Genome-wide association analysis for stripe rust resistance in spring wheat(Triticum aestivum L.) germplasm

Stripe rust is a continuous threat to wheat crop all over the world. It causes considerable yield losses in wheat crop every year. Continuous deployment of adult plant resistance(APR) genes in newly developing wheat cultivars is the most judicious strategy to combat this disease. Herein, we dissected the genetics underpinning stripe rust resistance in Pakistani wheat germplasm. An association panel of 94 spring wheat genotypes was phenotyped for two years to score the infestation of stripe rust on each accession and was scanned with 203 polymorphic SSRs. Based on D' measure, linkage disequilibrium(LD) exhibited between loci distant up to 45 c M. Marker-trait associations(MTAs) were determined using mixed linear model(MLM). Total 31 quantitative trait loci(QTLs) were observed on all 21 wheat chromosomes. Twelve QTLs were newly discovered as well as 19 QTLs and 35 previously reported Yr genes were validated in Pakistani wheat germplasm. The major QTLs were QYr.uaf.2 AL and QYr.uaf.3 BS(PVE, 11.9%). Dissection of genes from the newly observed QTLs can provide new APR genes to improve genetic resources for APR resistance in wheat crop.     

Combined Application of Biochar and Biocontrol Agents Enhances Plant Growth and Activates Resistance Against Meloidogyne incognita in Tomato

Gesunde Pflanzen - Biochar (BC) is known to enhance plant growth and may activate plant resistance to various soil borne pathogens. In this experiment, the rice husk (RH) BC was combined with...     

Performance of Pseudomonas spp. containing ACC-deaminase for improving growth and yield of maize (Zea mays L.) in the presence of nitrogenous fertilizer

Some plant-growth-promoting rhizobacteria (PGPR) promote plant growth by lowering the endogenous ethylene synthesis in the roots through their 1-aminocylopropane-1-carboxylate (ACC)-deaminase activity. However, in the vicinity of the roots may decrease the efficiency of these PGPR by stimulating ACC-oxidase activity resulting in greater ethylene production by the roots. This study was designed to assess the performance of PGPR containing ACC-deaminase for improving growth and yield of maize grown in N-amended soil. Several strains of rhizobacteria containing ACC-deaminase were screened for their growth-promoting activity in maize roots under gnotobiotic conditions. Six strains were selected and their effectiveness in soil amended with N at a concentration of 175 kg ha⁻¹ (1050 mg pot⁻¹) was investigated by conducting a pot trial on maize. Significant increases in plant height, root weight and total biomass were observed in response to inoculation. Based upon the results of pot trials, the three most efficient strains were selected and tested in the field for their effectiveness in the presence and absence of N fertilizer. Results of the field trial revealed that the inoculum performed relatively better in the absence of N-fertilizer application. Pseudomonas fluorescens biotype G (N₃) was the most effective strain both in the presence and absence of N fertilizer. Results may imply that even in the presence of optimum levels of nitrogenous fertilizers, inoculation with rhizobacteria containing ACC-deaminase activity could be effective to improve the growth and yield of inoculated plants.     

Effect of acetylene and ethylene gases released from encapsulated calcium carbide on growth and yield of wheat and cotton

Calcium carbide (CaC₂) is a rich source of the nitrification inhibitor acetylene (C₂H₂) and plant hormone ethylene (C₂H₄). C₂H₄ formed from biotic reduction of C₂H₂ released from CaC₂ may accumulate in soil at physiologically active concentrations. Laboratory studies were conducted to evaluate the potential of encapsulated CaC₂ for gradually releasing C₂H₂ and its product C₂H₄ in soil. The GC-FID analysis revealed that encapsulated CaC₂ released a copious amount of C₂H₂ (up to 23700 nmol kg⁻¹ soil), which was gradually reduced to C₂H₄ over a period of time via a strictly biotic reaction as no C₂H₄ was detected in CaC₂-amended sterilized soil. Ammonium oxidation was suppressed by the encapsulated CaC₂ indicating that C₂H₂ acted as a nitrification inhibitor. Results of pot trials conducted in the net house indicated that encapsulated CaC₂ applied at 30 mg kg⁻¹ soil significantly increased the number of tillers (up to 45.5%), root weight (up to 14.9%), straw (up to 32.8%) and grain yield (up to 37.3%) of wheat over the fertilizer application alone. In the case of cotton, the number of bolls, root, shoot and seed weight were also significantly increased in response to the application of encapsulated CaC₂. Moreover, application of encapsulated CaC₂ resulted in greater N-use efficiency (NUE) (up to 61.1%) by both wheat and cotton crops than that observed at the same rates of N fertilizer alone. These findings imply that CaC₂ affects plant growth through hormonal action of C₂H₄ as well as improved NUE; however, the latter factor might be a relatively more contributing. It is desirable that CaC₂ is formulated for gradually slow release of C₂H₂ and C₂H₄ in soil air.     

Microbial phytase activity and their role in organic P mineralization

Plants respond to their external environment to optimize their nutrition and production potential to minimize the food security issues and support sustainable agriculture system. Phosphorus (P) is an important nutrient for plants and is involved in plant metabolic processes. It is mostly available as orthophosphate and has a tendency to form complexes with cations. It has low mobility in soil, thus becoming unavailable for plant uptake that causes a reduction in plant growth and yield. Besides free P, phytate is the major form of organic P in soil and plant tissues. Phytases obtained from different sources, that is, plants, animals, and microorganisms, catalyze the hydrolysis of phytate and release available forms of inorganic P. The knowledge of mechanisms involved in catalytic activity of phytase obtained from microorganisms in soil is limited. This review summarizes the role of microbial phytase in releasing organic P by hydrolysis of phytate and factors affecting its activity in the soil.     

Biotechnological production of oil: Fatty acid composition of microbial oil

The fatty acid profile and the fatty acid composition of microbial lipids obtained from molds revealed that oil from Aspergillus sydowii, Fusarium oxysporum and F. equisetti had a high percentage of unsaturated fatty acids, particularly oleic acid, and had a similarity to the edible oils, groundnut and palm oil. This study sheds light on the possibilities of exploring the use of these oils as supplement to other edible fats and for other non-edible industrial purposes.     

A Novel Green Stabilization of TiO<Subscript>2</Subscript> Nanoparticles onto Cotton

Facile embedding of TiO₂ nanoparticles onto cotton fabric has been successfully attained by ultraviolet light irradiations. The adhesion of nanoparticles with fibre surface, tensile behaviour and physicochemical changes before and after ultraviolet treatment were investigated by scanning electron microscopy, energy dispersive X-ray and inductive couple plasma-atomic emission spectroscopy. Experimental variables i.e. dosage of TiO₂ nanoparticles, temperature of the system and time of ultraviolet irradiations were optimised by central composite design and response surface methodology. Moreover, two different mathematical models were developed for incorporated TiO₂ onto cotton and tensile strength of cotton after ultraviolet treatment and used further to testify the obtained results. Self-clean fabric through a synergistic combination of cotton with highly photo active TiO₂ nanoparticles was produced. Stability against ultraviolet irradiations and self-cleaning properties of the produced fabric were evaluated.     

QTL Mapping for Adult Plant Resistance to Powdery Mildew in Italian Wheat cv. Strampelli

The Italian wheat cv.Strampelli displays high resistance to powdery mildew caused by Blumeria graminis f.sp.tritici.The objective of this study was to map quantitative trait loci(QTLs) for resistance to powdery mildew in a population of 249 F 2:3 lines from Strampelli/Huixianhong.Adult plant powdery mildew tests were conducted over 2 yr in Beijing and 1 yr in Anyang and simple sequence repeat(SSR) markers were used for genotyping.QTLs Qpm.caas-3BS,Qpm.caas-5BL.1,and Qpm.caas-7DS were consistent across environments whereas,Qpm.caas-2BS.1 found in two environments,explained 0.4-1.6,5.5-6.9,27.1-34.5,and 1.0-3.5% of the phenotypic variation respectively.Qpm.caas-7DS corresponded to the genomic location of Pm38/Lr34/Yr18.Qpm.caas-4BL was identified in Anyang 2010 and Beijing 2011,accounting for 1.9-3.5% of phenotypic variation.Qpm.caas-2BS.1 and Qpm.caas-5BL.1 contributed by Strampelli and Qpm.caas-3BS by Huixianhong,seem to be new QTL for powdery mildew resistance.Qpm.caas-4BL,Qpm.caas-5BL.3,and Qpm.caas-7DS contributed by Strampelli appeared to be in the same genomic regions as those mapped previously for stripe rust resistance in the same population,indicating that these loci conferred resistance to both stripe rust and powdery mildew.Strampelli could be a valuable genetic resource for improving durable resistance to both powdery mildew and stripe rust in wheat.     

Eco-friendly gelatin-based electrospun fibers to control the release of chloramphenicol

Chloramphenicol, antibiotic drug is widely used in the developing countries, may cause bone marrow suppression during its topical treatment and affecting red blood cells. Because the accumulation of high dose of chloramphenicol is necessary for this side effect, controlling its release rate is a possible approach to reduce the risk of its topical application. In the present work, chloramphenicol was encapsulated into gelatin electrospun fibers that cross-linked with non-toxic crosslinker. β-cyclodextrin, cyclic oligosaccharides of 7 membered-sugar ring, was selectively oxidized to cleave the carboncarbon bond in positions C-2 and C-3 of the glucose units to yield two aldehyde groups and end up with poly aldehyde β- cyclodextrin (PA-β-CD). Matrix was designed to control chloramphenicol release rate from nontoxic and biodegradable electrospun mat for topical applications. Bead-free electrospun fibers were produced at the concentration of 24 % w/v gelatin solution at 15 kV with gap distance of 17 cm with a flow rate of 2 ml/hr. Electrospun fibers were produced in the nanoscale (450-150 nm). 6 % of chloramphenicol was chosen to carry out the cross-linked matrices by using PA-β-CD. The encapsulation efficacy was investigated by UV-isible spectroscopy and the antimicrobial activities were demonstrated against Staphylococcus aureus (gram positive) and Pseudomonas aeruginosa (gram negative bacteria) and Candida albicans. The results showed that the samples have a strong inhibitory activity against all pathogenic microorganisms used.     

软体沼气工程聚乙烯土工膜技术性能与成本分析

该研究以软体沼气工程聚乙烯土工膜为研究对象,对其技术性能和产品成本进行比对分析,以期为软体沼气工程膜材料提供理论参考与建议。研究材料为工程上常用的1.0~2.0 mm厚度的普通高密度聚乙烯土工膜(GH-1)、环保用光面高密度聚乙烯土工膜(GH-2S)、环保用单/双糙面高密度聚乙烯土工膜(GH-2T)和低密度聚乙烯土工膜(GL-1)。研究结果表明,2.0 mm厚度的不同型号土工膜材料成本是1.0 mm厚度土工膜的1.6~2.0倍;膜拉伸屈服强度以GH-2T为最高,而膜拉伸断裂强度和平均抗穿刺强度则以GH-2S为最高;膜的厚度与膜的抗老化、抗紫外线及使用年限无显著相关性。综合分析认为,高密度聚乙烯土工膜GH-2S材料成本适中,在抗拉伸性能、抗穿刺强度、抗紫外线和抗老化能力及使用年限方面具有不同程度的优势,可为软体沼气工程首选膜材料。