Effects of planting dates and shading on carbohydrate content,yield, and fiber quality in cotton with respect to fruiting positions

Two cotton (Gossypium hirsutum L.) cultivars, Kemian 1 (cool temperature-tolerant) and Sumian 15 (cool temperature-sensitive) were used to study the effects of cool temperature on carbohydrates, yield, and fiber quality in cotton bolls located at different fruiting positions (FP). Cool temperatures were created using late planting and low light. The experiment was conducted in 2010 and 2011 using two planting dates (OPD, the optimized planting date, 25 April; LPD, the late planting date, 10 June) and two shading levels of crop relative light rate (CRLR, 100 and 60%). Compared with fruiting position 1 (FP1), cotton yield and yield components (fiber quality, leaf sucrose and starch content, and fiber cellulose) were all decreased on FP3 under all treatments. Compared with OPD-CRLR 100%, other treatments (OPD-CRLR 60%, LPD-CRLR 100%, and LPD-CRLR 60%) had significantly decreased lint yield at both FPs of both cultivars, but especially at FP3 and in Sumian 15; this decrease was mainly caused by a large decline in boll number. All fiber quality indices decreased under late planting and shading except fiber length at FP1 with OPD-CRLR 60%, and a greater reduction was observed at FP3 and in Sumian 15. Sucrose content of the subtending leaf and fiber increased under LPD compared to OPD, whereas it decreased under CRLR 60% compared to CRLR 100%, which led to decreased fiber cellulose content. Therefore, shading primarily decreased the “source” sucrose content in the subtending leaf whereas late planting diminished translocation of sucrose towards cotton fiber. Notably, as planting date was delayed and light was decreased, more carbohydrates were distributed to leaf and bolls at FP1 than those at FP3, resulting in higher yield and better fiber quality at FP1, and a higher proportion of bolls and carbohydrates allocated at FP3 of Kemian 1 compared to that of Sumian 15. In conclusion, cotton yield and fiber quality were reduced less at FP1 compared to those at FP3 under low temperature and low light conditions. Thus, reduced cotton yield and fiber quality loss can be minimized by selecting low temperature tolerant cultivars under both low temperature and light conditions.     

Application of biochar in mitigation of negative effects of salinity stress in wheat (Triticum aestivum L.)

Salinity is a major abiotic stress that affects crop production throughout the world. Biochar is an activated carbon soil conditioner that can alleviate the negative impacts of salinity. The research was conducted to evaluate the ameliorative effect of 1% and 2% of biochar application on wheat seed germination and growth attributes under salinity. Both levels of biochar improved the germination and growth conditions under salinity; however, 2% biochar level was more effective compared to 1% level. Root and shoot length increased up to 23% and11% with 2% biochar, respectively. The maximum increase of 16% and 10% in leaf water potential and osmotic potential was noted with 2% biochar at 150 mM salt. The decrease in proline content and soluble sugar at 2% biochar was 51% and 27%, respectively. Decrease in superoxide dismutase activity was 15.3% at 2% level of biochar under stress biochar mitigates the negative effects of salinity and improved wheat productivity.     

Recent advances in molecular marker techniques: Insight into QTL mapping,GWAS and genomic selection in plants

Recent advances in sequencing technology have brought several novel platforms for marker development and subsequent genotyping. The high-throughput and cost effective marker techniques have changed the entire scenario of marker applications. The huge genotypic data obtained with next generation sequencing (NGS) also demands analytical tools, statistical advances, and comprehensive understanding to cope with breeding applications. In the present review, we discussed different available marker techniques, their strengths, and limitations. Emphasis was given on software tools, analytical pipelines, workbenches, and online resources available for marker development. Comparison of SNP genotyping involving complexity reduction techniques like GBS, RRL, RAD, and array-based platforms were presented in a view to describe suitability for specific purposes. We found that genotyping by whole genome re-sequencing has great potential, and could be a routine application in the near future with continuously decreasing cost of sequencing. Microsatellites, still a valuable option for breeders, have also advanced with NGS. Here a catalogue of tools for microsatellite evaluation in short sequence reads was provided. The most common applications of molecular marker like QTL mapping, genome-wide association mapping (GWAS), and genomic selection were highlighted. The present review will be helpful for the effective utilization of available resources and for the planning of crop improvement programs employing molecular marker techniques.     

Foliar Applied Phosphorous Enhanced Growth,Chlorophyll Contents,Gas Exchange Attributes and PUE in Wheat (Triticum aestivum L.)

A pot experiment was conducted to evaluate the foliar applied phosphorous with and without pre-plant dose (50 kg hac.^?1) of phosphorous on growth, chlorophyll contents, gas exchange parameters and phosphorous use efficiency (PUE) of wheat. The experiment was conducted in net house at Department of Crop Physiology, University of Agriculture Faisalabad, Pakistan. Two promising wheat cultivar AARI 2011 and FSD 2008 were used as a test crop with 5 foliar phosphorus (P) rates (0, 2, 4, 6, 8 kg ha^?1). The foliar applied P with pre-plant performed better than without pre-plant and control treatments. Foliar treatment of phosphorus at 6 kg ha^?1 P proved to be the best among other foliar treatments followed by 8 kg ha^?1 P. The foliar application of phosphorous at 6 kg hac.^?1 with pre-plant soil applied P increased the shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight. The chlorophyll contents (Chl. a and b) were increased with the foliar application of phosphorous. The gas exchange parameters (net carbon dioxide (CO₂) assimilation rate, transpiration rate, stomatal conductance and sub-stomatal CO₂ rate) were significantly improved by foliar applied P. The maximum values of net CO₂ assimilation rate (5.27 μ mol m^?2 sec.^?1), transpiration rate (3.44 μ mol m^?2 sec.^?1), stomatal conductance (0.81 μ mol m^?2 sec.^?1) and sub-stomatal CO₂ (271.67 μ mol m^?2 sec.^?1), were recorded in the treatment where P was foliar applied at 6 kg hac.^?1 with pre-plant soil applied Phosphorous. The foliar application of phosphorous with pre-plant soil applied P enhanced Phosphorous use efficiency (PUE) in both varieties. The maximum value of PUE (15.42%) was recorded in the treatment where foliar feeding of P was done at 6 kg hac.^?1 with pre-plant soil applied P in both genotypes.     

Progression of histomonosis in commercial chickens following experimental infection with an in vitro propagated clonal culture of Histomonas meleagridis

Four commercial strains of chickens, namely, ISA brown leghorn (ISA), TETRA-SL brown (TETRA-SL), Lohmann brown (LB), and Lohmann LSL (LSL), were infected with a well-defined clonal culture of Histomonas meleagridis (H. meleagridis/Turkey/Austria/2922-C6/04) to investigate their susceptibility to histomonosis. Each group included 16 chickens, which were housed under the same conditions in separate pens. All chickens were infected with 10(4) histomonads orally and intracloacally at 14 days of age. No mortality or clinical signs were observed during the experiment in all birds. Three birds of each chicken strain were euthanatized on days 4, 7, 10, 14, and 21 postinfection. Incidence of histomonosis on the basis of cecal lesions was found to be 64.00% in TETRA-SL, 62.50% in LB, 53.12% in LSL, and 43.75% in ISA chickens. Fewer lesions were noticed in livers than in ceca, with an incidence of 15.62% in TETRA-SL, 9.37% in LB, and 3.12% in ISA chickens. No liver lesions were found in the LSL chickens. Statistical analysis revealed that there was no significant difference (P > 0.05) in susceptibility to experimental H. meleagridis infection based on cecal and liver involvement. Polymerase chain reaction (PCR) and immunohistochemistry were found to be reliable tools to confirm the presence of histomonads and changes in the ceca. However, some negative PCR results were recorded from the livers despite the presence of macroscopic lesions. Additionally, DNA of H. meleagridis was detected by PCR in a few of the lungs, but immunohistochemistry was negative. Nucleic acid of the protozoan parasite was not detected in samples from kidney, brain, spleen, or bursa of Fabricius. Altogether, the high susceptibility of commercial chicken lines to histomonosis could be demonstrated and characterized by severe lesions in the ceca and insignificant involvement of the liver, approaching a maximum on days 7-14 postinfection.     

Decolorization of Textile Effluent by Soluble Fenugreek (Trigonella foenum-graecum L) Seeds Peroxidase

Peroxidase from fenugreek (Trigonella foenum-graecum) seeds was highly effective in the decolorization of textile effluent. Effluent was recalcitrant to the action of fenugreek seeds peroxidase (FSP). However, in order to effectively decolorize effluent by peroxidase, the role of six redox mediators has been investigated. The maximum decolorization of textile effluent was observed in the presence of 1.0 mM 1-hydroxybenzotrizole, 0.7 mM H₂O₂, and 0.4 U ml^?1 of FSP in the buffer of pH 5.0 at 40°C in 2.5 h. The decolorization of textile effluent in a batch process by peroxidase was 85% in 5 h, whereas the complete decolorization of textile effluent by membrane-entrapped FSP was observed within 11 h of its operation. The absorption spectra of treated effluent exhibited a marked diminution in the absorbance at different wavelengths compared to untreated effluent.     

Potassium isotherm partitioning based on modified quantity‐intensity relation and potassium buffering characterization of soils of North India

Background : Potassium (K) availability in soil and plant uptake is restrained by the dynamic interactions among the different pools of K. Aims : To understand these interactions, a study was undertaken to assess the quantity–intensity (Q/I) and buffering characteristics of rainfed maize (Zea mays L.) growing soils. Ten contrasting soils were evaluated for K partitioning changes in exchangeable K (ΔEK) and non‐exchangeable K (ΔNEK) pools in the soil‐solution phase and buffering characteristics using a modified version of Q/I approach. Results : The partitioned Q/I isotherms showed strong adsorption with the increase in K concentration ratio (CR^K) and the changes due to ΔEK were higher than changes due to ΔNEK. Total buffering capacity (PBC^K) significantly correlated (r = 0.92, p <0.01) with clay content with a major share contributed by buffering capacity owing to non‐exchangeable K ( ${\mathrm{PBC}}_{\Delta \mathrm{NEK}}^K$) rather than exchangeable K ( ${\mathrm{PBC}}_{\Delta \mathrm{EK}}^K$). The fixation capacity (β) factor, the magnitude of added K converted into a non‐exchangeable pool, ranged from 41 to 63%, whereas release (α) factor, the magnitude of added K converted to the exchangeable pool, ranged from 19 to 36%. Both threshold solution K (CK_r) and threshold exchangeable K (EK_r) values were found to be high in Satran clay loam (S2) and lower in Doon silty clay loam (S3) soils. The equilibrium exchangeable K (EK_o) was found close to minimum exchangeable K (E_min) in Doon silty clay loam (S3) and Babaweyl sandy clay loam (S1) soils and overall E_min constituted about 8.94 to 0.57% of the EK_o. Conclusion : It may be concluded that K Q/I isotherm partitioning provides a valuable insight to assess the dynamic relations. The ratio of α/β (K recharge index) could be used to evaluate the K enrichment capacity of soil to K additions while EK_r and E_min can be potentially useful in the elucidation of exchangeable K as K fertility index especially in soils with poor K fertilizer management.     

Genetic relationship in Vigna mungo (L.) Hepper and V. radiata (L.) R. Wilczek based on morphological traits and SDS-PAGE

Thirty seven diverse genotypes of Vigna mungo and three of V. radiataresembling to V. mungo for seed characters were studied to determine the extent of genetic variation based on morphological characters. In addition, 4black seeded genotypes in each species and8 green seeded V. radiata genotypes were included for SDS-PAGE analysis. Seed proteins were analyzed through slab type SDS-PAGE. High variance was observed for plant height, days to flowering, days to maturity, number of branches/plant, number of pods/plant, pod length, seeds per pod,biomass yield/plant, grain yield/plant and harvest index (%) during 2 consecutive years. First four components of PCA with eigenvalues >1 contributed 78.7 and79.1% of the total variance amongst 40genotypes during 1998 and 1999. The populations with high PC₁ values were expected to be high yielding characterised by earlyness, high seed weight and harvest index, all traits strictly related to reproductive phase. Four clusters of genotypes were observed during both the years and genetic diversity was in association for both the years. Based on SDS-PAGE, specific bands were suggested to be used for identifying Vigna radiatafrom mixed germplasm with Vigna mungo. The SDS-PAGE proved to be a powerful tool for differentiating Vigna radiata and Vigna mungo, whereas a low level inter-specific genetic diversity was observed and no clear differentiation was observed both for agronomic characteristics and for geographical origin. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of different nitrogen and carbon sources and concentrations on the mycelial growth of ectomycorrhizal fungi under in-vitro conditions

Effect of different nitrogen and carbon sources and their concentrations in liquid media on the mycelial growth of six different ectomycorrhizal (ECM) fungal species was studied. Differences were found in the utilization of the different nitrogen and carbon sources between the fungal species. All the species showed better mycelial growth in the medium containing ammonium as nitrogen source. Growth was low in all species in medium in which nitrogen was supplied in nitrate form. All the ECM isolates investigated showed reduced growth in the medium containing maleic acid as the carbon source. The effect of glucose and di-ammonium hydrogen orthophosphate concentrations on mycelia growth of all the six fungal species was studied with ranges for glucose of 2–40 g/l, and for di-ammonium hydrogen orthophosphate of 2–20 g/l. Cortinarius fulvoconicus and Cortinarius flexipes showed maximal mycelial growth at a glucose concentration greater than 20 g/l. Suillus luteus, Scleroderma citrinum, Laccaria laccata, and Tricholoma aurantium showed maximal growth at a glucose concentration of 20 g/l. All six species showed maximal mycelial growth at 5–10 g/l of di-ammonium hydrogen orthophosphate concentration and with increased concentration mycelial growth in all species decreased.