Volume 86, Issue 6
December 1977, pages 337-416
pp 337-360 December 1977
This presents the review of seventynine species and varieties of angiosperms in which androgenesis has been induced. The culture practices, probable factors (physiological, bio-chemical and cytogenetical) involved and the applied aspects of andromorphogenesis are analysed.
pp 361-369 December 1977
InCrotalaria burhia Buch-Ham.,C medicaginea Lamk.Tephrosia hamiltonii Drumm. andT. apollinea Link studied here, the floral organs develop in an acropetal sequence and are not congenitally fused. Calyx and staminal tubes are formed due to zonal intercalary growth at their bases.
Floral anatomy conforms to dihiate series inCrotalaria species with two sets of gaps and to unihiate series with single set of gaps inTephrosia species. InTephrosia species there is a glandular disc present on the inner side at the base of stamens which is vascularized by the staminal traces. InCrotalaria species, no prominent disc is present but some densely cytoplasmic cells lining the receptacular cup are clearly discernible which are nonvascularized.
Mucilage cells have been observed in the floral parts inTephrosia species. The mucilaginous cells are multinucleate, formed by the dissolution of cell walls of the surrounding cells.
pp 371-374 December 1977
Isocitrate lyase (ICL) activity is described in the quiescent and germinating pollen ofCalotropis procera. The behaviour of the enzyme depended upon the presence or absence of exogenous substrate. The activity of this enzyme in relation to some dehydrogenases (MDH; ICDH; G-6-PDH) is compared. Effects of actinomycin-D and cycloheximide on the activity of different enzymes is described. The increase in the activity of ICL and G-6-PDH, during the activation phase, is attributed to theirde novo synthesis. The possibility of sucrose in causing repressing effects on ICL synthesis and/or activation is brought out.
pp 375-380 December 1977
The node in all the 32 species investigated is unilacunar one-trace. However, several nodes inMillingtonia hortensis also showed a bilacunar two-trace condition. The single trace may be massive and semi-circular, shaped like a broad arc or a horse-shoe but inMillingtonia hortensis, it is poorly developed. A somewhat trilobed trace has been observed inTecoma stans. The trace enters the base of the petiole as such or it divides into three immediately after leaving the vascular cylinder. The laterals may branch further before entering the petiole. The trends of specialization in nodal anatomy have also been discussed.
pp 381-384 December 1977
The leaves are hypostomatic bearing the dia-mesogenous and diallelomesoperigenous stomata on the lower epidermis only. Less frequently occurring dia-mesogenous stomata have 2 subsidiaries of mesogenous origin, lying at right angles to long axis of the stomatal pore. The other type is more common and characterised by 4 or sometimes 3 subsidiaries of dual origin. Those two of the inner ring are mesogenous and the remaining two or one subsidiary cell of the outer ring, as the case may be, are of perigenous origin. However, the meristemoids of both types are dolabrate and the difference in the adult stomata is found to be dependent on the number of the cells encircling the meristemoid and the nature of the placement of the cross wall laid by the meristemoid producing protodermal cell.
pp 385-387 December 1977
Holcosorus bisulcatus (Hk). Ching is described in detail with illustrations as a new generic record of fern for the Indian region. The genusHolcosorus Moore is reported earlier from Borneo only.
pp 389-395 December 1977
The presence ofAzotobacter species, their population and nitrogen fixing capacity of some isolates from cultivated North Indian soils including a sample of ‘floating island’ were studied. The results indicated the presence ofAzotobacter chroococcum andAzotobacter agilis as the main species in all the samples including those having acid range of pH. The correlation coefficients between totalAzotobacter number/multiple regression ofAzotobacter with/and physico-chemical properties like pH, organic carbon, available phosphorus, exchangeable calcium and magnesium were obtained and have been discussed. ‘Floating island’ sample revealed the highest population of these bacteria (76×103/g). The nitrogen fixation capacity ofAzotobacter isolates was found to be stimulated by aeration of the medium in presence of molybdenum, i.e., in nitrogen free culture solution with molybdenum application and aeration the nitrogen fixation capacity was of the order of 2·8 to 28·7 mg/g of mannitol whereas without aeration and molybdenum application the range was in between 2·1 to 21·0 mg/g mannitol.
pp 397-404 December 1977
Light microscopic studies on the colonization and establishment ofSpirillum lipoferum in the roots of several plants and two callus cultures revealed that root hairs, epidermal cells and in rare instance xylem cells were filled with bacteria. Farm yard manure amended soil was found to be a suitable carrier for the organism which maintained its shelf life for a fairly long period. It was possible to isolateS. lipoferum from soils stored dry for 15 years, indicating the possibility of a perennating mechanism in the species.
pp 405-408 December 1977
The pre-ovipostion period, oviposition period, longevity and fecundity of the macropterous and brachypterous females of the rice brown planthopper,Nilaparvata lugens Stal, averaged 2·9 and 3·0 days; 8·4 and 9·2 days; 10·5 and 16·5 days; and 421·8 and 485·8, respectively. The egg-laying habit of this pest is described and its daily rate of oviposition illustrated.
pp 409-416 December 1977
Balanus kondakovi an operculate barnacle was chosen as an experimental material forin-situ characterisation of the adhesive material of its cement apparatus by standard histochemical techniques. Reactions of PAS, LTAS or Alcian Blue with cement were generally negative indicating the absence of polysaccharides. Sudan Black B test for lipids also gave poor reaction. The classic Millon’s reaction for tyrosine gave positive result and DMAB method for tryptophan developed weak blue colour in some areas of the cytoplasm. Protein bound sulfhydril or disulfide groups could be identified. The histochemical tests thus revealed that the cement material was generally poor in carbohydrates and lipid and that it had good proportion of protein.