Downy mildew resistance in opium poppy: resistance sources,inheritance pattern,genetic variability and strategies for crop improvement

Downy mildew (DM) caused by Peronospora arborescens is the most destructive disease of opium poppy which assumes considerable importance in India and other poppy growing countries. The present study was aimed at identification and evaluation of stable resistance sources of DM in opium poppy. Furthermore, genetic variability and inheritance pattern of DM resistance has also been studied which can help in making strategy for crop improvement. Evaluation of 35 selected germplasm accessions of opium poppy under glasshouse and field conditions during the three consecutive years (2004–2005 to 2006–2007) resulted in identification of two genotypes (I-14 and Pps-1) as highly resistant and stable sources for DM resistance. Genetic studies of DM resistance revealed polygenic control with the dominance of susceptibility over resistance. Significant reciprocal differences were found largely due to maternal transmission of DM resistance indicating the involvement of cytoplasmic genes in addition to nuclear control. Analysis of genetic variability and selection parameters indicated predominance of additive effects for DM resistance and other yield contributing traits. Multivariate analysis resulted in classification of 35 selected accessions into 11 different clusters revealing very high level of diversity among the genotypes. Cluster analysis suggested that hybridization program involving genotypes from cluster V (which included highly resistant genotypes Pps-1 and I-14) and cluster IX (which included highly susceptible Jawahar-16 having good economically important traits like seed yield) could be expected to give best recombinants for improvement in terms of DM resistance and high seed and straw yield in opium poppy. Analysis of selection parameters like heritability and genetic advance also suggested that simple selection methods will be effective in stabilizing resistance traits following hybridization with high yielding genotypes.     

10年生府竹丛生竹的离体无性繁殖

用10年生丛生竹的节片通过离体腋笋增殖和生根产生出府竹小苗。不同季节对无菌培养物的建立、腋芽发萌和初代培养的影响很大。3片丛生林中,无菌培养物的建立有差别,但腋芽发萌没有差别。用加有31.06uM BA和2.85um IAA的MS液体介质,最大的增值率为3.18;用加有20~25um IBA MS液体介质,离体生根率为66.7~77.8%。用不同的植物生长素,生根所用的天数也不同,而IBA液能在短期促进生根,仅仅为2-3周。成功炼苗后,在装有土壤、沙子和农家肥塑料袋里,离体繁殖的小苗成活率为90%,大约有2000株小苗用于野外栽植。     

Proteomics of muscle-specific beef color stability

The objective of the present study was to differentiate the sarcoplasmic proteome of color-stable (Longissimus lumborum; LL) and color-labile (Psoas major; PM) beef muscles. LL and PM muscles from seven beef carcasses (24 h post-mortem) were fabricated into 2.54 cm steaks, aerobically packaged, and assigned to refrigerated retail display for 9 days. LL steaks demonstrated greater (P < 0.05) color stability and lower (P < 0.05) lipid oxidation than PM steaks. Proteome analyses identified 16 differentially abundant proteins in LL and PM, including antioxidant proteins and chaperones. Proteins demonstrating positive correlation with redness (aldose reductase, creatine kinase, and β-enolase) and color stability (peroxiredoxin-2, peptide methionine sulfoxide reductase, and heat shock protein-27 kDa) were overabundant in LL, whereas the protein overabundant in PM (mitochondrial aconitase) exhibited negative correlation with redness. The color stability of LL could be attributed to the overabundance of antioxidant proteins and chaperones, and this finding suggests the necessity of developing muscle-specific processing strategies to improve beef color.     

Using contingent valuation to estimate the willingness of tourists to pay for urban forests: A study in Savannah, Georgia

This study estimated the monetary value of urban forests’ non-priced benefits to tourists. Data collected by a face-to-face self-administered survey of urban tourists in Savannah, Georgia, USA were used to estimate tourists’ willingness to pay (WTP) for urban forests by the contingent valuation method. Individual WTP was found higher among tourists with graduate school education. Results suggested that WTP for urban forests also increased significantly with income and destination loyalty of the tourists. Estimated mean and median WTP values were $11.25 (95% confidence interval: $7.34, $15.16) and $2.10 (95% confidence interval: $1.38, $2.82), respectively. Based on the estimated mean WTP, annual value of urban forests to tourists in Savanna in 2009 ranged from a minimum of $81 million to a maximum of $167 million with a 95% confidence interval. The annual value was $11.55 million (95% confidence interval: $7.59 million, $15.51 million) based on the estimated median WTP and assuming at least 50% of the tourists in Savannah would pay the median amount. As the mean was greatly influenced by extreme WTP values in the data, the annual value based on the median value was a more conservative estimate.     

Genetic variation and gene flow estimation of <Emphasis Type="Italic">Nepenthes khasiana</Emphasis> Hook. F- A threatened insectivorous plant of India as revealed by RAPD markers

Random Amplified Polymorphic DNA (RAPD) markers were utilized for determination of diversity within and among the three populations of Nepenthes khasiana Hook f., a threatened insectivorous plant of Meghalaya (India). A total of 90 bands were generated from 10 random amplification polymorphic DNA (RAPD) primers of which 71 were found to be polymorphic (78.89%). Nei’s gene diversity (h) ranged between 0.124–0.201 with overall diversity of 0.228 while Shannon’s information index I) values recorded between 0.187–0.308 with an average value of 0.352. The values of gene flow (Nm = 1.284) and the diversity among populations (0.280) recorded demonstrates higher genetic variation within the population. AMOVA analysis revealed a low level of genetic variation (21.96%) among the populations. This study indicates that some variation still exists within and between the existing populations of N. khasiana, thus, these populations could provide materials for re-establishing of this important rare and threatened species.     

Natural compounds enhancing growth and survival of rhizobial inoculants in vermicompost-based formulations

The present study demonstrates the usefulness of natural microbial growth-promoting compounds for improving the stability and life of vermicompost-based (both granular and its aqueous extract) bioformulations. Granular vermicompost maintained the number of cells of Rhizobium meliloti Rmd 201 up to 5.9 × 10⁸ after 180 days at 28°C compared with 2.1 × 10⁸ in charcoal (powdered), while aqueous extract of the vermicompost supported the 5.6 × 10⁷ rhizobia numbers even after 270 days. The addition of 25 μL/mL cow urine and 0.01 mM calliterpinone, a natural plant growth promoter, increased the rhizobia number significantly in granular vermicompost and its aqueous extract, respectively.     

Molecular characterization and phylogeny of phytoplasma associated with bunchy top disease in its new host Okra (<Emphasis Type="Italic">Abelmoschus esculentus</Emphasis>) in India reveal a novel lineage within the 16SrI group

Okra plants with bunchy top disease were found to be prevalent during the period of August–October 2009 in New Delhi, India. The common symptoms observed were shortening of internodes, aggregation of leaves at the apical region, reduced leaf lamina, stem reddening, fruit bending, phyllody and stunting of plants. The disease incidence ranged from 2–60% accompanied by significant reductions in production of both flowers and seeds. Nested polymerase chain reaction targeting phytoplasma specific 16S rDNA and rp genes revealed all symptomatic plants to be positive for phytoplasma. Homology searches depicted its closest identity to phytoplasmas of 16SrI ‘Candidatus Phytoplasma asteris’, like the Sugarcane yellows and Periwinkle phyllody phytoplasmas. Profiles for 16S rDNA obtained with 10 restriction endonucleases, differed in TaqI sites for two phytoplasma isolates (BHND5 & 10) from the standard pattern of 16SrI-B subgroup, the latter was seen in the case of isolate BHND1. Restriction fragment analysis of rp genes with AluI, Tsp509I matched with patterns of the rpI-B phytoplasmas. Phylogenetic reconstruction of rp genes revealed okra bunchy top phytoplasma (BHND1) as a divergent isolate, the subsequent sequence analysis of which showed the presence of a novel BslI site. These significant differences suggest that multiple phytoplasma strains are affecting okra, one of which is a diverging lineage within the 16SrI-B group while others represent a new 16SrI subgroup not reported so far. Additionally, this is the first report of a phytoplasma associated disease in okra plants worldwide.     

Sublethal Toxicity of the Herbicide Butachlor on the Earthworm Perionyx sansibaricus and its Histological Changes (5 pp)

Goal, Scope and Background   With the advent of the Green Revolution, there has been a quantum leap in the use of synthetic herbicides and pesticides throughout the world to sustain high-yielding crop varieties. Continuous use of these synthetic chemicals leads to loss of soil fertility and soil organisms. Histopathological studies may signal a damaging effect of organisms resulting from prior or ongoing exposure to toxic agents. A large number of studies have reported general histological changes in earthworms. A fewer studies have reported more specific types of histopathological studies in Eisenia foetida, Dendrodrilus rubidus, Lumbricus terrestris, Lumbricus rubellus and Octolasium transpandanum. However, no reports are available on Perionyx sansibaricus. The aim of the present study is (i) to determine the sublethal effects of the herbicide Butachlor on Perionyx sansibaricus on growth and cocoon production, (ii) to evaluate the histological changes in the exposed worms.Methods   The test substrate, namely powdered, dried cow dung, was contaminated with 0.0657, 0.1315 and 0.1973 mg kg–1 of Butachlor, and a control was maintained. Four groups of each 10-test species of Perionyx sansibaricus were used per concentration level (control, 0.0657, 0.1315 and 0.1973 mg kg–1). Various life history parameters such as biomass, cocoon production and histological changes were measured.Results   Worm growth was observed at various exposures over 60 days. While exposing the earthworm to the herbicide, no mortality was observed, not even at a higher dose. At the end of the experiment, the control group had a mean biomass of 0.0831±0.00 mg and, in the exposed group, at herbicide concentrations of 0.1973, 0.1315 and 0.0657 mg kg–1, the mean biomass was found to be 0.0497±0.00 mg, 0.0628±0.00 mg and 0.0781±0.00 mg, respectively. The mean earthworm biomass was found to be decreased with increasing herbicide concentration. Similarly, cocoon production was also reduced by the increasing herbicide concentration. All earthworms in the exposed group were found to have glandular cell enlargement and to be vacuolated. Conclusion   The results clearly indicate that Butachlor can retard the growth and cocoon production in Perionyx sansibaricus. The effect of the herbicide Butachlor can be assessed by the histological observation of the intestinal region, as evidenced by glandular cell enlargement at all the exposed concentrations, which may massively affect food intake and which in turn may indirectly inhibit the earthworm reproductive capacity.Recommendation and Outlook   Risk assessment is normally aimed at the protection of human health and the ecosystem, and the interrelationship of these two areas of protection is easy to perceive. The use of earthworms in risk assessment is to obtain more information on environmental quality and ensure environmental safety. There is an urgent need to test the chemicals causing toxicity to earthworms, because earthworms play a major role in soil fertility as well as acting as a transferring route from the soil to the terrestrial ecosystem.     

Role of bioinoculants in development of salt-resistant saplings of Morus alba (var. sujanpuri) in vivo

Pot experiments were conducted for the development of salt-resistant saplings of Morus alba (var. sujanpuri) involving bioinoculants, namely arbuscular mycorrhizal (AM) fungi, Azotobacter and indole butyric acid (IBA). The IBA and sodium chloride (NaCl) concentrations were optimized prior to the experiments. By using both low and high concentrations, 15 ppm IBA and 0.05% NaCl (w/v) were found to be optimum in acting synergistically with AM fungi and Azotobacter and also for increasing all the growth parameters and microbial count in the rhizosphere. For in vivo development of salt-resistant saplings, the optimal concentration of IBA, along with AM fungi and Azotobacter in different combinations, was applied. The saplings were irrigated regularly with 0.05% NaCl water. Although growth parameters such as AM infection percentage, AM spores per 100 g soil and Azotobacter cells/g soil were affected by NaCl watering, the inoculation of both bioinoculants significantly enhanced survival percentage of saplings from 25 to 50% under salt stress. Maximum survival (55%) of saplings was found with IBA (15 ppm)+AM fungi+Azotobacter.     

Efficient Use of Water and Nutrients Through Drip and Mulch in Apple

Fertigation offers vast potential for efficient use of water and nutrients in sustainable orchard management. Beside minimizing losses, their distribution within the rhizosphere is of utmost importance. In present investigations, most of feeder roots were observed within 30 cm soil depth. Under drip fertigation, wetting front extended horizontally up to 45 cm from emitter. However, the maximum moisture content remained confined within 30 cm distance. Vertically, soil moisture also remained higher in the 0–30 cm soil layers. Under surface irrigation, deeper soil layers registered higher moisture content. Available nitrogen (N) and potassium (K) under fertigation closely followed the moisture distribution pattern. Fertigation plus mulch resulted in 20% fertilizer and 15% water savings over fertigation without mulch. Beside 33% higher fruit yield and 25% water savings, and fertigation plus mulch resulted in 20 percent fertilizer and 40% water savings over surface irrigation.