Volume 95, Issue 3
October 1985, pages 139-219
pp 139-146 October 1985
Certain metals have been investigated in paper mills effluent channel and in the river Tungabhadra in relation to their distribution, seasonal fluctuations and their effect, if any, on algae. The concentrations of various metals analysed are in the order of Zn>Cu>Pb>Ni>Co>Mn. In general these metals indicated an increase in their concentration along with the increase in the concentrations of chlorides, total hardness, sulphates and total alkalinity. Blue-greens and diatoms seem to be more tolerant to these ions than Chlorophyceae.Stigeoclonium exhibited very good growth at high concentrations of zinc, copper and nickel and at low concentrations of cobalt and lead.Schizomeris attained good growth when the lead concentration was high and cobalt was low.
pp 147-152 October 1985
Two-day and eight-day old seedlings ofAsclepias curassavica, Calotropis procera andLeptadenia pyrotechnica were studied. The basipetally differentiating epicotylar vasculature and the root-hypocotyl-cotyledonary vasculature are ontogenetically separate units. The cotyledonary node is unilacunar two-trace and the foliar nodes, unilacunar one trace. The unilacunar two trace cotyledonary nodes in advanced families like Apocyanaceae and Asclepiadaceae seem phylogenetically significant.
pp 153-165 October 1985
Mature fruit structure of 8 species of Cocosoid palms representing 8 genera distributed in 3 alliances has been described along with developmental account in 2 species. The diagnostic features have been discussed in the light of the work done in other members of this group.
pp 167-172 October 1985
The apertures of stomata on isolated epidermal peels from both the leaf surfaces ofCommelina communis were reduced in response to chlorocholine chloride as the concentrations increased from 0·01–10·0 mol m−3. When chlorocholine chloride was applied in combination with different concentrations of indoleacetic acid, stomatal closure occurred only when a high concentration of chlorocholine chloride was applied with a low concentration of indoleacetic acid, while low concentrations of chlorocholine chloride did not affect the stimulation of aperture caused by indoleacetic acid treatments. Chlorocholine chloride treatments caused depletion of K+ from the guard cells while indoleacetic acid resulted in accumulation of K+.
pp 173-179 October 1985
A new antheridiogen fromPityrogramma calomelanos of the family Polypodiaceae (Sensu Bower) has been extracted and tested onPityrogramma calomelanos, Onychium siliculosum (Desv) C. chr, andOnychium japonicum (Thbg) Kze. The antheridiogen, here designated as Apit, did not produce uniform effect on the species tested. It promotes dark germination in all, but induces antheridia only inPityrogramma calomelanos andOnychium siliculosum under light and dark conditions. The antheridium-inducing capacity of Apit is markedly different on the two ferns, being more vigorous under light condition inPityrogramma calomelanos and less inOnychium siliculosum. Contrary to this, more antheridium-bearing prothalli have been counted in the latter under darkness. Higher dilutions are less effective in both. Dark germination has been found most effective in case ofOnychium japonicum. The results indicate that the intensity of the effect of antheridiogen varies under different conditions and between species of the same genus. Also, an antheridiogen is not specific in the induction of antheridia or dark germination of spores, but it may initiate any of the two or both.
pp 181-192 October 1985
Nitrogen assimilation was studied in two rice varieties, Taichung Native I, a high nitrogen tolerant strain and Ponni, a moderate nitrogen feeder. Nitrate and ammonia were supplied to the seedlings of the two strains at 3 levels 21, 42 and 84 μg N/ml of culture medium. Assimilation of nitrate and ammonia was followed by estimating levels of nitrate and nitrite reductases, glutamine synthetase and glutamate dehydrogenase activities. Growth, total nitrogen content, nitrate content and amino acid pool pattern were also determined at different age levels. It turned out that the high nitrogen tolerant variety T(N)1, most probably gets its nitrate reduction and ammonia assimilation done in the leaves with the photosynthetically generated reductant and energy, whereas in Ponni, much of these processes seem to occur in the roots at the expense of translocated photosynthates. Ammonia assimilation is primarilyvia GS/GOGAT pathway rather thanvia GDH and T(N)1 was higher in its assimilatory efficiency than Ponni.
pp 193-198 October 1985
The variability of the desmids was quite interesting to note that when the conditions such as temperature and illumination were altered, there was not only an increase in the abnormal forms but the number of the adherent cells were also more. This abnormal behaviour of the species was more or less directly proportionate to the altered status of these factors in culture. It was thus quite clear that due to an increase or decrease in temperature and light intensity, quite a number of variants were produced. Sometimes the cells departed so widely from the specific characteristic that one could mistake them as belonging to different taxa. It may be that under unfavourable conditions of growth the mechanism of cell division was disturbed lowering thereby the percentage of mitosis and finally leading to the tendency of morphological aberrations. Consequently, these observations induced to study the various species of desmids under different experimental conditions to find out the range of morphological variation in cultures because the feature which more than any other, has attracted algologists to study desmids especially placoderms is their considerable morphological variability. Morphological variations under different cultural conditions have been studied and it is presumed that the cell types are capable of maintaining their narrow specificity, which is genetically controlled under favourable conditions only, but, whenever, there is a change in environmental set-up, it has resulted in upsetting the metabolic behaviour leading to abnormal forms.
pp 199-202 October 1985
Effect of sulphur dioxide on the growth of pigeonpea (Cajanus cajan (L.) Millsp.) was studied. Five day old pigeonpea seedlings were exposed to 10 and 20 ppm SO2 in glass chambers for 3 hr/day continuously for two weeks. Analyses were made in 25-day old seedlings with respect to foliar injury, morphological characteristics, dry matter accumulation and nodule number. Sulphur dioxide affected leaves showed chlorosis, tip burn and marginal necrosis. Root growth and nodulation were very much reduced in fumigated seedlings. Sulphur dioxide exposure decreased dry matter accumulation in all the parts of the seedling.
pp 203-211 October 1985
The phenological and biochemical characteristics of male and female plants of Jojoba were studied during different seasons. The phenological studies indicated that the flowering and fruiting behaviour of this species in the semi-arid conditions of India change considerably with continuous flower formation and two fruiting cycles in a year. Marked differences in the carbohydrates, proteins and nucleic acids were observed between sexes and during different seasons. The pistillate plants had greater metabolic activities with more DNA and RNA than the staminate shrubs.
pp 213-219 October 1985
Embryology ofEnicostema hyssopifolium (Willd.) Verdoorn. andExacum saulieri L. has been investigated. Anther wall development is of the dicotyledonous type and at maturity consists of the epidermis, fibrous endothecium, 1–2 middle layers and the tapetum which is uniseriate with uninucleate cells. Connective tapetum is also differentiated. Pollen grains are triporate and 3-celled at anthesis. Pollen degeneration at various stages of development is common. The bicarpellary, syncarpous and unilocular ovary bears anatropous, unitegmic and tenuinucellate ovules on parietal placentae. Embryo sac development is of the polygonum type. Fertilisation is porogamous and the endosperm isab initio nuclear. Embryogeny is of the Solanad type.