Volume 90, Issue 3
June 1981, pages 183-273
pp 183-188 June 1981
Phosphate, succinate, acetate and maleate buffers were tested for buffering B5 liquid medium. Phosphate (0·02 M) and acetate (0·002 M) were the most suitable buffers as they promoted dry weight accumulation and nitrogen assimilation, they also exhibited less change in pH after 5 days cultivation of carrot cells. The pH increase from 5·5 up to 6·5 also increased the dry weight accumulation and cell size; pH 7·0 was detrimental to dry weight accumulation.
pp 189-197 June 1981
Effect of organic amendments on the microbial population of rhizosphere and non-rhizosphere soils was studied taking a number of dry and green plant materials. All the amendments had marked stimulatory/inhibitory effects on the population of fungi and bacteria in the rhizosphere but the magnitude varied with the amendment as well as variety and age of the plant. They also affected the relative population of different fungi in the rhizosphere. A number of them suppressed the population of Fusaria and stimulated that of Aspergilli.
pp 199-201 June 1981
A new species ofCassia kolabensis Kothari, Moorthy et Nayar is described with illustrations.
pp 203-205 June 1981
Brachystelma kolarenses Arekal et Ramakrishnasp. nov., (Asclepiadaceae) collected from Kolar district, Karnataka State, is described with illustrations.
pp 207-209 June 1981
Kunstleria keralensis C N Mohanan et N C Nair,sp. nov. is described and illustrated. The genus is new to the flora of India, earlier reports being from Malaya, Philippines and Australia. The present report on the occurrence of the genus from India is of phytogeographical significance.
pp 211-215 June 1981
Dormant rhizomes ofMentha spicata were subjected to various x-ray doses to induce mutations for herb yield and/or improvement in the quality characters of the essential oil. The investigation has led to the isolation of fourteen mutant clones including one with double the quantity of carvone.
pp 217-225 June 1981
The three forms D1, D2, D3 ofDactyloctenium aegyptium revealed different chromosome numbers,viz.n=20, 23, 27. Though these forms differed in the number of spikes and the length of the rachilla, they showed essentially a similar spikelet structure with small quantitative variations. Data were obtained from anatomical and especially from chemical studies to see if there existed sufficient discontinuity to warrant a distinct taxonomic recognition. The results are commented.
pp 227-230 June 1981
Cytomorphological characters ofSolanum retroflexum and tetraploidS. nigrum, and theirF1 hybrids were studied. The hybrids were fertile with highly regular meiosis. It is concluded that the species are differentiated primarily by genetic factors. The origin of the two species from the same or identical ancestors is discussed.
pp 231-236 June 1981
Seedling handedness has been studied in 76 genera and 137 species of of the Fabaceae out of which 35 genera and 78 species exhibit handedness. Its presence is more common or sporadic in some tribes and completely absent in other tribes. The taxonomic implications of this character is discussed. The possible causes for the existence of seedling handedness are discussed.
pp 237-243 June 1981
Seasonal variation and distribution of fungi from two freshwater ponds were studied for a period of one year employing ‘sector analysis’ method, baiting and plating techniques. A marked seasonal variation in mycoflora of the two pond waters has been found. Many species of aquatic fungi (Mastigomycotina) were obtained by baiting boiled hemp seeds, maize grains and grass leaves and also by sector analysis. Extra-aquatic fungi were isolated by plating organic detritus on PSA+strepto-penicillin medium. Fungi have been divided into monsoon, winter, summer and constant types based on their occurrence and periodicity. In all 36 species of fungi belonging to 23 genera were isolated from the two ponds. Pond A, which was slightly acidic (pH 5·8–6·2), supported many species of fungi than pond B, whose pH ranged between 7·6 and 8·2.Achlya, followed byPythium andAllomyces, formed the dominant genera.
pp 245-252 June 1981
Recent studies on the ontogeny of stomata in a number of plants have shown that the anomocytic stoma is not always perigenous or haplocheilic in origin as was previously believed but may be formed in a variety of ways. These are classified and reviewed in the present paper. The need to investigate ontogeny of this type of stoma in more plant groups is emphasized.
pp 253-272 June 1981
Twelve species ofSibbaldia L. are recognised, including one new combination and one new record for India. Key to the species, correct nomenclature of taxa dealt with, their systematic account, range of distribution, both in India and outside are given and specimens examined cited.
pp 273-273 June 1981 Erratum