Browsing by Author "Prajapati, Seema"

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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.
The floral androcarpel organ (ACO) mutation permits high alkaloid yields in opium poppy Papaver somniferum
(Indian Academy of Sciences, 2001) Prajapati, Seema; Bajpai, Suphla; Gupta, MM; Kumar, Sushil
Isolation of a recessive aco (androcarpel organ) mutation in opium poppy Papaver somniferum, is described. The aco (aco aco) mutant plants form androcarpels in place of inner whorl stamens in their flowers. The abnormal flowers are self-fertile, as stamens in the outer whorl are normal. In aco mutant the calyx, corolla and syncarpous gynoecium are formed like in the wild type ACO plants. The androcarpel walls of aco plants synthesize and accumulate alkaloids like the main carpel walls. The aco mutation provides a means for improving carpel wall husk mass and thereby the yield of alkaloids
Role of LLD, a new locus for leaflet/pinna morphogenesis in Pisum sativum
(Indian Academy of Sciences, 2001) Prajapati, Seema; Kumar, Sushil
Properties of a mutant at the LLD (LEAF-LET DEVELOPMENT) locus in pea Pisum sativum L. are reported in this paper. Plants homozygous for the Mendelian recessive mutation lld bear leaves in which a few to many leaflets are incompletely developed. Opposite pinnae of rachis nodes often formed fused incompletely developed leaflets. The lld mutation was observed to abort pinna development at almost all morphogenetic stages. The lld mutation demonstrated high penetrance and low expressivity. The phenotypes of lld plants in tl, tac, tl tac, tl af and tl af tac backgrounds suggested that LLD function is involved in the separation of lateral adjacent blastozones differentiated on primary, secondary and tertiary rachides and lamina development in leaflets. The aborted development of tendrils and leaflets in lld mutants was related to deficiency in vascular tissue growth. The morphological and anatomical features of the leaflets formed on a tl lld double mutant permitted a model of basipetal leaflet development. The key steps of leaflet morphogenesis include origin of the lamina by splitting of a radially symmetrical growing pinna having abaxial outer surface, opposite to the vascular cylinder, through an invaginational groove, differentiation of adaxial surface along the outer boundary of split tissue in the groove and expansion of the lamina ridges so formed into lamina spans.