Volume 97, Issue 1
February 1987, pages 1-79
pp 1-10 February 1987
This study reports the occurrence ofEleusine africana Kennedy O’Byrne for the first time in India. This wild taxon is believed to be the putative parent of the cultivarEleusine coracana (L.) Gaertn.Eleusine africana has been repeatedly considered by earlier workers to be non-existent in India. Its identity has been established by morphological, cytological, statistical and scanning electron microscopic studies. The discovery ofEleusine africana has led to various possibilities regarding the origin ofEleusine coracana.
pp 11-15 February 1987
The ratio of male to female flowers per inflorescence inAcalypha fruiticosa increases from bottom to top inflorescence of the plant and also along the altitudinal gradient. The increase is due to increase in male flower number per inflorescence. We explain these facultative changes in sex-ratio as fitness optimising strategies of the plant in response to altered success of males from the bottom to the top of the plant and along altitude which is primarily due to changes in pollen donation pattern.
pp 17-23 February 1987
The pericarp ofHibiscus sabdariffa can be differentiated into epicarp, mesocarp and endocarp. The epicarpic cells are vacuolated, compressed and tangentially elongated. The mesocarp becomes 5–7 layered thick and the vacuolation and disorganization of its cells are simultaneous with the fruit development. Three to five layered endocarp at mature stage possesses sclereids and fibers of diverse shapes. The dehiscence ofHibiscus sabdariffa fruit is loculicidally columnicidal.
pp 25-31 February 1987
The organographic distribution, structure and ontogeny of non-articulated laticifers are studied inPlumeria alba. The distribution of laticifer branches is studied in stem, pedicel, petiole, lamina, petal, stamen, ovary, wall, style and stigma. Laticifer branches are observed in all except anther lobes and stigma. The wall of the laticifers is thicker than in the other cells and the cytoplasm contains many nuclei. Round starch grains were found in the neighbouring parenchyma cells, but starch grains are lacking in the laticifers. The laticifer branch can occur on either side of procambium of the shoot and these cells can easily be distinguished from other cells by larger size, prominent nuclei and denser cytoplasm. Laticifers grow intrusively along the intercellular spaces.
pp 33-37 February 1987
There were significant differences in the amount of organic carbon exuded by the roots of different pearl millet varieties. The nitrogenase activity of the axenically grown pearl millet varieties inoculated withAzospirillum was related to the quantity of organic carbon released by their roots. However, the amount of exudate was found to be inadequate for the optimum expression of N2-ase activity which was considerably enhanced following the addition of carbon source. The stimulation of activity varied with the type of a carbon source and was related to preference shown by the organism for its growth in vitro. There was no significant change in the total plant dry weight following the addition of carbon to the root zone but there was a marginal reduction in the root growth and the root/shoot ratio.
pp 39-48 February 1987
Nitrogenous compounds such as total protein, true protein, soluble protein, non-protein nitrogen, total amides, ammonium, nitrate, nitrite, free amino acids and neutral and acid protease activities were estimated in a high protein wheat cv Shera (12·8% protein) and a relatively low protein wheat cv C-306 (10·4% protein) at different stages of grain development. All the nitrogenous compounds studied, as well as protease activities, were located in both testa-pericarp and endosperm. Developmental patterns and relative levels were, more or less, similar when expressed on per organ basis, or on dry weight basis. In the testa-pericarp; dry weight, total protein, soluble protein, true protein, amide, ammonium, nitrate and nitrite contents increased during development, and were higher in Shera, compared with cv C-306. Non-protein nitrogen content decreased during pericarp development, and was higher in cv Shera, compared with cv C-306. Free amino acid content and protease activities decreased in developing pericarp, and were lower in cv Shera, compared with cv C-306. Similar developmental patterns and relative levels of nitrogenous compounds and protease activities were found in endosperm. It is suggested that both testa—pericarp and endosperm make qualitatively similar contributions to the accumulation of nitrogenous compounds in developing wheat grain; higher protease activity in the endosperm of C-306 is not responsible for lower protein accumulation, and nitrate and nitrite are assimilated mainly in the green pericarp of the wheat grain. It appears that differences in protein contents of Shera and C-306 wheat arise primarily from differences in translocation of nitrogenous solutes from the phloem sap to the peduncle and pericarp, enroute endosperm.
pp 49-53 February 1987
Reciprocal hybrids were obtained betweenSolanum pubescens (non-spinous taxon) andSolanum incanum andSolanum indicum (spinous taxa) through modified hand pollination technique. The aspects studied relate to the cytomorphology of the F1 and F2 hybrids. On the basis of these studies it is concluded thatSolanum pubescens, Solanum incanum andSolanum indicum are cross compatible and have considerable homologies among them. The F1 hybrids were partially pollen sterile.
pp 55-61 February 1987
One of the colchicine treated plants of the cultivar Co2 ofCapsicum annuum L. was found to be a chromosome mosaic without seed-set and with as low as 4·95% pollen fertility. The growth of the plant was stunted. Its chromosome number (2n) varied from 38 to 96. Chromosome associations and chiasma frequencies were studied in each of the chromosome classes. Bivalents and association of 4 chromosomes were prevalent. Univalents were common. Laggards were observed at anaphases I and II. The chromosome mosaicism is attributed to the effect of colchicine on the spindle and physiological process.
pp 63-73 February 1987
Penicillium pinophilum, Aspergillus quadricinctus andGliomastix murorum secreted a complete extra-cellular cellulase complex comprising of endo-β-glucanase, exo-β-glucanase and β-glucosidase. The enzyme production was optimum with absorbent cotton and a combination of ammonium sulphate, urea and peptone inPenicillium pinophilum, with carboxymethylcellulose-7 MT and ammonium chloride inAspergillus quadricinctus, and with absorbent cotton and peptone inGliomastix murorum. The biosynthesis of cellulase was repressed by sugars in the presence of cellulose and only negligible amounts of cellulolytic enzymes were produced when sugars formed the sole carbon sources.
pp 75-79 February 1987
The chlorophylls, carotenoids and their ratios were determined in 6 liverworts and 4 mosses of Nainital, Kumaun Himalaya. The amount of chlorophylls and carotenoids was higher in liverworts except forStephensoniella brevipedunculata compared to mosses. Liverworts studied occurred in shady habitats, whereas the mosses occurred in open situations. The chlorophylla/b ratios were less than 1·5. This is a response of bryophytes to low light environments. The chlorophyll/carotenoid ratio did not show any remarkable difference among liverworts and mosses, as the study was carried out during the rainy season—the luxuriant growth period of bryophytes.