Ovule number as a rising star for regulating seed yield:Hope or hype

Rapeseed(Brassica napus L.)is the second most widely grown premium oilseed crop globally,mainly for its vegetable oil and protein meal.One of the main goals of breeders is producing high-yield rapeseed cultivars with sustainable production to meet the requirements of the fast-growing population.Besides the pod number,seeds per silique(SS),and thousand-seed weight(TSW),the ovule number(ON)is a decisive yield determining factor of individual plants and the final seed yield.In recent years,tremendous efforts have been made to dissect the genetic and molecular basis of these complex traits,but relatively few genes or loci controlling these traits have been reported thus far.This review highlights the updated information on the hormonal and molecular basis of ON and development in model plants(Arabidopsis thaliana).It also presents what is known about the hormonal,molecular,and genetic mechanism of ovule development and number,and bridges our understanding between the model plant species(A.thaliana)and cultivated species(B.napus).This report will open new pathways for primary and applied research in plant biology and benefit rapeseed breeding programs.This synopsis will stimulate research interest to further understand ovule number determination,its role in yield improvement,and its possible utilization in breeding programs.

Mycorrhiza and Phosphate Solubilizing Bacteria:Potential Bioagents for Sustainable Phosphorus Management in Agriculture

Phosphorus(P)is a critical nutrient that plays an essential role in improving soil fertility for optimum plant growth and productivity.It is one of the most deficient macro-nutrients in agricultural soils after nitrogen and is considered inadequate for plant growth and production.To P availability in soils,the farmers are applying huge amounts of synthetic P fertilizers that adversely affect the wider environment,groundwater,soil fertility and microbial population.Many beneficial microbes are known to release and supply soluble P for improving growth and yield of a variety of plants in a sustainable manner in P deficient soils.Thus,inoculation of these microbes,including arbuscular mycorrhizal fungi(AMF)and phosphate solubilizing bacteria(PSB)to soil to enhance crop production without harming the environment,is an alternative approach to chemical fertilizers.The combined role of AMF and PSB in P solubilization is not well understood and the application and mode of action of these microbial groups are often naive due to variation in the environment.Therefore,the current review article would develop a better understanding of the interactive role and mechanisms of AMF and PSB in improving P availability from both organic and inorganic sources in a sustainable crop production system.Finally,the current review would loop out further avenues for researchers interested to commercially produce effective AMF and PSB-based biofertilizers for sustainable management of phosphorus over a wide range of agricultural crops worldwide.

Synthesis and characterization of caprolactone based polyurethane with degradable and antifouling performance

In this work,a degradable polyurethane composed of caprolactone(CL)and L-Lactide(LLA)as soft segments,and 4,40-methylenebis(cyclohexyl isocyanate)(H12 MDI)and polytetramethylene ether glycol(PTMEG)as hard segments,was prepared.Hydrolytic degradation experiment revealed that the degradable polyurethane(PU)could be degraded in artificial seawater.It also showed that caprolactone-copolyurethane(CL-PU)copolymer with higher crystallinity degraded much slower in artificial seawater.However,the introduction of LLA resulted in an increase in the hydrophilicity and reduction in the crystallinity of degradable PU,as demonstrated by the contact angle analysis.The result of the scanning electron microscope showed that the surface of degradable PU renewed under static condition.Moreover,degradable PU was able to be used as a carrier,and it controlled the release rate of 4,5-dichloro-2-octyl-isothiazolone(DCOIT).The anti-diatom(Navicula incerta)test demonstrated that the(caprolactone-co-L-lactide)-co-polyurethane 4(CL/LAx-PU4)with DCOIT contents prevented the adhesion of diatom Navicula incerta(88.37%reduction)due to their self-polishing and the release of antifoulants.Therefore,the degradable PU consisted of CL,LLA,and DCOIT could be a durable resin with good antifouling activity for the application in the marine anti-biofouling field.

Effect of Different Levels of Nitrogen and Phosphorus on the Phenology and Yield of Maize Varieties

An experiment was conducted at Malakabad (Gadera) Dargai Malak and KPK to study the effect of different levels of nitrogen and phosphorus on the yield of maize varieties in randomize complete block design with split plot arrangement. Different fertilization treatments (0:0, 100:0, 100:50, 100:100, 150:0, 150:50, 150:100, 150:150 N:P kg·ha-1) were assigned to main plot while, maize varieties (Azam, Jalal and local) were kept in sub-plots. Data regarding emergence m-2, days to emergence, days to tasseling, days to silking, number of cobs plant-1, plant height, grains cob-1, 1000-grain weight and grain yield were recorded. Emergence m-2, days to emergence, days to tasseling, days to silking, plant ha-1 at harvest were not significantly affected by different levels of nitrogen and phosphorus while number of cob plant-1, thousand grains weight, plant height, grains cob-1 and grain yield were significantly affected. Maximum grain yield (5356 kg·ha-1) was recorded in Jalal variety, when it was fertilized with 150:100 N:P kg·ha-1. Of the factors included in this study, maize cultivars and NP fertilization treatments were dominant in determining grain yield as well as its related components, suggesting that cultivar selection and optimum fertilization are effective strategies to improve grain yield. However, multiplication and multi-year studies are required to test these results using different cultivars under varying edaphic and climatic conditions.

dep1 improves rice grain yield and nitrogen use efficiency simultaneously by enhancing nitrogen and dry matter translocation

The rice cultivars carrying dep1(dense and erect panicle 1)have the potential to achieve both high grain yield and high nitrogen use efficiency(NUE).However,few studies have focused on the agronomic and physiological performance of those cultivars associated with high yield and high NUE under field conditions.Therefore,we evaluated the yield performance and NUE of two near-isogenic lines(NILs)carrying DEP1(NIL-DEP1)and dep1-1(NIL-dep1)genes under the Nanjing 6 background at 0 and 120 kg N ha^(–1).Grain yield and NUE for grain production(NUEg)were 25.5 and 21.9%higher in NIL-dep1 compared to NIL-DEP1 averaged across N treatments and planting years,respectively.The yield advantage of NIL-dep1 over NIL-DEP1 was mainly due to larger sink size(i.e.,higher total spikelet number),grainfilling percentage,total dry matter production,and harvest index.N utilization rather than N uptake contributed to the high yield of NIL-dep1.Significantly higher NUEg in NIL-dep1 was associated with higher N and dry matter translocation efficiency,lower leaf and stem N concentration at maturity,and higher glutamine synthetase(GS)activity in leaves.In conclusion,dep1 improved grain yield and NUE by increasing N and dry matter transport due to higher leaf GS activity under field conditions during the grain-filling period.

Study on the synthesis of spin labeled poly(styrene-co-maleic acid)s and their segmental motion

Study of the segmental mobility of polymer chains is important when the polymer is used as drag reduction agents of crude oil.Electron spin resonance(ESR)spectroscopy can provide important information about segmental dynamics of polymer chains,which is related to their microenvironment.In this article,we employed an amphiphilic polymer to study the effect of hydrophilic/hydrophobic balance of the polymers on the segmental motion of polymer chains.Poly(styrene-co-maleic acid)(PSMA)was spin labeled with 4-amino TEMPO radicals by increasing the concentration of radical moiety on the polymer chains.The PSMA and spin labeled-PSMAs(SL-PSMAs)were characterized by nuclear magnetic resonance(NMR),Fourier transform infrared(FT-IR)spectroscopy,Cyclic voltammetry(CV)and ESR techniques.Inter-polymer complexes(IPCs)of SL-PSMA-2 were prepared by employing polyethylene glycols(PEGs)of varying molecular weights.The results showed that the increased hydrophobic interactions of nitroxide radicals on the SLPSMAs’chains reduced the rotational mobility of spin labels and the random coil-toglobular transition of polymer chains occurred at higher pH value for SL-PSMAs,which showed a slow motion component in the ESR spectra of SL-PSMAs.Further,by increasing the molecular weight of PEGs in IPCs the complexation was increased,which also reduced the rotational motion of spin labels due to interpolymer hydrogen bonding causing a slow motion component in the ESR spectra.©2021 The Authors.

Phenoloxidases: catechol oxidase - the temporary employer and laccase - the rising star of vascular plants

Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenolics.However,their origin,evolution,and differential roles during plant development and land colonization are unclear.We performed the phylogeny,domain,amino acids,compositional biases,and intron analyses to clarify the origin and evolution of COs and LACs,and analysed the structure,selective pressure,and chloroplast targeting to understand the species-dependent distribution of COs.We found that Streptophyta COs were not homologous to the Chlorophyta tyrosinases(TYRs),and might have been acquired by horizontal gene transfer from bacteria.COs expanded in bryophytes.Structural-functionality and selective pressure were partially responsible for the species-dependent retention of COs in embryophytes.LACs emerged in Zygnemaphyceae,having evolved from ascorbate oxidases(AAOs),and prevailed in the vascular plants and strongly expanded in seed plants.COs and LACs coevolved with the phenolic metabolism pathway genes.These results suggested that TYRs and AAOs were the first-stage phenoloxidases in Chlorophyta.COs might be the second key for the early land colonization.LACs were the third one(dominating in the vascular plants)and might be advantageous for diversified phenol substrates and the erect growth of plants.This work provided new insights into how phenoloxidases evolved and were devoted to plant evolution.

Response of Fodder Maize to Various Levels of Nitrogen and Phosphorus

Nitrogen (N) and Phosphorus (P) are of the most important and complex nutrients for the crop plants in particular for grain yield and quality. The field trials were laid out in randomized complete block design having three replications. Research trial plots were located at Agricultural Research Farm of Agricultural University Peshawar (Ameer Mohammad Khan Campus Mardan) during kharif season in 2012 to investigate the response of maize variety (Jalal) to three phosphorus rates (60, 90 and 120 kg&middotha-1) and four nitrogen rates (90, 120, 150, 180 kg&middotha-1) for agronomical traits. These traits investigated included number of plant per m2 (NP m2), plant height (PH), number of leaves plant-1 (NLP), leaf area plant-1&middotcm2 (LAP), fresh weight of plants kg&middotha-1 (FW) and dry weight of plant kg&middotha-1 (DW), were investigated. Results of the study showed that application of N @ 180 and P @ 120 kg&middotha-1 significantly increased fodder yield of maize. The linear increase in biomass yield clearly indicated that N was a limiting nutrient factor and that N demand along with P has a positive response. At higher application rates, N fertilizer significantly increased biomass component, improved N uptake with increasing nitrogen use efficiency and decreased its losses to the environment and below plant zone. So this study showed that the phosphorus and nitrogen fertilizers have a positive effect on the fodder yield of maize.

Effect of Different Levels of Nitrogen on Yield of Colocasia (<i>Colocasia esculenta</i>) at District Malakand Dargai

A field experiment was conducted to evaluate the response of colocasia (Colocasia esculenta) to different levels of 0, 60, 90, 120 and 150 kg N ha-1 under farmer’s field condition at Garhi Usmani Khel, District Malakand Dargai during 2013. The experiment was laid out in Randomized Complete Block design with three replications and treatment plot size of 2.74 × 2.43 m2. All levels of N in the form of urea along with uniform basal doze of 90 kg P2O5 ha-1 as Triple Super Phosphate (TSPPP) were applied to soil at time of seed bed followed by thorough mixing. Seeds of colocasia c.v. local variety were sown in these plots with row spacing of 30 cm and plant to plant distance of 12 cm in February, 2013. The results showed that application of N produced significantly higher colocasia tuber yield, number of tubers plant-1, 1000-tubers weight and size of tubers (mean length and diameter) over control but the differences among levels of N were nonsignificant. However, some parameters like tuber yield was maximum at 60 kg N ha-1 and tuber size especially the length of colocasia tuber was maximum at 150 kg N ha-1 suggesting that the response of each parameter was different to N levels. Based on maximum relative yield (100%) and increase over control (46.1%) still at lower N levels of 60 kg N ha-1, this level seems to be appropriate level for colocasia under the prevailing soil and climatic conditions.

Comparative Efficacy of Different Herbicides for Weed Management and Yield Attributes in Wheat

Weed competes with crops for water, nutrients and light so weed infestation is one of the major threats to crop. Present investigation was aimed to asses the comparative efficacy of different herbicides for weed management in wheat crop under agro-climatic conditions of Pakistan. This experiment was laid out in a randomized complete block design (RCBD) design with five replications. Different herbicides were used for weed management in wheat crop. The post emergence application of herbicides included Aim 40 DF @ 0.02 kg a.i. ha-1, Agritop 500 GL-1 @ 0.43 kg a.i. ha-1, Isoproturon 50 WP @ 1 kg a.i. ha-1, Puma super 75 EW @ 0.75 kg, Topik 15 WP @ 0.04 kg and Buctril super 60 EC @ 0.45 kg. For comparison hand weeding and weedy check were also included. In each replication six treatments of these six herbicides were kept. The significantly affected parameters were fresh weed biomass (kg·ha-1), thousand grain weight (g), number of tillers m-2, weed control efficiency (%) and grain yield (kg·ha-1). Statistical analysis showed that maximum weed efficiency (84%) was recorded for Isoproturon 50 WP whereas minimum value (37%) was for Aim 40 DF. Similarly maximum number of tillers m-2 (250) was recorded for Isoproturon 50 WP and minimum (133) in weedy check. The herbicide Isoproturon 50 WP @ 1.0 kg a.i. ha-1 was applied at post emergence performed well and exhibited effectively weed control and better yield in wheat.

Schools' Flood Emergency Preparedness in Khyber Pakhtunkhwa Province, Pakistan

Pakistan is highly exposed to climate-induced disasters, especially floods. Flooding history shows that educational establishments have been disproportionately hard-hit by flooding events. In Pakistan, school safety and preparedness is still a choice, rather than a mandatory requirement for all schools. But schools in Pakistan do have a responsibility to keep safe the students in their care,especially during and after the catastrophic events. This implies the need to maintain the environment in and around school property, so as to minimize the impacts of floods and to have the mechanisms in place to maximize a school's resilience. This study examined the emergency preparedness activities of 20 schools in four districts of Khyber Pakhtunkhwa Province that had recently been severely affected by floods. Through face to face interviews and a structured questionnaire(n = 100) we collected data on the four pillars of emergency preparedness:emergency planning, preparation measures, safe school facilities, and hazard education and training. The study revealed that the majority of the sample schools hadexperienced more than one natural hazard-induced disaster,predominantly flooding, yet despite this had not undertaken adequate emergency preparedness activities. There are particular gaps with regard to plans for students with disabilities, the continuity of school operations after a disaster,the presence of maps to identify evacuation routes, the availability of emergency equipment and resources, disaster preparedness guidelines, and psychological first aid and crisis counseling. The strengths, weaknesses, opportunities,and threats analysis that our researchers carried out indicates that, although schools in the survey have taken many steps towards flood preparedness, many weaknesses still exist and there remain significant opportunities to strengthen the preparedness level of many schools. The goal of this study is to inform policy decisions that improve school safety in Pakistan and to suggest the priority areas for future school disaster preparedness and management efforts.