Showing papers by "Annamalai University published in 1987"
TL;DR: Karyotypes in the Scrophulariaceae family show differences in absolute chromosome size indicating changes in nuclear DNA in evolution, and the meiotic chromosome number studied in 17 species is in confirmation with the mitotic chromosomes.
Abstract: The chromosome number of 21 species belonging to 17 genera of Scrophulariaceae from South India has been studied, of which first record of chromosome has been made in Lymnophila heterophylla, Moniera cuneifolia, Ilysanthes tenuifolia, I. oppositifolia, Micrargeria wightii and Sopulia trfda. Chromosome numbers determined in the present study range from 2n=12 to 20=80.Chromsome numbers determined in the present study and those reported previously in the family (Fedorov 1974) reveal the presence of a continuous series of basic number between n=6 to 84. The commonest basic number in the famly is n=8 and it is assumed to be the original basic number of the family. It appears that aneuploid changes of chromosome numbers produced the basic numbers of n=6, 7, 8, 9, 10, 11, 12, 13 and 14 in the early evolution of the family, after which polyploid and dibasic amphidiploid gave rise to the higher basic numbers (n=17 to n=84) now found in the family.Karyotypes in the family also show differences in absolute chromosome size indicating changes in nuclear DNA in evolution. The meiotic chromosome number studied in 17 species is in confirmation with the mitotic chromosomes. The presence of mutivalents and quadrivalents along with bivalents and the presence of anaphasic laggards and bridges and triplar anaphases show evidences in support of the aneuploid and polyploid nature of the species.
12 citations
TL;DR: Critical karyotype analyses of as many as 41 species of Rubiaceae showed asymmetrical karyotypes, which showed that this family may be considered as one of the most highly evolved families of Angiosperms.
Abstract: The chromosome number of 41 species belonging to 24 genera of Rubiaceae from South India has been studied. The chromosome numbers range from 2n=18 to 2n=72. First record of chromosome numbers have been made as many as 11 species and deviant records of chromosome number as against the previous reports have been worked out in 2 species. In the rest of the species studied, the present report of chromosome numbers confirms the previous records.A common survey of the chromosome numbers in Rubiaceae reveals the existence of graded series of haploid numbers from 6 to 110. Of those, haploid numbers n=11 and n=22 represented the highest frequency among the taxa studied. Therefore, it may be assumed that the original primary basic number may be 11 and it should have given rise to derived primary basic number 22. A process of chromosomal reduction as observed among the species of Crepis might have been in operation so that the basic number 11 might have got reduced to n=10, n=9 and finally to n=6 by a series of unequal translocations involving concurrent loss of inert heterochromatin parts of the chromosomes. The other higher haploid numbers above the level of n=11 should have been arisen by means of aneuploidy and euploidy.As revealed by karyotype analyses of 41 taxa of Rubiaceae studied it is clear that, there is a close correlation between the size and the number of somatic chromosomes. Karyotypes in Rubiaceae also show differences in absolute chromosome size indicating changes in nuclear DNA in evolution. No definite trend of either phylogenetic increase or decrease of chromosome size is indicated by the available limited data.In the present study, critical karyotype analyses of as many as 41 species of Rubiaceae showed asymmetrical karyotype. Along side this advanced character, and by the common occurrence of subterminal kinetochores showed that this family may be considered as one of the most highly evolved families of Angiosperms.
12 citations
TL;DR: Le developpement larvaire de Doclea muricata (Herbst), eleve au laboratoire, comprend deux stades Zoe et un stade megalope, utilisant des nauplii d'Artemia comme source of nourriture en cinq jours.
Abstract: Le developpement larvaire de Doclea muricata (Herbst), eleve au laboratoire, comprend deux stades Zoe et un stade megalope. Avec une salinite de 33 ± 1 %o et a la T° de 27 ± 1.5°C. Utilisant des nauplii d'Artemia (San Francisco Bay Brand) comme source de nourriture, le stade megalope a pu etre atteint en cinq jours. Les differents stades larvaires sont decrits et compares avec ceux appartenant a trois autres especes du meme genre.
10 citations
TL;DR: It is concluded that euploidy together with karyotype alterations of chromosomes play important role in speciation in Rosaceae.
Abstract: Karyotypic analyses were made using root tip mitosis in 19 species of South Indian Rosa-ceae. First record of chromosome numbers have been made in Rubus wightii (2n=14), R. rugosus (2n=14), R. fairholmianus (2n=14), R. gardnerianus (2n=14), R. micropetalus (2n=14), Fragaria indica (2n=14), Potentilla leschenaultiana (2n=28) and Alchemilla indica (2n=16). Most of the species studied show 2n=14 and 2n=28 chromosomes. Therefore, it is concluded that euploidy together with karyotype alterations of chromosomes play important role in speciation in Rosaceae.
9 citations
TL;DR: In this paper, the kinetics of cyclohexanol by 1-Chlorobenzotriazole (CBT) have been studied at 40°C in 50% aqueous acetic acid.
Abstract: The kinetics of oxidation of cyclohexanol by 1-Chlorobenzotriazole (CBT) has been studied at 40°C in 50% aqueous acetic acid The reaction is first order with respect to oxidant and first order with respect to substrate The rate is found to increase with increase in acid concentration and percentage ofAcOH in the mixture The kinetic parameters have been calculated A suitable mechanism is proposed
5 citations
4 citations
Journal Article•
TL;DR: Among the ecological factors, salinity is found to play an importaiit role in the reproductive cycle and the maturation of gonads takes place immediately after spawning.
Abstract: The hard clam, Meretrix mereirix '(L), in VeMar estuaiy ha® an extended breeding period from February to September and the maturation of gonads takes place immediately after spawning. Both males, which are slightly more dominant, and females attain maturity at the same size. The spat settlement starts from March onwards. Among the ecological factors, salinity is found to play an importaiit role in the reproductive cycle.
3 citations
2 citations
TL;DR: In this article, both forms of humic acid (dissolved and particulate) in water were estimated quantitatively from three unique biotopes of Porto Novo in Southeast coast of India, viz, the sea, the estuary and the mangrove, from June 1982 to July 1983 The relative and progressive humification index of the water bodies as noted by E4 E 6 ratio, has also been described Sources, abundance and seasonal ariation of HAs in each biotope in particular and humification in general have been discussed
1 citations
TL;DR: In this paper, the kinetics of cyclohexanol by 1-Chlorobenzotriazole (CBT) was studied at 40°C in 50% aqueous acetic acid.
Abstract: The kinetics of oxidation of cyclohexanol by 1-Chlorobenzotriazole (CBT) has been studied at 40°C in 50% aqueous acetic acid. The reaction is first order with respect to oxidant and first order with respect to substrate. The rate is found to increase with increase in acid concentration and percentage ofAcOH in the mixture. The kinetic parameters have been calculated. A suitable mechanism is proposed.
Journal Article•
TL;DR: Early life history of an unidentified species of Stolephorus {Stolephurus macrops?
Abstract: Early life history of an unidentified species of Stolephorus {Stolephorus macrops?) was studied, rearing five earlier stages in the laboratory and collecting the subsequent postlarvae and juvenile (6 stages) from the plankton. The eggs had occurred in the marine zone of the estuary (salinity 32.58-33.37 %=) during February- March. The larvae were common in zones ranging in salinity from 15.35 %•> to 33.37 %.. during March-April. The different stages are illustrated.
01 Jul 1987
TL;DR: It was concluded from the in vitro studies that the prostate gland may be dependent on a gonadal hormone for functional differentiation, which in turn is under the control of trophic factors released from the brain.
Abstract: Prostate glands from mature and juvenileCryprozona belangeri were culturedin vitro for 8 days in single or double association with cerebral ganglia. visceral ganglionic complex and gonads obtained from adult snails. The histology of the glands was studied and compared with those of normal glands and with glands culturedin vitro without any organ association. Functional differentiation was not evident in glands cultured in isolation or in single association with gonad or brain. In double associations, involving cerebral ganglia, visceral ganglionic complex and gonad response from the gland was obtained only when the gonad was involved. The cerebral ganglia and visceral ganglionic complex acting through the gonad elicit differential responses from the prostate gland. It was concluded from thein vitro studies that the prostate gland may be dependent on a gonadal hormone for functional differentiation, which in turn is under the control of trophic factors released from the brain.