The extent of genetic diversity among Vanilla species: Comparative results for RAPD and ISSR

Vanilla is a large genus of about 110 species in the orchid family (Orchidaceae), including the species Vanilla planifolia from which commercial vanilla flavoring is derived. Since most species of vanilla are considered rare and endangered there is an urgent need to conserve them through genetic analysis and propagation/conservation studies on this crop.The present study investigated the genetic diversity among nine leafy- and leaf-less Vanilla species employing 30 decamer RAPD primers and 10 ISSR primers. The species under study were diverse and displayed a range of variability (0–66% and 0–81% for RAPD and ISSR, respectively). A total of 154 RAPD polymorphic markers (83.24%, h = 0.378) and 93 ISSR polymorphic markers (86.11%, h = 0.363) were used to generate a genetic similarity matrix followed by the cluster analysis. Specific groupings were revealed by each cluster analysis with slight variation between two different markers. Among the nine species studied, V. planifolia, Vanilla aphylla and Vanilla tahitensis revealed very low level of variation within their collections, thus indicating a narrow genetic base. The large genetic distance of Vanilla andamanica from other species suggests its different origin. A close genetic affinity was observed between the pairs V. planifolia, V. tahitensis and Vanilla albida, V. aphylla. These are the first comparative results for RAPD and ISSR reporting inter-relationship among nine cultivated, wild and hybrid Vanilla species.     

Effects of Confluent, Roscovitine Treatment and Serum Starvation on the Cell-cycle Synchronization of Bovine Foetal Fibroblasts

The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors.     

Yield components,light interception and marker compound accumulation of stevia (Stevia rebaudiana Bertoni) affected by planting material and plant density under western Himalayan conditions

A field experiment was conducted to study the effect of planting material and plant density on stevia (Stevia rebaudiana Bertoni) under western Himalayan conditions during 2011 and 2012. The experiment conducted in a split plot design consisted of two types of planting material (rooted slips and fresh seedlings) in the main plot and five inter- and intra-row spacing in subplots with three replications. Yield attributes and dry leaf biomass yield of stevia were not affected by the type of planting material; however, plant density significantly influenced the yield attributes and leaf and stem dry biomass. Although the wider spacing (60 × 45 cm) gave more leaves, higher leaf area index, higher leaf dry mass per plant as compared to closer spacing, it resulted in lower values of these attributes per unit area. Plants spaced in 30 × 30 cm accumulated 41.2% and 42.8% more total biomass than 60 × 45 cm. Steviol glycoside content did not change due to different planting materials and plant densities; however, closer plant spacing (30 × 30 cm) recorded 114.8% and 70.0% higher steviol glycoside accumulation compared to wider row spacing (60 × 45 cm) in 2011 and 2012, respectively.     

Papaya yellow leaf curl virus: A newly identified begomovirus infecting Carica papaya L. from the Indian Subcontinent

India is one of the world’s largest producers of papaya. Viruses, mainly begomoviruses and potyviruses, cause a significant loss in papaya production. The study described here has identified a new species of begomovirus and a new species of betasatellite infecting Carica papaya in India. The sequences of the begomovirus and betasatellite show 90.03% nucleotide sequence identity to an isolate of Radish leaf curl virus and 92.25% identity to an isolate of Tomato leaf curl betasatellite, respectively. Maximum likelihood phylogenetic tree of begomovirus sequence of isolate DP2 (KX353622) showed distant relationships with previously characterised begomoviruses. Recombination analysis proposed six recombination breakpoints in begomovirus genome with other geographical begomovirus isolates.     

Heavy infection of Ichthyophthirius multifiliis in striped catfish (Pangasianodon hypophthalmus,Sauvage 1878) and its treatment trial by different therapeutic agents in a control environment

ABSTRACT

Striped catfish (Pangasianodon hypophthalmus) fingerlings were stocked (60 fishes/m³) in cemented square tanks for ornamental fishery purposes at the College Fish Farm in Mangalore. A total of 400 fishes with a mean weight (g) ranging from 3.24 ± 1.21 to 6.70 ± 1.13 and a mean length (cm) of 7.50 ± 0.94 to 9.50 ± 1.10 were examined. A severe outbreak of salt-like granule white spots was found on the body surface. Ichthyophthirius multifiliis, a ciliate pathogen, was identified as the causative agent by clinical signs, wet mount, and histopathological observations. Infected fishes were transferred and equally distributed to the 0.45 m³ glass aquaria and treated with three treatments: (T1) methylene blue + salt; (T2) raising temperature with salt; and (T3) formalin + malachite green. The best fingerling survival (55 ± 9.36%) was obtained by elevated water temperature with salt in T2.     

Process Optimization for the Development of Nutritionally Enhanced Nuggets using Ficus geniculata: A Nutritional Approach

Plant Foods for Human Nutrition - Ficus geniculata (FG) is one of the underutilized fig species in India and throughout the world. However, the different parts of the plant have numerous...     

APEX model simulation of runoff and sediment losses for grazed pasture watersheds with agroforestry buffers

Buffers have been found to reduce non-point source pollution (NPSP) from watersheds. Hydrologic simulation models assist in predicting the effects of buffers on runoff and sediment losses from small watersheds. The objective of this study was to calibrate, validate and simulate runoff and sediment losses and compare buffer effects on NPSP losses relative to control watersheds (no buffer) for seven years. The experimental design consists of four watersheds under pasture management which were monitored from 2002 through 2008; two with agroforestry buffers (AgB 100 and AgB 300) and two control watersheds (CW 400 and CW 600). Pasture areas included red clover (Trifolium pretense L.) and lespedeza (Kummerowia stipulacea Maxim.) planted into fescue (Festuca arundinacea Schreb.) while the agroforestry buffer area included Eastern cottonwood trees (Populus deltoids Bortr. ex Marsh.) planted into fescue. The APEX model was calibrated from 2002 to 2005 and was validated from 2006 to 2008. The r ² and NSE values for the calibration and validation periods of the runoff varied from 0.52 to 0.78 and 0.50 to 0.74, respectively. The model did not predict sediment loss very well probably due to insufficient number of measured events and low measured sediment loss. The measured runoff was 57% higher for CW watersheds compared to AgB watersheds. The measured sediment loss was 95% higher for CW watersheds compared to AgB watersheds. After calibrating and validating the model, it was run for long-term scenario analyses for 10 years from 1999 to 2008. Simulated buffer width had a significant influence on runoff. Simulated runoff decreased by 24% when the buffer width was doubled compared to losses associated with the measured buffer width. Simulated runoff from the CW watersheds was 11% higher with double stocking density (relative to measured density) compared to AgB watersheds with double stocking density. With half stocking density (relative to measured density), the AgB watershed had 18% lower runoff compared to CW. Results from this study imply that establishment of agroforestry buffers on grazed pasture watersheds reduce runoff and sediment losses compared to control watersheds without buffers.     

Optimized loop-mediated isothermal amplification assay for <Emphasis Type="Italic">Tomato leaf curl New Delhi virus-[potato]</Emphasis> detection in potato leaves and tubers

Apical leaf curl disease of potato is caused by a whitefly transmitted begomovirus, Tomato leaf curl New Delhi virus-[potato] (ToLCNDV-[potato]) in India. Detection of this virus is essential to manage the disease, particularly in healthy potato seed production systems. Large scale testing of micro-plants demands a simple, rapid and sensitive assay. Hence, loop-mediated isothermal amplification (LAMP) method was developed for specific detection of ToLCNDV-[potato]. Six primers that recognize the coat protein gene sequence of ToLCNDV-[potato] were designed and LAMP assay was optimized using different concentrations of magnesium sulphate, betaine, dNTPs, Bst DNA polymerase and temperature. The results were assessed by visual observation of turbidity, colour change using SYBR green dye and also by gel electrophoresis. The assay successfully detected the virus in infected plants collected from potato fields whereas no cross-reactions were observed with healthy plants and other potato viruses. The optimized assay was as sensitive as PCR assay and could detect up to 0.002 pg of total DNA. The assay could detect the virus in infected potato tubers and also in asymptomatic plants. Print-capture LAMP assay was developed and its application could reduce the cost and time of the assay in large scale testing under seed production.