Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing toler...Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing tolerance.This study evaluated four traits(mesocotyl length at 10 and 20 cm planting depths and seedling emergence rate on days 6 and 12)related to deep-sowing tolerance using a large maize population containing 386 inbred lines genotyped with 0.5 million high-quality single nucleotide polymorphisms(SNPs).The genomewide association study detected that 273 SNPs were in linkage disequilibrium(LD)with the genetic basis of maize deep-sowing tolerance.The RNA-sequencing analysis identified 1944 and 2098 differentially expressed genes(DEGs)in two comparisons,which shared 281 DEGs.By comparing the genomic locations of the 273 SNPs with those of the 281 DEGs,we identified seven candidate genes,of which GRMZM2G119769 encoded a sucrose non-fermenting 1 kinase interactor-like protein.GRMZM2G119769 was selected as the candidate gene because its homologs in other plants were related to organ length,auxin,or light response.Candidate gene association mapping revealed that natural variations in GRMZM2G119769 were related to phenotypic variations in maize mesocotyl length.Gene expression of GRMZM2G119769 was higher in deep-sowing tolerant inbred lines.These results suggest that GRMZM2G119769 is the most likely candidate gene.This study provides information on the deep-sowing tolerance of maize germplasms and identifies candidate genes,which would be useful for further research on maize deep-sowing tolerance.展开更多
Ruhrstahl-Hereaeus（RH）上升管内的气液两相流是整个装置的重要动力源,并对钢液的流动、混匀及精炼过程有重要影响.上升管及真空室内的气液两相流决定了钢包内钢液的流动状态,为了研究真空室及上升管内气液两相流,通过1∶6的300 t RH...Ruhrstahl-Hereaeus（RH）上升管内的气液两相流是整个装置的重要动力源,并对钢液的流动、混匀及精炼过程有重要影响.上升管及真空室内的气液两相流决定了钢包内钢液的流动状态,为了研究真空室及上升管内气液两相流,通过1∶6的300 t RH的物理模型模拟了RH上升管及真空室内气泡行为过程,并测量了RH循环流量的变化用于计算上升管内含气率以及气泡运动速度最终得到气泡在真空室内的停留时间,同时记录了气泡在真空室内的存在形式.气泡在真空室的存在形式的主要影响因素为提升气体流量,研究发现了气泡从规则独立的大气泡经历聚合长大,碰撞破碎成小气泡,最后变成小气泡和不规则大气泡共存的现象.液面高度达到80 mm之后,气泡在真空室内的停留时间达到一个平衡值,不再随真空室液面高度的增加而发生改变.当提升气体量达3000 L·min-1,气泡停留时间减小趋势弱,对应3000 L·min-1情况下,真空室内气泡开始聚合长大.研究认为对于300 t RH的真空室液面高度应为80 mm,提升气体量应在3500 L·min-1左右,优化后,脱碳时间由原工艺的21.4 min缩短至现工艺的17.5 min.展开更多
基金supported by the National Key R&D Program of China(2018YFD0100903)the China Agriculture Research System of MOF and MARA(CARS-02-13)the Natural Science Fund of Liaoning Province,China(20170540806)。
文摘Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing tolerance.This study evaluated four traits(mesocotyl length at 10 and 20 cm planting depths and seedling emergence rate on days 6 and 12)related to deep-sowing tolerance using a large maize population containing 386 inbred lines genotyped with 0.5 million high-quality single nucleotide polymorphisms(SNPs).The genomewide association study detected that 273 SNPs were in linkage disequilibrium(LD)with the genetic basis of maize deep-sowing tolerance.The RNA-sequencing analysis identified 1944 and 2098 differentially expressed genes(DEGs)in two comparisons,which shared 281 DEGs.By comparing the genomic locations of the 273 SNPs with those of the 281 DEGs,we identified seven candidate genes,of which GRMZM2G119769 encoded a sucrose non-fermenting 1 kinase interactor-like protein.GRMZM2G119769 was selected as the candidate gene because its homologs in other plants were related to organ length,auxin,or light response.Candidate gene association mapping revealed that natural variations in GRMZM2G119769 were related to phenotypic variations in maize mesocotyl length.Gene expression of GRMZM2G119769 was higher in deep-sowing tolerant inbred lines.These results suggest that GRMZM2G119769 is the most likely candidate gene.This study provides information on the deep-sowing tolerance of maize germplasms and identifies candidate genes,which would be useful for further research on maize deep-sowing tolerance.
文摘Ruhrstahl-Hereaeus（RH）上升管内的气液两相流是整个装置的重要动力源,并对钢液的流动、混匀及精炼过程有重要影响.上升管及真空室内的气液两相流决定了钢包内钢液的流动状态,为了研究真空室及上升管内气液两相流,通过1∶6的300 t RH的物理模型模拟了RH上升管及真空室内气泡行为过程,并测量了RH循环流量的变化用于计算上升管内含气率以及气泡运动速度最终得到气泡在真空室内的停留时间,同时记录了气泡在真空室内的存在形式.气泡在真空室的存在形式的主要影响因素为提升气体流量,研究发现了气泡从规则独立的大气泡经历聚合长大,碰撞破碎成小气泡,最后变成小气泡和不规则大气泡共存的现象.液面高度达到80 mm之后,气泡在真空室内的停留时间达到一个平衡值,不再随真空室液面高度的增加而发生改变.当提升气体量达3000 L·min-1,气泡停留时间减小趋势弱,对应3000 L·min-1情况下,真空室内气泡开始聚合长大.研究认为对于300 t RH的真空室液面高度应为80 mm,提升气体量应在3500 L·min-1左右,优化后,脱碳时间由原工艺的21.4 min缩短至现工艺的17.5 min.
