Cytotaxonomical analysis of <Emphasis Type="Italic">Momordica</Emphasis> L. (Cucurbitaceae) species of Indian occurrence

Somatic chromosome number and detailed karyotype analysis were carried out in six Indian Momordica species viz. M. balsamina, M. charantia, M. cochinchinensis, M. dioica, M. sahyadrica and M. cymbalaria (syn. Luffa cymbalaria; a taxon of controversial taxonomic identity). The somatic chromosome number 2n = 22 was reconfirmed in monoecious species (M. balsamina and M. charantia). Out of four dioecious species, the chromosome number was reconfirmed in M. cochinchinensis (2n = 28), M. dioica (2n = 28) and M. subangulata subsp. renigera (2n = 56), while in M. sahyadrica (2n = 28) somatic chromosome number was reported for the first time. A new chromosome number of 2n = 18 was reported in M. cymbalaria against its previous reports of 2n = 16, 22. The karyotype analysis of all the species revealed significant numerical and structural variations of chromosomes. It was possible to distinguish chromosomes of M. cymbalaria from other Momordica species and also between monoecious and dioecious taxa of the genus. Morphology and crossability among the dioecious species was also studied. Evidence from morphology, crossability, pollen viability and chromosome synapsis suggests a segmental allopolyploid origin for M. subangulata subsp. renigera. The taxonomic status of the controversial taxon M. cymbalaria was also discussed using morphological, karyological and crossability data.     

Large scale development of selectively amplified microsatellite polymorphic loci (SAMPL) markers in spruce (Picea)

The spruce (Picea) species are ecologically and economically important in Canada. Highly informative markers with high multiplex ratios are needed to assist spruce genomics, genetics, and breeding programs. Selectively amplified microsatellite polymorphic loci (SAMPL) markers are highly suitable for these programs. We have developed, optimized, and characterized a set of 10 new SAMPL primers in combination with 16 MseI primers and resolved a large number of polymorphic SAMPL markers in spruce. The SAMPL primers were designed from the compound microsatellite repeats found in Norway spruce (Picea abies) and white spruce (Picea glauca). A total of 6313 polymorphic SAMPL makers were produced by 160 SAMPL–MseI primers combinations in eight progeny of a spruce mapping population.     

Studies in the Physiology of Parasitism: XXV. Some Propertles of the Pectic Enzymes secreted by Pythium debaryanum

The pectic enzymes of Pythium debaryanum have been comparedwith those from two other soft-rot causing organisms, Erwiniaaroideae and Botrytis cinerea, by their effects (viscosity reduction,acid production, and reducing power) on 1 per cent, solutionsof (a) high methoxyl pectin, (b) sodium polypectate, and (c)sodium pectate (2 types). The Pythium debaryanum preparationdiffered particularly in giving no increase in reducing poweror evidence of galacturonic-acid-like derivatives. It maceratedthe walls of potato-tissue freely but had nopolygalacturonaseor pectinesterase activity.     

Stimulation of Nitrate Reductase by Light and Ammonium in Spirodela oligorrhiza

Light-enhanced nitrate reductase (NR) activity was 8 times greaterthan the dark control. Exogenous application of sucrose, glucoseand fructose increased the induction of NR in the light as wellas in the dark, whereas glycolate had no effect. DCMU [3-(3,4-dichlorophenyl)-1, 1-dimethyl urea] completely inhibited thedevelopment of NR in light. Sucrose, when added with DCMU, reversedthis inhibitory effect NR in vivo was more stable in light thanin darkness, the half-lives being 9.6 h and 6.4 h, respectively.The addition of sucrose did not change the half-life of NR ineither light or darkness. Ammonium, the end product of the inorganicnitrogen assimilatory pathway, stimulated the NR activity whereasamino acids decreased it. Key words: Spirodela oligorrhiza, nitrate reductase, ammonium, light     

Fine Needle Aspiration of Sister Mary Joseph''s Nodule

A case of Sister Mary Joseph's nodule (umbilical metastasis) is described from a primary adenocarcinoma of the transverse colon. Needle aspiration cytology made the diagnosis which was confirmed by immunocytochemical localization of CEA, B72.3, EMA, and cytokeratin in the tumour cells. Extensive mucus production in the tumour cells was demonstrated by alcian blue and mucicarmine stains.     

Morphogenesis in Tissue Cultures of Different Organs of Nigella sativa

Calli were isolated from root, stem and leaf segments of Nigella sativa (Fam. Ranunculaceae) on White's medium containing napthaleneacetic acid and coconut milk. From all the three types of calli, roots were differentiated. Shoot development occurred in stem and leaf calli only after the omission of first coconut milk and then of auxin from the basal medium and also in IAA (2.0 mg/ml) and coconut milk (15 % v/v) in the medium. Frequency of organ formation and the maintenance of this capacity depend upon the nature as well as the age of the callus tissue.