Foliar Application of Phosphorus Enhances Photosynthesis and Biochemical Characteristics of Maize under Drought Stress

Water is essential for the growth period of crops;however,water unavailability badly affects the growth and physiological attributes of crops,which considerably reduced the yield and yield components in crops.Therefore,a pot experiment was conducted to investigate the effect of foliar phosphorus(P)on morphological,gas exchange,biochemical traits,and phosphorus use efficiency(PUE)of maize(Zea mays L.)hybrids grown under normal as well as water deficit situations at the Department of Agronomy,University of Agriculture Faisalabad,Pakistan in 2014.Two different treatments(control and P@8 kg ha^(−1))and four hybrids(Hycorn,31P41,65625,and 32B33)of maize were tested by using a randomized complete block design(RCBD)with three replications.Results showed that the water stress caused a remarkable decline in total soluble protein(9.7%),photosynthetic rate(9.4%)and transpiration rate(13.4%),stomatal conductance(10.2%),and internal CO_(2)rate(20.4%)comparative to well-watered control.An increase of 37.1%,36.8%,and 24.5%were recorded for proline,total soluble sugar,and total free amino acid,respectively.However,foliar P application minimized the negative impact of drought by improving plant growth,physio-biochemical attributes,and PUE in maize plants under water stress conditions.Among the hybrids tested,the hybrid 6525 performed better both under stress and non-stress conditions.These outcomes confirmed that the exogenous application of P improved drought stress tolerance by modulating growth,physio-biochemical attributes,and PUE of maize hybrids.

Evaluation of Germplasm of Pearl Millet(Penissetum glaucum L.)for Agronomic,Physiological and Biochemical Traits under Semi-arid Conditions of Hamelmalo

A field experiment was conducted at the experimental farm of Hamelmalo Agricultural College during summer 2017,to evaluate the agronomic,physiological,and biochemical performance of the collected Eritrean germplasm of pearl millet.A total of 16 accessions were tested,out of which 2 were improved varieties included as a check.The experiment was laid out in 4 x 4 Simple Lattice Design with Randomized Block using 4 replications with a gross plot size of 3.0 m x 1.2 m,row to row spacing of 75 cm and plant to plant spacing of 30 cm.The data collected were Agronomic parameters(growth,development,yield,and yield contributing characters);Physiological parameters(Relative water content and Water Use Efficiency);and Biochemical parameters(crude fat,crude fiber,protein content,TSS,and ash content).The data were analyzed using GENSTAT software and correlation analysis was worked to see the positive and negative contribution of agronomic,physiological,and biochemical attributes.The results of the study showed that Bariyay908 and Kona being statistically at par with Bariyay 910,Hagaz,Zibedi,Shleti,Delkata,Tokroray,and Kunama produced significantly higher grain yield.However,among these Baryay908 because of its superior agronomic characteristics,lower incidence of downy mildew,relatively higher water use efficiency and higher crude protein content were found to be comparatively superior to the check improved varieties Kona and Hagaz.Grain yield has shown a positive and significant correlation with harvest index,number of seeds per panicle,panicle length,leaf area and water use efficiency.These promising accessions need to be further tested for future breeding programs to develop varieties higher in productivity and resistant to downy mildew under semi-arid conditions of Eritrea.

Phyllosticta species associated with citrus diseases in China

Phyllosticta species associated with diseases of four commercial Citrus species grown in China are reported.Totally,496 Phyllosticta strains were isolated from mandarins(Citrus reticulata),pomeloes(C.maxima),oranges(C.sinensis)and lemons(C.limon)in the main citrus producing regions across China,and 74 strains were selected for phylogenetic analysis.Analyses inferred from the sequences of internal transcribed spacer region(ITS1,5.8S nrDNA and ITS2),partial translation elongation factor 1-alpha(TEF1)and partial actin gene(ACT),showed these representative Phyllosticta isolates clustered in four distinct clades corresponding to three known,and one undescribed species.The newly resolved taxon,Phyllosticta citrichinaensis was isolated from leaves and fruits of all four Citrus species and is introduced in this paper.This taxon caused minor damage,showing irregular spots or freckles.Phyllosticta citriasiana,associated with tan spot of pomeloes,was isolated only from pomeloes,and never from lemons,mandarins and oranges.Phyllosticta citricarpa,the citrus black spot pathogen,which is presently subjected to phytosanitary legislation in the EU and United States,was isolated from lemons,mandarins and oranges,but never from pomeloes.The isolates of P.citricarpa clustered in two subclades,one from mandarins,the other from oranges and lemons.P.capitalensis was isolated from all four Citrus species as an endophyte,causing false melanose,or together with P.citricarpa or P.citriasiana.Morphological,cultural and biochemical characters were consistent with the results of phylogenetic analysis.In addition,a specific primer pair Pca8/ITS4 was designed and selected,and its corresponding PCR procedure was developed for the detection of P.citriasiana in this study.