un-weighted pair group method with arithmetic mean) analysis was performed and a dendrogram was constructed using Jaccard's similarity matrix. The 12 genotypes used grouped into 5 clusters. SRAP markers were found suitable for determining variability among the pomegranate genotypes studied.

Keywords

Pomegranate, Molecular Markers, SRAP, Genetic Diversity.

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P. Kavitha ¹, K. S. Shivashankara ¹, T. K. Roy ¹, K. C. Pavithra ¹, V. K. Rao ¹, A. T. Sadashiva ², K. V. Ravishankar ³, G. J. Sathish ⁴

Affiliations
1 Division of Plant Physiology and Biochemistry, ICAR-Indian Institute of Horticultural Research, Hesaraghatta lake post, Bengaluru –560 089, IN
2 Division of Vegetable Crops, ICAR-Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bengaluru-560 089, IN
3 Division of Biotechnology, ICAR-Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bengaluru-560 089, IN
4 Department of Biochemistry, Kuvempu University, Shankaraghatta-577 451, Karnataka, IN

Abstract

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.

Keywords

Tomato, B Vitamins, LC-MS/MS-MRM, Fruit Ripening, Green Stage, Breaker Stage.

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V. Swarupa ¹, A. Rekha ², K. V. Ravishankar ¹

Affiliations
1 Division of Biotechnology, ICAR - Indian Institute of Horticultural Research, Hesaraghatt Lake Post, Bengaluru - 560089, IN
2 Division of Fruit Crops, ICAR - Indian Institute of Horticultural Research, Bengaluru, IN

Abstract

Management of the most devasting disease, Fusarium wilt of banana, caused by the fungus Fusarium oxysporum f. sp., cubense, is a challenge to the plant pathologist and the banana grower. Currently, genomics is providing the way for understanding plant defense mechanism, having acquired an important place in crop improvement. To identify the relevant genes and to understand the defense mechanism induced during Fusarium wilt infection, a normalized cDNA library was constructed from infected ischolar_main samples of a tolerant banana genotype, Musa acuminata spp. burmannicoides 'Calcutta-4', by duplex specific nuclease (DSN) based normalization, using the SMART (switching mechanism at 5' end of RNA transcript) full-length cDNA construction method. Sequencing and analysis of 600 clones revealed 392 non-redundant clones. In all, of 88% of the sequences were annotated using Musa genome database, and the remaining 12% were identified as novel loci not annotated. We observed several resistance genes, ROS scavenging genes and genes involved in ubiquitin-proteosome pathway in this study. These genes may have a possible role against Foc infection. These sequences would enrich the EST data developed against specific stress, which is an indispensable tool for predicting functional genes and understanding the defense mechanism.

Keywords

Fusarium oxysporum f.sp. cubense, Banana, cDNA Library, Defense Response, Normalization.

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K. V. Ravishankar ¹, T. S. Aghora ², N. Mohan ², A. H. Naveen ², M. Krishnareddy ³

Affiliations
1 Division of Biotechnology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore - 560 089, IN
2 Division of Vegetable Crops, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore - 560 089, IN
3 Division of Plant Pathology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore - 560 089, IN

Abstract

Mungbean yellow mosaic virus (MYMV) causes yield loss up to 80 % and is becoming problematic in French bean growing areas. Molecular marker linked selection to MYMV resistance is helpful in rapid identification of genotypes carrying resistant genes. Hence, the present study was undertaken to identify the RAPD marker associated with MYMV resistance in French bean (Phaseolus vulgaris L.). Bulk segregant analysis (BSA) was used to identify RAPD marker linked to MYMV resistance. More than 140 random decamers were surveyed for identification of polymorphic markers between the DNA bulks of resistant and susceptible F₂ individuals and their contrasting parents. Ninety eight per cent of these primers amplified DNA in both parents and bulks. Twenty two primers produced specific bands for resistant parent which was absent in the susceptible parent. Out of 22 primers, four primers produced specific fragments viz., OPG 13₄₅₈, OPX 5₆₇₀, OPW 17₃₈₀ and OPP 07₇₃₀, respectively in resistant parent and bulk, which were absent in susceptible parent and bulk. Amplification of individual DNA samples of segregating F₂ resistant individuals using putative marker, OPP 07730, a decamer revealed polymorphism in all four resistant and four susceptible F₂ segregants, indicating that the marker OPP 07₇₃₀ was associated with MYMV resistance in IC-525260, a resistant genotype.

Keywords

Bulk Segregant Analysis, MYMV, Phaseolus vulgaris L., RAPD Marker.

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P. Shilpa ¹, K. V. Ravishankar ², K. S. Shivashankara ³, A. T. Sadashiva ³, N. Sunil Kumar ²

Affiliations
1 Division of Biotechnology, ICAR-Indian Institute of Horticultural Research, Bengaluru 560 089, IN
2 Division of Biotechnology, ICAR- Indian Institute of Horticultural Research, Bengaluru 560 089, IN
3 Division of Plant Physiology and Biochemistry, ICAR- Indian Institute of Horticultural Research, Bengaluru 560 089, IN

Abstract

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.

Keywords

Carotenoid Biosynthesis, Regulation, Plastid, Fruit, Transcription Factor.

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B. Padmakar ¹, M. R. Dinesh ², K. V. Ravishankar ¹

Affiliations
1 Division of Biotechnology, ICAR-Indian Institute of Horticultural Research Hessaraghatta Lake Post, Bengaluru 560089, Karnataka, IN
2 Division of Fruit Crops, ICAR-Indian Institute of Horticultural Research Hessaraghatta Lake Post, Bengaluru 560089, Karnataka, IN

Abstract

In the present study, putative marker-trait associations were identified within a core collection of mango cultivars by simple-sequence-repeat marker based association study. A panel of 48 mango varieties which represented the core collection of the South-West region of India, were characterized at the molecular level using 31 simple sequence repeat markers. Morphological characterization included important fruit characteristics viz., fruit weight, total soluble solids (TSS), pulp content and acidity. The study on population structure revealed two sub-groups in the core collection. Association analysis, computed by General Linear Model (GLM), using TASSEL resulted in the identification of seven markers being associated with the trait titrable acidity where as one marker each of the traits fruit weight and TSS. These traitspecific markers were highly significant at p<0.05 and explained a good amount of phenotypic variation by exhibiting substantial R2 values ranging from 0.71 to 0.86 for acidity, 0.61 for TSS and 0.59 for fruit weight. This is the first report on marker-trait associations (MTA) in mango.

Keywords

Marker-Trait Association, Fruit Characters, Mango, Mangifera indica L.

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Shilpa Pandurangaiah ¹, A. T. Sadashiva ¹, K. S. Shivashankar ¹, D. V. Sudhakar Rao ¹, K. V. Ravishankar ¹

Affiliations
1 ICAR- Indian Institute of Horticultural Research, Bengaluru - 560 089, IN

Abstract

Cherry tomatoes are rich sources of carotenoids. The carotenoids are known to be precursors of vitamin A and also act as an antioxidant. It is important to visually judge the tomato surface color for higher β carotene content since this is the major provitamin A carotenoid. Estimation of carotenoids by HPLC (High Performance Liquid Chromatography) and spectrophotometric methods in tomatoes are very expensive and time consuming. Therefore, colorimeters can be used to describe the color and determine the carotenoid content in a relatively easy and inexpensive manner. The objective of this study was to determine, if the carotenoid content within cherry tomatoes measured by conventional method could correlate with colorimetric CIE (Commission International del’Eclairage) L*, a*, b* color space values. Strong correlations were found between color surface value a* and total carotenoids (0.82) and lycopene content (0.87). We also observed positive correlation for the b* color value with β carotene (0.86). The L* value was negatively correlated (-0.78) with an increase in carotenoids. These close associations between color space values L*, a*, b* and carotenoids will help the breeders to quickly screen large germplasm/ breeding lines in their breeding program for improvement in carotenoid content through this time saving, inexpensive and nondestructive method at fully ripe stage.

Keywords

β Carotene, Carotenoid, Lycopene, Tomato.

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M. R. Dinesh ¹, M. Sankaran ¹, K. V. Ravishankar ¹, Sunil Gowda ¹

Affiliations
1 ICAR-Indian Institute of Horticultural Research, Bengaluru - 560 089, IN

Abstract

No Abstract.

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