Molecular genetic mapping of quantitative trait loci associated with loaf volume in hexaploid wheat (Triticum aestivum)

Major efforts in wheat research are being made to improve the yield and quality of wheat. Loaf volume (Lv) is the main quality parameter deciding the bread making potential of wheat. To genetically dissect quantitative trait loci (QTLs) for Lv, a Recombinant Inbred Line (RIL) population (F₈) was developed from a cross between two Indian wheat varieties “HI 977” and “HD 2329”. A total of 914 SSR and 100 ISSR primers were used for molecular analysis and the genetic map comprising 19 chromosomes was constructed with 202 SSR markers and 2 HMW glutenin subunit loci: Glu-B1 and Glu-D1. The phenotypic data were collected from six environments including three different agro-climatic zones for 2 consecutive years. Dissection of Lv through AMMI model revealed significant G×E variance for the trait. QTL analysis was performed using composite interval mapping. A total of 30 QTLs for Lv were detected and significant QTLs were identified on 6B and 6D chromosomes; 1B, 1D, 2A, 3A, 5B and 5D also contributed genetically to Lv. Association between 6B and 6D QTLs and variable expression of gliadins on group 6 chromosomes were discussed. QTLs detected in this study were compared with other QTL analysis in wheat.     

Explaining the latitudinal distribution of sunspots with deep meridional flow

Sunspots, dark magnetic regions occurring at low latitudes on the Sun's surface, are tracers of the magnetic field generated by the dynamo mechanism. Recent solar dynamo models, which use the helioseismically determined solar rotation, indicate that sunspots should form at high latitudes, contrary to observations. We present a dynamo model with the correct latitudinal distribution of sunspots and demonstrate that this requires a meridional flow of material that penetrates deeper than hitherto believed, into the stable layers below the convection zone. Such a deep material flow may have important implications for turbulent convection and elemental abundance in the Sun and similar stars.     

Linking nest histories,remotely sensed land use data and wildlife crime records to explore the impact of grouse moor management on peregrine falcon populations

Wildlife crime can be difficult to quantify, and its true impact on populations can be underestimated if rates are under-recorded. The illegal killing of birds of prey is an important form of wildlife crime, which in the UK, is often associated with land managed for the recreational shooting of red grouse Lagopus lagopus scoticus. In the UK, increases in peregrine falcons Falco peregrinus following recovery from organo-chlorine pesticides have not been uniform, with slow growth and localised declines in some areas, including those managed for red grouse shooting. In this study, we combined 1081 peregrine nest histories across northern England between 1980 and 2006 with a remotely sensed map of grouse moor management, to test whether breeding performance was lower in areas with active management for grouse shooting. Productivity of pairs on grouse moors was 50% lower than pairs breeding on non-grouse moor habitat. However, clutch size and brood size of successful nests did not differ between habitat types, suggesting that food constraints were unlikely to explain this difference. Population models suggested source-sink dynamics, with populations on grouse moors unable to sustain themselves without immigration. Population data confirmed that growth rates were indeed lower on grouse moors than on non-grouse moor sites. Analysis of wildlife crime data confirmed that persecution of the species was more frequent on grouse moors than in other habitat types. This population will be more secure, and better able to function as a barometer of environmental health and climate change, if illegal persecution of the species ceases on areas of land managed for grouse shooting.     

Concomitant production of lipase, protease and enterocin by Enterococcus faecium NCIM5363 and Enterococcus durans NCIM5427 isolated from fish processing waste

Enterococci are widely distributed in the environment ranging from foods to humans and are gaining industrial importance due to their technological traits. In the present study, enterococci (Enterococcus faecium NCIM5363 (EF-63) and Enterococcus durans NCIM5427 (ED-27)) which are native to fish processing waste with an ability to produce lipase, protease and enterocin concomitantly were characterised. Lipase assay was performed by titrimetry and protease activity and was estimated using haemoglobin and casein as substrates in the presence of buffers at acidic, basic and neutral pH. Furthermore, enterocin produced by the isolates was characterised. Enterocin was also checked for its stability at different pH, temperature and proteolytic enzymes. Lipase production was found to be 22 and 10 U/ml in the absence of tributryin and increased to 40 and 24 U/ml in its presence for EF-63 and ED-27, respectively, indicating that the lipase produced is substrate dependent. Protease production was confirmed by protease assay, and the protease produced showed more affinity towards the acidic substrate. Enterocin produced was stable at low pH (2 to 3) and high temperature (121°C, 15 min) and had a molecular weight of approximately 6 kDa. It exhibited antibacterial activity against both Gram-positive and Gram-negative food-borne pathogens. Proteinase K inactivated enterocin completely, whereas trypsin did not. Novelty of this work lies in the immense industrial importance these cultures hold as they are capable of producing lipase, protease and enterocin apart from being useful in recovering proteins and lipids from fish processing wastes.     

Estimation of gut contents of freshwater mussel, Lamellidens marginalis L.

This study examined the food organisms found in the gut of freshwater mussels, Lamellidens marginalis L. A total of 34 taxa of food organisms were recorded, out of which 30 taxa belonged to phytoplankton and four taxa to zooplankton. Both the groups comprised three families each: Cyanophyceae (blue‐green algae), Chlorophycea (green algae) and Bacillariophyceae (diatoms) constituted phytoplankton, whereas Euglenaceae, Chlamydodontidae and Brachionidae belonged to zooplankton. The total number of frequencies of phytoplankton (n=537) were almost nine times more than that of zooplankton (n=60). When blue‐green algae, green algae, diatoms and zooplankton (all the three families together) were tested for significant difference (P<0.05) following Duncan's multiple range test, the result showed only two groups. Blue‐green algae, green algae and zooplankton were not significantly different (P<0.05), forming group A, whereas diatoms were significantly different from others, forming group B. The present study showed that the maximum number of organisms that mussels feed upon belong to green algae, followed by diatoms, blue‐green algae and few taxa of zooplankton.     

Use of thraustochytrid <Emphasis Type="Italic">Schizochytrium</Emphasis> sp. as source of lipid and fatty acid in a formulated diet for abalone <Emphasis Type="Italic">Haliotis asinina</Emphasis> (Linnaeus) juveniles

The effects of using thraustochytrid Schizochytrium sp. as source of lipid and fatty acids in a formulated diet on growth, survival, body composition, and salinity tolerance of juvenile donkey’s ear abalone, Haliotis asinina, were investigated. Treatments consisted of diets either containing a 1:1 ratio of cod liver oil (CLO) and soybean oil (SBO) (Diet 1) or thraustochytrid (Diet 2) as source of lipid and fatty acids at 2 % level. Natural diet Gracilariopsis heteroclada (Diet 3) served as the control. No significant difference in growth was observed in abalone fed Diet 3 (SGR: 5.3 % BW day^?1; DISL: 265 μm day^?1) and Diet 2 (SGR: 5.2 % BW day^?1; DISL: 255 μm day^?1). Survival ranged from 78 to 85 % for all treatments and was not significantly different from each other. A 96-h salinity stress test showed highest survival of 84 % in abalone fed Diet 2 compared with those fed diets 1 and 3 (42 %). The high growth rate of abalone fed Diet 2 and high tolerance to low salinity could be attributed to its high DHA content (8.9 %), which resulted to its high DHA/EPA ratio of 10.5 %. These fatty acids play a significant role in abalone nutrition. The fatty acid profile of abalone meat is a reflective of the fatty acid profile of the oil sources in the diet. The present study suggests that the use of Schizochytrium oil in lieu of CLO and SBO can support good growth of abalone which is comparable with abalone fed the natural seaweeds diet.     

Encapsulation of shoot tips of guava (Psidium guajava L.) for short-term storage and germplasm exchange

Shoot tips obtained from in vitro grown plantlets of guava (Psidium guajava L.) were encapsulated in calcium alginate beads for short-term storage and germplasm exchange. A gelling matrix of 3% sodium alginate and 100 mM calcium chloride was found most suitable for formation of ideal calcium alginate beads. Maximum percent response for conversion of encapsulated shoot tips into plantlets was obtained on growth regulator free full strength liquid MS medium. The regrowth ability of encapsulated shoot tips was affected by medium strength and sucrose concentrations in the medium. Encapsulated shoot tips could be stored at low temperature (4 °C) up to 30 days with a survival frequency of 25%. After 60 days of storage under minimal growth conditions (sucrose lacking medium), about 75% encapsulated shoot tips were converted into plantlets when subcultured on 3% sucrose containing medium. Plantlets regenerated from encapsulated shoot tips were acclimatized successfully.     

Free-range system and supplementation of 25-hydroxicholecalciferol increases the performance and serum vitamin levels in mixed-parity sows

Improvements in sow productivity have raised questions regarding dietary vitamin D recommendations. The present study aimed to evaluate the effects of the housing system with access to sunlight exposure and supplementation of 25-hydroxicholecalciferol on performance and serum levels of 25(OH)D₃ in sows during gestation and lactation. Sows were distributed in an experimental design with two housing systems: gestation crates or gestation free-range system with external area for sunlight exposure; and two diets: 0 or 50 μg of 25-hydroxicholecalciferol kg⁻¹. The use of 25-hydroxicholecalciferol tended (P = 0.052) to improve total born and influenced (P = 0.046) on number of born alive. Litter weight at birth was also increased (P = 0.01) by 25-hydroxicholecalciferol supplementation; 25-hydroxicholecalciferol supplementation and housing system (free-range with sunlight exposure) tended to increase weaning weight (P = 0.07) and litter daily gain (P = 0.051) during lactation. Exposure to sunlight and 25-hydroxicholecalciferol supplementation increased 25(OH)D₃ serum levels when compared with control treatment during gestation (136.95 vs. 113.92 ng mL⁻¹; P = 0.035) and lactation (120.29 vs. 88.93 ng mL⁻¹; P = 0.026). In conclusion, the association of 25-hydroxicholecalciferol supplementation with exposure to sunlight during gestation improved significantly 25(OH)D₃ serum levels and consequently performance traits in gestation and lactation.     

Molecular evidence supports hypervariability in Phytophthora colocasiae associated with leaf blight of taro

The oomycete Phytophthora colocasiae that causes taro leaf blight is the most devastating disease of taro and is widely distributed worldwide. Molecular and phenotypic techniques were employed for assessing and exploiting the genetic variability among four populations of P. colocasiae obtained from a fine spatial scale (multiple leaf blight lesions on single taro leaf). Phenotypic characters such as virulence, morphology and mating type showed no variation. ITS characterization revealed detectable polymorphism among isolates of P. colocasiae. The mean number of haplotypes (H), haplotype diversity (HD), nucleotide diversity (π), and nucleotide substitution rate (θ) among analyzed sequences were 6.75, 1.00, 0.069, and 0.088 respectively. High levels of inter and intra specific variation were detected by random amplified polymorphic DNA (RAPD) assays. Moderate genetic diversity (H?=?0.2651) was observed among populations of P. colocasiae. Analysis of molecular variance (AMOVA) confirmed that most of the genetic variability was confined to within a population (63.54 %). The coefficient of genetic differentiation among populations (G _ST ) was 0.2007 and estimates of gene flow (Nm) among populations was 1.991 migrants per generation. Cluster analysis using UPGMA revealed that individuals from the same population failed to cluster in one distinct group. The results of the study reveal considerable genetic diversity among and within populations of P. colocasiae obtained from fine spatial scale. The possible mechanisms and implications of this genetic variation are discussed.