Chlorophyll <Emphasis Type="Italic">a</Emphasis> fluorescence,under half of the adaptive growth-irradiance,for high-throughput sensing of leaf-water deficit in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> accessions

Background

Non-invasive and high-throughput monitoring of drought in plants from its initiation to visible symptoms is essential to quest drought tolerant varieties. Among the existing methods, chlorophyll a fluorescence (ChlF) imaging has the potential to probe systematic changes in photosynthetic reactions; however, prerequisite of dark-adaptation limits its use for high-throughput screening.

Results

To improve the throughput monitoring of plants, we have exploited their light-adaptive strategy, and investigated possibilities of measuring ChlF transients under low ambient irradiance. We found that the ChlF transients and associated parameters of two contrasting Arabidopsis thaliana accessions, Rsch and Co, give almost similar information, when measured either after ~20 min dark-adaptation or in the presence of half of the adaptive growth-irradiance. The fluorescence parameters, effective quantum yield of PSII photochemistry (Φ_PSII) and fluorescence decrease ratio (R _FD) resulting from this approach enabled us to differentiate accessions that is often not possible by well-established dark-adapted fluorescence parameter maximum quantum efficiency of PSII photochemistry (F _V/F _M). Further, we screened ChlF transients in rosettes of well-watered and drought-stressed six A. thaliana accessions, under half of the adaptive growth-irradiance, without any prior dark-adaptation. Relative water content (RWC) in leaves was also assayed and compared to the ChlF parameters. As expected, the RWC was significantly different in drought-stressed from that in well-watered plants in all the six investigated accessions on day-10 of induced drought; the maximum reduction in the RWC was obtained for Rsch (16%), whereas the minimum reduction was for Co (~7%). Drought induced changes were reflected in several features of ChlF transients; combinatorial images obtained from pattern recognition algorithms, trained on pixels of image sequence, improved the contrast among drought-stressed accessions, and the derived images were well-correlated with their RWC.

Conclusions

We demonstrate here that ChlF transients and associated parameters measured even in the presence of low ambient irradiance preserved its features comparable to that of measured after dark-adaptation and discriminated the accessions having differential geographical origin; further, in combination with combinatorial image analysis tools, these data may be readily employed for early sensing and mapping effects of drought on plant’s physiology via easy and fully non-invasive means.

     

Identification of sperm motility markers in bovine transition protein genes

Transition proteins (TNPs) are essential in chromatin condensation during spermiogenesis, and hence, they are the candidate genes for identifying sperm motility markers. Coding and in silico predicted promoter regions of these genes were investigated in crossbred and purebred cattle, and also, their mRNA quantification was done to explore its use as a diagnostic tool of infertility. PCR‐SSCP analysis revealed two band patterns in fragment III of TNP1 and fragment II of TNP2 gene. Sequence analysis revealed a deletion of “G” nucleotide in 3′UTR region of TNP1 and C>T SNP in intronic region of TNP2 gene. Least square analysis of variance did not reveal any significant influence of nucleotide deletion on any sperm motility parameters in both crossbred and purebred cattle. However, C>T SNP had a significant effect on initial progressive motility (p < 0.05) in purebred cattle and post‐thaw motility in overall cattle population. RT‐qPCR analysis did not reveal any significant variation in TNP1 and TNP2 gene expression among poorly motile and good quality spermatozoa of Vrindavani bulls.     

Comparative analysis of mechanical properties of size film. II. Effect of blend composition and lubricants

The advent of very high speed shuttleless looms has increased the importance of sizing. Starch has been the most popular and economic size material. Synthetic binders are also being blended with starch to improve weaving loom efficiency. Blending may lead to give different properties, which can be suited for particular application. In the present study effect of blend composition in modified starch and synthetic size blends have been evaluated and mechanical properties like cohesion power, adhesion power, abrasion resistance, bending rigidity etc were studied. In general, it is being observed that paste characteristics and film properties of polyester resin blends are better but because of economic reasons PVA and acrylic polymers are preferred. In this study the effect of lubricant is also observed. It is analyzed that lubricant improves the various mechanical properties and hence the weaving performance of the material.     

Studies in Forest Pathology

A survey for the parasitic alga. Cephaleuros virescens Künze in relation to its seasonal distribution in different forest types has been done. The alga was absent in gymnosperms and was common in angiosperms. The disease severity was more in summer and the rainy season and absent in winter, Combretum decandrum was found to be most susceptible to this parasite alga. Altogether 49 hosts were recorded out of which 26 were new host records. Healthy leaves contain higher amounts of total nitrogen and total phenol, whereas in algal infected leaves the amounts of total sugar, total amino acid and dry weight were higher.     

Which food-related behaviours are associated with healthier intakes of fruits and vegetables among women?

OBJECTIVE: To examine associations between shopping, food preparation, meal and eating behaviours and fruit and vegetable intake among women. DESIGN: Cross-sectional survey. SETTING: Community-based sample from metropolitan Melbourne, Australia. SUBJECTS: A sample of 1136 women aged 18-65 years, randomly selected from the electoral roll. RESULTS: Food-related behaviours reflecting organisation and forward-planning, as well as enjoyment of and high perceived value of meal shopping, preparation and consumption were associated with healthier intakes of fruits and vegetables. For example, women who more frequently planned meals before they went shopping, wrote a shopping list, enjoyed food shopping, planned in the morning what they will eat for dinner that night, planned what they will eat for lunch, reported they enjoy cooking, liked trying new recipes and who reported they sometimes prepare dishes ahead of time were more likely to consume two or more servings of vegetables daily. Conversely, women who frequently found cooking a chore, spent less than 15 minutes preparing dinner, decided on the night what they will eat for dinner, ate in a fast-food restaurant, ate takeaway meals from a fast-food restaurant, ate dinner and snacks while watching television and who frequently ate on the run were less likely to eat two or more servings of vegetables daily. CONCLUSIONS: Practical strategies based on these behavioural characteristics could be trialled in interventions aimed at promoting fruit and vegetable consumption among women.     

Detection of Babesia bigemina DNA in ticks by DNA hybridization using a nonradioactive probe generated by arbitrary PCR

The Dig-labeled probe specific to Babesia bigemina generated from monomorphic RAPD fragment of approximately 873 bp size amplified by a 10 mer CGGTGGCGAA, detected up to 100 ng of template DNA. This nonradioactive probe also detected B. bigemina in preparations of larval tick DNA from two of the five samples on dot-blot hybridization.     

Seed variability in <Emphasis Type="Italic">Madhuca longifolia</Emphasis> (Koenig) J. F. Macbride,a source of oil for use as bio-energy

Madhuca longifolia (Koenig) J. F. Macbride is native to India. Seeds contain 20–50% oil (Mahua oil) and the seed cake is used as manure. Mahua oil is used by rural communities for protection against storage pests. Almost all parts of this tree have medicinal properties. Four explorations and collection missions was conducted during July–October 2007 in Tamil Nadu and the Union Territory of Puducherry. This resulted in the collection of 55 accessions. Characterisation and analysis of 7 seed characters were done. The existence of enormous variability in seed length, thickness and 100 seed weight indicates scope for utilization of these accessions for selection of promising material for extraction of oil. Oil content of kernels has been evaluated. Kernel oil ranged from 44.43 to 61.50%. Three accessions IC556617 with 61.50, IC556632 with 60.80 and IC556632 with 60.55% of kernel oil are superior to the rest. Further collections in the site of these oil rich accessions are promising for more productive Madhuca longifolia genetic resources.     

High antigenic cross-reaction among the bacterial species responsible for diseases of cultured freshwater fishes and strategies to overcome it for specific serodiagnosis

Antigenic sharing among the most commonly bacterial pathogens such as Aeromonas hydrophila, Edwardsiella tarda and Pseudomonas fluorescens of Indian major carps has been studied using immunological reactions such as cross-agglutination, disc diffusion and indirect enzyme linked immunosorbent assay (ELISA). The data were analysed using statistical analysis (SAS), version 6.12. The results showed high antigenic similarities among the bacterial whole cells, whole cell lysates, somatic 'O' antigens, lipopolysaccharides (LPS) and extracellular products (ECP). However, few or no similarities were observed in ECP components of <20kD. The present study indicates a need to develop differential diagnostic methods based on serology by choosing the highly specific less cross-reactive ECP antigen.