Volume 95, Issue 2
September 1985, pages 65-138
pp 65-69 September 1985
The hyphae ofBipolaris sorokiniana (Sacc. in Sorok) Shoemaker, a fungus belonging to the hyphomycetes, branched profusely while growing on a medium containing sodium chloride. Non-ionic osmotic compounds and other salts failed to induce branching. It appears that the Na ion of NaCl is responsible for inducing the hyphae to branch.
pp 71-78 September 1985
The contents of various free sugars in large and small wheat grains were compared with those in normal grains at different stages of grain development. Their content paralleled grain weight only upto 14 days after anthesis (A+14). On a dry weight basis, no positive correlations were observed between the concentrations of various free sugars and grain weight at any of the stages. Differences in grain weight were dependent mainly on the number of cells formed in the endosperm which in turn seemed to be regulated by the assimilate supply available to the grain during the first 14daa.
pp 79-86 September 1985
The effect of established populations of two sympatric annual weeds,Galinsoga ciliata (Raf) Blake andG. parviflora Cav on their newly emerged seedling cohorts was studied. These weeds occur abundantly in croplands and early successional communities in the northeastern hill region of India. Seed germination, survivorship and growth in both cases were reduced owing to competition from their established plants. The established cohorts ofG. ciliata exercised greater suppressive effect than those of G. parviflora. Twenty five-day old cohort ofG. ciliata caused maximum suppression on foliage production, seed output and dry matter yield of the newly emerged individuals ofG. parviflora.
pp 87-94 September 1985
Veinlet sheathing of twenty-six species ofPancheria is described and illustrated. Within the genus foliar vein sheathing varies from almost completely lacking to abundant, and individual sheath cells show much variation in cell wall composition and structure. The topographical distribution of sheath cells along the vein system, when coupled with the structure of individual sheathing elements, can be utilized to distinguish three anatomical groups of species. Although the evolutionary sequence and ecological significance of the diverse sheath types are at present unresolved, features of vein sheathing appear to be of systematic significance and may provide an additional basis for a better understanding of infraspecific relationships within this genus.
pp 95-101 September 1985
The developmental morphology and histochemistry of the solid indehiscent galls ofPongamia glabra Vent. are presented. Hyperplasy and hypertrophy of the medullary ray and pith cells causes the separation of the vascular cylinder which contributes to the radial enlargement of the stem. Hyperactivity of acid phosphatase, peroxidase, polyphenol oxidase and an increased level of proteins was detected in the gall tissues and has been discussed in relation to the gall development.
pp 103-120 September 1985
The host relations ofCrotonothrips withMemecylon on the criterion of gall formation appear interesting. In the light of the morphogenetic courses that the susceptible host organ, the leaf, show, an attempt has been made to assess their functional efficiency in terms of structural adaptations envisaging the organisation of a nutritive zone, and tissue dynamics takingMemecylon edule, Memecylon lushingtonii, andMemecylon umbellatum as models.
pp 121-127 September 1985
Effect of environmental factors on the shedding of tetraspores inAglaothamnion cordatum was studied. Submerged condition of the plants and salinities between 30–40‰ were found to be favourable for the maximum shedding of tetraspores. Light intensity of 2000 lux and 4∶20 L∶D regime found to be the suitable conditions for maximum liberation of tetraspores. Spore output varied at different times of the day and the highest values were recorded between 10pm and 2am.
pp 129-138 September 1985
The enzymes succinate dehydrogenase and peroxidase were localized histochemically in the leaf epidermal cells and in the young stems of:Annona squamosa L.,Coccinia indica W. and A.,Bougainvillea spectabilis Willd.,Azadirechta indica L.,Ficus benghalensis L.,Lantana camara L. var.aculeata, Mangifera indica L.,Manilkara hexandra (Roxb) Dub.,Streblus asper Lour,Syzygium cumini L.,Tamarindus indica L., andZizyphus oenoplia L., from the areas around the Gujarat State Fertilizer Company, near Baroda (22°−30′ N latitude, 73°−60′ E longitude), and nearly-normal area of Vallabh Vidyanagar (22°−50′ N latitude, 73°−10′ E longitude). The soil types, temperature, rainfall, humidity and agricultural patterns of the two localities are identical. Intensities of enzyme activity vary in different cell types of the epidermis and in various tissues of the stem. Intensities of succinate dehydrogenase and peroxidase in epidermal cells is low in majority of the pollution-affected plants. Except inAzadirechta indica andManilkara hexandra, stem of all the other pollution-affected species showed lower succinate dehydrogenase activity than in the normal. Vascular parenchyma in the stems of pollution-affected plants ofAzadirechta indica andManilkara hexandra showed high succinate dehydrogenase activity than that in the normal, whereas in extravascular regions it is almost identical with that of the normal stem. Peroxidase activity in the stem of pollution-affected plants ofManilkara hexandra andStreblus asper is higher than that in normal, and in rest of the species it is lower than or almost the same as in the normal.