Root Growth of a Salt Susceptible and a Salt Resistant Rice (Oryza sativa L.) During Seedling Establishment Under NaCl Salinity

The salt susceptible rice ( Oryza sativa L.) cv. Jaya and salt resistant cv. Damodar seed germination and seedling growth rates were studied in laboratory and field conditions. The effect of salinity on seed germination, shoot and root length, seedling vigour index (SVI) and increase in the root: shoot length ratio in the laboratory was relatively more in cv. Jaya than in cv. Damodar. The relative susceptibility to salinity was more in cv. Jaya than in cv. Damodar in the field also. However, their responses varied with growth period. The root: shoot length and fresh and dry weight ratios increased with salinity at 15 days in cv. Jaya. The root: shoot fresh and dry weight ratio decreased with salinity at 15 days in cv. Damodar. However, the root: shoot fresh weight ratio decreased with salinity at 25 days in the susceptible cv. Jaya. The root and shoot length fresh and dry weight of cv. Damodar was enhanced at 0.5% (w/v) NaCl treatment compared to the control seedlings at 25 days. SVI in cv. Jaya decreased with salinity in the laboratory and field conditions. SVI in cv. Damodar, SVI showed little change at 15 days but decreased with salinity of 1–3% NaCl with an enhancement at 0.5% NaCl level in the laboratory and at 25 days in field conditions.     

Effect of temperature on transtadial transmission of Theileria annulata in Hyalomma anatolicum anatolicum ticks.

The effect of temperature on the transtadial transmission of Theileria annulata in Hyalomma anatolicum anatolicum was studied. Variation in temperature (4-40 degrees C) had a significant effect on moulting rate of the ticks and transmission of theilerial parasites from nymphs to resultant adults. The temperatures above 40 degrees C and below 12 degrees C prevented moulting. Maximum infection levels were obtained in salivary glands of adult ticks when the infected engorged nymphs were incubated at 24-28 degrees C. The infection rate in salivary glands was assessed using a methyl green pyronin technique.     

Effect of endosulfan in female rats growing on low- and high-protein cereal diet

Endosulfan (α,β-1,2,3,4,7,7-hexachlorobicyclo(2,2,1)-heptene-(2)-bis-hydroxymethylene(5,6)sulfite) fed daily 0.5 and 100 ppm in the diet proved significantly toxic to female rats (initial weight 40–50 g) growing on a low-protein (5%) diet as compared to those growing on a high-protein (24%) diet. The toxic symptoms which developed exclusively in low-protein-fed rats included growth retardation, low blood counts, low RNA and protein levels in liver, and high glutathione levels in liver and blood. However, no changes in the activities of liver RNase, blood glucose-6-phosphate dehydrogenase, and glutathione reductase were observed. Liver glucose-6-phosphatase activity increased significantly. Endosulfan induced an increased accumulation of perirenal adipose in rats raised both on low- and high-protein diets. Endosulfan elicited cumulative toxic manifestations as evident from the relative degree of toxicity caused by 0.5 ppm and 18 weeks feeding. α-Endosulfan, β-endosulfan, and endosulfan sulfate were recovered from adipose tissue, the recovery being higher in adipose tissue of rats raised on a low-protein diet.     

Characterisation of peacock (Pavo cristatus) mitochondrial 12S rRNA sequence and its use in differentiation from closely related poultry species

1. Poaching of peacocks, the national bird of India, is illegal. People kill this beautiful pheasant bird for tail feathers and mix the meat with chicken or turkey. Differentiation of the meat of these species is essential in order to address the ambiguity about the origin of the sample. 2. The present study was carried out to investigate the use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of mitochondrial 12S rRNA gene for identification of these species. 3. Peacock mitochondrial 12S rRNA partial gene was amplified using universal primers, cloned and characterised. It was found to be 446 nucleotides long. 4. Sequence analysis revealed 86.8 and 84.1% similarity with reported turkey and chicken sequences, respectively. Sequence and phylogenetic analysis showed that the peacock is much closer to the turkey than the chicken. 5. PCR-RFLP of 446 bp amplicon using commonly available restriction enzymes AluI and Sau3AI produced a differential pattern for identifying these poultry species unambiguously.     

Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage

Surface meltwater that reaches the base of an ice sheet creates a mechanism for the rapid response of ice flow to climate change. The process whereby such a pathway is created through thick, cold ice has not, however, been previously observed. We describe the rapid (<2 hours) drainage of a large supraglacial lake down 980 meters through to the bed of the Greenland Ice Sheet initiated by water-driven fracture propagation evolving into moulin flow. Drainage coincided with increased seismicity, transient acceleration, ice-sheet uplift, and horizontal displacement. Subsidence and deceleration occurred over the subsequent 24 hours. The short-lived dynamic response suggests that an efficient drainage system dispersed the meltwater subglacially. The integrated effect of multiple lake drainages could explain the observed net regional summer ice speedup.     

Remeasuring the double helix

DNA is thought to behave as a stiff elastic rod with respect to the ubiquitous mechanical deformations inherent to its biology. To test this model at short DNA lengths, we measured the mean and variance of end-to-end length for a series of DNA double helices in solution, using small-angle x-ray scattering interference between gold nanocrystal labels. In the absence of applied tension, DNA is at least one order of magnitude softer than measured by single-molecule stretching experiments. Further, the data rule out the conventional elastic rod model. The variance in end-to-end length follows a quadratic dependence on the number of base pairs rather than the expected linear dependence, indicating that DNA stretching is cooperative over more than two turns of the DNA double helix. Our observations support the idea of long-range allosteric communication through DNA structure.     

Optimization of process parameters influencing the submerged fermentation of extracellular lipases from Pseudomonas aeruginosa, candida albicans and Aspergillus flavus

The present study was aimed at optimization, production and partial purification of lipases from Pseudomonas aeruginosa, Candida albicans and Aspergillus flavus. Various nutritional and physical parameters affecting lipase production such as carbon and nitrogen supplements, pH, temperature, agitation speed and incubation time were studied. Refined sunflower oil (1% v/v) and tryptone at a pH of 6.2 favored maximum lipase production in Pseudomonas at 30 degrees C and 150 rpm, when incubated for 5 days. In C. albicans refined sunflower oil (3% v/v) and peptone resulted in maximum lipase production at pH 5.2, 30 degrees C and 150 rpm, when incubated for 5 days. In A. flavus coconut oil (3% v/v) and peptone yielded maximum lipase at pH 6.2, 37 degrees C, 200 rpm after an incubation period of 5 days. The lipases were partially purified by ammonium sulphate precipitation and dialysis. In P. aeruginosa enzyme activity of the dialyzed fraction was found to be 400 U mL-' and for C. albicans 410 U mL(-1). The dialysed lipase fraction from A. flavus demonstrated an activity of 460 U mL(-1). The apparent molecular weights of the dialyzed lipases were determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The dialyzed lipase fraction obtained from P. aeruginosa revealed molecular weights of 47, 49 and 51 kDa, whereas, lipases from C. albicans and A. flavus demonstrated 3 bands (16.5, 27 and 51 kDa) and one band (47 kDa), respectively. These extracellular lipases may find wide industrial applications.     

Efficiency of mannose-binding plant lectins in controlling a homopteran insect,the red cotton bug

Yield losses of different crops due to the attack of various classes of insects are a worldwide problem. Sucking type homopteran pests causing damage to many crop species are not controlled by commonly known insecticidal proteins, namely, Bacillus thuringiensis delta-endotoxin (Bt). This study describes the purification of mannose-binding lectins from three different monocotyledonous plants (Allium sativum, Colocasia esculenta, and Diffenbachia sequina) and their effects on a homopteran insect, the red cotton bug. All of them had a detrimental effect on the growth and development of the insect, where A. sativum bulb lectin showed the highest mortality of all, in particular. The same bulb lectin not only affected the growth and fecundity of the insect but also imparted drastic changes in the color, weight, and size, even on the second generation of the insects which have been reared on artificial diet supplemented with a sublethal dose of the lectin. Thus, this finding opens up a possibility of using this lectin as an important component in crop management.     

Association mapping,trait variation,interaction and population structure analysis in cucumber (Cucumis sativus L.)

Genetic Resources and Crop Evolution - In several regions of the world, low productivity in this crop is attributed to several factors including poor understanding of the genomic complexity of...