Volume 94, Issue 4-6
June 1985, pages 539-694
pp 539-551 June 1985
Using the HCl-Giemsa banding technique, the total proportion of condensed chromatin was determined by planimetry in 23 plant species and was found to vary from 14–77%. Comparison of condensed chromatin values withDNA content indicated that the latter was involved in determining the interphase nuclear structure. The actual amounts of differentDNA components in these species were estimated in terms of picograms. Statistical analysis of condensed chromatin values with quantities of different types ofDNA sequences showed the best correlation with highly repeatedDNA sequences, suggesting that these sequences could be playing an important role in governing the species-specific chromatin condensation in plants. The amount ofDNA packaged per unit length of chromatin was also shown to be a determinant of interphase nuclear structure.
pp 553-559 June 1985
The development of gametophytes and initiation of integument are described inPrenanthes brunoniana. Anther wall layers consist of an epidermis, endothecium, a middle layer and tapetum. Endothecium develops fibrous thickenings. Tapetum is of secretary type. Cytokinesis in of simultaneous type. Pollen tetrads are tetrahedral and are shed at the 3-celled stage. Ovule is anatropous, unitegmic and tenuinucellate. Integumentary vascular supply is present. The cells of dermatogen, subdermatogen and inner core all take part in the integument formation. Embryo sac development is of the Polygonum type.
pp 561-566 June 1985
Variations in the microtopography of seed coat in eight natural populations ofV. radiata var.sublobata inhabiting the Palney Hills of Western Ghats (Tamil Nadu) were investigated with the help ofSEM. The seed coat patterns are population specific, and the different patterns can be conveniently classified into two types. It appears that the polymorphism in seed coat patterns is of genetic origin and is the consequence of adaptation to spatio-temporal environments.
pp 567-574 June 1985
One hundred and fifty soil samples collected from three climatologically different sites were screened for laccase production using lignin-guaiacol agar plates. All the 12 fungi isolated excepting one gave positive test for qualitative lignin degradation. Five fungi were selected further for quantitative study of wood/lignin degradation. The basidiomycetes proved to be better laccase producers and decomposers of wood/lignin. These gave comparable results to a known white-rot fungus,Polyporus versicolor (L.) Fr. and degraded wood sawdust causing a total weight loss of 7–8% and lignin loss up to 10% in 30 days.
pp 575-582 June 1985
Immunogenic analyses were carried out for the rhizobial isolates collected from South Indian soils using the extracellular polysaccharide as the antigen. They are immunogenic eventhough their immunogenic nature was not established unequivocally in the previous studies. There was wide variation in their monosaccharide composition which could not be correlated with serological reactions.IR studies of these exopolysaccharides reveal that there are two major functional groups, amide and carboxyl in most of the isolates. The immunodiffusion analysis revealed that there are four distinct bands common to all the isolates. The antisera of the isolates D2, D9, V2, V3, Sa1 and P1 showed an additional hazy line.
pp 583-587 June 1985
Hydrobiological studies of two ponds and two lakes of Dharwad (Karnataka State) for one year showed highest biomass in the nutrient rich Laxman Singh pond. Devaragudihal lake was comparatively poor in nutrients and showed lowest phytoplankton biomass. Both Kyarakoppa pond and Nuggikeri lake did not exhibit significant difference with respect to physical and chemical factors and also standing crop of phytoplankton.
pp 589-606 June 1985
“Dhava” is unanimously ascribed toAnogeissus latifolia Bedd. which is a large deciduous tree having most of the curative properties as credited to its stem-bark, root and leaves. A detailed pharmacognosy of the stem-bark and the root of the above species has been dealt with in the present paper. The study revealed that while the stem-bark is characterised by its short-complete fracture, exclusively narrow phloem rays and small irregular concentric phloem fibre strands; the root is identified for its bark having fracture laminated, some considerably broad phloem rays in outer part of phloem, large regular concentric phloem fibre strands and the wood with diffused vessels, xylem parenchyma typically aliform to confluent with some scattered cells and xylem rays exclusively narrow. The fluorescence analysis of drug powders and their behaviour on treatment with different chemical reagents, percentage extractives and ash values, preliminary phytochemical studies includingTLC patterns of various extractives have also provided useful parameters to distinguish these plant-parts and check the adulteration.
pp 607-618 June 1985
Cytological studies have been made on 59 woody species of Polypetalae. Two genera (Gynocardia odorata,n=23;Pahudia martabanica,n=12) and 9 species (Talauma candollei,n=19;Cratoxylon polyanthum,n=11;Sterculia villosa,n=20;Grewia hirsuta,n=9;Millettia brandisiana, 2n=22+0−2B;Phanera glauca,n=14;Terminalia oliveri,n=12;Psidium coriaceum, 2n=77;P. pumilum,n=11) are counted for the first time. Additional and/or varied chromosome numbers are recorded for 8 species. Presence ofB-Chromosomes has been detected inCrataeva nurvala (n=13+0−3B),Erythrina caffra (n=21+0−3B) andMillettia brandisiana (2n=22+0−2B). Existence of some multivalents in the tetraploid taxa ofEugenia jambolana (2n=44) andHydnocarpus laurifolia (2n=48) indicates their segmental alloploid nature. But the presence of cent per cent trivalents (11III) in the triploid cytotype ofEugenia uniflora (2n=33) reveals the autotriploid nature. Presence of some univalents in diploid taxa ofMillettia brandisiana (2n=22) may be due to asynapsis and/or desynapsis. Variation in chromosome number inPMCs and some pollen sterility inHydnocarpus kurzii seems to be the consequence of cytomixis. Abnormalities in microsporogenesis in one of the cultivated trees ofFirmiana pallens (2n=40) are due to spindle irregularities.
pp 619-626 June 1985
Chromosomal analysis of 33 species of Labiatae from South India have indicated that 23·53% are polyploids. Several taxa are investigated for the first time. Analysis of results in totality for the region indicates that shrubby and perennial species have higher incidence of polyploidy. Polybasic nature of the family as well as the investigated taxa is quite apparent and this indicates the role of eu- and aneuploidy in evolution of various taxa in the family.
pp 627-632 June 1985
Results on seasonal growth, fruiting behaviour and spore output inPterocladia heteroplatos are presented. Populations ofP. heteroplatos were recorded in all months of the year with a maximum development of plants from November to January. Tetrasporophytes occurred throughout the year without any seasonal variation in their abundance but carposporophytes were rarely found in natural population. The tetraspore and carpospore outputs ranged from 1427–7 94 055 and 39 996–1 67 040 spores/g fresh weight of the plant respectively. Seasonal changes were not found in the formation and liberation of reproductive bodies inP. heteroplatos.
pp 633-638 June 1985
Vascular orientation of one week old seedling ofBrassica campestris Linn. has been studied. The studies rule out the possibility of splitting and torsion of xylem; instead there is a gradual inward shifting of the xylem differentiation pole. Unlike the existing reports,Brassica campestris Linn., in spite of having epigeal germination, shows the continuity of primary vasculature of root-hypocotyl-cotyledon in the first and second foliar node. The cotyledonary node is unilacunar two trace which supports Bailey’s suggestion of unilacunar double trace as a basic type.
pp 639-654 June 1985
Studies on leaves of the genera belonging to the two sub-groups: theLyonia and theGaultheria of the tribe Andromedeae were investigated anatomically. In both the groups there are clear vein ending types and also sclereid idioblasts confined to each taxa. Their morphological features could be regarded as diagnostic criteria of taxonomic value and may also serve as an adjunct character in the relationship of species or groups of species within a genus.
pp 655-661 June 1985
The present study has revealed that 24 out of 39 taxa ofPetrophile possess diverse types of sclereids. Further, it is observed that similar types of sclereids are present at the various sectional levels as recognised by Bentham. Their morphological aspects and systematic applicability have been discussed.
pp 663-670 June 1985
The abscission responses of petiolar explants of NP 46-A and Pusa jwala cultivars of chilli (Capsicum annuum L) to proximal and distal applications of growth substances were investigated. Ethephon, abscisic acid and ascorbic acid proved to be accelerants of abscission irrespective of age of explants and site of application. The synthetic auxin (naphthalene acetic acid) retarded abscission in younger explants regardless of the site of application but in the older explants proximal application of the auxin promoted abscission while distal application retarded the process. Gibberellic acid showed effects opposite to those caused by the auxin. The proximal application of gibberellic acid retarded abscission irrespective of age of explants while distal application effectively accelerated abscission. The cytokinin (benzyl adenine) and morphactin delayed abscission of petiolar explants on distal as well as proximal applications. The abscission responses to combinations of growth substances were highly variable depending on the age of explants, site of applications and varietal source of experimental material. The morphactin and benzyl adenine exhibited additive interaction in retarding the abscission up to such extent that ethephon and abscisic acid could only partially counteract their effects in combination of two growth substances. The auxin and gibberellin showed irregular and mixed interactions with other bioregulants studied.
pp 671-676 June 1985
The effect of foliar application of potassium on the growth pattern and yield components of three cultivars of pigeonpea (Cajanus cajan (L.) Millsp.), were studied. Potassium increased plant height and dry matter accumulation in all the three cultivars. Days to maturity was not much effected. Potassium increased yield in all the cultivars but at different levels. Flower drop was reduced conspicuously. However among the cultivars studied, cv.PDM1 showed better response than the others.
pp 677-682 June 1985
The small berry ofWithania somnifera is enclosed in an inflated calyx. Its pericarp is histologically differentiated into a 5–6 layered compressed collenchymatous epicarp, a multilayered zone of parenchymatous mesocarp and a 3–4 layer thick endocarp. The anomocytic stomata surrounded by 4–6 epidermal cells occur only in the basal region of the fruit. The number of cells of the mesocarp does not increase much, but its cells become enlarged, vacuolated and separated at maturity. The endocarpic lobes adhere to the placental false septa and enclose the individual seeds in separate chambers.
pp 683-694 June 1985
The response of abaxial and adaxial stomata to various growth substances were examined in leaves ofTagetes erecta L. From stomatal studies it is clear that growth substances produced several variations in the morphology of stomata. The anomalies recorded include persistent stomatal initial, loss of one or both guard cells in a significant percentage of stomata, contiguous stomata, cytoplasmic connections, one and a half contiguous stomata etc. Significant changes in frequency of epidermal cells and stomata, size of epidermal cells and stomata and stomatal index were noticed in various treatments.