Earthquake,tsunami,nuclear plantb reakdown.Each is a major catast rophe.But Japan has been hit by all of them.Homelessness,economic losses,release of radiation.Each is a huge challenge.Now Japan must face all three.Ho...Earthquake,tsunami,nuclear plantb reakdown.Each is a major catast rophe.But Japan has been hit by all of them.Homelessness,economic losses,release of radiation.Each is a huge challenge.Now Japan must face all three.How will Japan respond to the domino-like disaster展开更多
Purpose–This study aims to introduce the achievements and benefits of applying wheel/rail-force–based maintenance interval extension of the C80 series wagon in China.Design/methodology/approach–Chinese wagons’exis...Purpose–This study aims to introduce the achievements and benefits of applying wheel/rail-force–based maintenance interval extension of the C80 series wagon in China.Design/methodology/approach–Chinese wagons’existing maintenance strategy had left a certain safety margin for the characteristics of widely running range,unstable service environment and submission to transportation organization requirements.To reduce maintenance costs,China railway(CR)has attempted to extend the maintenance interval since 2020.The maintenance cycle of C80 series heavy haul wagons is extended by three months(no stable routing)or 50,000 km(regular routing).However,in the meantime,the alarming rate of the running state,a key index to reflect the severe degree of hunting stability,by the train performance detection system(TPDS)for the C80 series heavy haul wagons has increased significantly.Findings–The present paper addresses a big data statistical way to evaluate the risk of allowing the C80 series heavy haul wagons to remain in operation longer than stipulated by the maintenance interval initial set.Through the maintenance and wayside-detectordata,whichis divided intothreestages,the extension period(three months),the current maintenance period and the previous maintenance period,this method reveals the alarming rate of hunting was correlated with maintenance interval.The maintainability of wagons will be achieved by utilizing wagon performance degradation modeling with the state of the wheelset and the often-contact side bearing.This paper also proposes a statistical model to return to the average safety level of the previous maintenance period’s baseline through correct alarming thresholds for unplanned corrective maintenance.Originality/value–The paper proposes an approach to reduce safety risk due to maintenance interval extension by effective maintenance program.The results are expected to help the railway company make the optimal solution to balance safety and the economy.展开更多
Sorghum[Sorghum bicolor(L.)Moench],a multipurpose C4 crop,is also a model species of the Poaceae family for plant research.During the process of domestication,the modification of seed dispersal mode is considered a ke...Sorghum[Sorghum bicolor(L.)Moench],a multipurpose C4 crop,is also a model species of the Poaceae family for plant research.During the process of domestication,the modification of seed dispersal mode is considered a key event,as the loss of seed shattering caused a significant increase in yield.In order to understand the seed shattering process in sorghum,we further studied eight previously identified divergent sorghum germplasm with different shattering degrees.We described their phenotypes in great detail,analyzed the histology of abscission zone,and conducted a gene co-expression analysis.We observed that the abscission layer of the most strong-shattering varieties began to differentiate before the 5-10 cm panicles development stage and was completely formed at flag leaf unfolding.The protective cells on the pedicels were also fully lignified by flowering.Through the weighted gene correlation network analysis(WGCNA),we mined for candidate genes involved in the abscission process at the heading stage.We found that these genes were mainly associated with such biological processes as hormone signal transmission(SORBI_3003G361300,SORBI_3006G216500,SORBI_3009G027800,SORBI_3007G077200),cell wall modification and degradation(SORBI_3002G205500,SORBI_3004G013800,SORBI_3010G022400,SORBI_3003G251800,SORBI_3003G254700,SORBI_3003G410800,SORBI_3009G162700,SORBI_3001G406700,SORBI_3004G042700,SORBI_3004G244600,SORBI_3001G099100),and lignin synthesis(SORBI_3004G220700,SORBI_3004G062500,SORBI_3010G214900,SORBI_3009G181800).Our study has provided candidate genes required for shedding for further study.We believe that function characterization of these genes may provide insight into our understanding of seed shattering process.展开更多
Pod shatter resistance of rapeseed is of great importance for modem farming practice. In order to determine the combining ability of elite inbred lines and the breeding potential of rapeseed hybrids in terms of pod sh...Pod shatter resistance of rapeseed is of great importance for modem farming practice. In order to determine the combining ability of elite inbred lines and the breeding potential of rapeseed hybrids in terms of pod shatter resistance, analysis of a 6×6 incomplete diallel cross was conducted at two locations. Results showed that a significant variation existed among breeding lines and their F1 hybrids for pod shatter resistant index (SRI), pod length and width. Pod shatter resistance was significantly positively correlated with pod length. The general combining ability (GCA) effects (GCA=l.58) played a more important role than specific combining ability (SCA) effects (SCA=0.20) for pod shatter trait. The elite lines R1, 1019B and 1055B displayed significant positive GCA effects for pod shatter resistance. Four crosses (1019B×R1, 1015B×R1, 6098B×R1, and 8908B×R1) with high mean performance and positive SCA effects were recommended for developing new hybrids for mechanical harvest in the middle reaches of the Yangtze River.展开更多
Paclobutrazol was sprayed at 0, 150, and 300 mg L-1 during the closed canopy stage and the early bud stage with two high-yielding cultivars of rapeseed, Yangguang 2009 and Fengyou 520. The impact of paclobutrazol on t...Paclobutrazol was sprayed at 0, 150, and 300 mg L-1 during the closed canopy stage and the early bud stage with two high-yielding cultivars of rapeseed, Yangguang 2009 and Fengyou 520. The impact of paclobutrazol on the accumulation and distribution of biomass and its relationship with yield, resistance to lodging and pod shattering were determined. All the treatments increased the resistance as well as yield. The maximum yield was obtained when paclobutrazol was applied during the closed canopy stage at 150 mg L-1. The plant's resistance to both lodging and pod shattering was the maximum when paclobutrazol was applied during the early bud stage at 300 mg L-1. Paclobutrazol also delayed senescence, with the higher concentration or later spraying leading to more obvious effects; improved the net assimilation rate before the early bud stage; and promoted the relative growth rate of the main growth organ at each stage of growth and maximized the rate and quantities of biomass accumulation. However, at the higher concentration and later spraying, the increments were smaller. The spraying also increased the rates of biomass allocation to roots, leaves, and pods, but the rate of allocation to stems decreased as the plants grew shorter. The higher allocation to roots and the lower allocation to stems favoured resistance to both lodging and pod shattering whereas higher allocation to leaves and pods favoured yield. The higher concentration or late spraying led to excessive biomass being allocated to roots, which decreased leaf biomass during the bud stage, leading to greater resistance but lower yields.展开更多
Pod shattering causes severe yield loss in rapeseed(Brassica napus L.)under modern agricultural practice.Identification of highly shatter-resistant germplasm is desirable for the development of rapeseed cultivars for ...Pod shattering causes severe yield loss in rapeseed(Brassica napus L.)under modern agricultural practice.Identification of highly shatter-resistant germplasm is desirable for the development of rapeseed cultivars for mechanical harvesting.In the present study,an elite line OR88 with strong shatter resistance and a lignified-layer bridge(LLB)structure was identified.The LLB structure was unique to OR88 and co-segregated with high pod-shatter resistance.The LLB structure is differentiated at stage 12 of gynoecium development without any gynoecium defects.Genetic analysis showed that LLB is controlled by a single recessive gene.By BSA-Seq and map-based cloning,the resistance gene location was delimited to a0.688 Mb region on chromosome C09.Transcriptome analysis suggested Bn TCP8.C09 as the gene responsible for LLB.The expression of Bn TCP.C09 was strongly downregulated in OR88,suppressing cell proliferation in the pod valve margin.KASP markers linked to the candidate gene were developed.This pod shatter-resistant line could be used in rapeseed breeding programs by direct transfer of the gene with the assistance of the DNA markers.展开更多
Seed shattering is a common problem in early soybean production system (ESPS) in the Midsouth, which mainly uses maturity group (MG) IV soybeans. Many studies have been conducted on the genetics of soybean shattering ...Seed shattering is a common problem in early soybean production system (ESPS) in the Midsouth, which mainly uses maturity group (MG) IV soybeans. Many studies have been conducted on the genetics of soybean shattering resistance for individual varieties;however, information on the physiology of soybean shattering pattern under specific environmental conditions, which is often critical to soybean growers, is very limited. Field experiments were conducted at Stoneville MS from 2007 to 2009 to investigate the shattering patterns of 80-132 MG IV soybean varieties each year. Results from 2007 and 2008 indicated that, when April-planted MG IV soybeans matured in mid- to late August, pods of most soybean varieties did not shatter within the first three weeks after maturity (WAM) and there was no significant shattering effect on final yields. However, differences in pod shattering among the varieties became apparent in the fourth WAM. Late-planted MG IV soybeans, which matured in early September, had a low shattering rate and could hold seeds up to 6 WAM before reaching a critical shattering point. Most soybean varieties planted in April 2009 did not show significant pod shattering by the end of the fourth WAM. The critical point of shattering was not reached until 6 - 7 WAM. Relatively lower temperatures and abundant rainfall during the late growing season in 2009 may be the main reasons causing delayed shattering in April-planted MG IV soybeans. Results from the May-planting of 2007 and the April-planting of 2009 indicated that soybeans maturing after September have much less problematic shattering. Different weather patterns, especially temperature and rainfall in each year could be essential factors affecting seed shattering patterns.展开更多
Seed shattering refers to the phenomenon in which the pods split along the abdominal and back sutures before the crop is received,so that the seeds are spread.Seed shattering is vital to the reproduction of their offs...Seed shattering refers to the phenomenon in which the pods split along the abdominal and back sutures before the crop is received,so that the seeds are spread.Seed shattering is vital to the reproduction of their offspring in wild plants,but it is also the main cause of crop yield loss reason.Pod-explosion resistance is a complex process of physical and physiological and biochemical reactions.Soybean seed shattering phenomenon is widespread,which severely restricts the development of soybean industry.Seed shattering(pod cracking or fruit dropping)is essential for the reproduction of its offspring in wild plants,but it is also the main cause of crop yield loss.This article analyzes the morphology and structure of pods related to seed shattering from the morphology of pods.On the basis of the regularity of the occurrence of seed shattering and the summary of phenotypic index identification methods,physiologically introduced the regulation mechanism of key enzymes and endogenous hormones on seed shattering.The localization,labeling and cloning of seed shattering genes are introduced in molecular biology.The study focused on reviewing the latest advances in the research on soybean seed shattering characteristics,and discussed with the research results of related crops.Finally,the research and application of soybean seed shattering resistance were prospected for several aspects.展开更多
At low temperatures,gun propellant grains may become brittle and this can lead to fracture or shatter of the grains during gun firing.Should this event occur then it will result in an increase in the burning surface o...At low temperatures,gun propellant grains may become brittle and this can lead to fracture or shatter of the grains during gun firing.Should this event occur then it will result in an increase in the burning surface of the propellant and will give rise to a change in ballistic performance.Also,if the resultant over pressure is sufficient,a breech failure may result.Understanding the propensity of a grain to fracture or shatter is therefore important in determining its safety in use.This document describes a test that may be used to derive knowledge and to quantify the physical behaviour of a gun propellant grain at the low temperatures at which fracture or shatter is most likely to occur.展开更多
Pod shattering is an important domesticated trait which can cause great economic loss of crop yield in cultivated soybean.In this study,we utilized two recombinant inbred line populations(RILs,CY,Huachun 2×Wayao;...Pod shattering is an important domesticated trait which can cause great economic loss of crop yield in cultivated soybean.In this study,we utilized two recombinant inbred line populations(RILs,CY,Huachun 2×Wayao;GB,Guizao 1×B13)to identify quantitative trait loci(QTLs)associated with pod shattering in soybean across multiple environments.A total of 14 QTLs for pod shattering were identified in the two RIL populations,which had LOD scores ranging from 2.64 to 44.33 with phenotypic variance explanation(PVE)ranging from 1.33 to 50.85%.One QTL qPS16-1,located on chromosome 16,included a well-known functional gene Pod dehiscence 1(Pdh1)that was reported previously.Ten new putative QTLs were validated in two RIL populations,and their LOD scores were between 2.55 and 4.24,explaining 1.33 to 2.60%of the phenotypic variation.Of which four novel QTLs(qPS01-1,qPS03-2,qPS05-1,and qPS07-1)could be detected in two environments where nine genes had specific changes in gene expression.Although the nine genes may have significant effects on pod shattering of soybean,their detailed functions still need to be further explored in the future.The results of this study will facilitate a better understanding of the genetic basis of the pod shattering-resistant trait and benefit soybean molecular breeding for improving pod shattering resistance.展开更多
The newly developed hybrid rice combination 'Xieyou 9308' (Xieqingzao A/T9308) has been regarded as a super-high-yielding rice variety, of which the yield potential reached as high as 12 t/ha. However, its hig...The newly developed hybrid rice combination 'Xieyou 9308' (Xieqingzao A/T9308) has been regarded as a super-high-yielding rice variety, of which the yield potential reached as high as 12 t/ha. However, its high shattering characteristic (as high as 60%) has limited its wider application. In the current experiment, a non-shattering mutant line, M9308, was developed from T9308 by gamma irradiation. Comparisons were made but no marked differences were found between T9308 and M9308 as well as between their F1 hybrids crossed to Xieqingzao A for major agronomic and grain quality characters as well as resistance to diseases. Genetic analysis indicated that the non-shattering character of M9308 was governed by a single recessive gene.展开更多
In this paper we present summation of thirteen year’s investigation of the all diamond-bearing structures of Mongolia. Four gold and diamond-bearing astropipe structures of exemplified by the Agit Khangay, Khuree Man...In this paper we present summation of thirteen year’s investigation of the all diamond-bearing structures of Mongolia. Four gold and diamond-bearing astropipe structures of exemplified by the Agit Khangay, Khuree Mandal, Bayan Khuree and Tsenkher astropipes of Mongolia. Detailed geological and gas-geochemical investigation of the diamond and gold-astropipe structures show that diamond genesis is an expression of collision of the lithospheric mantle with the explosion process initiated in an impact collapse meteor crater.展开更多
Pod coloration is a domestication-related trait in soybean,with modern cultivars typically displaying brown or tan pods,while their wild relative,Glycine soja,possesses black pods.However,the factors regulating this c...Pod coloration is a domestication-related trait in soybean,with modern cultivars typically displaying brown or tan pods,while their wild relative,Glycine soja,possesses black pods.However,the factors regulating this color variation remain unknown.In this study,we cloned and characterized L1,the classical locus responsible for black pods in soybean.By using map-based cloning and genetic analyses,we identified the causal gene of L1 and revealed that it encodes a hydroxymethylglutaryl-coenzyme A(CoA)lyase-like(HMGL-like)domain protein.Biochemical assays showed that L1 functions as a eucomic acid synthase and facilitates the synthesis of eucomic acid and piscidic acid,both of which contribute to coloration of pods and seed coats in soybean.Interestingly,we found that L1 plants are more prone to pod shattering under light exposure than l1 null mutants because dark pigmentation increases photothermal efficiency.Hence,pleiotropic effects of L1 on pod color and shattering,as well as seed pigmentation,likely contributed to the preference forl1 alleles during soybean domestication and improvement.Collectively,our study provides new insights into the mechanism of pod coloration and identifies a new target for future de novo domestication oflegume crops.展开更多
The origin of cultivated rice has puzzled plant biologists for decades. This is due, at least in part, to the complex evolutionary dynamics in rice cultivars and wild progenitors, particularly rapid adaptive different...The origin of cultivated rice has puzzled plant biologists for decades. This is due, at least in part, to the complex evolutionary dynamics in rice cultivars and wild progenitors, particularly rapid adaptive differentiation and continuous gene flow within and between cultivated and wild rice. The long-standing controversy over single versus multiple and annual versus perennial origins of cultivated rice has been brought into shaper focus with the rapid accumulation of genetic and phylogenetic data. Molecular phylogenetic analyses revealed ancient genomic differentiation between rice cultivars, suggesting that they were domesticated from divergent wild populations. However, the recently cloned domestication gene sh4, responsible for the reduction of grain shattering from wild to cultivated rice, seems to have originated only once. Herein, we propose two models to reconcile apparently conflicting evidence regarding rice domestication. The snowoballing model considers a single origin of cultivated rice. In this model, a core of critical domestication alleles was fixed in the founding cultivar and then acted to increase the genetic diversity of cultivars through hybridization with wild populations. The combination model considers multiple origins of cultivated rice. In this model, Initial cultivars were domesticated from divergent wild populations and fixed different sets of domestication alleles. Subsequent crosses among these semi-domesticated cultivars resulted in the fixation of a similar set of critical domestication alleles in the contemporary cultivars. In both models, introgression has played an important role in rice domestication. Recent and future introgression of beneficial genes from the wild gene pool through conventional and molecular breeding programs can be viewed as the continuation of domestication.展开更多
Shatter cones are conical fragments of rock characterized by striations that radiate from the apex. In 1905, they were first observed at Steinheim Basin in Germany. In the United States, the well-known occurrence site...Shatter cones are conical fragments of rock characterized by striations that radiate from the apex. In 1905, they were first observed at Steinheim Basin in Germany. In the United States, the well-known occurrence site of shatter cones is Kentland, Indiana. In 1938, when the existence of terrestrial impact crater was still a hypothesis, J. D. Boon had suggested that the structures similar to the Kentland were the products of meteoritic crater. In 1947, when making frequent investigations on Kentland quarry, R. S. Dietz pointed out that the axes of these cones were oriented normal to the bedding, with the apexes pointing toward the top of the bed. Thus, they were formed by giant forces which came from above rather than below. Because except the impact of meteorite, there is not any giant force from space, shatter cones should be 'root' of crater. This argument was proved because of the discovery展开更多
文摘Earthquake,tsunami,nuclear plantb reakdown.Each is a major catast rophe.But Japan has been hit by all of them.Homelessness,economic losses,release of radiation.Each is a huge challenge.Now Japan must face all three.How will Japan respond to the domino-like disaster
文摘Purpose–This study aims to introduce the achievements and benefits of applying wheel/rail-force–based maintenance interval extension of the C80 series wagon in China.Design/methodology/approach–Chinese wagons’existing maintenance strategy had left a certain safety margin for the characteristics of widely running range,unstable service environment and submission to transportation organization requirements.To reduce maintenance costs,China railway(CR)has attempted to extend the maintenance interval since 2020.The maintenance cycle of C80 series heavy haul wagons is extended by three months(no stable routing)or 50,000 km(regular routing).However,in the meantime,the alarming rate of the running state,a key index to reflect the severe degree of hunting stability,by the train performance detection system(TPDS)for the C80 series heavy haul wagons has increased significantly.Findings–The present paper addresses a big data statistical way to evaluate the risk of allowing the C80 series heavy haul wagons to remain in operation longer than stipulated by the maintenance interval initial set.Through the maintenance and wayside-detectordata,whichis divided intothreestages,the extension period(three months),the current maintenance period and the previous maintenance period,this method reveals the alarming rate of hunting was correlated with maintenance interval.The maintainability of wagons will be achieved by utilizing wagon performance degradation modeling with the state of the wheelset and the often-contact side bearing.This paper also proposes a statistical model to return to the average safety level of the previous maintenance period’s baseline through correct alarming thresholds for unplanned corrective maintenance.Originality/value–The paper proposes an approach to reduce safety risk due to maintenance interval extension by effective maintenance program.The results are expected to help the railway company make the optimal solution to balance safety and the economy.
基金supported by the National Key Research and Development Program of China(2018YFD1000706,2018YFD1000700).
文摘Sorghum[Sorghum bicolor(L.)Moench],a multipurpose C4 crop,is also a model species of the Poaceae family for plant research.During the process of domestication,the modification of seed dispersal mode is considered a key event,as the loss of seed shattering caused a significant increase in yield.In order to understand the seed shattering process in sorghum,we further studied eight previously identified divergent sorghum germplasm with different shattering degrees.We described their phenotypes in great detail,analyzed the histology of abscission zone,and conducted a gene co-expression analysis.We observed that the abscission layer of the most strong-shattering varieties began to differentiate before the 5-10 cm panicles development stage and was completely formed at flag leaf unfolding.The protective cells on the pedicels were also fully lignified by flowering.Through the weighted gene correlation network analysis(WGCNA),we mined for candidate genes involved in the abscission process at the heading stage.We found that these genes were mainly associated with such biological processes as hormone signal transmission(SORBI_3003G361300,SORBI_3006G216500,SORBI_3009G027800,SORBI_3007G077200),cell wall modification and degradation(SORBI_3002G205500,SORBI_3004G013800,SORBI_3010G022400,SORBI_3003G251800,SORBI_3003G254700,SORBI_3003G410800,SORBI_3009G162700,SORBI_3001G406700,SORBI_3004G042700,SORBI_3004G244600,SORBI_3001G099100),and lignin synthesis(SORBI_3004G220700,SORBI_3004G062500,SORBI_3010G214900,SORBI_3009G181800).Our study has provided candidate genes required for shedding for further study.We believe that function characterization of these genes may provide insight into our understanding of seed shattering process.
基金supported by the National Basic Research Program of China (973 Program, 2011CB109302)the National High-Tech R&D Program of China (863 Program,2011AA10A104)the earmarked fund for China Agriculture Research System (CARS-13)
文摘Pod shatter resistance of rapeseed is of great importance for modem farming practice. In order to determine the combining ability of elite inbred lines and the breeding potential of rapeseed hybrids in terms of pod shatter resistance, analysis of a 6×6 incomplete diallel cross was conducted at two locations. Results showed that a significant variation existed among breeding lines and their F1 hybrids for pod shatter resistant index (SRI), pod length and width. Pod shatter resistance was significantly positively correlated with pod length. The general combining ability (GCA) effects (GCA=l.58) played a more important role than specific combining ability (SCA) effects (SCA=0.20) for pod shatter trait. The elite lines R1, 1019B and 1055B displayed significant positive GCA effects for pod shatter resistance. Four crosses (1019B×R1, 1015B×R1, 6098B×R1, and 8908B×R1) with high mean performance and positive SCA effects were recommended for developing new hybrids for mechanical harvest in the middle reaches of the Yangtze River.
基金funded by the National Key Technology Research and Development Program of China(2014BAD11B03)the earmarked fund for the China Agricultural Research System(CARS-13)the Fundamental Research Funds for the Central Universities of China(2013PY001)
文摘Paclobutrazol was sprayed at 0, 150, and 300 mg L-1 during the closed canopy stage and the early bud stage with two high-yielding cultivars of rapeseed, Yangguang 2009 and Fengyou 520. The impact of paclobutrazol on the accumulation and distribution of biomass and its relationship with yield, resistance to lodging and pod shattering were determined. All the treatments increased the resistance as well as yield. The maximum yield was obtained when paclobutrazol was applied during the closed canopy stage at 150 mg L-1. The plant's resistance to both lodging and pod shattering was the maximum when paclobutrazol was applied during the early bud stage at 300 mg L-1. Paclobutrazol also delayed senescence, with the higher concentration or later spraying leading to more obvious effects; improved the net assimilation rate before the early bud stage; and promoted the relative growth rate of the main growth organ at each stage of growth and maximized the rate and quantities of biomass accumulation. However, at the higher concentration and later spraying, the increments were smaller. The spraying also increased the rates of biomass allocation to roots, leaves, and pods, but the rate of allocation to stems decreased as the plants grew shorter. The higher allocation to roots and the lower allocation to stems favoured resistance to both lodging and pod shattering whereas higher allocation to leaves and pods favoured yield. The higher concentration or late spraying led to excessive biomass being allocated to roots, which decreased leaf biomass during the bud stage, leading to greater resistance but lower yields.
基金the National Natural Science Foundation of China(U19A2029)the National Key Research and Development Program of China(2018YFE0108000)+1 种基金Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences(CAAS-ZDRW202105)China Agriculture Research System of MOF and MARA。
文摘Pod shattering causes severe yield loss in rapeseed(Brassica napus L.)under modern agricultural practice.Identification of highly shatter-resistant germplasm is desirable for the development of rapeseed cultivars for mechanical harvesting.In the present study,an elite line OR88 with strong shatter resistance and a lignified-layer bridge(LLB)structure was identified.The LLB structure was unique to OR88 and co-segregated with high pod-shatter resistance.The LLB structure is differentiated at stage 12 of gynoecium development without any gynoecium defects.Genetic analysis showed that LLB is controlled by a single recessive gene.By BSA-Seq and map-based cloning,the resistance gene location was delimited to a0.688 Mb region on chromosome C09.Transcriptome analysis suggested Bn TCP8.C09 as the gene responsible for LLB.The expression of Bn TCP.C09 was strongly downregulated in OR88,suppressing cell proliferation in the pod valve margin.KASP markers linked to the candidate gene were developed.This pod shatter-resistant line could be used in rapeseed breeding programs by direct transfer of the gene with the assistance of the DNA markers.
文摘Seed shattering is a common problem in early soybean production system (ESPS) in the Midsouth, which mainly uses maturity group (MG) IV soybeans. Many studies have been conducted on the genetics of soybean shattering resistance for individual varieties;however, information on the physiology of soybean shattering pattern under specific environmental conditions, which is often critical to soybean growers, is very limited. Field experiments were conducted at Stoneville MS from 2007 to 2009 to investigate the shattering patterns of 80-132 MG IV soybean varieties each year. Results from 2007 and 2008 indicated that, when April-planted MG IV soybeans matured in mid- to late August, pods of most soybean varieties did not shatter within the first three weeks after maturity (WAM) and there was no significant shattering effect on final yields. However, differences in pod shattering among the varieties became apparent in the fourth WAM. Late-planted MG IV soybeans, which matured in early September, had a low shattering rate and could hold seeds up to 6 WAM before reaching a critical shattering point. Most soybean varieties planted in April 2009 did not show significant pod shattering by the end of the fourth WAM. The critical point of shattering was not reached until 6 - 7 WAM. Relatively lower temperatures and abundant rainfall during the late growing season in 2009 may be the main reasons causing delayed shattering in April-planted MG IV soybeans. Results from the May-planting of 2007 and the April-planting of 2009 indicated that soybeans maturing after September have much less problematic shattering. Different weather patterns, especially temperature and rainfall in each year could be essential factors affecting seed shattering patterns.
基金Jilin Province Education Department Science and Technology Research Project[JJKH20210350KJ]Jilin Province Science and Technology Guidance Program Project[20200402023NC]+1 种基金Jilin Provincial Natural Science Foundation Project[20200201027JC]Innovation and Entrepreneurship Training Program for College Students in Jilin Province[2021].
文摘Seed shattering refers to the phenomenon in which the pods split along the abdominal and back sutures before the crop is received,so that the seeds are spread.Seed shattering is vital to the reproduction of their offspring in wild plants,but it is also the main cause of crop yield loss reason.Pod-explosion resistance is a complex process of physical and physiological and biochemical reactions.Soybean seed shattering phenomenon is widespread,which severely restricts the development of soybean industry.Seed shattering(pod cracking or fruit dropping)is essential for the reproduction of its offspring in wild plants,but it is also the main cause of crop yield loss.This article analyzes the morphology and structure of pods related to seed shattering from the morphology of pods.On the basis of the regularity of the occurrence of seed shattering and the summary of phenotypic index identification methods,physiologically introduced the regulation mechanism of key enzymes and endogenous hormones on seed shattering.The localization,labeling and cloning of seed shattering genes are introduced in molecular biology.The study focused on reviewing the latest advances in the research on soybean seed shattering characteristics,and discussed with the research results of related crops.Finally,the research and application of soybean seed shattering resistance were prospected for several aspects.
文摘At low temperatures,gun propellant grains may become brittle and this can lead to fracture or shatter of the grains during gun firing.Should this event occur then it will result in an increase in the burning surface of the propellant and will give rise to a change in ballistic performance.Also,if the resultant over pressure is sufficient,a breech failure may result.Understanding the propensity of a grain to fracture or shatter is therefore important in determining its safety in use.This document describes a test that may be used to derive knowledge and to quantify the physical behaviour of a gun propellant grain at the low temperatures at which fracture or shatter is most likely to occur.
基金supported by the Research and Development Program in the Key Areas of Guangdong Province,China(2020B020220008)the China Agriculture Research System of MOF and MARA(CARS-04-PS09)+1 种基金the Guangdong Agricultural Research System,China(2020KJ136)the Research Project of the State Key Laboratory of Agricultural and Biological ResourcesProtection and Utilization in Subtropics,China。
文摘Pod shattering is an important domesticated trait which can cause great economic loss of crop yield in cultivated soybean.In this study,we utilized two recombinant inbred line populations(RILs,CY,Huachun 2×Wayao;GB,Guizao 1×B13)to identify quantitative trait loci(QTLs)associated with pod shattering in soybean across multiple environments.A total of 14 QTLs for pod shattering were identified in the two RIL populations,which had LOD scores ranging from 2.64 to 44.33 with phenotypic variance explanation(PVE)ranging from 1.33 to 50.85%.One QTL qPS16-1,located on chromosome 16,included a well-known functional gene Pod dehiscence 1(Pdh1)that was reported previously.Ten new putative QTLs were validated in two RIL populations,and their LOD scores were between 2.55 and 4.24,explaining 1.33 to 2.60%of the phenotypic variation.Of which four novel QTLs(qPS01-1,qPS03-2,qPS05-1,and qPS07-1)could be detected in two environments where nine genes had specific changes in gene expression.Although the nine genes may have significant effects on pod shattering of soybean,their detailed functions still need to be further explored in the future.The results of this study will facilitate a better understanding of the genetic basis of the pod shattering-resistant trait and benefit soybean molecular breeding for improving pod shattering resistance.
文摘The newly developed hybrid rice combination 'Xieyou 9308' (Xieqingzao A/T9308) has been regarded as a super-high-yielding rice variety, of which the yield potential reached as high as 12 t/ha. However, its high shattering characteristic (as high as 60%) has limited its wider application. In the current experiment, a non-shattering mutant line, M9308, was developed from T9308 by gamma irradiation. Comparisons were made but no marked differences were found between T9308 and M9308 as well as between their F1 hybrids crossed to Xieqingzao A for major agronomic and grain quality characters as well as resistance to diseases. Genetic analysis indicated that the non-shattering character of M9308 was governed by a single recessive gene.
文摘In this paper we present summation of thirteen year’s investigation of the all diamond-bearing structures of Mongolia. Four gold and diamond-bearing astropipe structures of exemplified by the Agit Khangay, Khuree Mandal, Bayan Khuree and Tsenkher astropipes of Mongolia. Detailed geological and gas-geochemical investigation of the diamond and gold-astropipe structures show that diamond genesis is an expression of collision of the lithospheric mantle with the explosion process initiated in an impact collapse meteor crater.
基金the National Key Research and Development Program of China(2021YFD1201601,2021YFF1001201)the earmarked fund for CARS(CARS-04-PSO1)+2 种基金the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciencesthe National Natural Science Foundation of China(grant no.32201734)the China Postdoctoral Science Foundation(grant no.2021M693465).
文摘Pod coloration is a domestication-related trait in soybean,with modern cultivars typically displaying brown or tan pods,while their wild relative,Glycine soja,possesses black pods.However,the factors regulating this color variation remain unknown.In this study,we cloned and characterized L1,the classical locus responsible for black pods in soybean.By using map-based cloning and genetic analyses,we identified the causal gene of L1 and revealed that it encodes a hydroxymethylglutaryl-coenzyme A(CoA)lyase-like(HMGL-like)domain protein.Biochemical assays showed that L1 functions as a eucomic acid synthase and facilitates the synthesis of eucomic acid and piscidic acid,both of which contribute to coloration of pods and seed coats in soybean.Interestingly,we found that L1 plants are more prone to pod shattering under light exposure than l1 null mutants because dark pigmentation increases photothermal efficiency.Hence,pleiotropic effects of L1 on pod color and shattering,as well as seed pigmentation,likely contributed to the preference forl1 alleles during soybean domestication and improvement.Collectively,our study provides new insights into the mechanism of pod coloration and identifies a new target for future de novo domestication oflegume crops.
基金Supported by the National Science Foundation of USA and the Rackham Research Endowment Fund (to TS) and the Program for Key International S & T Cooperation Project of China (2001 CB711103) and the National Natural Science Foundation of China (30121003 to SG). Publication of this paper is supported by the National Natural Science Foundation of China (30624808).
文摘The origin of cultivated rice has puzzled plant biologists for decades. This is due, at least in part, to the complex evolutionary dynamics in rice cultivars and wild progenitors, particularly rapid adaptive differentiation and continuous gene flow within and between cultivated and wild rice. The long-standing controversy over single versus multiple and annual versus perennial origins of cultivated rice has been brought into shaper focus with the rapid accumulation of genetic and phylogenetic data. Molecular phylogenetic analyses revealed ancient genomic differentiation between rice cultivars, suggesting that they were domesticated from divergent wild populations. However, the recently cloned domestication gene sh4, responsible for the reduction of grain shattering from wild to cultivated rice, seems to have originated only once. Herein, we propose two models to reconcile apparently conflicting evidence regarding rice domestication. The snowoballing model considers a single origin of cultivated rice. In this model, a core of critical domestication alleles was fixed in the founding cultivar and then acted to increase the genetic diversity of cultivars through hybridization with wild populations. The combination model considers multiple origins of cultivated rice. In this model, Initial cultivars were domesticated from divergent wild populations and fixed different sets of domestication alleles. Subsequent crosses among these semi-domesticated cultivars resulted in the fixation of a similar set of critical domestication alleles in the contemporary cultivars. In both models, introgression has played an important role in rice domestication. Recent and future introgression of beneficial genes from the wild gene pool through conventional and molecular breeding programs can be viewed as the continuation of domestication.
基金Project supported by the National Natural Science Foundation of China
文摘Shatter cones are conical fragments of rock characterized by striations that radiate from the apex. In 1905, they were first observed at Steinheim Basin in Germany. In the United States, the well-known occurrence site of shatter cones is Kentland, Indiana. In 1938, when the existence of terrestrial impact crater was still a hypothesis, J. D. Boon had suggested that the structures similar to the Kentland were the products of meteoritic crater. In 1947, when making frequent investigations on Kentland quarry, R. S. Dietz pointed out that the axes of these cones were oriented normal to the bedding, with the apexes pointing toward the top of the bed. Thus, they were formed by giant forces which came from above rather than below. Because except the impact of meteorite, there is not any giant force from space, shatter cones should be 'root' of crater. This argument was proved because of the discovery