Showing papers by "Archana Sharma published in 1961"

Chromosome Studies of some Varieties of Narcissus Tazetta L.

Abstract: SUMMARYFive East Himalayan varieties of Narcissus tazetta L. were investigated, namely: 1. N. tazetta var. « chastity » (2n = 30).2. N. tazetta var. « ponterius » (2n = 14).3. N. tazetta var. « paper white » (2n = 32).4. N. tazetta var. « cheerfulness » (2n = 24).5. N. tazetta var. « king daffodil » (2n = 28).A thorough karyotype analysis been performed of all these types. The importance of both structural and numerical alterations of chromosomes in the evolution of species has been pointed out.The occurrence of 2 n = 14 in variety » ponterius » of N. tazetta, so far not recorded in this species, brings it closer to the other species of Narcissus.Inconstancy in chromosome complements in the somatic tissue is present and as such, the role of somatic mutation in speciation has been emphasized.

Cytology of Some Members of the Family Iridaceae

Abstract: Cytological study has been carried out on seven species of Iridaceae, distributed under four genera, namely, 1. Babiana sulphurea 2n=142. Tritonia crocata 2n=603. T. crocata Type I 2n=224. Tigridia pavonia 2n=265. Moraea iridioides var. Mcleyii 2n=406. M. iridioides var. bicolor 2=407. M. iridioides var. johnsonii 2n=20On the basis of the data obtained and taking into account previous reports, it has been suggested that n=7 is probably the basic number for Babiana. A distinct line of evolution has been drawn for this genus, unrelated with the three other genera studied here.Tigridia pavonia shows abrupt size difference among the members of its complement and a different line of evolution for this genus too has been proposed.Tritonia crocata Type I, formerly included under Montbretia, has been observed to be cytologically allied to the genus Crocosmia. Its inclusion under the latter or its status as a member of a separate genus Montbretia, is urged.Tritonia crocata and the three varieties of Moraea iridioides show affinities in chromosome number and karyotype. A common evolutionary line had been assumed for them.Numerical and structural alterations of chromosomes in the somatic tissue have been noticed and their significance in evolution has been emphasized.

A comparative study of the effect of RNA and DNA treatment on somatic nuclei in plant cells

Abstract: The effect of different concentrations of ribonucleic acid (RNA) and desoxyribonucleic acid (DNA) has been studied on meristematic somatic cells ofAllium cepa. The principal effects noted with both are polyploidy and reductional separation of chromosomes.