North Eastern Hill University

About: North Eastern Hill University is a education organization based out in Shillong, Meghalaya, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 2318 authors who have published 4476 publications receiving 48894 citations.

Karyological studies in ten species of Citrus(Linnaeus, 1753) (Rutaceae) of North-East India.

Abstract: Ten Citrus (Linnaeus, 1753) species of North-East India have been karyo-morphologically analysed. All studied species had 2n=18 chromosomes without any evidence of numerical variation. All the chromosomes were found to be of metacentric and sub-metacentric in all the species; the morphology of the chromosomes showing size difference only. Symmetrical karyotype which does not have much difference in the ratio of longest to shortest chromosome in all the species was observed. Three species, C. grandis (Osbeck, 1757), C. reticulata (Blanco, 1837) and C. medica (Linnaeus, 1753) are identified as true basic species from asymmetry studies of karyotypes as they reflect on the primitive nature of their genomes. C. indica (Tanaka, 1937) occupies a special taxonomic position within the genus Citrus as a progenitor for other cultivated species.

Achene germination of Parthenium hysterophorus L.: effects of light, temperature, provenance and achene size

Abstract: Summary: Resume: Zusammenfassung Ray achenes of Parthenium hysterophorus L. from widely separated localities showed a positive relationship between length and weight, and those from northern India (higher latitude) were heavier than those from the south (lower latitude). The achenes germinated well in continuous light and in the dark, but maximum germination was obtained with a 10-h photoperiod. Increasing duration of light pretreatment from 6 to 48 h resulted in greater subsequent germination in the dark. The achenes germinated over a wide range of alternating temperature regimes, but achieved maximum percentage germination at 25–30°C/15–20°C. Despite significant quantitative variation, the overall germination behaviour of achenes of different sizes was similar, although large achenes always gave higher germination than small ones. Germination was significantly influenced by seed source. The north Indian populations showed higher percentage germination than those from south India. The patterns of response of achenes of different provenances to light and alternating diurnal temperatures were slightly different. Germination des akenes de Parthenium hysterophorus L.: effets de lu lumiere, temperature et de la taille et origine des akenes Des akenes de Parthenium hysterophorus L. issus de localites tres largement eloignees ont montre une correlation positive entre la longueur et le poids; ceux du nord de l'Inde (latitude plus elevee) etaient plus lourds que ceux du sud (latitude plus basse). Les akenes ont bien germes tant en lumiere continue, qu'a l'obscurite, mais le maximum de germination a ete observe sous une photoperiode de 10 heures. Une augmentation d'une preexposition a la lumiere de 6 h a 48 h aboutit ensuite a une plus grande germination a l'obscurite. Les akenes ont germe sur un tres large eventail de regimes de temperatures alternees mais on a obtenu le maximum de pourcentage de germination a 25–30°C/15–20°C. En depit de variations quantitatives significatives, le comportement general de germination des akenes de tailles differentes a ete comparable, meme si les grands akenes germent toujours mieux que les petits. La germination est influencee de facon significative par la provenance de la graine. Les populations du nord de l'Inde expriment un pourcentage de germination plus eleve que celles du sud. Les comportements de reponse des akenes de differentes provenances a la lumiere, et aux temperatures diurnes ont ete legerement differentes. Keimung der Achanen von Parthenium hysterophorus L.: Wirkung von Licht, Temperatur und Herkunft sowie Grosse der Achanen Die Achanen von Parthenium hysterophorus L. von weit voneinander liegenden Orten zeigten ein positives Langen-Gewicht-Verhaltnis, wobei sie in Nordindien schwerer waren als im Suden. Die Achanen keimten im Dauerlicht und im Dunkeln gut, aber bei 10stundiger Lichtperiode am besten. Wenn sie zunachst einer von 6 bis auf 48 h gesteigerten Licht-Behandlung unterworfen wurden, keimten sie im Dunkeln besser. Die Achanen keimten uber eine weite Spanne wechselnder Temperatur; die maximale Keimrate wurde bei 25–30/15–20°C gefunden. Trotz signifikanter Unterschiede war die Keimung verschieden grosser Achanen im grossen und ganzen ahnlich, wenn auch die grossen immer starker als die kleinen keimten. Die Keimung war signifikant von der Herkunft beeinflusst: Die Achanen aus Nordindien hatten eine grossere Keimrate als die aus dem Suden. Das Verhalten der Achanen verschiedener Herkunft gegenuber Licht und wechselnder Tagestemperatur war wenig unterschiedlich.

Molecular phylogeny of Cyclophyllidea (Cestoda: Eucestoda): an in-silico analysis based on mtCOI gene

Abstract: Order Cyclophyllidea (of cestode platyhelminths) has a rich diversity of parasites and includes many families and species that are known to cause serious medical condition in humans and domestic and wild animals. Despite various attempts to resolve phylogenetic relationships at the inter-family level, uncertainty remains. In order to add resolution to the existing phylogeny of the order, we generated partial mtCO1 sequences for some commonly occurring cyclophyllidean cestodes and combined them with available sequences from GenBank. Phylogeny was inferred taking a total 83 representative species spanning 8 families using Bayesian analysis. The phylogenetic tree revealed Dilepididae as the most basal taxon and showed early divergence in the phylogenetic tree. Paruterinidae, Taeniidae and Anoplocephalidae showed non-monophyletic assemblage; our result suggests that the family Paruterinidae may represent a polyphyletic group. The diverse family Taeniidae appeared in two separate clades; while one of them included all the members of the genus Echinococcus and also Versteria, the representatives of the genera Taenia and Hydatigera clubbed in the other clade. A close affinity of Dipylidiidae with Taenia and Hydatigera was seen, whereas existence of a close relationship between Mesocestoididae and Echinococcus (of Taeniidae) is also demonstrated. The crown group comprised the families Anoplocephalidae, Davaineidae, Hymenolepididae and Mesocestoididae, and also all species of the genus Echinococcus and Versteria mustelae; monophyly of these families (excepting Anolplocephalidae) and the genus Echinococcus as well as its sister-taxon relation with V. mustelae is also confirmed. Furthermore, non-monophyly of Anoplocephalidae is suggested to be correlated with divergence in the host selection.

Diversity of plant species in arecanut agroforests of south Meghalaya, north-east India.

Abstract: In south Meghalaya, farmers maintain a variety of economically important plant species in arecanut agroforestry systems. We investigated plant species composition of arecanut agroforests of south Meghalaya and encountered 160 plants, which included 83 tree species, 22 shrub species, 41 herb species and 14 climber species. The study reveals that arecanut agroforests provide cash income, medicine, timber, fuelwood and edibles for household consumption as well as for sale. We conclude that these agroforestry systems serve as home for many economically important plant species, harbour rich biodiversity and mimic the natural forests both in structural composition as well as ecological and economic functions.