Herbicide safeners alleviate herbicide toxicity while preserving weed-control efficacy in common buckwheat.A three-year field experiment was performed to measure the effects of quizalofop-P-ethyl(QPE)alone or in combi...Herbicide safeners alleviate herbicide toxicity while preserving weed-control efficacy in common buckwheat.A three-year field experiment was performed to measure the effects of quizalofop-P-ethyl(QPE)alone or in combination with gibberellin or brassinolide on soil enzyme activity and yield components in common buckwheat.The herbicide-brassinolide application yielded the greatest increases in soil enzyme activity and yield components without sacrificing weed control efficacy.It is recommended for use in common buckwheat cultivation in the Loess Plateau.展开更多
Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the m...Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant line.The higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and lignification.Additionally,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription factor.The gene could potentially be used for breeding of drought-tolerant cultivars.展开更多
Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We id...Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We identified three strong signals at the qFT02-2 locus(Chr02:12037319–12238569),which were associated with flowering time in three environments:Gongzhuling,Mengcheng,and Nanchang.By analyzing linkage disequilibrium,gene expression patterns,gene annotation,and the diversity of variants,we identified an AP1 homolog as the candidate gene for the qFT02-2 locus,which we named GmAP1d.Only one nonsynonymous polymorphism existed among 1490 soybean accessions at position Chr02:12087053.Accessions carrying the Chr02:12087053-T allele flowered significantly earlier than those carrying the Chr02:12087053-A allele.Thus,we developed a cleaved amplified polymorphic sequence(CAPS)marker for the SNP at Chr02:12087053,which is suitable for marker-assisted breeding of flowering time.Knockout of GmAP1d in the‘Williams 82’background by gene editing promoted flowering under long-day conditions,confirming that GmAP1d is the causal gene for qFT02-2.An analysis of the region surrounding GmAP1d revealed that GmAP1d was artificially selected during the genetic improvement of soybean.Through stepwise selection,the proportion of modern cultivars carrying the Chr02:12087053-T allele has increased,and this allele has become nearly fixed(95%)in northern China.These findings provide a theoretical basis for better understanding the molecular regulatory mechanism of flowering time in soybean and a target gene that can be used for breeding modern soybean cultivars adapted to different latitudes.展开更多
A set of 45 diverse Asian and African origin/bred populations of pearl millet were investigated multi-locationally for morphological traits including grain yield and assessed for their fertility restoration ability on...A set of 45 diverse Asian and African origin/bred populations of pearl millet were investigated multi-locationally for morphological traits including grain yield and assessed for their fertility restoration ability on three cytoplasmic male sterility(CMS) systems in two contrasting seasons. Significant genetic variation was found for all the yield linked traits. Multivariate analysis for grain yield and its component traits grouped these populations into five clusters. Most of the Asian origin populations grouped into single cluster(Cluster III) and separated from the rest of the African origin populations indicating the presence of correspondence between clustering pattern and geographical origin of the populations. Clusters dominated with Asian populations(As-As) had linkages with early flowering, short plant height, more number of tillers, small and thin panicles, small seeded and low grain yield compared to the clusters dominated by African populations(Af-Af) or African origin and Asian bred(Af-As) populations.Genetically related populations having common parentage were found grouped in same clusters.Fertility restoration/maintainer frequency of 45 populations on three diverse CMS systems revealed that overall fertility restoration frequency was highest for A1(86%) followed by A4(37%) and for A5(7%) CMS system. Five populations were identified as potential sources for developing maintainer lines for all three CMS systems and eight populations were identified specifically for A;and A;CMS systems. A set of 11 and four populations were identified for restorer line development exclusively for A;and A;CMS system,respectively. Six populations were identified for the development of dual restorers for both A;and A;CMS system.展开更多
Soybean[Glycine max(L.)Merr.]is a global protein source and is currently expanding in Central and Northern Europe.Protein and oil content are two important quality traits that have been studied in different germplasm,...Soybean[Glycine max(L.)Merr.]is a global protein source and is currently expanding in Central and Northern Europe.Protein and oil content are two important quality traits that have been studied in different germplasm,however,their genetic architecture in earlymaturing European soybean has not been investigated yet.In this study,we therefore performed QTL mapping for both traits using 944 recombinant inbred lines derived from eight families from a half-diallel crossing design.We identified five QTL for each trait,with the QTL on chromosomes 8,15,and 20 being identified for both protein content and oil content.The known major QTL on chromosome 20 was detected in four families whereas the other QTL were only found in single families.Further analyses revealed the QTL to have pleiotropic but inverse effects on both traits.The effect of the major QTL was comparable between families,illustrating that it is largely independent from the genetic background.Collectively,our results illustrate the quantitative nature of protein and oil content in early European soybean.Marker-assisted selection for the QTL is possible,but the inverse effect on protein and oil content should be kept in mind.展开更多
Heterosis is an important biological phenomenon and widely applied in agriculture.Although many studies have been performed by using vegetative organs of F_(1) hybrid plants,how heterosis (or hybrid vigor) is initiate...Heterosis is an important biological phenomenon and widely applied in agriculture.Although many studies have been performed by using vegetative organs of F_(1) hybrid plants,how heterosis (or hybrid vigor) is initiated and formed,particularly the underlying molecular mechanism,remain elusive.Hybrid contemporary seeds of rice indica varieties 9311 and PA64 were innovatively used and analysis of DNA methylome of embryo and endosperm at early developing stages revealed the globally decreased DNA methylation.Genes,especially those relate to hormones function and transcriptional regulation present non-additive methylation.Previously identified heterosis-related superior genes are non-additively methylated in early developing hybrid contemporary seeds,suggesting that key genes/loci responsible for heterosis are epigenetically modified even in early developing hybrid seeds and hypomethylation of hybrid seeds after cross-pollination finally result in the long-term transcriptional change of F_(1) hybrid vegetative tissues after germination,demonstrating that altered DNA methylation in hybrid seeds is essential for initiation regulation and maintenance of heterosis exhibiting in F_(1) hybrid plants.Notably,a large number of genes show non-additive methylation in the endosperm of reciprocal hybrids,suggesting that endosperm might also contribute to heterosis.展开更多
Verticillium wilt, a devastating disease in cotton caused by Verticillium dahliae, reduces cotton quality and yield. Heterotrimeric GTP-binding proteins, consisting of Ga, Gb, and Gc subunits, transducers of receptor ...Verticillium wilt, a devastating disease in cotton caused by Verticillium dahliae, reduces cotton quality and yield. Heterotrimeric GTP-binding proteins, consisting of Ga, Gb, and Gc subunits, transducers of receptor signaling, function in a wide range of biological events. However, the function of Ga proteins in the regulation of defense responses in plants is largely unexplored, except for a few reports on model species. In the present study, a cotton G-protein a-subunit-encoding gene(GhGPA) was isolated from Verticillium wilt-resistant Gossypium hirsutum(upland cotton) cv. ND601. GhGPA transcription was up-regulated under V. dahliae stress, with higher expression in tolerant than in susceptible cotton cultivars.Subcellular localization revealed GhGPA to be located in the plasma membrane. GhGPA shows high(85.0%) identity with Arabidopsis AT2 G26300(AtGPA1), and AtGPA1 gpa1-4 mutants displayed susceptibility to V. dahliae. Ectopic expression of GhGPA successfully restored the resistance of Arabidopsis gpa1-4 mutants to Verticillium wilt and made them more resistant than the wild type. Overexpression of GhGPA in Arabidopsis markedly increased the resistance and resulted in dramatic up-regulation of pathogenesis-related(PR) genes and increased in H2 O2 accumulation and salicylic acid(SA) and jasmonic acid(JA) contents. However, suppressing GhGPA expression via virus-induced gene silencing(VIGS)increased susceptibility to Verticillium wilt, down-regulated the expression of PR and marker genes in SA and JA signaling pathways, and reduced H2 O2 content. The contents of SA and JA in Arabidopsis gpa1-4 and VIGS cotton were lower than those in the wild type and empty-vector control. However,GhGPA-overexpressing Arabidopsis contained more SA and JA than the wild type when inoculated with V. dahliae. Thus, GhGPA plays a vital role in Verticillium wilt resistance by inducing SA and JA signaling pathways and regulating the production of reactive oxygen species. These findings not only broaden our knowledge about the biological role of GhGPA, but also shed light on the defense mechanisms involving GhGPA against V. dahliae in cotton.展开更多
Heterosis,which describes the superior vigor and yield of F_1 hybrids with respect to their parents,is observed in many rice hybrid crosses.The exploitation of heterosis is a great leap in the history of rice breeding...Heterosis,which describes the superior vigor and yield of F_1 hybrids with respect to their parents,is observed in many rice hybrid crosses.The exploitation of heterosis is a great leap in the history of rice breeding.With advances in genomics and genetics,high-resolution mapping and functional identification of heterosis-associated loci have been performed in rice.Here we summarize advances in understanding the genetic basis of grain yield heterosis in hybrid rice and provide a vision for the genetic study and breeding application of rice heterosis in the future.展开更多
Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance...Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance using molecular marker-assisted selection is able to facilitate the development of drought-tolerant soybean varieties.In this study,we used a high-yielding and drought-sensitive cultivar‘Zhonghuang 35’and a drought-tolerant cultivar‘Jindou 21’to establish F6:9 recombinant inbred lines.We constructed a highdensity genetic map using specific locus amplified fragment sequencing(SLAF-Seq)technology.The genetic map contained 8078 SLAF markers distributing across 20 soybean chromosomes with a total genetic distance of 3780.98 c M and an average genetic distance of0.59 c M between adjacent markers.Two treatments(irrigation and drought)were used in the field tests,the Additive-Inclusive Composite Interval Mapping(ICIM-ADD)was used to call QTL,and plant height and seed weight per plant were used as the indicators of drought tolerance.We identified a total of 23 QTL related to drought tolerance.Among them,seven QTL(q PH2,q PH6,q PH7,q PH17,q PH19-1,q PH19-2,and q PH19-3)on chromosomes 2,6,7,17,and 19 were related to plant height,and five QTL(q SWPP2,q SWPP6,q SWPP13,q SWPP17,and q SWPP19)on chromosomes 2,6,13,17,and 19 were related to seed weight and could be considered as the major QTL.In addition,three common QTL(q PH6/q SWPP6,q PH17/q SWPP17,and q PH19-3/q SWPP19)for both plant height and seed weight per plant were located in the same genomic regions on the same chromosomes.Three(q PH2,q PH17,and q PH19-2)and four novel QTL(q SWPP2,q SWPP13,q SWPP17,and q SWPP19)were identified for plant height and seed weight per plant,respectively.Two pairs of QTL(q PH2/q SWPP2 and q PH17/q SWPP17)were also common for both plant height and seed weight per plant.These QTL and closely linked SLAF markers could be used to accelerate breeding for drought tolerant cultivars via MAS.展开更多
Rice(Oryza sativa L.)is a major food crop worldwide.Plant height and yield are important agronomic traits of rice.Several genes regulating plant height and/or yield have been cloned.However,the molecular mechanisms co...Rice(Oryza sativa L.)is a major food crop worldwide.Plant height and yield are important agronomic traits of rice.Several genes regulating plant height and/or yield have been cloned.However,the molecular mechanisms coordinating plant height and yield are not fully characterized.Here,we report a novel gene,OstMAPKKK5 that encodes a truncated variant of a mitogen-activated protein kinase kinase kinase 5(OsMAPKKK5)lacking an intact kinase domain.Transgenic plants overexpressing OstMAPKKK5 in indica cultivar 9311 showed increased plant height,grain length,grain width,1000-grain weight,grain number per main panicle,and yield.Real-time quantitative PCR showed that OstMAPKKK5 was widely expressed in various tissues and developmental stages.The increased plant height and yield were attributed to enlarged cell size.Overexpression of OstMAPKKK5 led to higher contents of various forms of endogenous gibberellin(GA),especially the most common active forms,GA1,GA3,GA4.We concluded that OstMAPKKK5 positively regulates plant height and yield in rice by affecting cell size,and that its underlying mechanism is based on increased endogenous GA content.展开更多
Besides leaves, non-foliar green organs such as stem and spike are also considered photosynthetic organs. To assess the photosynthetic contributions of these organs, the correlations between these photosynthetic areas...Besides leaves, non-foliar green organs such as stem and spike are also considered photosynthetic organs. To assess the photosynthetic contributions of these organs, the correlations between these photosynthetic areas and single-spike weight were investigated in a winter wheat(Triticum aestivum L.) under four nitrogen and mulching treatments: N120,N150, N195, and N195 + M. Two-year repeated field experiments were conducted on the Loess Plateau of China. Non-foliar photosynthetic area, grain-filling ratio and duration,grain yield, and in particular, single-spike weight, were measured, recorded and analyzed.Under the N195 + M treatment, plants showed the largest area of photosynthetic organs(flag leaf and non-foliar organs) and the highest grain yield and single spike weight. Singlespike weight was positively correlated with the areas of all examined non-foliar photosynthetic organs, in particular with the area above the flag leaf node(R^2= 0.761*)and the area above the exposed part of the peduncle(EXP)(R^2= 0.800**). In addition, singlespike weight was highly correlated with average grain-filling ratio(R^2= 0.993**), whereas it was less highly correlated with grain-filling duration(R^2= 0.533). The morphological traits of non-foliar photosynthetic organs were also more highly correlated with average grainfilling ratio than with average grain-filling duration. The significant correlation between each of the morphological traits(area, length and width) of EXP and single-spike weight indicates that morphological traits of EXP are important in determining spike weight in the Loess Plateau environment.展开更多
To evaluate the effects of various rotation systems on rice grain yield and N use efficiency, a paddy–upland cropping experiment(2013–2016) was conducted in southeastern China. The experiment was designed using six ...To evaluate the effects of various rotation systems on rice grain yield and N use efficiency, a paddy–upland cropping experiment(2013–2016) was conducted in southeastern China. The experiment was designed using six different rice––winter crop rotations: rice–fallow(RF),rice–wheat(RW), rice–potato with rice straw mulch(RP), rice–green manure(Chinese milk vetch; RC–G), rice–oilseed rape(RO), and rice–green manure crop(oilseed rape with fresh straw incorporated into soil at flowering; RO–G) and three N rates, N0(0 kg N ha-1), N1(142.5 kg N ha-1), and N2(202.5 kg N ha-1). Average rice yields in the RF(5.93 t ha-1) rotation were significantly lower than those in the rotations with winter crops(7.20–7.48 t ha-1)under the N0 treatment, suggesting that incorporation of straw might be more effective for increasing soil N than winter fallow. The rice yield differences among the rotations varied by year with the N input. In general, the grain yields in the RP and RO–G rotations –were respectively 11.6–28.5% and 14.80–37.19% higher than those in the RF in plots with N applied. Increasing the N rate may have tended to minimize the average yield gap between the RF and the other rotations; the yield gaps were 18.55%, 4.14%, and 0.23% in N0, N1, and N2, respectively. However, the N recovery efficiency in the RF was significantly lower than that in other rotations, except for 2015 under both N1 and N2 rates, a finding that implies a large amount of chemical N loss. No significant differences in nitrogen agronomic efficiency(NAE) and physiological efficiency(NPE) were found between the rotations with legume(RC–G) and non–legume(RO and RW) winter crops, a result that may be due partly to straw incorporation. For this reason, we concluded that the return of straw could reduce differences in N use efficiency between rotations with and without legume crops. The degree of synchrony between the crop N demand and the N supply was evaluated by comparison of nitrogen balance degree(NBD) values. The NBD values in the RP and RW were significantly lower than those in the other rotations under both N1 and N2 rates. Thus,in view of the higher grain yield in the RP compared to the RW under the N1 rate, the RP rotation might be a promising practice with comparable grain yield and greater N use efficiency under reduced N input relative to the other rotations. The primary yield components of the RF and RP were identified as number of panicles m-2 and numbers of kernels panicle-1, respectively. The NAE and NPE were positively correlated with harvest index, possibly providing a useful indicator for evaluating N use efficiency.展开更多
Leaf senescence is normally the last stage of plant development. Early senescence of functional leaves significantly reduces the photosynthetic time and efficiency, seriously affecting grain yield and quality in wheat...Leaf senescence is normally the last stage of plant development. Early senescence of functional leaves significantly reduces the photosynthetic time and efficiency, seriously affecting grain yield and quality in wheat. Discovering genes responsible for early leaf senescence(els) are necessary for developing novel germplasms and cultivars with delayed leaf-senescence through molecular manipulation and marker assisted selection. In this study, we identified an early leaf senescence line M114 in a derivative of a wheat breeding population. Genetic analysis indicated that early leaf senescence in M114 is controlled by a single recessive gene, provisionally designated els1. By applying bulked segregant analysis and RNA-Seq(BSR-Seq), seven polymorphic markers linked to els1 were developed and the gene was located on chromosome arm 2 BS in a 1.5 c M genetic interval between markers WGGB303 and WGGB305. A co-segregating marker, WGGB302, provide a starting point for fine mapping and map-based cloning of els1.展开更多
The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in c...The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in cowpea using diallel analysis. For this purpose,half-diallel crosses were made among seven diverse parents. The amount of total soluble sugar was estimated by the phenol sulfuric acid reagent method and reducing sugar were measured by the DNS(3,5-dinitrosalicylic acid) reagent method. The total soluble sugar ranged from 11.12(VYA) to 40.79 mg g^(-1)(IT93 K-693-2) with a mean of 22.31 mg g^(-1).Reducing soluble sugar showed a mean value of 9.11 mg g^(-1) and ranged from 13.61(TVx3236) to 4.98 mg g^(-1)(Lori niebe). Diallel analysis showed that both additive and non-additive gene effects were significant in the genetic control of these traits. However,dominance variance was greater than additive variance for soluble sugar. The traits were controlled mainly by an overdominance model, suggesting the advantage of delaying selection to later generations. Soluble sugar content was found to be highly heritable, with broad-sense heritability ranging from 0.987 to 0.976. Narrow-sense heritability ranged from0.154 to 0.422 and revealed the lower importance of additive variance. Parents and F_1 hybrids differed significantly on the basis of their general and specific combining abilities,respectively. Recessive alleles had positive effects on total soluble sugar and reducing soluble sugar. These results could help cowpea breeders improve the acceptability of cowpea seeds and cowpea-based foods by appropriate selection.展开更多
Salinity-imposed limitations on plant growth are manifested through osmotic and ionic imbalances. However, because salinity-induced responses vary considerably among crop plants, monitoring of such responses at an ear...Salinity-imposed limitations on plant growth are manifested through osmotic and ionic imbalances. However, because salinity-induced responses vary considerably among crop plants, monitoring of such responses at an early stage has relevance. In this study,physiological(seed germination, seed vigor index, root length, shoot length, fresh weight,dry weight) and biochemical attributes(osmoprotectants, K^+/Na^+ ratio) were analyzed for a time-course assessment of salt responses in Indian mustard(Brassica juncea L.) with an emphasis on early monitoring. The results showed strong correlations for total soluble sugars at germination phase(24 h), proline content in the seedling establishment phase(48 h) and various physiological parameters including seed vigor index(R^2= 0.901), shoot length(R^2= 0.982), and fresh weight(R^2= 0.980) at 72 h(adaptation under stress). In addition, transcriptional changes were observed under NaCl treatment for key genes belonging to the family of selective ion transporters(NHX, HKT) and abscisic acid synthesis(AAO-3). The status of mitochondrial respiration was also examined as a probe for salinity tolerance at an early stage. The results suggested that although all the analyzed parameters showed correlations(negative or positive) with salt stress magnitude, their critical response times differed, with most of the studied biochemical, physiological, or molecular markers providing valuable information only after radicle emergence, whereas mitochondrial respiration via alternative oxidase was useful for the early detection of salt responses.展开更多
The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogen...The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogenic and mycotoxigenic. This research investigates the influence of nitrogen sources on growth and production of mycotoxins by eight different isolates of P. tritici-repentis. A synthetic agar medium(SAM) was used with different nitrogen sources, both inorganic [(NH4Cl, NH4NO3and(NH4)2SO4)] and organic(L-alanine, L-histidine, and L-lysine), at a concentration of 37.5 mmol L-1. Individual isolates exhibited different growth rates that varied according to the nitrogen source added to the medium. The choice of nitrogen source also had a major effect on production of the mycotoxins emodin, catenarin and islandicin. The highest concentrations of emodin, 54.40 ± 4.46 μg g-1, 43.07 ± 23.39 μg g-1and28.91 ± 4.64 μg g-1of growth medium, were produced on the complex medium(V8-potato dextrose agar) by the isolates Alg-H2, 331-2 and TS93-71 B, respectively. A relatively high concentration of emodin also was produced by isolates Az35-5(28.29 ± 4.71 μg g-1of medium)and TS93-71B(27.03 ± 4.09 μg g-1of medium) on synthetic medium supplemented with L-alanine. The highest concentrations of catenarin(174.54 ± 14.46 μg g-1and 104.87 ±6.13 μg g-1of medium) were recorded for isolates TS93-71 B and Alg-H2 on synthetic medium supplemented with L-alanine and NH4 Cl, respectively. The highest concentration of islandicin(4.64 ± 0.36 μg g-1medium) was observed for isolate 331-2 in the presence of L-lysine. There was not a close relationship between mycelial growth and mycotoxin production by the fungal isolates. This is the first report on the influence of nitrogen sources on the production of mycotoxins by P. tritici-repentis.展开更多
Genotype and plant type affect photosynthetic production by changing the canopy structure in crops.To analyze the mechanism of action of heterosis and plant type on canopy structure in cotton(Gossypium hirsutum L.),we...Genotype and plant type affect photosynthetic production by changing the canopy structure in crops.To analyze the mechanism of action of heterosis and plant type on canopy structure in cotton(Gossypium hirsutum L.),we had selected two cotton hybrids(Shiza 2,Xinluzao 43) and two conventional varieties(Xinluzao 13,Xinluzao 33) with different plant types in this experiment.We studied canopy characteristics and their correlation with photosynthesis in populations of different genotypes and plant types during yield formation in Xinjiang,China.Canopy characteristics including leaf area index(LAI),mean foliage tilt angle(MTA),canopy openness(DIFN),and chlorophyll relative content(SPAD).The results showed that LAI and SPAD peak values were higher and their peak values arrived later,and the adjustment capacity of MTA during the flowering and boll-forming stages was stronger in Xinluzao 43,with the normal-leaf,pagoda plant type,than these values in other varieties.DIFN of Xinluzao 43 remained between0.09 and 0.12 during the flowering and boll-forming stages,but was lower than that in the other varieties during the boll-opening stage.Thus,these characteristics of Xinluzao 43 were helpful for optimizing the light environment and maximizing light interception,thereby increasing photosynthetic capability.The photosynthetic rate and photosynthetic area were thus affected by cotton genotype as changes in the adjustment range of MTA,increases in peak values of LAI and SPAD,and extension of the functional stage of leaves.Available photosynthetic area and canopy light environment were affected by cotton plant type as changes in MTA and DIFN.Heterosis expression and plant type development were coordinated during different growth stages,the key to optimizing the canopy structure and further increasing yield.展开更多
The genus Beta encompasses economically important root crops such as sugar and table beet.A Beta diversity set including the wild relative B.vulgaris ssp.maritima was grown in the field,and a large phenotypic diversit...The genus Beta encompasses economically important root crops such as sugar and table beet.A Beta diversity set including the wild relative B.vulgaris ssp.maritima was grown in the field,and a large phenotypic diversity was observed.The genomes of 290 accessions were sequenced,and more than 10 million high-quality SNPs were employed to study genetic diversity.A genome-wide association study was performed,and marker-trait associations were found for nine phenotypic traits.The candidate gene within the M locus controlling monogermity on chromosome 4 was previously unknown.The most significant association for monogermity was identified at the end of chromosome 4.Within this region,a non-synonymous mutation within the zinc-finger domain of the WIP2 gene co-segregated with monogermity.This gene plays a regulatory role in AGL8/FUL in Arabidopsis.Intriguingly,commercial hybrids are in a heterozygous state at this position.Thus,the long-sought gene for monogermity was identified in this study.Red and yellow pigmentation due to betalain accumulation in shoots and roots is an important characteristic of table and leaf beets.The strongest associations were found upstream or downstream of two genes encoding Cytochrome P450 and anthocyanin MYB-like transcription factor proteins involved in betalain biosynthesis.Significant associations for Cercospora leaf spot resistance were identified on chromosomes 1,2,7,and 9.The associated regions harbor genes encoding proteins with leucinerich repeats and nucleotide binding sites whose homologs are major constituents of plant-pathogen defense.展开更多
Male reproductive development is necessary for the alternation of the life cycle in angiosperms.Due to functional redundancy of genes in the allohexaploid genome of common wheat,there are only two loci of recessive nu...Male reproductive development is necessary for the alternation of the life cycle in angiosperms.Due to functional redundancy of genes in the allohexaploid genome of common wheat,there are only two loci of recessive nuclear genic male sterility(GMS)mutations reported in wheat.Here,we report a new wheat recessive GMS gene,Ta Ms6,which encodes a GDSL esterase/lipase protein(GELP).Ta Ms6 is predominantly expressed in the anther during meiosis and the unicellular microspore stage,especially in meiotic cells(MCs),dyad cells,tapetum,and middle layer.The loss of Ta Ms6 function leads to male sterility,likely due to the downregulation of some pollen development-related genes and changes in lipid composition during meiosis.The ms6 mutant and Ms6 gene can potentially be utilized for developing commercialscale hybrid wheat breeding systems.We also systematically analyzed the GELP gene family in wheat,providing a comprehensive understanding of the Ta GELP family and offering valuable references for indepth genetic studies.Additionally,we discovered the nonallelic noncomplementation of two malesterile mutants,which presents an interesting and promising research direction.展开更多
基金supported by the Science and Technology Key Research&Development Project of Shaanxi Province(2022NY-178)the Technical System of Minor Cereals Industry in Shaanxi Province(NYKJ-2022-YL(XN)28)the Special Fund for Seed Industrial Development in Shaanxi Province(K3031223130).
文摘Herbicide safeners alleviate herbicide toxicity while preserving weed-control efficacy in common buckwheat.A three-year field experiment was performed to measure the effects of quizalofop-P-ethyl(QPE)alone or in combination with gibberellin or brassinolide on soil enzyme activity and yield components in common buckwheat.The herbicide-brassinolide application yielded the greatest increases in soil enzyme activity and yield components without sacrificing weed control efficacy.It is recommended for use in common buckwheat cultivation in the Loess Plateau.
基金supported by the State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2022ZZ-4)the Key Research and Development Projects of Hebei Province(21326319D)。
文摘Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant line.The higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and lignification.Additionally,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription factor.The gene could potentially be used for breeding of drought-tolerant cultivars.
基金supported by the National Natural Science Foundation of China(U22A20473)the National Key Research and Development Program of China(2021YFD1201600)+2 种基金the China Agriculture Research System(CARS-04-PS01)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences,Scientific Innovation 2030 Project(2022ZD0401703)the Platform of National Crop Germplasm Resources of China。
文摘Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We identified three strong signals at the qFT02-2 locus(Chr02:12037319–12238569),which were associated with flowering time in three environments:Gongzhuling,Mengcheng,and Nanchang.By analyzing linkage disequilibrium,gene expression patterns,gene annotation,and the diversity of variants,we identified an AP1 homolog as the candidate gene for the qFT02-2 locus,which we named GmAP1d.Only one nonsynonymous polymorphism existed among 1490 soybean accessions at position Chr02:12087053.Accessions carrying the Chr02:12087053-T allele flowered significantly earlier than those carrying the Chr02:12087053-A allele.Thus,we developed a cleaved amplified polymorphic sequence(CAPS)marker for the SNP at Chr02:12087053,which is suitable for marker-assisted breeding of flowering time.Knockout of GmAP1d in the‘Williams 82’background by gene editing promoted flowering under long-day conditions,confirming that GmAP1d is the causal gene for qFT02-2.An analysis of the region surrounding GmAP1d revealed that GmAP1d was artificially selected during the genetic improvement of soybean.Through stepwise selection,the proportion of modern cultivars carrying the Chr02:12087053-T allele has increased,and this allele has become nearly fixed(95%)in northern China.These findings provide a theoretical basis for better understanding the molecular regulatory mechanism of flowering time in soybean and a target gene that can be used for breeding modern soybean cultivars adapted to different latitudes.
基金financially supported by the CGIAR Research Program on Dryland Cereals Scholarship(CRP-DC)S.M.Sehgal Foundation Fund,USA for carrying out a doctoral study of K.Sudarshan Patil at ICRISAT。
文摘A set of 45 diverse Asian and African origin/bred populations of pearl millet were investigated multi-locationally for morphological traits including grain yield and assessed for their fertility restoration ability on three cytoplasmic male sterility(CMS) systems in two contrasting seasons. Significant genetic variation was found for all the yield linked traits. Multivariate analysis for grain yield and its component traits grouped these populations into five clusters. Most of the Asian origin populations grouped into single cluster(Cluster III) and separated from the rest of the African origin populations indicating the presence of correspondence between clustering pattern and geographical origin of the populations. Clusters dominated with Asian populations(As-As) had linkages with early flowering, short plant height, more number of tillers, small and thin panicles, small seeded and low grain yield compared to the clusters dominated by African populations(Af-Af) or African origin and Asian bred(Af-As) populations.Genetically related populations having common parentage were found grouped in same clusters.Fertility restoration/maintainer frequency of 45 populations on three diverse CMS systems revealed that overall fertility restoration frequency was highest for A1(86%) followed by A4(37%) and for A5(7%) CMS system. Five populations were identified as potential sources for developing maintainer lines for all three CMS systems and eight populations were identified specifically for A;and A;CMS systems. A set of 11 and four populations were identified for restorer line development exclusively for A;and A;CMS system,respectively. Six populations were identified for the development of dual restorers for both A;and A;CMS system.
基金funded by the German Federal Ministry of Food and Agriculture(BMEL,grants numbers 2814500110,2814EPS011)by the Federal Ministry of Education and Research of Germany(BMBF,grant numbers 031B0339A,031B0339B)。
文摘Soybean[Glycine max(L.)Merr.]is a global protein source and is currently expanding in Central and Northern Europe.Protein and oil content are two important quality traits that have been studied in different germplasm,however,their genetic architecture in earlymaturing European soybean has not been investigated yet.In this study,we therefore performed QTL mapping for both traits using 944 recombinant inbred lines derived from eight families from a half-diallel crossing design.We identified five QTL for each trait,with the QTL on chromosomes 8,15,and 20 being identified for both protein content and oil content.The known major QTL on chromosome 20 was detected in four families whereas the other QTL were only found in single families.Further analyses revealed the QTL to have pleiotropic but inverse effects on both traits.The effect of the major QTL was comparable between families,illustrating that it is largely independent from the genetic background.Collectively,our results illustrate the quantitative nature of protein and oil content in early European soybean.Marker-assisted selection for the QTL is possible,but the inverse effect on protein and oil content should be kept in mind.
基金supported by the Ministry of Science and Technology of China (2012CB944804)the National Transformation Science and Technology Program (2016ZX08001006-009)the National Key Research and Development Program of China (2016YFD0100501, 2016YFD0100902)。
文摘Heterosis is an important biological phenomenon and widely applied in agriculture.Although many studies have been performed by using vegetative organs of F_(1) hybrid plants,how heterosis (or hybrid vigor) is initiated and formed,particularly the underlying molecular mechanism,remain elusive.Hybrid contemporary seeds of rice indica varieties 9311 and PA64 were innovatively used and analysis of DNA methylome of embryo and endosperm at early developing stages revealed the globally decreased DNA methylation.Genes,especially those relate to hormones function and transcriptional regulation present non-additive methylation.Previously identified heterosis-related superior genes are non-additively methylated in early developing hybrid contemporary seeds,suggesting that key genes/loci responsible for heterosis are epigenetically modified even in early developing hybrid seeds and hypomethylation of hybrid seeds after cross-pollination finally result in the long-term transcriptional change of F_(1) hybrid vegetative tissues after germination,demonstrating that altered DNA methylation in hybrid seeds is essential for initiation regulation and maintenance of heterosis exhibiting in F_(1) hybrid plants.Notably,a large number of genes show non-additive methylation in the endosperm of reciprocal hybrids,suggesting that endosperm might also contribute to heterosis.
基金supported by the National Key Research and Development Program of China(2016YFD0101006)the China Agricultural Research System(CARS15-03)the Outstanding Youth Found of Hebei Province(C2019204365)。
文摘Verticillium wilt, a devastating disease in cotton caused by Verticillium dahliae, reduces cotton quality and yield. Heterotrimeric GTP-binding proteins, consisting of Ga, Gb, and Gc subunits, transducers of receptor signaling, function in a wide range of biological events. However, the function of Ga proteins in the regulation of defense responses in plants is largely unexplored, except for a few reports on model species. In the present study, a cotton G-protein a-subunit-encoding gene(GhGPA) was isolated from Verticillium wilt-resistant Gossypium hirsutum(upland cotton) cv. ND601. GhGPA transcription was up-regulated under V. dahliae stress, with higher expression in tolerant than in susceptible cotton cultivars.Subcellular localization revealed GhGPA to be located in the plasma membrane. GhGPA shows high(85.0%) identity with Arabidopsis AT2 G26300(AtGPA1), and AtGPA1 gpa1-4 mutants displayed susceptibility to V. dahliae. Ectopic expression of GhGPA successfully restored the resistance of Arabidopsis gpa1-4 mutants to Verticillium wilt and made them more resistant than the wild type. Overexpression of GhGPA in Arabidopsis markedly increased the resistance and resulted in dramatic up-regulation of pathogenesis-related(PR) genes and increased in H2 O2 accumulation and salicylic acid(SA) and jasmonic acid(JA) contents. However, suppressing GhGPA expression via virus-induced gene silencing(VIGS)increased susceptibility to Verticillium wilt, down-regulated the expression of PR and marker genes in SA and JA signaling pathways, and reduced H2 O2 content. The contents of SA and JA in Arabidopsis gpa1-4 and VIGS cotton were lower than those in the wild type and empty-vector control. However,GhGPA-overexpressing Arabidopsis contained more SA and JA than the wild type when inoculated with V. dahliae. Thus, GhGPA plays a vital role in Verticillium wilt resistance by inducing SA and JA signaling pathways and regulating the production of reactive oxygen species. These findings not only broaden our knowledge about the biological role of GhGPA, but also shed light on the defense mechanisms involving GhGPA against V. dahliae in cotton.
基金funded by the National Key Research and Development Program of China(2016YFD0100902)。
文摘Heterosis,which describes the superior vigor and yield of F_1 hybrids with respect to their parents,is observed in many rice hybrid crosses.The exploitation of heterosis is a great leap in the history of rice breeding.With advances in genomics and genetics,high-resolution mapping and functional identification of heterosis-associated loci have been performed in rice.Here we summarize advances in understanding the genetic basis of grain yield heterosis in hybrid rice and provide a vision for the genetic study and breeding application of rice heterosis in the future.
基金supported by the National Key Research and Development Program of China(2016YFD0100201 and 2016YFD0100304)the National Science and Technological Innovation Program of China。
文摘Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance using molecular marker-assisted selection is able to facilitate the development of drought-tolerant soybean varieties.In this study,we used a high-yielding and drought-sensitive cultivar‘Zhonghuang 35’and a drought-tolerant cultivar‘Jindou 21’to establish F6:9 recombinant inbred lines.We constructed a highdensity genetic map using specific locus amplified fragment sequencing(SLAF-Seq)technology.The genetic map contained 8078 SLAF markers distributing across 20 soybean chromosomes with a total genetic distance of 3780.98 c M and an average genetic distance of0.59 c M between adjacent markers.Two treatments(irrigation and drought)were used in the field tests,the Additive-Inclusive Composite Interval Mapping(ICIM-ADD)was used to call QTL,and plant height and seed weight per plant were used as the indicators of drought tolerance.We identified a total of 23 QTL related to drought tolerance.Among them,seven QTL(q PH2,q PH6,q PH7,q PH17,q PH19-1,q PH19-2,and q PH19-3)on chromosomes 2,6,7,17,and 19 were related to plant height,and five QTL(q SWPP2,q SWPP6,q SWPP13,q SWPP17,and q SWPP19)on chromosomes 2,6,13,17,and 19 were related to seed weight and could be considered as the major QTL.In addition,three common QTL(q PH6/q SWPP6,q PH17/q SWPP17,and q PH19-3/q SWPP19)for both plant height and seed weight per plant were located in the same genomic regions on the same chromosomes.Three(q PH2,q PH17,and q PH19-2)and four novel QTL(q SWPP2,q SWPP13,q SWPP17,and q SWPP19)were identified for plant height and seed weight per plant,respectively.Two pairs of QTL(q PH2/q SWPP2 and q PH17/q SWPP17)were also common for both plant height and seed weight per plant.These QTL and closely linked SLAF markers could be used to accelerate breeding for drought tolerant cultivars via MAS.
基金supported by the National Natural Science Foundation of China (31471461, 31671655)the National Transgenic Major Project of China (2016ZX08001004-001)Shanghai Agriculture Applied Technology Development Program, China (G2014070102)
文摘Rice(Oryza sativa L.)is a major food crop worldwide.Plant height and yield are important agronomic traits of rice.Several genes regulating plant height and/or yield have been cloned.However,the molecular mechanisms coordinating plant height and yield are not fully characterized.Here,we report a novel gene,OstMAPKKK5 that encodes a truncated variant of a mitogen-activated protein kinase kinase kinase 5(OsMAPKKK5)lacking an intact kinase domain.Transgenic plants overexpressing OstMAPKKK5 in indica cultivar 9311 showed increased plant height,grain length,grain width,1000-grain weight,grain number per main panicle,and yield.Real-time quantitative PCR showed that OstMAPKKK5 was widely expressed in various tissues and developmental stages.The increased plant height and yield were attributed to enlarged cell size.Overexpression of OstMAPKKK5 led to higher contents of various forms of endogenous gibberellin(GA),especially the most common active forms,GA1,GA3,GA4.We concluded that OstMAPKKK5 positively regulates plant height and yield in rice by affecting cell size,and that its underlying mechanism is based on increased endogenous GA content.
基金the financial support of the National Basic Research Program of China (2015CB150402)National Natural Science Foundation of China (51479189)+1 种基金Open Foundation of State Key Laboratory, Institute of Water and Soil Conservation, Chinese Academy of Sciences, Ministry of Water Resources (A314021402-1610)Key Research Foundation of Baoji University of Arts and Sciences (ZK16066)
文摘Besides leaves, non-foliar green organs such as stem and spike are also considered photosynthetic organs. To assess the photosynthetic contributions of these organs, the correlations between these photosynthetic areas and single-spike weight were investigated in a winter wheat(Triticum aestivum L.) under four nitrogen and mulching treatments: N120,N150, N195, and N195 + M. Two-year repeated field experiments were conducted on the Loess Plateau of China. Non-foliar photosynthetic area, grain-filling ratio and duration,grain yield, and in particular, single-spike weight, were measured, recorded and analyzed.Under the N195 + M treatment, plants showed the largest area of photosynthetic organs(flag leaf and non-foliar organs) and the highest grain yield and single spike weight. Singlespike weight was positively correlated with the areas of all examined non-foliar photosynthetic organs, in particular with the area above the flag leaf node(R^2= 0.761*)and the area above the exposed part of the peduncle(EXP)(R^2= 0.800**). In addition, singlespike weight was highly correlated with average grain-filling ratio(R^2= 0.993**), whereas it was less highly correlated with grain-filling duration(R^2= 0.533). The morphological traits of non-foliar photosynthetic organs were also more highly correlated with average grainfilling ratio than with average grain-filling duration. The significant correlation between each of the morphological traits(area, length and width) of EXP and single-spike weight indicates that morphological traits of EXP are important in determining spike weight in the Loess Plateau environment.
基金The National Key Research and Development Program of China(2016YFD0300108,2016YFD0300208-02)the National Natural Science Foundation of China(31671638)+1 种基金the China Agriculture Research System(CARS-01-04A)the Special Fund for Agro-scientific Research in the Public Interest(201203096)partly supported this study
文摘To evaluate the effects of various rotation systems on rice grain yield and N use efficiency, a paddy–upland cropping experiment(2013–2016) was conducted in southeastern China. The experiment was designed using six different rice––winter crop rotations: rice–fallow(RF),rice–wheat(RW), rice–potato with rice straw mulch(RP), rice–green manure(Chinese milk vetch; RC–G), rice–oilseed rape(RO), and rice–green manure crop(oilseed rape with fresh straw incorporated into soil at flowering; RO–G) and three N rates, N0(0 kg N ha-1), N1(142.5 kg N ha-1), and N2(202.5 kg N ha-1). Average rice yields in the RF(5.93 t ha-1) rotation were significantly lower than those in the rotations with winter crops(7.20–7.48 t ha-1)under the N0 treatment, suggesting that incorporation of straw might be more effective for increasing soil N than winter fallow. The rice yield differences among the rotations varied by year with the N input. In general, the grain yields in the RP and RO–G rotations –were respectively 11.6–28.5% and 14.80–37.19% higher than those in the RF in plots with N applied. Increasing the N rate may have tended to minimize the average yield gap between the RF and the other rotations; the yield gaps were 18.55%, 4.14%, and 0.23% in N0, N1, and N2, respectively. However, the N recovery efficiency in the RF was significantly lower than that in other rotations, except for 2015 under both N1 and N2 rates, a finding that implies a large amount of chemical N loss. No significant differences in nitrogen agronomic efficiency(NAE) and physiological efficiency(NPE) were found between the rotations with legume(RC–G) and non–legume(RO and RW) winter crops, a result that may be due partly to straw incorporation. For this reason, we concluded that the return of straw could reduce differences in N use efficiency between rotations with and without legume crops. The degree of synchrony between the crop N demand and the N supply was evaluated by comparison of nitrogen balance degree(NBD) values. The NBD values in the RP and RW were significantly lower than those in the other rotations under both N1 and N2 rates. Thus,in view of the higher grain yield in the RP compared to the RW under the N1 rate, the RP rotation might be a promising practice with comparable grain yield and greater N use efficiency under reduced N input relative to the other rotations. The primary yield components of the RF and RP were identified as number of panicles m-2 and numbers of kernels panicle-1, respectively. The NAE and NPE were positively correlated with harvest index, possibly providing a useful indicator for evaluating N use efficiency.
基金supported by the National Key Research and Development Program of China(2017YFD0101004)Science and Technology Service Network Initiative of Chinese Academy of Sciences(KFJ-STSZDTP-024)
文摘Leaf senescence is normally the last stage of plant development. Early senescence of functional leaves significantly reduces the photosynthetic time and efficiency, seriously affecting grain yield and quality in wheat. Discovering genes responsible for early leaf senescence(els) are necessary for developing novel germplasms and cultivars with delayed leaf-senescence through molecular manipulation and marker assisted selection. In this study, we identified an early leaf senescence line M114 in a derivative of a wheat breeding population. Genetic analysis indicated that early leaf senescence in M114 is controlled by a single recessive gene, provisionally designated els1. By applying bulked segregant analysis and RNA-Seq(BSR-Seq), seven polymorphic markers linked to els1 were developed and the gene was located on chromosome arm 2 BS in a 1.5 c M genetic interval between markers WGGB303 and WGGB305. A co-segregating marker, WGGB302, provide a starting point for fine mapping and map-based cloning of els1.
基金supported in part by funds from International Foundation for Science(C/5262-1)
文摘The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in cowpea using diallel analysis. For this purpose,half-diallel crosses were made among seven diverse parents. The amount of total soluble sugar was estimated by the phenol sulfuric acid reagent method and reducing sugar were measured by the DNS(3,5-dinitrosalicylic acid) reagent method. The total soluble sugar ranged from 11.12(VYA) to 40.79 mg g^(-1)(IT93 K-693-2) with a mean of 22.31 mg g^(-1).Reducing soluble sugar showed a mean value of 9.11 mg g^(-1) and ranged from 13.61(TVx3236) to 4.98 mg g^(-1)(Lori niebe). Diallel analysis showed that both additive and non-additive gene effects were significant in the genetic control of these traits. However,dominance variance was greater than additive variance for soluble sugar. The traits were controlled mainly by an overdominance model, suggesting the advantage of delaying selection to later generations. Soluble sugar content was found to be highly heritable, with broad-sense heritability ranging from 0.987 to 0.976. Narrow-sense heritability ranged from0.154 to 0.422 and revealed the lower importance of additive variance. Parents and F_1 hybrids differed significantly on the basis of their general and specific combining abilities,respectively. Recessive alleles had positive effects on total soluble sugar and reducing soluble sugar. These results could help cowpea breeders improve the acceptability of cowpea seeds and cowpea-based foods by appropriate selection.
基金supported by departmental grants under the Plan Project of Nuclear Agriculture and Biotechnology Division(NA&BTD),Mumbai
文摘Salinity-imposed limitations on plant growth are manifested through osmotic and ionic imbalances. However, because salinity-induced responses vary considerably among crop plants, monitoring of such responses at an early stage has relevance. In this study,physiological(seed germination, seed vigor index, root length, shoot length, fresh weight,dry weight) and biochemical attributes(osmoprotectants, K^+/Na^+ ratio) were analyzed for a time-course assessment of salt responses in Indian mustard(Brassica juncea L.) with an emphasis on early monitoring. The results showed strong correlations for total soluble sugars at germination phase(24 h), proline content in the seedling establishment phase(48 h) and various physiological parameters including seed vigor index(R^2= 0.901), shoot length(R^2= 0.982), and fresh weight(R^2= 0.980) at 72 h(adaptation under stress). In addition, transcriptional changes were observed under NaCl treatment for key genes belonging to the family of selective ion transporters(NHX, HKT) and abscisic acid synthesis(AAO-3). The status of mitochondrial respiration was also examined as a probe for salinity tolerance at an early stage. The results suggested that although all the analyzed parameters showed correlations(negative or positive) with salt stress magnitude, their critical response times differed, with most of the studied biochemical, physiological, or molecular markers providing valuable information only after radicle emergence, whereas mitochondrial respiration via alternative oxidase was useful for the early detection of salt responses.
基金provided by the Natural Sciences and Engineering Research Council of Canada to S.E.Strelkov
文摘The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogenic and mycotoxigenic. This research investigates the influence of nitrogen sources on growth and production of mycotoxins by eight different isolates of P. tritici-repentis. A synthetic agar medium(SAM) was used with different nitrogen sources, both inorganic [(NH4Cl, NH4NO3and(NH4)2SO4)] and organic(L-alanine, L-histidine, and L-lysine), at a concentration of 37.5 mmol L-1. Individual isolates exhibited different growth rates that varied according to the nitrogen source added to the medium. The choice of nitrogen source also had a major effect on production of the mycotoxins emodin, catenarin and islandicin. The highest concentrations of emodin, 54.40 ± 4.46 μg g-1, 43.07 ± 23.39 μg g-1and28.91 ± 4.64 μg g-1of growth medium, were produced on the complex medium(V8-potato dextrose agar) by the isolates Alg-H2, 331-2 and TS93-71 B, respectively. A relatively high concentration of emodin also was produced by isolates Az35-5(28.29 ± 4.71 μg g-1of medium)and TS93-71B(27.03 ± 4.09 μg g-1of medium) on synthetic medium supplemented with L-alanine. The highest concentrations of catenarin(174.54 ± 14.46 μg g-1and 104.87 ±6.13 μg g-1of medium) were recorded for isolates TS93-71 B and Alg-H2 on synthetic medium supplemented with L-alanine and NH4 Cl, respectively. The highest concentration of islandicin(4.64 ± 0.36 μg g-1medium) was observed for isolate 331-2 in the presence of L-lysine. There was not a close relationship between mycelial growth and mycotoxin production by the fungal isolates. This is the first report on the influence of nitrogen sources on the production of mycotoxins by P. tritici-repentis.
基金support of the National Natural Science Foundation of China (U1203283)the National Key Technology R&D Program of China (2014BAD09B03)the Natural Science Foundation of Hebei (C2015301051)
文摘Genotype and plant type affect photosynthetic production by changing the canopy structure in crops.To analyze the mechanism of action of heterosis and plant type on canopy structure in cotton(Gossypium hirsutum L.),we had selected two cotton hybrids(Shiza 2,Xinluzao 43) and two conventional varieties(Xinluzao 13,Xinluzao 33) with different plant types in this experiment.We studied canopy characteristics and their correlation with photosynthesis in populations of different genotypes and plant types during yield formation in Xinjiang,China.Canopy characteristics including leaf area index(LAI),mean foliage tilt angle(MTA),canopy openness(DIFN),and chlorophyll relative content(SPAD).The results showed that LAI and SPAD peak values were higher and their peak values arrived later,and the adjustment capacity of MTA during the flowering and boll-forming stages was stronger in Xinluzao 43,with the normal-leaf,pagoda plant type,than these values in other varieties.DIFN of Xinluzao 43 remained between0.09 and 0.12 during the flowering and boll-forming stages,but was lower than that in the other varieties during the boll-opening stage.Thus,these characteristics of Xinluzao 43 were helpful for optimizing the light environment and maximizing light interception,thereby increasing photosynthetic capability.The photosynthetic rate and photosynthetic area were thus affected by cotton genotype as changes in the adjustment range of MTA,increases in peak values of LAI and SPAD,and extension of the functional stage of leaves.Available photosynthetic area and canopy light environment were affected by cotton plant type as changes in MTA and DIFN.Heterosis expression and plant type development were coordinated during different growth stages,the key to optimizing the canopy structure and further increasing yield.
基金the financial support from the German Research Foundation(Deutsche Forschungsgemeinschaft,DFG)—Project Number 400993799(Project 2 within the Research Training Group 2501 Translational Evolutionary Research,https://gepris.dfg.de/gepris/projekt/400993799)supported by the BMBF-funded de.NBI Cloud,part of the German Network for Bioinformatics(de.NBI)。
文摘The genus Beta encompasses economically important root crops such as sugar and table beet.A Beta diversity set including the wild relative B.vulgaris ssp.maritima was grown in the field,and a large phenotypic diversity was observed.The genomes of 290 accessions were sequenced,and more than 10 million high-quality SNPs were employed to study genetic diversity.A genome-wide association study was performed,and marker-trait associations were found for nine phenotypic traits.The candidate gene within the M locus controlling monogermity on chromosome 4 was previously unknown.The most significant association for monogermity was identified at the end of chromosome 4.Within this region,a non-synonymous mutation within the zinc-finger domain of the WIP2 gene co-segregated with monogermity.This gene plays a regulatory role in AGL8/FUL in Arabidopsis.Intriguingly,commercial hybrids are in a heterozygous state at this position.Thus,the long-sought gene for monogermity was identified in this study.Red and yellow pigmentation due to betalain accumulation in shoots and roots is an important characteristic of table and leaf beets.The strongest associations were found upstream or downstream of two genes encoding Cytochrome P450 and anthocyanin MYB-like transcription factor proteins involved in betalain biosynthesis.Significant associations for Cercospora leaf spot resistance were identified on chromosomes 1,2,7,and 9.The associated regions harbor genes encoding proteins with leucinerich repeats and nucleotide binding sites whose homologs are major constituents of plant-pathogen defense.
基金supported by Shandong Provincial Natural Science Foundation(ZR2022ZD22,ZR2021ZD30,SYS202206)Shandong Agricultural University Dezhou(Qihe)Wheat Research Institute。
文摘Male reproductive development is necessary for the alternation of the life cycle in angiosperms.Due to functional redundancy of genes in the allohexaploid genome of common wheat,there are only two loci of recessive nuclear genic male sterility(GMS)mutations reported in wheat.Here,we report a new wheat recessive GMS gene,Ta Ms6,which encodes a GDSL esterase/lipase protein(GELP).Ta Ms6 is predominantly expressed in the anther during meiosis and the unicellular microspore stage,especially in meiotic cells(MCs),dyad cells,tapetum,and middle layer.The loss of Ta Ms6 function leads to male sterility,likely due to the downregulation of some pollen development-related genes and changes in lipid composition during meiosis.The ms6 mutant and Ms6 gene can potentially be utilized for developing commercialscale hybrid wheat breeding systems.We also systematically analyzed the GELP gene family in wheat,providing a comprehensive understanding of the Ta GELP family and offering valuable references for indepth genetic studies.Additionally,we discovered the nonallelic noncomplementation of two malesterile mutants,which presents an interesting and promising research direction.
