Effect of seed mass on emergence and seedling development in Pterocarpus marsupium Roxb.

We investigated the effect of seed mass on emergence, seedling survival and growth ofPterocarpus marsupium Roxb., a medium to large, commercially valuable and deciduous tree species. Among the three size classes viz. small （10-12 mm）, medium （13-15 mm） and large （16-17 mm）, the maximum proportion, of seed by number （54.12%） and dry weight （51.87%） was recorded, in the medium size seed class. Seed length and seed width were greatest in the large seed class （16.50 mm, 7.33 mm） followed by medium （13.50 mm, 5.60 mm） and small （11.37 ram, 3.66 mm）. Similarly, hundred seed weight （100 sw） varied from a maximum of 12.92 g in the large seed class to intermediate 10.95 g in the medium seed class and minimum of 7.02 g in the small seed class. The large seed size showed maximum emergence and shoot length over the medium and small seed class. After six months of growth, significant variations due to seed size were also observed for the growth and dry weight of P. marsupium seedlings. Seedling vigour, expressed in terms of height, collar diameter, number of leaves and dry biomass, was sig- nificantly affected by seed class. Seedlings that emerged from large seeds showed better growth and produced heavier seedlings as compared to medium and small seeds.     

Composting of Tropical Toxic Weed Lantana camera L. Biomass and Its Suitability for Agronomic Applications

ABSTRACT

Lantana camara is an evergreen, which is the most notorious toxic weed of the terrestrial ecosystem. It is native to subtropical and tropical America, but a few taxa are indigenous to tropical Asia and Africa. An enormous quantity of green foliage is produced by this weed, which cannot be used as livestock feed due to its toxic properties. Management through utilization seems the only sustainable option for this problem. In this study, the composting of Lantana biomass was done and changes in chemical characteristics of waste biomass were measured. The composting caused decreases in pH, organic carbon, C:N ratio _totK and _totC by 2.0-, 1.25-, 1.66-, and 19-fold, respectively, but increases in electrical conductivity (EC), ash content, _totN, _totP, _totZn, and _totMg of 2.0-, 1.11-, 3.36-, 1.76-, 1.28-, and 1.70-fold, respectively. The C/N ratio (20.1) and soil respiration rate (47.12–66.20 mg CO₂-C/100 g) suggested the compost maturity at 52 days. The high bacterial (38.67 CFU × 10^?7 g^?1), fungal (30.0 CFU × 10^?3 g^?1), and actinomycetes (32.0 CFU × 10^?5 g^?1) population in composted material suggested the suitability of compost for agronomic purposes. Phytotoxity measured through compost:water extract and compost pot trial suggested the germination index (GI) in the ranges of 52.3%–122.3% and 74.5%–166.9%, respectively. The high ranges of chlorophyll, protein, and carotenoids in seedling than control suggested the non-toxicity of ready materials. Results suggested that composting can be a potential technology to manage Lantana biomass for sustainable land fertility management programs.     

A new secoiridoid glycoside from Lonicera angustifolia

A new secoiridoid glycoside, 6'-O-beta-apiofuranosylsweroside (1), together with the known compounds sweroside, loganin, beta-sitosterol, oleanolic acid, ursolic acid and methyl-4-hydroxy benzoate have been identified from the leaves of Lonicera angustifolia. The structure of the new compound has been elucidated on the basis of spectroscopic and chemical evidence.     

Titrimetric determination of ascorbic acid using chloranil

Ascorbic acid is oxidized and quantitatively titrated with chloranil (2,3,5,6-tetrachloro-1,4-benzoquinone) in the presence of hexamethylenetetramine in acetone-water; the end point is determined visually by the appearance of a golden yellow color. Colored solutions are assayed by setting the initial absorbance at 451 nm to zero or the minimum, titrating with chloranil solution, and measuring absorbance after each increment of titrant. A plot of the volume of chloranil added against the absorbance gives a straight line with the volume intercept as the end point. Interference by the thiol group of cysteine, glutathione, etc., is avoided by masking with acrylamide; interference by iron(II) is masked with ammonium thiocyanate and sodium potassium tartrate. Hydrogen sulfite and thiourea (which do not interfere) are added as antioxidants during extraction of ascorbic acid from drugs and fruits.     

Chemical kinetics of stress relaxation of compressed wood blocks

Summary Methods of chemical kinetics are used to study stress relaxation behaviour of wood blocks made fromPinus sylvestris and compressed parallel to grain at 20°C and 65% relative humidity. The effect of stress levels on stress behaviour is investigated. It is found that both activation volume and activation energy decrease with increasing stress level. The results prove the validity of the chemical kinetics approach in describing stress relaxation of wood blocks in compression. Suggestive explanations are given for the variations in activation energy and activation volume with stress level.Part of this work was carried out at the School of Agriculture and Forestry Sciences, University of North Wales, Bangor, UK through an ODA TCT fellowship granted to one of the authors (SPSR). He would like to thank Director General, ICFRE (India) and Director, IWST, Bangalore (India) for providing him with the opportunity to work in UK. He would also like to acknowledge the help received from Mrs. Helen Simpson and Dr. Robert Brooke of School of Agriculture and Forestry Sciences, University of North Wales, Bangor, U.K     

Isolation and expression analysis of defensin gene and its promoter from Brassica juncea

Journal of Plant Diseases and Protection - The full-length pathogen-inducible plant defensin gene encoding 80 amino acid sequences of pathogen-related gene PR12 (Bjdefensin) was isolated from...     

Studies on some Drought Resistant Traits of Pearl Millet Cultivars and their Association with Grain Production under Natural Drought

A field experiment was conducted to evaluate the performance of hybrid (BJ 104, MBH 110, CM 46 and GHB 27) and composites (PSB 3, PSB 8, WCC 75 and Local) of pearl-millet on the soils (pH 7.1, Organic carbon 0.5 %, P₂O₅ 9.6 kg/ha, K₂O 80 kg/ha, soil depth 65 cm and profile moisture 8.6 cm) of Indian Grassland and Fodder Research Institute, Jhansi under extreme drought condition (340 mm total precipitation during the crop season). It was observed that hybrids, by and large, gave higher production than composites and local variety even failed to bloom. Further the highest yield from hybrid MBH 110 was due to its drought escaping character (earliness), drought enduring capacity (CSI-12), efficient translocation and better sink strength. BJ 104 and CM 46, though were also drought escaping and possessed capacity to endure drought but inferior to MBH 110 in sink strength which was ultimately reflected in production.
An appraisal of the various agro-physiological traits revealed that earliness, high harvest index, low CSI value (chlorophyll stability index) and high sink strength were directly correlated with productivity of cultivars under drought condition which could be used as a guide lines for breeding drought resistant cultivars of pearl millet.