Vaccinium darrowii Camp(2 n=2×=24)is a native North American blueberry species and an important source oftraits such as low chill requirement in commercial southern highbush blueberry breeding(Vaccinium coymbosum...Vaccinium darrowii Camp(2 n=2×=24)is a native North American blueberry species and an important source oftraits such as low chill requirement in commercial southern highbush blueberry breeding(Vaccinium coymbosum,2n=4 ×=48).We present a chromosomal-scale genome of V.darrowii generated by the combination of PacBio sequencing and high throughput chromatin conformation capture(Hi-C)scaffolding technologies,yielding a total length of 1.06 Gigabases(Gb).Over 97.8%of the genome sequences are scaffolded into 24 chromosomes representing the two haplotypes.The primary haplotype assembly of V,darrowii contains 34,809 protein-coding genes.Comparison to a V.corymbosum haplotype assembly reveals high collinearity between the two genomes with small intrachromosomal rearrangements in eight chromosome pairs.With small RNA sequencing,the annotation was further expanded to include more than 200,000 small RNA loci and 638 microRNAs expressed in berry tissues.Transcriptome analysis across fruit development stages indicates that genes involved in photosynthesis are downregulated,while genes involved in flavonoid and anthocyanin biosynthesis are signi ficantly increased at the late stage of berry ripening.A high-quality reference genome and accompanying annotation of V.darrowii is a signi ficant new resource for assessing the evergreen blueberry contribution to the breeding of southern highbush blueberries.展开更多
Inheritance of purple,gold,and variegated foliage types,weeping architecture,and double flower was explored in F1,F2,and backcross families resulting from controlled hybridization of eastern redbud(Cercis canadensis L...Inheritance of purple,gold,and variegated foliage types,weeping architecture,and double flower was explored in F1,F2,and backcross families resulting from controlled hybridization of eastern redbud(Cercis canadensis L.).Potential allelic relationships were explored when possible.Inheritance analysis in families derived from controlled hybridization of‘Covey’(green leaf)and‘Forest Pansy’(purple leaf)suggest that purple leaf color and weeping architecture are both controlled by single recessive genes,for which the symbols pl1 and wp1 are proposed,respectively.Inheritance of gold leaf was explored in families of‘Covey’(green leaf)בHearts of Gold’(gold leaf).Interpretation of inheritance of gold leaf in these families was confounded by the recovery of a leaf color phenotype in the F2 family unlike either parent.However,data suggested the action of a single locus controlling gold leaf color in‘Hearts of Gold’,and that instability of gold leaf expression may be based on transposable element activity.Segregation of gold leaf in the F2 families of‘Texas White’[green leaf(C.canadensis var.texensis)]בJN2’[gold leaf(The Rising Sun)]did not fit a Mendelian ratio.Analysis of progeny of‘Silver Cloud’and‘Floating Clouds’(both showing white/green leaf variegation)with non-variegated cultivars demonstrated that variegation in‘Silver Cloud’is controlled by a single recessive nuclear gene,while variegation in‘Floating Clouds’is controlled by cytoplasmic factors.The symbol var1 is proposed for the gene controlling variegation in‘Silver Cloud’.Double flower in progeny derived from‘Flame’(double flower)suggested that double flower is dominant to single flower,and that‘Flame’is heterozygous at the double-flower locus,for which the symbol Df1 is proposed.Allelism studies showed that the gene controlling purple leaf in‘Forest Pansy’is allelic to the purple leaf gene in‘Greswan’and that the gene controlling weeping phenotype in‘Traveller’(C.canadensis var.texensis)is non-allelic to the weeping gene found in‘Covey’.Allelism of the gold leaf trait in‘Hearts of Gold’and‘JN2’was investigated,but no clear conclusions regarding allelism could be made due to recovery of leaf color phenotypes unlike either parent.展开更多
Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bio...Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bioinformatic and transgenic plant analyses,we demonstrate that the CKXs of land plants most likely originated from an ancient chlamydial endosymbiont during primary endosymbiosis.We refer to the CKXs retaining evolutionarily ancient characteristics as“ancient CKXs”and those that have expanded and functionally diverged in angiosperms as“non-ancient CKXs”.We show that the expression of some non-ancient CKXs is rapidly inducible within 15 min upon the dehydration of Arabidopsis,while the ancient CKX(AtCKX7)is not drought responsive.Tobacco plants overexpressing a non-ancient CKX display improved oxidative and drought tolerance and root growth.Previous mutant studies have shown that non-ancient CKXs regulate organ development,particularly that of flowers.Furthermore,ancient CKXs preferentially degrade cis-zeatin(cZ)-type cytokinins,while non-ancient CKXs preferentially target N6-(Δ2-isopentenyl)adenines(iPs)and trans-zeatins(tZs).Based on the results of this work,an accompanying study(Wang et al.https://doi.org/10.1038/s41438-019-0211-x)and previous studies,we hypothesize that non-ancient CKXs and their preferred substrates of iP/tZ-type cytokinins regulate angiosperm organ development and environmental stress responses,while ancient CKXs and their preferred substrates of cZs play a housekeeping role,which echoes the conclusions and hypothesis described in the accompanying report(Wang,X.et al.Evolution and roles of cytokinin genes in angiosperms 1:Doancient IPTs play housekeeping while non-ancient IPTs play regulatory roles?Hortic Res 7,(2020).https://doi.org/10.1038/s41438-019-0211-x).展开更多
The diversity of prokaryotic communities in soil is shaped by both biotic and abiotic factors.However,little is known about the major factors shaping soil prokaryotic communities at a large scale in agroecosystems.To ...The diversity of prokaryotic communities in soil is shaped by both biotic and abiotic factors.However,little is known about the major factors shaping soil prokaryotic communities at a large scale in agroecosystems.To this end,we undertook a study to investigate the impact of maize production cropping systems,soil properties and geographic location(latitude and longitude)on soil prokaryotic communities using metagenomic techniques,across four distinct maize production regions in China.Across all study sites,the dominant prokaryotes in soil were Alphaproteobacteria,Gammaproteobacteria,Betaproteobacteria,Gemmatimonadetes,Acidobacteria,and Actinobacteria.Non-metric multidimensional scaling revealed that prokaryotic communities clustered into the respective maize cropping systems in which they resided.Redundancy analysis(RDA)showed that soil properties especially pH,geographic location and cropping system jointly determined the diversity of the prokaryotic communities.The functional genes of soil prokaryotes from these samples were chiefly influenced by latitude,soil pH and cropping system,as revealed by RDA analysis.The abundance of genes in some metabolic pathways,such as genes involved in microbe–microbe interactions,degradation of aromatic compounds,carbon fixation pathways in prokaryotes and microbial metabolism were markedly different across the four maize production regions.Our study indicated that the combination of soil pH,cropping system and geographic location significantly influenced the prokaryotic community and the functional genes of these microbes.This work contributes to a deeper understanding of the composition and function of the soil prokaryotic community across large-scale production systems such as maize.展开更多
Drought is the most critical abiotic factor reducing rice yield in rainfed and drought prone areas. Majority of rice cultivated area in south Asia are under rainfed, where water stress at any of the critical growth st...Drought is the most critical abiotic factor reducing rice yield in rainfed and drought prone areas. Majority of rice cultivated area in south Asia are under rainfed, where water stress at any of the critical growth stage causes sharp decline in yield. Research was conducted in western Nepal at farmers field around the close vicinity of Regional Agriculture Research Center (RARS) Nepalgunj. Ten different rice cultivars were evaluated under drought stress and non-stress condition during the year 2017 to identify superior stress tolerant cultivars. Different drought tolerance indices like stress tolerance (TOL), Stress tolerance index (STI), Stress susceptibility index (SSI), were tested in screening superior rice cultivars. Significant reduction in mean grain yield was observed under drought stress in all rice cultivars under the study. The rice cultivars with high STI values and low TOL and SSI were identified as superior drought tolerant cultivars. Based on results of different tolerance indices, Sukha series of rice, Sukha Dhan 1-6 and Radha-4 showed low TOL and SSI and high STI values and were identified as drought tolerant cultivars. The present study reveals that selection based on drought tolerance indices can be an efficient tool in identification of superior drought tolerant cultivars with higher yield and stability.展开更多
The bird cherry-oat aphid (Rhopalosiphum padi [Linnaeus, 1758]) is considered a key pest of cereal crops worldwide, causing direct damage through sap feeding and by acting as a vector for viral diseases. Managing aphi...The bird cherry-oat aphid (Rhopalosiphum padi [Linnaeus, 1758]) is considered a key pest of cereal crops worldwide, causing direct damage through sap feeding and by acting as a vector for viral diseases. Managing aphids is challenging because of their biology and potential resistance to insecticides. Developing resistant barley genotypes is a sustainable strategy for managing BCOA. In this study, we assessed responses of susceptible “Morex” and resistant “BCO R001” barley, Hordeum vulgare L. genotypes to different initial BCOA densities (0, 50, 100 or 200 aphids.plant<sup>-1</sup>). Physiological and morphological parameters were measured weekly for four weeks after infestation. Chlorophyll content, photosynthetic rate, plant aerial fresh and dry weight were greater for the resistant cultivar at lower aphid abundances and up to three weeks after infestation. Carbon assimilation curves (A/Ci) of infested “BCO R001” were similar to controls 15 days post infestation, differing from Morex. However, BCOA infestation of 50 aphid.plant<sup>-1</sup> for two weeks negatively impacted the fitness of both genotypes. Initial resistance by BCO R001 to BCOA infestation can allow growers and natural enemies more time contributing to more effective and sustainable management of BCOA infestations.展开更多
Protein kinases(PKs)have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions.Only a fraction of plant PKs,however,have been func...Protein kinases(PKs)have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions.Only a fraction of plant PKs,however,have been functionally characterized even in model plant species.In the present study,the entire grapevine kinome was identified and annotated using the most recent version of the grapevine genome.A total of 1168 PK-encoding genes were identified and classified into 20 groups and 121 families,with the RLK-Pelle group being the largest,with 872 members.The 1168 kinase genes were unevenly distributed over all 19 chromosomes,and both tandem and segmental duplications contributed to the expansion of the grapevine kinome,especially of the RLK-Pelle group.Ka/Ks values indicated that most of the tandem and segmental duplication events were under purifying selection.The grapevine kinome families exhibited different expression patterns during plant development and in response to various stress treatments,with many being coexpressed.The comprehensive annotation of grapevine kinase genes,their patterns of expression and coexpression,and the related information facilitate a more complete understanding of the roles of various grapevine kinases in growth and development,responses to abiotic stress,and evolutionary history.展开更多
Computational tool-assisted primer design for real-time reverse transcription(RT)PCR(qPCR)analysis largely ignores the sequence similarities between sequences of homologous genes in a plant genome.It can lead to false...Computational tool-assisted primer design for real-time reverse transcription(RT)PCR(qPCR)analysis largely ignores the sequence similarities between sequences of homologous genes in a plant genome.It can lead to false confidence in the quality of the designed primers,which sometimes results in skipping the optimization steps for qPCR.However,the optimization of qPCR parameters plays an essential role in the efficiency,specificity,and sensitivity of each gene’s primers.Here,we proposed an optimized approach to sequentially optimizing primer sequences,annealing temperatures,primer concentrations,and cDNA concentration range for each reference(and target)gene.Our approach started with a sequence-specific primer design that should be based on the single-nucleotide polymorphisms(SNPs)present in all the homologous sequences for each of the reference(and target)genes under study.By combining the efficiency calibrated and standard curve methods with the 2−ΔΔCt method,the standard cDNA concentration curve with a logarithmic scale was obtained for each primer pair for each gene.As a result,an R 2≥0.9999 and the efficiency(E)=100±5% should be achieved for the best primer pair of each gene,which serve as the prerequisite for using the 2^(−ΔΔCt) method for data analysis.We applied our newly developed approach to identify the best reference genes in different tissues and at various inflorescence developmental stages of Tripidium ravennae,an ornamental and biomass grass,and validated their utility under varying abiotic stress conditions.We also applied this approach to test the expression stability of six reference genes in soybean under biotic stress treatment with Xanthomonas axonopodis pv.glycines(Xag).Thus,these case studies demonstrated the effectiveness of our optimized protocol for qPCR analysis.展开更多
During the survey of freshwater fungi from Greater Mekong subregion,four fresh collections were collected from Yunnan and Tibet of China.Phylogenetic analyses of combined LSU,SSU,ITS,TEF1-αand RPB2 sequence data plac...During the survey of freshwater fungi from Greater Mekong subregion,four fresh collections were collected from Yunnan and Tibet of China.Phylogenetic analyses of combined LSU,SSU,ITS,TEF1-αand RPB2 sequence data placed them in Lindgomycetaceae,the analyses showed that four strains clustered together and were sister to Hongkongmyces thailandica.A new species,Hongkongmyces brunneisporus,is introduced for the four fresh collections based on multi-locus phylogenetic analyses.H.brunneisporus is the second sexual species of Hongkongmyces,which can be easily distinguished from another sexual species,H.thailandica by the ascomata with dark brown to black setae near the ostiole region and the fusiform,reddish-brown to dark brown,multi-septate ascospores with obtuse and narrow ends.Description and illustration of the new species are provided.Comparison between the new species and its affined species is given.展开更多
Tomato spotted wilt(TSW)is a serious virus disease of peanut in the United States.Breeding for TSWV resistance would be facilitated by the implementation of marker-assisted selection in breeding programs;however,genes...Tomato spotted wilt(TSW)is a serious virus disease of peanut in the United States.Breeding for TSWV resistance would be facilitated by the implementation of marker-assisted selection in breeding programs;however,genes associated with resistance have not been identified.Association mapping is a type of genetic mapping that can exploit relationships between markers and traits in many lineages.The objectives of this study were to examine genetic diversity and population structure in the U.S.peanut mini-core collection using simple sequence repeat(SSR)markers,and to conduct association mapping between SSR markers and TSWV resistance in cultivated peanuts.One hundred and thirty-three SSR markers were used for genotyping 104 accessions.Four subpopulations,generally corresponding to botanical varieties,were classified by population structure analysis.Association mapping analysis indicated that five markers:pP GPseq5D5,GM1135,GM1991,TC23C08,and TC24C06,were consistently associated with TSW resistance by the Q,PCA,Q+K,and PCA+K models.These markers together explained 36.4%of the phenotypic variance.Moreover,pP GPseq5D5 and GM1991 were associated with both visual symptoms of TSWV and ELISA values with a high R^2.The potential of these markers for use in a marker-assisted selection program to breed peanut for resistance to TSWV is discussed.展开更多
Hundreds of billions of insects are produced each year in insectaries or laboratories. These insects are reared for programs of pest control, as feed, for production of various products such as textiles and food, for ...Hundreds of billions of insects are produced each year in insectaries or laboratories. These insects are reared for programs of pest control, as feed, for production of various products such as textiles and food, for research and education, among many purposes. The concept is advanced here that rearing conditions are expected to simulate the natural environments from which target insects are derived. Simply speaking, the rearing container and rearing facility are the insect’s microhabitat and its overall environment. Therefore, the central premise of this paper is that rearing systems are human-made ecosystems. If our expectations are to be met, that reared insects are healthy, fit, and of high quality—simulating their wild counterparts, rearing personnel must engineer conditions that meet all the insects’ needs. In this review, major advancements and progress are documented within the context of the ecology involved in artificial rearing technology. In this review, attention is paid to the food, environmental factors (temperature, humidity or water—in the case of aquatic insects—lighting, gas exchange, and soil—for soil-inhabiting insects), containment, and some special features of rearing systems that were designed to meet special needs of a target insect’s biology. Because there are thousands of publications on rearing advancements, the focus is on publications that had the strongest influence on modern day insect rearing systems, as well as papers that represent historically novel rearing concepts. Where the chain of information is missing on how or from where rearing innovations were derived, papers are referenced as documentation of the various rearing system features.展开更多
There is an increasing demand in the peanut industry for high oleic peanuts and also for the incorporation of the high oleate trait into newly released varieties. Early generation screening of breeding lines for high ...There is an increasing demand in the peanut industry for high oleic peanuts and also for the incorporation of the high oleate trait into newly released varieties. Early generation screening of breeding lines for high oleic acid content greatly increases the efficiency of developing new peanut varieties. The objective of this study was to compare the accuracy of methods used to classify individual peanut seed as high oleic or not high oleic. Results from capillary electrophoresis (CE), two variations of near-infrared reflectance spectroscopy (NIRS), and real-time polymerase chain reaction (RT-PCR) genotyping, were compared with the traditionally accepted reference standard results from gas chromatography (GC). Three hundred and seventy-four (374) seeds, spanning twenty-three (23) genotypes and all four peanut market-types (runner, Spanish, Valencia and Virginia), were individually tested by each method. Percent accuracy levels for rating individual seed as high oleic (H) ranged from 97.4% (NIRS) to 99.5% (CE). All of the methods examined in this study carry only a minor risk for miss-classification (loss of material) and are suitable for use by peanut breeding programs in early generation breeding line screening.展开更多
In insects,larval and adult defenses against predators have been well studied.However,pupal(also known as resting stage)defenses have been overlooked and not examined thoroughly.Although some pupa possess antipredator...In insects,larval and adult defenses against predators have been well studied.However,pupal(also known as resting stage)defenses have been overlooked and not examined thoroughly.Although some pupa possess antipredator strategies such as hairs,spines,cryptic coloration,and exudation of chemicals,few studies have tested these responses and the factors affecting them.Here,we investigated the behavioral responses in tobacco hornworm Manduca sexta that pupates in soil by introducing an external stimulus using vibrations from an electric toothbrush to mimic predation.We observed that M.sexta made violent wriggling(twitching),followed by pulsating movements in response to the vibrational stimulus.Detailed examination showed that these twitches and pulsating events occurred more frequently and for longer periods of time in male pupa and were dependent on the magnitude of the stress(high and low frequency).However,when we estimated the angular force exerted by pupa using radian and angular momentum of twitches,it was found to be independent of pupal sex.A follow-up experiment on possible cascading effects of stress exposure on eclosion success revealed that low-and high-frequency stress exposure didn’t cause any of the common defects in eclosed adults.Our study clearly demonstrates that the so-called defenseless pupal stage uses a wide range of measurable defense behaviors that can actively defend against predators and should be examined further-linking observed behavior with underlying mechanisms.展开更多
We are studying seed and fruit inhabiting fungi in Thailand and this paper introduces a new species,Diaporthe collariana,from Magnolia champaca fruits,collected in Chiang Rai Province.Molecular analysis of a combined ...We are studying seed and fruit inhabiting fungi in Thailand and this paper introduces a new species,Diaporthe collariana,from Magnolia champaca fruits,collected in Chiang Rai Province.Molecular analysis of a combined ITS,TEF1,TUB and CAL sequence DNA and morphological data provide evidence to justify the new species.Diaporthe collariana is characterized by producing alpha and beta conidia,and conidiogenous cells with prominent,flared collarettes.The new species is compared with closely related species in the genus.展开更多
The reniform nematode (Rotylenchulus reniformis) is among the most economically damaging plant pathogens in the United States. This nematode is mostly known for its damage to cotton but tomato is also well-within its ...The reniform nematode (Rotylenchulus reniformis) is among the most economically damaging plant pathogens in the United States. This nematode is mostly known for its damage to cotton but tomato is also well-within its vast host range that includes 314 plant species across 77 plant families. Nematode-resistant genotypes offer an effective, environmentally safe alternative to agro-chemicals for reniform nematode management. Resistance genes can be introgressed into cultivars through plant improvement efforts. Tomato is a diploid species which is more amenable to identification of resistance genes in contrast to cotton where cultivars are either tetraploid or hexaploid.This greenhouse study examined cultivated and wild Solanum species represented by 40 tomato accessions, to identify resistance and susceptibility responses to R. reniformis. Accessions were evaluated by using single plants in six replicates. Seeds were germinated in sterile soil and inoculated with mixed vermiform R. reniformis. After seven weeks, eggs and vermiform stages were extracted from the root system and counted. A susceptible control S. lycopersicum “Rutgers” (LA1090) was included. Seven putatively resistant tomato genotypes were identified. These genotypes in increasing order of resistance are S. chilense (LA1029), S. lycopersicum (LA1792), S. chilense (LA1932), S. peruvianum var. humifusum (LA0385) S. pimpinellifolium (LA2934), S. peruvianum f. glandulosum (LA1283) and S. pimpinellifolium (LA1579).展开更多
Several thousands of chemical substances are registered every year for different purposes, and sometimes many of them are claimed to play the same role. To establish and compare their toxicities, the determination of ...Several thousands of chemical substances are registered every year for different purposes, and sometimes many of them are claimed to play the same role. To establish and compare their toxicities, the determination of the lethal concentrations is usually necessary and should account for natural mortality. However, many of the statistical software packages used for that purpose do not readily integrate control mortality or adjust the best link function to the data during the process. This manuscript proposes an ＂lc＂ function in the R open source that aims at the effective determination of lethal concentrations. Furthermore, it performs the procedure with the appropriate link function. The ＂lc＂ application on the example provided revealed that the complementary log link function is adequate.展开更多
Five reduced-risk insecticides were compared for their toxicities to male and female third instar larvae of diamondback moth （DBM）, Plutella xylostella L. （Lepidoptera：Plutellidae） obtained from a laboratory colo...Five reduced-risk insecticides were compared for their toxicities to male and female third instar larvae of diamondback moth （DBM）, Plutella xylostella L. （Lepidoptera：Plutellidae） obtained from a laboratory colony. Leaf-dip bioassays were used to assess larval mortality at different insecticides rates （ranging from 0.01 mg AI/L to 100 mg A1/L） and exposure times （24, 48 and 72 h after treatment）. Toxicity of the insecticides generally increased with rate and exposure time. At 72 h after treatment, median lethal concentrations （LCs0s） of methoxyfenozide, spinosad, novaluron, indoxacarb and Bacillus thuringiensis （Bt） against the male third instar larvae of P, xylostella were 0.0524, 0.1117, 0.9149, 1.1939 and 4.4983 mg AI/L, respectively, and were 0.1008, 0.2583, 1.0649, 0.2850 and 5.3053 mg AI/L against female third instar larvae, respectively. At 0.1% of the approximate recommended field rates, methoxyfenozide （60%-75%） and spinosad （53%-57%） were the most toxic, while Bt （30%-45% mortality） was the least toxic to male and female P. xylostella larvae. Spinosad was the fastest acting and the only insecticide that caused significant larval mortality （17%） at 24 h after exposure. Significant sexual differences were recorded in the susceptibility of P. xylostella larvae to two of the insecticides： spinosad and indoxacarb. Male larvae were two-fold more susceptible to spinosad but 10-fold more tolerant to indoxacarb than female larvae.展开更多
Greenhouse whitefly （GHWF）, Trialeurodes vaporariorum （Westwood） is a very important pest of greenhouse plants, but its resistance to pesticides has rendered it difficult to control by chemical methods in recent y...Greenhouse whitefly （GHWF）, Trialeurodes vaporariorum （Westwood） is a very important pest of greenhouse plants, but its resistance to pesticides has rendered it difficult to control by chemical methods in recent years. Sterile insect technique （SIT） is a biological control method which has been used in Area Wide Integrated Pest Management （AWIPM）. This study conducted the possibility of sterilising GHWF adults by gamma radiations emitted from cobalt 60. Longevity of the adults, and the amount of egg laying and sterilisation of eggs were determined under the influence of 50, 60, 70, 80, 90 Gy doses under controlled conditions （65 ± 5% RH, 25 ± 2 ℃, L/D = 16/8）. Normal insects were considered as control （0 dose）. The best combination for mating of normal and sterile adults （normal male × normal female as control, normal male and irradiated female, irradiated male × normal female, and irradiated male × irradiated female） was studied using a factorial design （n = 4）. Results showed that the best irradiating doses were 70 and 80 Gy for females and males respectively. Longevity of irradiated males and females was not significantly different from that of non-irradiated specimens. The best mating model was irradiated males and females.展开更多
This article suggests standards for insect rearing papers, to make them more suitable for publication. It provides guidelines for publishing 1) insect rearing-technology papers and 2) insect rearing-science papers. Th...This article suggests standards for insect rearing papers, to make them more suitable for publication. It provides guidelines for publishing 1) insect rearing-technology papers and 2) insect rearing-science papers. The technology papers offer rearing methodology or practical aspects of rearing system development and optimization. The rearing science papers would include outcomes of rearing experiments developed with controls, variables and are based on explicitly stated rationale and explicit hypotheses. This paper also suggests welcoming papers based on discoveries of various aspects of feeding biology and treating scientifically rearing systems’ components and properties. It is suggested that the treatment of insect rearing systems should be modelled after the extensive and successful practices of the food science and food technology community. The food science model includes welcoming papers that do not involve directly living subjects. It is argued here that the outcomes of following these suggestions will greatly enhance the progress of insect rearing inquiry, and this progress will support a much greater practical and basic science-based understanding of insect biology.展开更多
基金This research was funded in part by the U.S.Department of Agriculture Agricultural Research Service(USDA ARS)including ARS project numbers 6062-21000-010-00-D and 6066-21310-005-00D.
文摘Vaccinium darrowii Camp(2 n=2×=24)is a native North American blueberry species and an important source oftraits such as low chill requirement in commercial southern highbush blueberry breeding(Vaccinium coymbosum,2n=4 ×=48).We present a chromosomal-scale genome of V.darrowii generated by the combination of PacBio sequencing and high throughput chromatin conformation capture(Hi-C)scaffolding technologies,yielding a total length of 1.06 Gigabases(Gb).Over 97.8%of the genome sequences are scaffolded into 24 chromosomes representing the two haplotypes.The primary haplotype assembly of V,darrowii contains 34,809 protein-coding genes.Comparison to a V.corymbosum haplotype assembly reveals high collinearity between the two genomes with small intrachromosomal rearrangements in eight chromosome pairs.With small RNA sequencing,the annotation was further expanded to include more than 200,000 small RNA loci and 638 microRNAs expressed in berry tissues.Transcriptome analysis across fruit development stages indicates that genes involved in photosynthesis are downregulated,while genes involved in flavonoid and anthocyanin biosynthesis are signi ficantly increased at the late stage of berry ripening.A high-quality reference genome and accompanying annotation of V.darrowii is a signi ficant new resource for assessing the evergreen blueberry contribution to the breeding of southern highbush blueberries.
基金Research supported by funds provided by the North Carolina Agricultural Research Service(NCARS),North Carolina Nursery and Landscape Association(NCNLA),J.Frank Schmidt Family Charitable Foundation,PlantHaven International,and the US Department of Agriculture(Grant#58-6404-1637).
文摘Inheritance of purple,gold,and variegated foliage types,weeping architecture,and double flower was explored in F1,F2,and backcross families resulting from controlled hybridization of eastern redbud(Cercis canadensis L.).Potential allelic relationships were explored when possible.Inheritance analysis in families derived from controlled hybridization of‘Covey’(green leaf)and‘Forest Pansy’(purple leaf)suggest that purple leaf color and weeping architecture are both controlled by single recessive genes,for which the symbols pl1 and wp1 are proposed,respectively.Inheritance of gold leaf was explored in families of‘Covey’(green leaf)בHearts of Gold’(gold leaf).Interpretation of inheritance of gold leaf in these families was confounded by the recovery of a leaf color phenotype in the F2 family unlike either parent.However,data suggested the action of a single locus controlling gold leaf color in‘Hearts of Gold’,and that instability of gold leaf expression may be based on transposable element activity.Segregation of gold leaf in the F2 families of‘Texas White’[green leaf(C.canadensis var.texensis)]בJN2’[gold leaf(The Rising Sun)]did not fit a Mendelian ratio.Analysis of progeny of‘Silver Cloud’and‘Floating Clouds’(both showing white/green leaf variegation)with non-variegated cultivars demonstrated that variegation in‘Silver Cloud’is controlled by a single recessive nuclear gene,while variegation in‘Floating Clouds’is controlled by cytoplasmic factors.The symbol var1 is proposed for the gene controlling variegation in‘Silver Cloud’.Double flower in progeny derived from‘Flame’(double flower)suggested that double flower is dominant to single flower,and that‘Flame’is heterozygous at the double-flower locus,for which the symbol Df1 is proposed.Allelism studies showed that the gene controlling purple leaf in‘Forest Pansy’is allelic to the purple leaf gene in‘Greswan’and that the gene controlling weeping phenotype in‘Traveller’(C.canadensis var.texensis)is non-allelic to the weeping gene found in‘Covey’.Allelism of the gold leaf trait in‘Hearts of Gold’and‘JN2’was investigated,but no clear conclusions regarding allelism could be made due to recovery of leaf color phenotypes unlike either parent.
基金supported by the National Natural Science Foundation of China[grant number 31471860 to J.D.and number 31401842 to H.W.]the Open Project of the State Key Laboratory of Crop Genetics and Germplasm Enhancement[grant number ZW2014008 to H.W.].
文摘Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bioinformatic and transgenic plant analyses,we demonstrate that the CKXs of land plants most likely originated from an ancient chlamydial endosymbiont during primary endosymbiosis.We refer to the CKXs retaining evolutionarily ancient characteristics as“ancient CKXs”and those that have expanded and functionally diverged in angiosperms as“non-ancient CKXs”.We show that the expression of some non-ancient CKXs is rapidly inducible within 15 min upon the dehydration of Arabidopsis,while the ancient CKX(AtCKX7)is not drought responsive.Tobacco plants overexpressing a non-ancient CKX display improved oxidative and drought tolerance and root growth.Previous mutant studies have shown that non-ancient CKXs regulate organ development,particularly that of flowers.Furthermore,ancient CKXs preferentially degrade cis-zeatin(cZ)-type cytokinins,while non-ancient CKXs preferentially target N6-(Δ2-isopentenyl)adenines(iPs)and trans-zeatins(tZs).Based on the results of this work,an accompanying study(Wang et al.https://doi.org/10.1038/s41438-019-0211-x)and previous studies,we hypothesize that non-ancient CKXs and their preferred substrates of iP/tZ-type cytokinins regulate angiosperm organ development and environmental stress responses,while ancient CKXs and their preferred substrates of cZs play a housekeeping role,which echoes the conclusions and hypothesis described in the accompanying report(Wang,X.et al.Evolution and roles of cytokinin genes in angiosperms 1:Doancient IPTs play housekeeping while non-ancient IPTs play regulatory roles?Hortic Res 7,(2020).https://doi.org/10.1038/s41438-019-0211-x).
基金supported by the National Program for Support of Top-notch Young Professionals,Chinathe Open Research Fund of State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection,Chinese Academy of Agricultural Sciences(SKLQF201508)the Project of Plant Protection Key Discipline of Henan Province,China。
文摘The diversity of prokaryotic communities in soil is shaped by both biotic and abiotic factors.However,little is known about the major factors shaping soil prokaryotic communities at a large scale in agroecosystems.To this end,we undertook a study to investigate the impact of maize production cropping systems,soil properties and geographic location(latitude and longitude)on soil prokaryotic communities using metagenomic techniques,across four distinct maize production regions in China.Across all study sites,the dominant prokaryotes in soil were Alphaproteobacteria,Gammaproteobacteria,Betaproteobacteria,Gemmatimonadetes,Acidobacteria,and Actinobacteria.Non-metric multidimensional scaling revealed that prokaryotic communities clustered into the respective maize cropping systems in which they resided.Redundancy analysis(RDA)showed that soil properties especially pH,geographic location and cropping system jointly determined the diversity of the prokaryotic communities.The functional genes of soil prokaryotes from these samples were chiefly influenced by latitude,soil pH and cropping system,as revealed by RDA analysis.The abundance of genes in some metabolic pathways,such as genes involved in microbe–microbe interactions,degradation of aromatic compounds,carbon fixation pathways in prokaryotes and microbial metabolism were markedly different across the four maize production regions.Our study indicated that the combination of soil pH,cropping system and geographic location significantly influenced the prokaryotic community and the functional genes of these microbes.This work contributes to a deeper understanding of the composition and function of the soil prokaryotic community across large-scale production systems such as maize.
文摘Drought is the most critical abiotic factor reducing rice yield in rainfed and drought prone areas. Majority of rice cultivated area in south Asia are under rainfed, where water stress at any of the critical growth stage causes sharp decline in yield. Research was conducted in western Nepal at farmers field around the close vicinity of Regional Agriculture Research Center (RARS) Nepalgunj. Ten different rice cultivars were evaluated under drought stress and non-stress condition during the year 2017 to identify superior stress tolerant cultivars. Different drought tolerance indices like stress tolerance (TOL), Stress tolerance index (STI), Stress susceptibility index (SSI), were tested in screening superior rice cultivars. Significant reduction in mean grain yield was observed under drought stress in all rice cultivars under the study. The rice cultivars with high STI values and low TOL and SSI were identified as superior drought tolerant cultivars. Based on results of different tolerance indices, Sukha series of rice, Sukha Dhan 1-6 and Radha-4 showed low TOL and SSI and high STI values and were identified as drought tolerant cultivars. The present study reveals that selection based on drought tolerance indices can be an efficient tool in identification of superior drought tolerant cultivars with higher yield and stability.
文摘The bird cherry-oat aphid (Rhopalosiphum padi [Linnaeus, 1758]) is considered a key pest of cereal crops worldwide, causing direct damage through sap feeding and by acting as a vector for viral diseases. Managing aphids is challenging because of their biology and potential resistance to insecticides. Developing resistant barley genotypes is a sustainable strategy for managing BCOA. In this study, we assessed responses of susceptible “Morex” and resistant “BCO R001” barley, Hordeum vulgare L. genotypes to different initial BCOA densities (0, 50, 100 or 200 aphids.plant<sup>-1</sup>). Physiological and morphological parameters were measured weekly for four weeks after infestation. Chlorophyll content, photosynthetic rate, plant aerial fresh and dry weight were greater for the resistant cultivar at lower aphid abundances and up to three weeks after infestation. Carbon assimilation curves (A/Ci) of infested “BCO R001” were similar to controls 15 days post infestation, differing from Morex. However, BCOA infestation of 50 aphid.plant<sup>-1</sup> for two weeks negatively impacted the fitness of both genotypes. Initial resistance by BCO R001 to BCOA infestation can allow growers and natural enemies more time contributing to more effective and sustainable management of BCOA infestations.
基金This research was financially supported in part by the Priority Academic of Jiangsu Province and the Tennessee Agricultural Experiment Station Hatch Project 1009395Kaikai Zhu was supported by the China Scholarship Council(CSC,No.201606850052).
文摘Protein kinases(PKs)have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions.Only a fraction of plant PKs,however,have been functionally characterized even in model plant species.In the present study,the entire grapevine kinome was identified and annotated using the most recent version of the grapevine genome.A total of 1168 PK-encoding genes were identified and classified into 20 groups and 121 families,with the RLK-Pelle group being the largest,with 872 members.The 1168 kinase genes were unevenly distributed over all 19 chromosomes,and both tandem and segmental duplications contributed to the expansion of the grapevine kinome,especially of the RLK-Pelle group.Ka/Ks values indicated that most of the tandem and segmental duplication events were under purifying selection.The grapevine kinome families exhibited different expression patterns during plant development and in response to various stress treatments,with many being coexpressed.The comprehensive annotation of grapevine kinase genes,their patterns of expression and coexpression,and the related information facilitate a more complete understanding of the roles of various grapevine kinases in growth and development,responses to abiotic stress,and evolutionary history.
基金The authors thank the USDA National Institute of Food and Agriculture Hatch project 02685 and North Carolina State University for the startup funds to the Liu laboratorythe NSFC fund 31871646 to the Zhao laboratory。
文摘Computational tool-assisted primer design for real-time reverse transcription(RT)PCR(qPCR)analysis largely ignores the sequence similarities between sequences of homologous genes in a plant genome.It can lead to false confidence in the quality of the designed primers,which sometimes results in skipping the optimization steps for qPCR.However,the optimization of qPCR parameters plays an essential role in the efficiency,specificity,and sensitivity of each gene’s primers.Here,we proposed an optimized approach to sequentially optimizing primer sequences,annealing temperatures,primer concentrations,and cDNA concentration range for each reference(and target)gene.Our approach started with a sequence-specific primer design that should be based on the single-nucleotide polymorphisms(SNPs)present in all the homologous sequences for each of the reference(and target)genes under study.By combining the efficiency calibrated and standard curve methods with the 2−ΔΔCt method,the standard cDNA concentration curve with a logarithmic scale was obtained for each primer pair for each gene.As a result,an R 2≥0.9999 and the efficiency(E)=100±5% should be achieved for the best primer pair of each gene,which serve as the prerequisite for using the 2^(−ΔΔCt) method for data analysis.We applied our newly developed approach to identify the best reference genes in different tissues and at various inflorescence developmental stages of Tripidium ravennae,an ornamental and biomass grass,and validated their utility under varying abiotic stress conditions.We also applied this approach to test the expression stability of six reference genes in soybean under biotic stress treatment with Xanthomonas axonopodis pv.glycines(Xag).Thus,these case studies demonstrated the effectiveness of our optimized protocol for qPCR analysis.
基金Supported by the National Natural Science Foundation of China(31860006,31970021)Fungal Diversity Conservation and Utilization Innovation Team of Dali University(ZKLX2019213)。
文摘During the survey of freshwater fungi from Greater Mekong subregion,four fresh collections were collected from Yunnan and Tibet of China.Phylogenetic analyses of combined LSU,SSU,ITS,TEF1-αand RPB2 sequence data placed them in Lindgomycetaceae,the analyses showed that four strains clustered together and were sister to Hongkongmyces thailandica.A new species,Hongkongmyces brunneisporus,is introduced for the four fresh collections based on multi-locus phylogenetic analyses.H.brunneisporus is the second sexual species of Hongkongmyces,which can be easily distinguished from another sexual species,H.thailandica by the ascomata with dark brown to black setae near the ostiole region and the fusiform,reddish-brown to dark brown,multi-septate ascospores with obtuse and narrow ends.Description and illustration of the new species are provided.Comparison between the new species and its affined species is given.
基金the Peanut Foundation (04-811-16)the National Peanut Board (RIA16PID456BID1426-CC)+1 种基金Alabama Peanut Producers Associationthe Hatch program of the USDA-NIFA
文摘Tomato spotted wilt(TSW)is a serious virus disease of peanut in the United States.Breeding for TSWV resistance would be facilitated by the implementation of marker-assisted selection in breeding programs;however,genes associated with resistance have not been identified.Association mapping is a type of genetic mapping that can exploit relationships between markers and traits in many lineages.The objectives of this study were to examine genetic diversity and population structure in the U.S.peanut mini-core collection using simple sequence repeat(SSR)markers,and to conduct association mapping between SSR markers and TSWV resistance in cultivated peanuts.One hundred and thirty-three SSR markers were used for genotyping 104 accessions.Four subpopulations,generally corresponding to botanical varieties,were classified by population structure analysis.Association mapping analysis indicated that five markers:pP GPseq5D5,GM1135,GM1991,TC23C08,and TC24C06,were consistently associated with TSW resistance by the Q,PCA,Q+K,and PCA+K models.These markers together explained 36.4%of the phenotypic variance.Moreover,pP GPseq5D5 and GM1991 were associated with both visual symptoms of TSWV and ELISA values with a high R^2.The potential of these markers for use in a marker-assisted selection program to breed peanut for resistance to TSWV is discussed.
文摘Hundreds of billions of insects are produced each year in insectaries or laboratories. These insects are reared for programs of pest control, as feed, for production of various products such as textiles and food, for research and education, among many purposes. The concept is advanced here that rearing conditions are expected to simulate the natural environments from which target insects are derived. Simply speaking, the rearing container and rearing facility are the insect’s microhabitat and its overall environment. Therefore, the central premise of this paper is that rearing systems are human-made ecosystems. If our expectations are to be met, that reared insects are healthy, fit, and of high quality—simulating their wild counterparts, rearing personnel must engineer conditions that meet all the insects’ needs. In this review, major advancements and progress are documented within the context of the ecology involved in artificial rearing technology. In this review, attention is paid to the food, environmental factors (temperature, humidity or water—in the case of aquatic insects—lighting, gas exchange, and soil—for soil-inhabiting insects), containment, and some special features of rearing systems that were designed to meet special needs of a target insect’s biology. Because there are thousands of publications on rearing advancements, the focus is on publications that had the strongest influence on modern day insect rearing systems, as well as papers that represent historically novel rearing concepts. Where the chain of information is missing on how or from where rearing innovations were derived, papers are referenced as documentation of the various rearing system features.
文摘There is an increasing demand in the peanut industry for high oleic peanuts and also for the incorporation of the high oleate trait into newly released varieties. Early generation screening of breeding lines for high oleic acid content greatly increases the efficiency of developing new peanut varieties. The objective of this study was to compare the accuracy of methods used to classify individual peanut seed as high oleic or not high oleic. Results from capillary electrophoresis (CE), two variations of near-infrared reflectance spectroscopy (NIRS), and real-time polymerase chain reaction (RT-PCR) genotyping, were compared with the traditionally accepted reference standard results from gas chromatography (GC). Three hundred and seventy-four (374) seeds, spanning twenty-three (23) genotypes and all four peanut market-types (runner, Spanish, Valencia and Virginia), were individually tested by each method. Percent accuracy levels for rating individual seed as high oleic (H) ranged from 97.4% (NIRS) to 99.5% (CE). All of the methods examined in this study carry only a minor risk for miss-classification (loss of material) and are suitable for use by peanut breeding programs in early generation breeding line screening.
文摘In insects,larval and adult defenses against predators have been well studied.However,pupal(also known as resting stage)defenses have been overlooked and not examined thoroughly.Although some pupa possess antipredator strategies such as hairs,spines,cryptic coloration,and exudation of chemicals,few studies have tested these responses and the factors affecting them.Here,we investigated the behavioral responses in tobacco hornworm Manduca sexta that pupates in soil by introducing an external stimulus using vibrations from an electric toothbrush to mimic predation.We observed that M.sexta made violent wriggling(twitching),followed by pulsating movements in response to the vibrational stimulus.Detailed examination showed that these twitches and pulsating events occurred more frequently and for longer periods of time in male pupa and were dependent on the magnitude of the stress(high and low frequency).However,when we estimated the angular force exerted by pupa using radian and angular momentum of twitches,it was found to be independent of pupal sex.A follow-up experiment on possible cascading effects of stress exposure on eclosion success revealed that low-and high-frequency stress exposure didn’t cause any of the common defects in eclosed adults.Our study clearly demonstrates that the so-called defenseless pupal stage uses a wide range of measurable defense behaviors that can actively defend against predators and should be examined further-linking observed behavior with underlying mechanisms.
基金The Research of Featured Microbial Resources and Diversity Investigation in Southwest Karst area(Project No.2014FY120100)is thanked for financial supportthe Chinese Academy of Sciences,project number 2013T2S0030,for the award of a Visiting Professorship for Senior International Scientists at Kunming Institute of Botanyextend their appreciation to the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP#0089.
文摘We are studying seed and fruit inhabiting fungi in Thailand and this paper introduces a new species,Diaporthe collariana,from Magnolia champaca fruits,collected in Chiang Rai Province.Molecular analysis of a combined ITS,TEF1,TUB and CAL sequence DNA and morphological data provide evidence to justify the new species.Diaporthe collariana is characterized by producing alpha and beta conidia,and conidiogenous cells with prominent,flared collarettes.The new species is compared with closely related species in the genus.
文摘The reniform nematode (Rotylenchulus reniformis) is among the most economically damaging plant pathogens in the United States. This nematode is mostly known for its damage to cotton but tomato is also well-within its vast host range that includes 314 plant species across 77 plant families. Nematode-resistant genotypes offer an effective, environmentally safe alternative to agro-chemicals for reniform nematode management. Resistance genes can be introgressed into cultivars through plant improvement efforts. Tomato is a diploid species which is more amenable to identification of resistance genes in contrast to cotton where cultivars are either tetraploid or hexaploid.This greenhouse study examined cultivated and wild Solanum species represented by 40 tomato accessions, to identify resistance and susceptibility responses to R. reniformis. Accessions were evaluated by using single plants in six replicates. Seeds were germinated in sterile soil and inoculated with mixed vermiform R. reniformis. After seven weeks, eggs and vermiform stages were extracted from the root system and counted. A susceptible control S. lycopersicum “Rutgers” (LA1090) was included. Seven putatively resistant tomato genotypes were identified. These genotypes in increasing order of resistance are S. chilense (LA1029), S. lycopersicum (LA1792), S. chilense (LA1932), S. peruvianum var. humifusum (LA0385) S. pimpinellifolium (LA2934), S. peruvianum f. glandulosum (LA1283) and S. pimpinellifolium (LA1579).
文摘Several thousands of chemical substances are registered every year for different purposes, and sometimes many of them are claimed to play the same role. To establish and compare their toxicities, the determination of the lethal concentrations is usually necessary and should account for natural mortality. However, many of the statistical software packages used for that purpose do not readily integrate control mortality or adjust the best link function to the data during the process. This manuscript proposes an ＂lc＂ function in the R open source that aims at the effective determination of lethal concentrations. Furthermore, it performs the procedure with the appropriate link function. The ＂lc＂ application on the example provided revealed that the complementary log link function is adequate.
文摘Five reduced-risk insecticides were compared for their toxicities to male and female third instar larvae of diamondback moth （DBM）, Plutella xylostella L. （Lepidoptera：Plutellidae） obtained from a laboratory colony. Leaf-dip bioassays were used to assess larval mortality at different insecticides rates （ranging from 0.01 mg AI/L to 100 mg A1/L） and exposure times （24, 48 and 72 h after treatment）. Toxicity of the insecticides generally increased with rate and exposure time. At 72 h after treatment, median lethal concentrations （LCs0s） of methoxyfenozide, spinosad, novaluron, indoxacarb and Bacillus thuringiensis （Bt） against the male third instar larvae of P, xylostella were 0.0524, 0.1117, 0.9149, 1.1939 and 4.4983 mg AI/L, respectively, and were 0.1008, 0.2583, 1.0649, 0.2850 and 5.3053 mg AI/L against female third instar larvae, respectively. At 0.1% of the approximate recommended field rates, methoxyfenozide （60%-75%） and spinosad （53%-57%） were the most toxic, while Bt （30%-45% mortality） was the least toxic to male and female P. xylostella larvae. Spinosad was the fastest acting and the only insecticide that caused significant larval mortality （17%） at 24 h after exposure. Significant sexual differences were recorded in the susceptibility of P. xylostella larvae to two of the insecticides： spinosad and indoxacarb. Male larvae were two-fold more susceptible to spinosad but 10-fold more tolerant to indoxacarb than female larvae.
文摘Greenhouse whitefly （GHWF）, Trialeurodes vaporariorum （Westwood） is a very important pest of greenhouse plants, but its resistance to pesticides has rendered it difficult to control by chemical methods in recent years. Sterile insect technique （SIT） is a biological control method which has been used in Area Wide Integrated Pest Management （AWIPM）. This study conducted the possibility of sterilising GHWF adults by gamma radiations emitted from cobalt 60. Longevity of the adults, and the amount of egg laying and sterilisation of eggs were determined under the influence of 50, 60, 70, 80, 90 Gy doses under controlled conditions （65 ± 5% RH, 25 ± 2 ℃, L/D = 16/8）. Normal insects were considered as control （0 dose）. The best combination for mating of normal and sterile adults （normal male × normal female as control, normal male and irradiated female, irradiated male × normal female, and irradiated male × irradiated female） was studied using a factorial design （n = 4）. Results showed that the best irradiating doses were 70 and 80 Gy for females and males respectively. Longevity of irradiated males and females was not significantly different from that of non-irradiated specimens. The best mating model was irradiated males and females.
文摘This article suggests standards for insect rearing papers, to make them more suitable for publication. It provides guidelines for publishing 1) insect rearing-technology papers and 2) insect rearing-science papers. The technology papers offer rearing methodology or practical aspects of rearing system development and optimization. The rearing science papers would include outcomes of rearing experiments developed with controls, variables and are based on explicitly stated rationale and explicit hypotheses. This paper also suggests welcoming papers based on discoveries of various aspects of feeding biology and treating scientifically rearing systems’ components and properties. It is suggested that the treatment of insect rearing systems should be modelled after the extensive and successful practices of the food science and food technology community. The food science model includes welcoming papers that do not involve directly living subjects. It is argued here that the outcomes of following these suggestions will greatly enhance the progress of insect rearing inquiry, and this progress will support a much greater practical and basic science-based understanding of insect biology.
