Volume 89, Issue 2
March 1980, pages 79-160
pp 79-90 March 1980
From a survey of 104 herbaceous species from the Madurai Kamaraj University Campus collected for isolating intact mesophyll protoplasts 36 species belonging to C3, C4 and CAM photosynthetic pathways were found to yield between 15–85% of protoplasts. Species which easily yielded intact mesophyll cells by mild mechanical grinding were not amenable for protoplast isolation. The protoplasts of CAM species were the largest and those of C4 were the smallest in size. The isolated mesophyll protoplasts were photosynthetically active in terms of CO2 fixation and O2 evolution. Potassium ferricyanide was ineffective as Hill oxidant while dichlorophenolindophenol induced high Hill activity with the isolated protoplasts. The protoplasts maintained their photosynthetic stability up to 12 hr after isolation.
pp 91-104 March 1980
Pharmacognosy of the fruit ofDillenia indica has been studied in detail to find out reliable criteria for distinguishing the drug from its possible adulterants. The present paper deals with the anatomy of the pedicel, the fruit and also microscopic characters of the pollen and seed. Other possible parameters studied includes physico-chemical constants such as ash values, titrable acid number, percentages of tannins, sugars and different extractives. Qualitative detection of broad chemical constituents of the various extractives, their thin layer chromatography and fluorescence tests of the drug powder have also been carried out.
pp 105-108 March 1980
Comparison of mineral nutrients composition in petioles of Perlette (a prolific bearer) and Thompson Seedless (a shy bearer) vines revealed that the former accumulated more nitrogen and less phosphorus besides differing in their capacity for absorbing micro nutrient elements like zinc and copper. Peak content of nitrogen occurred after harvest in both the cultivars particularly Thompson Seedless resulting in excessive vegetative growth causing damage to vines. Phosphorus showed a peak in August for Thompson Seedless and September for Perlette. Potassium showed peaks in April and September in Thompson Seedless, and April, August and November in Perlette. The pattern of iron, zinc, manganese and copper accumulation differed in vines growing in monsoon region and those growing in temperate and sub-temperate region.
pp 109-115 March 1980
The present investigation deals with the localisation of polysaccharides, RNA, DNA, basic protein and ascorbic acid in the healthy andMeloidogyne incognita infectedCapsicum annuum root galls. In general, infected root galls were richer in RNA, DNA, basic protein and ascorbic acid as compared to healthy roots. The nema bodies were also overstained. Thick-walled cells of the infected root are darkly stained. Starch grains were confined to cortical cells; the giant cells and the cells around them were without any starch grains.
pp 117-121 March 1980
Cytomorphological characters ofSolanum indicum L. andS. melongena L., and of their hybrids (F1) were studied. The hybrids were fertile with mostly normal meiosis. It is concluded from cytology of the hybrids that small structural differences exist between the chromosomes of the parents. The potential ability of the parents to produce new recombinations inF2 is discussed. The conflicting observations of different workers on these species crosses are likely due to occurrence of variability in genetic architecture ofS. indicum andS. melongena. The plants ofF2 progeny were tested againstFusarium oxysporum,Phomopsis vexans andLeucinodes orbonalis. The plants found to be resistant were used in the study and from the subsequent studies a large population ofF4 generation was raised with desirable agricultural features.
pp 123-130 March 1980
Residues of methyl parathion, fenitrothion, malathion and endosulfan were determined in various parts of rice plant using gas liquid chromatography. The decline of residues were followed for 15 days in leaves and in harvested whole grain and dehusked grains. Effect of sun drying and par boiling of rice, on the reduction of residues was also studied. Factors influencing the residues are correlated. The decline of these pesticide levels in the leaves although fast are still above environmental protection agency tolerance limits even after 15 days. The same is true with whole grain and dehusked grain and hay immediately after harvest. However sun drying and par boiling the rice reduces the residues to 90%.
pp 131-138 March 1980
Sclerospora sorghi has been cultured in callus tissues ofSorghum vulgare maintained on a modified White’s medium. Cultures of healthy and diseased calluses were initiated from surface sterilised explants of stem apices and axes of inflorescences of healthy and diseased plants, and subcultured. The fungus developed internally in the callus and also spread over its surface as a white cottony mycelium. Healthy callus tissue and the sorghum seedlings were infected by placing them in contact with the mycelium produced on diseased callus. Mycelium spread from infected callus onto the culture medium, but remained viable only if physical contact with the callus was maintained. Only mycelium and oogonia were observed in infected callus. The number of nuclei in the oogonia varied. Some oogonia were abnormal both in size and shape. None of the oogonia developed oospores.
pp 139-142 March 1980
Fruits developed under long day treatment had considerably higher phenol contents than in normal day treatment. Phenolic compounds diminished gradually as fruits developed and the decrease is correlated with the activities of monophenolase and O-diphenolase. Tissue browning occurred due to the high activity of O-diphenolase.
pp 143-149 March 1980
Seed coat and fruit development have been studied inVigna catjang Walp. andVigna cylindrica (L.) Skeels. The ovules are crassinucellate, bitegmic and campylotropous. The seed coat, which is contributed by the outer integument, consists of ligniflcd epidermis, hypodermis, and inner parenchymatous layers. The vascular bundle has a post-chalazal extension. The mature pericarp has three distinct zones—the exocarp, mesocarp and the endocarp. The epidermis has papillate cuticle and the hypodermis is poorly lignified. Lysigenous cavities appear in the mesocarp. Taxonomical resemblances withPhaseolus are discussed.
pp 151-160 March 1980
A study of the soil mycoflora of mango orchards over a 10 month period revealed a significant correlation between soil moisture and fungal populations. On the other hand, soil reaction, organic matter, soil temperature and conductivity showed no significant correlation with fungal population. Marked variations in the fungal flora from month to month were observed.Aspergillus flavus, Aspergillus niger andCladosporium herbarum showed the capacity to decompose mango leavesin vitro. Small concentrations of mango leaf powder had a stimulating effect on the mycelial growth as well as sporulation of these species. These factors perhaps contribute to the dominance of the three fungal species in mango orchards.