Showing papers by "North Eastern Hill University published in 1979"
TL;DR: In this article, the mass spectrum of pentacarbonyl(η 1 -pentachlorocyclopentadienyl)manganese is discussed, and the products are characterised by elemental analysis, IR and mass spectral studies.
7 citations
TL;DR: Differential response of normal and gall tissues in culture to growth regulators was established, and in vivo, gall tissue contained more total carbohydrates, reducing sugars, and activity of α-amylase as compared to normal tissue.
4 citations
TL;DR: Embryonic and post-embryonic temperature tolerance and development of Rana limnocharis Wiegmann, the common streaked frog found at Shillong and in the eastern tropics, and the wide distribution of this species appears to be related to its wide temperature tolerance range.
Abstract: The influence of embryonic limiting temperatures on the embryonic and post-embryonic development of Rana limnocharis Wiegmann has been studied. Incubation at constant low temperature (5oC) induced delayed development resulting in abnormal embryos with heavy mortality; whereas incubation at constant high temperature (28oC) showed faster rates of development during the embryonic stages and inhibited the rate of development during post-embryonic stages. This temperature tolerance range (5o-28oC) is very wide when compared to the tolerance range of other anurans, and appears to be related to the wide distribution of this species.
SUMMARY
Embryonic and post-embryonic temperature tolerance and development of Rana limnocharis Wiegmann, the common streaked frog found at Shillong (5000 ft above sea level) and in the eastern tropics, has been studied. The females of Rana limnocharis were induced to ovulate by injecting them with homoplastic ituitaries preserved earlier in absolute ethyl alcohol at a dosage of 0.1 mg/g of the body weight. The eggs were artificially fertilized and allowed to develop. The developing embryos were incubated at room temperature (14o-22oC), and at previously established upper (28oC) and lower (5oC) embryonic limiting temperatures. Larva grown at the upper limiting temperatures showed accelerated development up to hatching and then inhibition in development. The low limiting temperature induced abnormalities and heavy mortality after hatching. Normal development was observed at room temperature which fluctuated between (14oC (night) and 22oC (day). The wide distribution of this species appears to be related to its wide temperature tolerance range.
1 citations
TL;DR: Tetraploidy seems to be the upper limit of ploidy in this species and some PMC's of mixoploid plants showed less than 32 chromosomes suggesting that somatic reduction had occurred at some stage of growth after the treatment.
Abstract: The autotetraploids of Trigonella foenum-graecum (2n=4X=32) showed an unfavourable response to colchicine and dimethyl sulfoxide treatment to produce octoploids. It resulted in the production of mixoploid plants. Some PMC's of mixoploid plants showed less than 32 chromosomes suggesting that somatic reduction had occurred at some stage of growth after the treatment. A few PMC's with octoploid chromosome number (2n=8X=64) were also observed. All mixoploid plants were sterile. Tetraploidy seems to be the upper limit of ploidy in this species.
1 citations