Browsing by Author "Kumar, Sushil"

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2-Hydroxyacetophenone, the main component of the essential oil of the roots of Carissa opaca Stapf ex Haines
(Taylor & Francis Group, 2009) Mallavarupu, Gopal R.; Mishra, Raghvendra K.; Chaudhary, Swati; Pandey, Richa; Gupta, Sarika; Kumar, Sushil
The volatile oil obtained by hydrodistillation of the roots of Carissa opaca was analyzed by GC and GC/MS to study its composition. Thirty-five compounds representing 98.3% of the oil were identified. Si-gel chromatography of the oil yielded 2-hydroxyacetophenone, which was characterized by spectral methods (1H-, 13C-NMR and mass), as the main component, amounting to 89.5% of the oil.
Abnormal Leaf morphologies associated with primary and secondary vein patterning defects in Catharanthus roseus: mid-vein defect converts simple leaf into binate compound leaf
(Springer, 2013) Kumar, Sushil; Sharma, Vishakha
Simple petiolated leaves are formed on the wild type plants of apocynaceous medicinal-cum-floricultural species Catharanthus roseus. A C. roseus variant line homozygous for two loss-of-function mutations, an induced leafless inflorescence (lli) mutations and a natural bisected leaf (bil) mutation, was isolated on account of its unique leaf bisection phenotype which was characterized. The lli bil phenotype was highly penetrant but poorly expressed. Only about one-fourth of leaves of lli bil plants were bisected. Leaf bisection was correlated with premature termination of midvein. Degree of bisection varied from a nick at the apex of lamina to formation of two complete leaflets. The notch in 43 % of the bisected leaves bore a pin-like apical adventitious growth. The features of bisected leaves showed that midvein was essential for symmetrical development of smooth lamina spans on its either side; although the development of spans was independent. Several lateral veins emerged from proximal midvein and grew acropetally. Lamina development in the proximal region failed in the absence of local lateral veins. Bisected leaves were also formed as bi-lobed simple leaves, each lobe having its own primary (mid) vein arising from proximally bifurcated midvein. Also formed were completely bisected leaves. In these binately compound leaves, each leaflet had its own petiolule attached to the leaf petiole. The lli bil genotype of C. roseus perhaps provides the only example of a compound leaved variant evolving from a simple leaved species. This phenotype of lli bil leaves supports the suggestion that simple leaf form was ancestral in angiosperms.
Agronomic characteristics of autumn and winter seeded photoperiod insensitive spring wheat in agro-climate of north-west India
(Indian National Science Academy, 2012) Kumar, Sushil; Sharma, Vishakha; Chaudhary, Swati; Kumar, Arvind; Kumari, Renu
Alkaloid profiles of the Indian land races of the opium poppy Papaver somniferum L
(Kluwer Academic Publishers, 2002) Prajapati, Seema; Bajpai, Suphla; Singh, Digvijay; Luthra, Rajesh; Gupta, Madan M.; Kumar, Sushil
The capsule husks of a set of 115 Indian land races of opium poppy Papaver somniferum L. obtained over two cropping seasons were screened for the percent contents of papaverine, reticuline, narcotine, thebaine, codeinone, codeine, morphine and oripavine. Among the accessions screened 36, 7 and 1 did not accumulate papaverine, papaverine and narcotine and codeine and morphine, respectively. The alkaloid profiles and correlations between alkaloids in all the four classes of accessions showed that in the Indian genetic resources of P. somniferum (a) morphine is synthesized from codeine rather than oripavine, (b) net alkaloid contents are low under narcotine deficiency, and (c) accumulation of morphine and codeine was limited upstream of codeinone and morphinone. The accessions identified to be harboring genetic blocks in the phenenthrine and benzylisoquinoline biosynthetic pathways will be useful for understanding the genetic control of secondary metabolism in opium poppy.
Analysis of linalool content in the inflorescence (flower) essential oil and leaf oil of Lippia alba cultivar ‘Kavach’
(Taylor & Francis Group, 2010) Mishra, Raghvendra K.; Chaudhary, Swati; Pandey, Richa; Gupta, Sarika; Mallavarapu, Gopal R.; Kumar, Sushil
Lippia alba cultivar ‘Kavach’ is an aromatic, multi-branched, trailing, deep-rooted shrub that can be planted on slopes to control soil erosion. Cuttings of this genotype were planted on the edges of field plots developed by depositing agricultural soil on the rocky terrain of Aravalli mountain range land on which the Institute is located in New Delhi. Shoots harvested several times a year in the third, fourth and fifth year from planting were sampled for leaves and flowers bearing inflorescences to determine their biomass yield. The inflorescences and leaves sampled from the harvests of third year were analyzed by GC and GC/MS for their oil quality. Altogether 55 compounds were identified in leaf and inflorescence oils; a set of 47 compounds made up 96.3% of the leaf oil and 46 compounds made up 97.0% of inflorescence oil. The concentrations of linalool and 1,8-cineole were 67.7% and 6.4% in the leaf oil, whereas these were 79.3% and 5.2%, respectively, in inflorescence oil. The inflorescence oil also contained cis- and trans-linalool oxides (2.8%). The importance of the flower oil of L. alba cultivar ‘Kavach’ as a linalool-rich oil resource is discussed in terms of traditional sources of such oil and unique features of the cultivar.
An analysis of vascular system in the compound tendrilled afila leaf in Pisum sativum
(National Institute of Science Communication and Information Resources-NISCAIR, 2014) Sharma, Vishakha; Kumar, Arvind; Kumar, Sushil
Recent work on the venation patterning and morphogenesis of leaf/leaflet has posed the question how different are these in tendrils, which are another type of vegetative lateral organ. Here, the venation patterns of leaflets, stipules and tendrils were compared in the model species, P. sativum. Unlike reticulated venation in leaflets and stipules, venation in tendrils comprised of one or more primary veins. A few secondaries were attached to a primary vein, mostly distally. Bilaterally symmetrical secondary veins were rare. The primary veins in tendrils were daughter strands from dichotomously divided mother veins in rachis, connected finally to vascular strands in stem. A tendril received primary vein from one or more mother strands. Some mother strands contributed primary veins to proximal, distal and terminal domain tendrils of af leaf. The tendrils shared the multi-primary vein character with stipules. Vein redundancy provided a mechanism for survival of tendril/leaf against injury to some of the veins/mother veins. The presence of aborted primary veins that did not reach apex, rows of cambium cells attached to primary vein(s) at apex, the pattern of attachment of primary veins to mother veins and cessation of vein growth in apical direction in aborted tendrils of af lld genotype indicated that the growth of primary veins and tendril was acropetal. Loss-of-function of AF extended the repression of TL and MFP genes on leaflet development from distal and apical domains to proximal domain of leaves in af mutants.
Apomixis revisited
(Indian Academy of Sciences, 2006) Kumar, Sushil
The discussions recently published in Current Science, as reviews on apomixis in higher plants, by Kaushal et al. and Bhat et al., are valuable contributions for generating new ideas in this agriculturally important area. Besides describing the characteristics of the various forms of apomixis, the authors1,2 have also attempted to identify techniques that can be used to observe the occurrence of apomixis, and features to be present in model systems, as also approaches that should be employed in these to understand the biology of apomixis in molecular terms. The authors have reached the conclusion that, to unravel the enigma of apomixis (formation of seeds having maternal genotype without fertilization), detailed knowledge of the molecular biology of plant reproductive process is a prerequisite for its apomictic manipulation. They have advised that new experimentation on apomixis be directed in Arabidopsis and rice plants and it be designed to reveal the regulation of meiosis, endosperm development and parthenogenetic or apomictic embryo development. They have opined that knowledge-based deregulation of the key regulatory step(s) of the above-mentioned plant processes might help engineer apomixis in these systems. The conclusion is unquestionable.
Auxin transport inhibitor induced low complexity petiolated leaves and sessile leaf-like stipules and architectures of heritable leaf and stipule mutants in Pisum sativum suggest that its simple lobed stipules and compound leaf represent ancestral forms in angiosperms
(Indian Academy of Sciences, 2013) Kumar, Arvind; Sharma, Vishakha; Khan, Moinuddin; Hindala, Mali Ram; Kumar, Sushil
In angiosperms, leaf and stipule architectures are inherited species-specific traits. Variation in leaf and stipule sizes, and forms result from the interaction between abiotic and biotic stimuli, and gene regulatory network(s) that underlie the leaf and stipule developmental programme(s). Here, correspondence between variation in leaf and stipule architectures described for extant angiosperms and that induced mutationally and by imposition of stress in model angiosperm species, especially in Pisum sativum, was detected. Following inferences were drawn from the observations. (i) Several leaf forms in P. sativum have origin in fusion of stipule and leaf primordia. Perfoliate (and amplexicaul and connate) simple sessile leaves and sessile adnate leaves are the result of such primordial fusions. Reversal of changes in the gene regulatory network responsible for fusion products are thought to restore original stipule and leaf conditions. (ii) Compound leaf formation in several different model plants, is a result of promotion of pathways for such condition by gene regulatory networks directed by KNOx1 and LEAFY transcription factors or intercalation of the gene networks directed by them. (iii) Gene regulatory network for compound leaves in P. sativum when mutated generates highly complex compound leaves on one hand and simple leaves on other hand. These altered conditions are mutationally reversible. (vi) Simple leaves in model plants such as Arabidopsis thaliana despite overexpression of KNOx1 orthologues do not become compound. (v) All forms of leaves, including simple leaf, probably have origins in a gene regulatory network of the kind present in P. sativum.
Biodiesel production from seed oil of Cleome viscosa L.
(CSIR-NISCAIR, 2012) Kumari, Rashmi; Jain, Vinod Kumar; Kumar, Sushil
Edible oil seed crops, such as rapeseed, sunflower, soyabean and safflower and non-edible seed oil plantation crops Jatropha and Pongamia have proved to be internationally viable commercial sources of vegetable oils for biodiesel production. Considering the paucity of edible oils and unsustainability of arable land under perennial plantation of Jatropha and Pongamia in countries such as India, the prospects of seed oil producing Cleome viscosa, an annual wild short duration plant species of the Indogangetic plains, were evaluated for it to serve as a resource for biodiesel. The seeds of C. viscosa resourced from its natural populations growing in Rajasthan, Haryana and Delhi areas of Aravali range were solvent extracted to obtain the seed oil. The oil was observed to be similar in fatty acid composition to the non-edible oils of rubber, Jatropha and Pongamia plantation crops and soybean, sunflower, safflower, linseed and rapeseed edible oil plants in richness of unsaturated fatty acids. The Cleome oil shared the properties of viscosity, density, saponification and calorific values with the Jatropha and Pongamia oils, except that it was comparatively acidic. The C. viscosa biodiesel had the properties of standard biodiesel specified by ASTM and Indian Standard Bureau, except that it had low oxidation stability. It proved to be similar to Jatropha biodiesel except in cloud point, pour point, cold filter plugging point and oxidation stability. In view of the annual habit of species and biodiesel quality, it can be concluded that C. viscosa has prospects to be developed into a short-duration biodiesel crop.
Characterization and genetic linkage mapping of the horticulturally important mutation leafless inflorescence (lli) in periwinkle Catharanthus roseus
(Elsevier, 2011) Chaudhary, Swati; Sharma, Vishakha; Prasad, Manoj; Bhatia, Sabhyata; Tripathi, Bhumi Nath; Yadav, Gitanjali; Kumar, Sushil
Catharanthus roseus is a seasonal to perennial garden plant and the exclusive source of the anticancer drugs vincristine and vinblastine. Its horticultural importance is due to the compound racemose inflorescence architecture of branches in which pairs of prominent flowers are subtended by one of the two leaves per node. Here is reported the construction of a molecular framework genetic linkage map and mapping on it of the LEAF-LESS INFLORESCENCE (LLI) locus. It is quantitatively shown that the adult lli mutant plants produce altered inflorescence of improved horticultural value, wherein axes are excessively branched, two flowers are formed per node that are bare of subtending leaves, and several times more open flowers are displayed each day, as compared to LLI plants.
Characterization of variation and quantitative trait loci related to terpenoid indole alkaloid yield in a recombinant inbred line mapping population of Catharanthus roseus
(Indian Academy of Sciences, 2012) Sharma, Vishakha; Chaudhary, Swati; Srivastava, Suchi; Pandey, Richa; Kumar, Sushil
Improved Catharanthus roseus cultivars are required for high yields of vinblastine, vindoline and catharanthine and/or serpen- tine and ajmalicine, the pharmaceutical terpenoid indole alkaloids. An approach to derive them is to map QTL for terpenoid indole alkaloids yields, identify DNA markers tightly linked to the QTL and apply marker assisted selection. Towards the end, 197 recombinant inbred lines from a cross were grown over two seasons to characterize variability for seven biomass and 23 terpenoid indole alkaloids content-traits and yield-traits. The recombinant inbred lines were genotyped for 178 DNA markers which formed a framework genetic map of eight linkage groups (LG), spanning 1786.5 cM, with 10.0 cM average intermarker distance. Estimates of correlations between traits allowed selection of seven relatively more important traits for terpenoid indole alkaloids yields. QTL analysis was performed on them using single marker (regression) analysis, simple interval mapping and composite interval mapping procedures. A total of 20 QTL were detected on five of eight LG, 10 for five traits on LG1, five for four traits on LG2, three for one trait on LG3 and one each for different traits on LG three and four. QTL for the same or different traits were found clustered on three LG. Co-location of two QTL for biomass traits was in accord of correlation between them. The QTL were validated for use in marker assisted selection by the recombinant inbred line which transgressively expressed 16 traits contributory to the yield vinblastine, vindoline and catharanthine from leaves and roots that possessed favourable alleles of 13 relevant QTL.
Chemical composition of the fatty oils of the seeds of Cleome viscosa accessions
(Natural Product Communications Inc., 2012) Kumari, R; Mallavarapu, GR; Jain, VK; Kumar, Sushil
Fatty oils of the seeds of Cleome viscosa accessions from Delhi, Jaipur, Faridabad, Surajkund and Hyderabad were methylated and analyzed by GC and GC-MS.The major fatty acids, identified as their methyl esters, of the oils from these five locations were palmitic acid (10.2-13.4%), stearic acid (7.2-10.2%), oleic acid (16.9-27.1%) and linoleic acid (47.0-61.1%). In addition, palmitoleic acid,octadec-(11E)-enoicacid, arachidic acid, eicosa-(11Z)-enoic acid, linolenic acid, heneicosanoic acid, behenic acid, lignoceric acid, pentacosanoic acid, hexacosanoic acid, 12-oxo-stearic acid, and the alkanes tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triocontane, hentriacontane and dotriacontane, were also identified as minor and trace constituents in some of these oils.
Climate change and crop breeding objectives in the twenty first century
(Indian Academy of Sciences, 2006) Kumar, Sushil
The earth’s climate system is experiencing a warmer phase. Concomitantly, India is facing a climate change of considerable magnitude. Recently, researchers have projected region-wise scenarios of rainfall and temperature changes, impact on hydrology of river basins and conse- quences for India in the twenty-first century respectively
Co-regulation of biomass partitioning by leafblade morphology genes AFILA, MULTIFOLIATE-PINNA, TENDRIL-LESS and UNIFOLIATA in grain pea Pisum sativum
(Indian National Science Academy, 2010) Kumar, Sushil; Mishra, Raghvendra Kumar; Chaudhary, Swati; Pandey, Richa; Yadav, Gitanjali
In grain pea Pisum sativum, 16 genotypes constructed by combining wild type and mutant alleles of MULTIFOLIATE- PINNA (MFP), AFILA (AF), TENDRIL-LESS (TL) and UNIFOLIATA (UNI) genes, which differed in leaf blade morphology, were quantitatively phenotyped for allometry. The biomass partitioning among root, stem, stipule, leaf blade and seeds was unique for these genotypes suggesting that MFP, AF, TL and UNI genes determined leaf blade and plant architecture. Gene actions were inferred on the basis of mutant phenotypes. Biomass of all the organs was found to be increased in the tl single mutant. The af mutation singly and in combination with mfp, mfp tl, mfp uni-tac or mfp tl uni-tac decreased biomass of all the organs. Allocation of biomass to leaves was increased at the expense of that to seeds or seeds and stems by a single mfp mutation or in combination with uni-tac, af tl, tl uni-tac and af tl uni-tac mutations. The AF and MFP functions are essential in pea cultivars for high yield of grains.The mechanism for simultaneous control of leaf blade and plant architecture suggested by mutant phenotypes has three elements. The MFP, AF, TL and UNI genes exercise control over meristematic activity in all the organs. Their determination of leaf blade morphology and size affect net photosynthesis or metabolite supply. The quantities of available metabolites determine numbers and sizes of organs or partitioned total biomass. The tl allele is identified as a genetic marker/determinant for breeding tendril-less prolific pea cultivars for obtaining herbage and grains in high yields.
COCHLEATA controls leaf size and secondary inflorescence architecture via negative regulation of UNIFOLIATA (LEAFY ortholog) gene in garden pea Pisum sativum
(Indian Academy of Sciences, 2012) Sharma, Vishakha; Chaudhary, Swati; Kumar, Arvind; Kumar, Sushil
UNIFOLIATA [(UNI) or UNIFOLIATA-TENDRILLED ACACIA (UNI-TAC)] expression is known to be negatively regulated by COCHLEATA (COCH) in the differentiating stipules and flowers of Pisum sativum. In this study, additional roles of UNI and COCH in P. sativum were investigated. Comparative phenotyping revealed pleiotropic differences between COCH (UNI-TAC and uni-tac) and coch (UNI-TAC and uni-tac) genotypes of common genetic background. Secondary inflorescences were bracteole-less and bracteolated in COCH and coch genotypes, respectively. In comparison to the leaves and corresponding sub-organs and tissues produced on COCH plants, coch plants produced leaves of 1.5-fold higher biomass, 1.5-fold broader petioles and leaflets that were 1.8-fold larger in span and 1.2-fold dorso-ventrally thicker. coch leaflets possessed epidermal cells 1.3-fold larger in number and size, 1.4-fold larger spongy parenchyma cells and primary vascular bundles with 1.2-fold larger diameter. The transcript levels of UNI were at least 2-fold higher in coch leaves and secondary inflorescences than the corresponding COCH organs. It was concluded that COCH negatively regulated UNI in the differentiating leaves and secondary inflorescences and thereby controlled their sizes and/or structures. It was also surmised that COCH and UNI (LFY homolog) occur together widely in stipulate flowering plants.
Coevolution mechanisms that adapt viruses to genetic code variations implemented in their hosts
(Indian Academy of Sciences, 2016) Kumar, Sushil; Kumari, Renu; Sharma, Vishakha
Viruses, the preponderant species, are the agents of horizontal gene transfer between cellular organisms, a major means for generation of genetic variability that drives evolution in varying environments. Recent work on virus × host interaction has led to revision of the conventional idea that the genetic code of the virus and host must be same so that the host translational system facilitates efficient, accurate and complete expression of the infecting viral genome. There is evidence now that differences between the genetic codes of viruses and their hosts are not an absolute barrier to virus multiplication. The recent work on mechanisms by which viruses overcome the mismatch in codon usage of host versus theirs is discussed here contextually. Examples of coevolution of viruses and their hosts, in terms of genetic code usage, discussed here agree with the concept that their evolution is reciprocally driven and therefore suggestive of a kind of long-term interdependent symbiotic relationship between them.
Common and distinguishing characteristics of genes and genomes and their evolution in the genome sequenced legumes
(Indian National Science Academy, 2013) Kumar, Sushil; Kumari, Renu; Sharma, Vishakha; Yadav, Gitanjali
By March 2013, genome sequences have been published for five legume species- Cicer arietinum (pulse crop chickpea), Cajanus cajan (pulse crop pigeonpea), Glycine max (pulse-cum-oil seed crop soybean), Lotus japonicus and Medicago truncatula (both model plants). The genome sequenced legumes belong to the subfamily papilionoideae of the angiosperm family leguminoseae, C. arietinum, L. japonicus and M. truncatula to the galegoid clade and C. cajan and G. max to millettioid clade. These diploid species have 2n number varying from 12 in L. japonicus, 16 in M. truncatula and C. arietinum, 22 in C. cajan and 40 in G. max. Comparisons among their genome sequences have revealed several important properties about structure and evolution of their genomes. Thirty five to 60% of genome is in the form of repititive elements, mainly transposons. Genome carries less than 50,000 protein-coding genes, 56 to 87% in two or more copies. All the five species arose from a common pre-papilionoid parent produced by inter-species hybridization accompanied by whole genome duplication (WGD or allotetraploidy) about 58 million years ago (Mya). Separation of clades and speciation occurred via sequence changes, over a period of > 40 million years. Individual genes underwent substitution and frameshift mutations. Chromosomal level rearrangements involved deletions, inversions, translocations, fission and fusions. There was spread of individual genes or blocks of genes followed by their tandem duplication. Deletion of orthologues was also involved in lineage specific changes. Ancestors of Glycine underwent an allotetraploid event after separation of C. cajan in the millettioid clade about 13 Mya. Developments relating to the applications of legume genome sequence knowledge are also discussed.
Composition of the essential oil from the roots of Artemisia annua
(Springer, 2007) Goel, Divya; Goel, Richa; Singh, Vijender; Ali, Mohammed; Mallavarapu, Gopal Rao; Kumar, Sushil
Upon hydrodistillation, dried roots of Artemisia annua L. cultivar Jwarharti gave a pleasantly fragrant essential oil with a yield of 0.25%. GC and GC–MS analyses of the oil enabled the identification of 52 components representing 83.2% of the oil. The oil was rich in sesquiterpenes and oxygenated sesquiterpenes and had cis-arteannuic alcohol (25.9%), (E)-β-farnesene (6.7%), β-maaliene (6.3%), β-caryophyllene (5.5%), caryophyllene oxide (4.4%) and 2-phenylbenzaldehyde (3.5%) as its major components. The oil was found to possess considerable fumigant activity and ability to repel adult Tribolium castaneum beetles.
Construction of genetic linkage map of the medicinal and ornamental plant Catharanthus roseus
(Indian Academy of Sciences, 2007) Gupta, Sarika; Pandey-Rai, Sashi; Srivastava, Suchi; Naithani, Subhas Chandra; Prasad, Manoj; Kumar, Sushil
An integrated genetic linkage map of the medicinal and ornamental plant Catharanthus roseus, based on different types of molecular and morphological markers was constructed, using a F2 population of 144 plants. The map defines 14 linkage groups (LGs) and consists of 131 marker loci, including 125 molecular DNA markers (76 RAPD, 3 RAPD combinations; 7 ISSR; 2 EST-SSR from Medicago truncatula and 37 other PCR based DNA markers), selected from a total of 472 primers or primer pairs, and six morphological markers (stem pigmentation, leaf lamina pigmentation and shape, leaf petiole and pod size, and petal colour). The total map length is 1131.9 cM (centiMorgans), giving an average map length and distance between two markers equal to 80.9 cM and 8.6 cM, respectively. The morphological markers/genes were found linked with nearest molecular or morphological markers at distances varying from 0.7 to 11.4 cM. Linkage was observed between the morphological markers concerned with lamina shape and petiole size of leaf on LG1 and leaf, stem and petiole pigmentation and pod size on LG8. This is the first genetic linkage map of C. roseus.
Conventional and new concepts of species and genetic mechanisms for the origin of species
(Indian National Science Academy, 2007) Kumar, Sushil