Rain-induced fruit cracking is a major problem in sweet cherry cultivation.Basic research has been conducted to disentangle the physiological and mechanistic bases of this complex phenomenon,whereas genetic studies ha...Rain-induced fruit cracking is a major problem in sweet cherry cultivation.Basic research has been conducted to disentangle the physiological and mechanistic bases of this complex phenomenon,whereas genetic studies have lagged behind.The objective of this work was to disentangle the genetic determinism of rain-induced fruit cracking.We hypothesized that a large genetic variation would be revealed,by visual field observations conducted on mapping populations derived from well-contrasted cultivars for cracking tolerance.Three populations were evaluated over 7–8 years by estimating the proportion of cracked fruits for each genotype at maturity,at three different areas of the sweet cherry fruit:pistillar end,stem end,and fruit side.An original approach was adopted to integrate,within simple linear models,covariates potentially related to cracking,such as rainfall accumulation before harvest,fruit weight,and firmness.We found the first stable quantitative trait loci(QTLs)for cherry fruit cracking,explaining percentages of phenotypic variance above 20%,for each of these three types of cracking tolerance,in different linkage groups,confirming the high complexity of this trait.For these and other QTLs,further analyses suggested the existence of at least two-linked QTLs in each linkage group,some of which showed confidence intervals close to 5 cM.These promising results open the possibility of developing marker-assisted selection strategies to select cracking-tolerant sweet cherry cultivars.Further studies are needed to confirm the stability of the reported QTLs over different genetic backgrounds and environments and to narrow down the QTL confidence intervals,allowing the exploration of underlying candidate genes.展开更多
Background:Since the commercial release of Bt cotton in Burkina Faso in 2009,the issue of seed purity in producers’fields has rarely been addressed in an unbiased and objective manner.The potential for contamination ...Background:Since the commercial release of Bt cotton in Burkina Faso in 2009,the issue of seed purity in producers’fields has rarely been addressed in an unbiased and objective manner.The potential for contamination of conventional seed varieties with Bt traits and the consequent threat to the continuation of organic cotton production has been documented.However,studies are rare on the varietal purity of Bt cotton seeds,despite the implications for the effectiveness and sustainability of their use.This paper compensates for the lack of research on the varietal purity of cotton seeds in Burkina Faso by reporting the results of Enzyme linked immunosorbent assay tests collected in 2015 on samples of both conventional and Bt varieties from 646 fields.Results:According to the conservative criteria used to declare the presence of a Bt gene in a given variety(more than 10%of seeds of conventional variety exhibit Bt traits,and at least 90%of seeds of Bt variety exhibit Bt traits),seed purity was very questionable for both types of variety.For the supposedly conventional variety,the Cry1Ac gene was observed in 63.6%of samples,the Cry2Ab gene was observed in 59.3%of samples,and both genes were detected in 52.2%of the seed samples.Only 29.3%of the seeds that were supposed to be of conventional type contained no Bt genes.Conversely,for the labeled Bt variety,the Cry1Ac gene was found in only 59.6%of samples,the Cry2Ab gene was found in 53.6%of the samples,and both genes were found in 40.4%of the samples.Finally,for the seeds that were supposed to contain both genes(Bollguard 2),both Cry1Ac and Cry2Ab genes were found in only 40.4%of the samples,only one of the genes was found in 32.4%of the samples,and 27.2%of the seeds in the samples contained neither.Two factors are responsible for the severe lack of seed purity.First,conventional varieties are being contaminated with Bt traits because of a failure to revise the seed production scheme in Burkina Faso to prevent cross-pollination.Second,the original Bt seeds provided to Burkina Faso lacked varietal purity.The organic sector plays a very minor role in the cotton sector of Burkina Faso(production of organic cotton totaled 453 t in 2018/2019,out of national cotton production of 183000 t).Nevertheless,the lack of purity in conventional seed varieties is a threat to efforts to expand certified organic cotton production.The poor presence of Bt proteins in supposed Bt varieties undermines their effectiveness in controlling pests and increases the likelihood of the development of resistance among pest populations.Conclusion:Our results show the extent of purity loss when inadequate attention is paid to the preservation of seed purity.Pure conventional seeds could vanish in Burkina Faso,while Bt seeds do not carry the combination of the expected Bt traits.Any country wishing to embark on the use of Bt cotton,or to resume its use,as in the case of Burkina Faso,must first adjust its national seed production scheme to ensure that procedures to preserve varietal purity are enforced.The preservation of varietal purity is necessary to enable the launch or the continuation of identity-cotton production.In addition,the preservation of varietal purity is necessary to ensure the sustainable effectiveness of Bt cotton.In order to ensure that procedures to preserve varietal purity are observed,seed purity must be tested regularly,and test results must be published.展开更多
Aims Invasive species,which recently expanded,may help understand how climatic niche can shift at the time scale of the current global change.Here,we address the climatic niche shift of an invasive shrub(common gorse,...Aims Invasive species,which recently expanded,may help understand how climatic niche can shift at the time scale of the current global change.Here,we address the climatic niche shift of an invasive shrub(common gorse,Ulex europaeus)at the world and regional scales to assess how it could contribute to increasing invasibility.Methods Based on a 28187 occurrences database,we used a combination of 9 species distribution models(SDM)to assess regional climatic niche from both the native range(Western Europe)and the introduced range in different parts of the world(North-West America,South America,North Europe,Australia and New Zealand).Important Findings Despite being restricted to annual mean temperature between 4℃ and 22℃,as well as annual precipitation higher than 300 mm/year,the range of bioclimatic conditions suitable for gorse was very large.Based on a native versus introduced SDM comparison,we highlighted a niche expansion in North-West America,South America and to a lesser degree in Australia,while a niche displacement was assessed in North Europe.These niche changes induced an increase in potential occupied areas by gorse by 49,111,202 and 283%in Australia,North Europe,North-West America and South America,respectively.On the contrary,we found no evidence of niche change in New Zealand,which presents similar climatic condition to the native environment(Western Europe).This study highlights how niche expansion and displacement of gorse might increase invasibility at regional scale.The change in gorse niche toward new climatic conditions may result from adaptive plasticity or genetic evolution and may explain why it has such a high level of invasibility.Taking into account the possibility of a niche shift is crucial to improve invasive plants management and control.展开更多
基金the INRAE sweet cherry breeding program,which is supported by INRAE BAP division and by INRAE’s private partner,CEP Innovation.
文摘Rain-induced fruit cracking is a major problem in sweet cherry cultivation.Basic research has been conducted to disentangle the physiological and mechanistic bases of this complex phenomenon,whereas genetic studies have lagged behind.The objective of this work was to disentangle the genetic determinism of rain-induced fruit cracking.We hypothesized that a large genetic variation would be revealed,by visual field observations conducted on mapping populations derived from well-contrasted cultivars for cracking tolerance.Three populations were evaluated over 7–8 years by estimating the proportion of cracked fruits for each genotype at maturity,at three different areas of the sweet cherry fruit:pistillar end,stem end,and fruit side.An original approach was adopted to integrate,within simple linear models,covariates potentially related to cracking,such as rainfall accumulation before harvest,fruit weight,and firmness.We found the first stable quantitative trait loci(QTLs)for cherry fruit cracking,explaining percentages of phenotypic variance above 20%,for each of these three types of cracking tolerance,in different linkage groups,confirming the high complexity of this trait.For these and other QTLs,further analyses suggested the existence of at least two-linked QTLs in each linkage group,some of which showed confidence intervals close to 5 cM.These promising results open the possibility of developing marker-assisted selection strategies to select cracking-tolerant sweet cherry cultivars.Further studies are needed to confirm the stability of the reported QTLs over different genetic backgrounds and environments and to narrow down the QTL confidence intervals,allowing the exploration of underlying candidate genes.
基金The study was implemented on request of the interprofessional body of the cotton sector in Burkina Faso(AICB)with the allocation of a specific fund.
文摘Background:Since the commercial release of Bt cotton in Burkina Faso in 2009,the issue of seed purity in producers’fields has rarely been addressed in an unbiased and objective manner.The potential for contamination of conventional seed varieties with Bt traits and the consequent threat to the continuation of organic cotton production has been documented.However,studies are rare on the varietal purity of Bt cotton seeds,despite the implications for the effectiveness and sustainability of their use.This paper compensates for the lack of research on the varietal purity of cotton seeds in Burkina Faso by reporting the results of Enzyme linked immunosorbent assay tests collected in 2015 on samples of both conventional and Bt varieties from 646 fields.Results:According to the conservative criteria used to declare the presence of a Bt gene in a given variety(more than 10%of seeds of conventional variety exhibit Bt traits,and at least 90%of seeds of Bt variety exhibit Bt traits),seed purity was very questionable for both types of variety.For the supposedly conventional variety,the Cry1Ac gene was observed in 63.6%of samples,the Cry2Ab gene was observed in 59.3%of samples,and both genes were detected in 52.2%of the seed samples.Only 29.3%of the seeds that were supposed to be of conventional type contained no Bt genes.Conversely,for the labeled Bt variety,the Cry1Ac gene was found in only 59.6%of samples,the Cry2Ab gene was found in 53.6%of the samples,and both genes were found in 40.4%of the samples.Finally,for the seeds that were supposed to contain both genes(Bollguard 2),both Cry1Ac and Cry2Ab genes were found in only 40.4%of the samples,only one of the genes was found in 32.4%of the samples,and 27.2%of the seeds in the samples contained neither.Two factors are responsible for the severe lack of seed purity.First,conventional varieties are being contaminated with Bt traits because of a failure to revise the seed production scheme in Burkina Faso to prevent cross-pollination.Second,the original Bt seeds provided to Burkina Faso lacked varietal purity.The organic sector plays a very minor role in the cotton sector of Burkina Faso(production of organic cotton totaled 453 t in 2018/2019,out of national cotton production of 183000 t).Nevertheless,the lack of purity in conventional seed varieties is a threat to efforts to expand certified organic cotton production.The poor presence of Bt proteins in supposed Bt varieties undermines their effectiveness in controlling pests and increases the likelihood of the development of resistance among pest populations.Conclusion:Our results show the extent of purity loss when inadequate attention is paid to the preservation of seed purity.Pure conventional seeds could vanish in Burkina Faso,while Bt seeds do not carry the combination of the expected Bt traits.Any country wishing to embark on the use of Bt cotton,or to resume its use,as in the case of Burkina Faso,must first adjust its national seed production scheme to ensure that procedures to preserve varietal purity are enforced.The preservation of varietal purity is necessary to enable the launch or the continuation of identity-cotton production.In addition,the preservation of varietal purity is necessary to ensure the sustainable effectiveness of Bt cotton.In order to ensure that procedures to preserve varietal purity are observed,seed purity must be tested regularly,and test results must be published.
基金supported by the Centre Nationale de la Recherche Scientifique(CNRS)the MARIS Agence Nationale de la Recherche project(ANR grant ANR-14-CE03-0007-01)Institut National de la Recherche Agronomique(INRA Institute).
文摘Aims Invasive species,which recently expanded,may help understand how climatic niche can shift at the time scale of the current global change.Here,we address the climatic niche shift of an invasive shrub(common gorse,Ulex europaeus)at the world and regional scales to assess how it could contribute to increasing invasibility.Methods Based on a 28187 occurrences database,we used a combination of 9 species distribution models(SDM)to assess regional climatic niche from both the native range(Western Europe)and the introduced range in different parts of the world(North-West America,South America,North Europe,Australia and New Zealand).Important Findings Despite being restricted to annual mean temperature between 4℃ and 22℃,as well as annual precipitation higher than 300 mm/year,the range of bioclimatic conditions suitable for gorse was very large.Based on a native versus introduced SDM comparison,we highlighted a niche expansion in North-West America,South America and to a lesser degree in Australia,while a niche displacement was assessed in North Europe.These niche changes induced an increase in potential occupied areas by gorse by 49,111,202 and 283%in Australia,North Europe,North-West America and South America,respectively.On the contrary,we found no evidence of niche change in New Zealand,which presents similar climatic condition to the native environment(Western Europe).This study highlights how niche expansion and displacement of gorse might increase invasibility at regional scale.The change in gorse niche toward new climatic conditions may result from adaptive plasticity or genetic evolution and may explain why it has such a high level of invasibility.Taking into account the possibility of a niche shift is crucial to improve invasive plants management and control.
基金supported by the French Agence Nationale de la Recherche(project MARIS ANR-14-CE03-0007-01andprojectSWATCHANR-18-PRIM-0006)by the'Institut national de recherche pour I'agriculture,I'alimentation et I'environnement'(INRAE)supported by the Conseil Regional de La Réunion,the French Ministry of Agriculture and Food,the European Union(Feader program,grant n°AG/974/DAAF/2016-00096 and Feder program,grant n°GURTDI20151501-0000735).
