向日葵是重要的耐旱、耐盐碱油料作物,其产量与品质对地区经济有重要影响。NAC转录因子是植物中最大的蛋白家族之一,广泛参与植物多种生命活动,并在植物响应非生物与生物胁迫中起重要作用。为揭示向日葵NAC转录因子(HaNAC)密码子的使用...向日葵是重要的耐旱、耐盐碱油料作物,其产量与品质对地区经济有重要影响。NAC转录因子是植物中最大的蛋白家族之一,广泛参与植物多种生命活动,并在植物响应非生物与生物胁迫中起重要作用。为揭示向日葵NAC转录因子(HaNAC)密码子的使用模式和形成原因,利用CUSP、CodonW等软件程序对124个HaNAC基因进行密码子使用模式分析。结果表明,HaNAC基因密码子第1(GC1)、第2(GC2)和第3位碱基(GC3)的GC含量表现为GC1>GC3>GC2,且均低于50%,表明向日葵HaNAC基因密码子偏好使用A/T。有效密码子数(effective number of codons,ENC)表明,HaNAC基因密码子偏好性弱。密码子适应指数(codon adaptation index,CAI)表明,HaNAC基因表达水平低。向日葵NAC基因密码子偏好性受自然选择影响较大,突变压力次之。在HaNAC基因密码子中AGA使用频率最高,共有29个高频密码子和20个最优密码子,且最优密码子偏好A/T结尾。综上,向日葵HaNAC基因密码子使用以A/T碱基为主且偏好A/T结尾,其密码子偏好性主要受自然选择驱动,且偏好性较弱、基因表达水平较低。以上结果为向日葵NAC转录因子的密码子优化、偏好机制及遗传进化研究提供了参考。展开更多
Despite Morocco's reliance on sunflower as an oilseed crop,little is known about its agronomic performance when sown in autumn or early winter.This knowledge gap is critical,as spring-sown varieties have shown dec...Despite Morocco's reliance on sunflower as an oilseed crop,little is known about its agronomic performance when sown in autumn or early winter.This knowledge gap is critical,as spring-sown varieties have shown declining performance in recent years under intensifying climate stress.Therefore,targeted breeding strategies could discover genotypes suitable for autumn or early winter sowing,with cold tolerance as a key selection criterion.Currently,‘Ichraq'is the only autumn-planted sunflower variety officially registered in Morocco,although efforts to release additional tolerant varieties are underway.This study evaluated 31 genotypes(MGB1to MGB31)selected from various environments under autumn planting conditions and conserved in the Moroccan Gene Bank.These genotypes were planted in early winter at a mountainous site known for its pronounced winter cold.Eighteen Morphological,physiological and agronomic parameters including initial vigor,leaf area,seed yield,oil content etc.,were assessed using both univariate and multivariate statistical approaches.Analysis of variance revealed significant genotypic differences across most traits,indicating substantial genetic variation.Notably,seed oil content ranged from 23.28%(MGB26)to 43.88%(MGB5),and seed yield from1400 kg/ha(MGB7)to 5400 kg/ha(MGB8).Principal component analysis(PCA)identified that the first principal component,accounting for over 24%of the total phenotypic variance,exhibits a strong positive loading of yield-related traits and chlorophyll content,while displaying a pronounced negative loading for oil content variables.This opposing gradient indicates a clear trade-off between vegetative productivity and oil accumulation across the evaluated genotypes.Hierarchical cluster analysis resolved the germplasm into two principal clusters with high within-group similarity,each further partitioned into relatively homogeneous subgroups.Notably,several genotypes outperformed the control variety Ichraq,underscoring their potential for autumn or early winter cultivation.Nonetheless,essential multi-environment trials remain to validate their phenotypic stability and to ascertain their value as genetic resources for sunflower breeding programs in Morocco and other Mediterranean agro-ecosystems.展开更多
文摘向日葵是重要的耐旱、耐盐碱油料作物,其产量与品质对地区经济有重要影响。NAC转录因子是植物中最大的蛋白家族之一,广泛参与植物多种生命活动,并在植物响应非生物与生物胁迫中起重要作用。为揭示向日葵NAC转录因子(HaNAC)密码子的使用模式和形成原因,利用CUSP、CodonW等软件程序对124个HaNAC基因进行密码子使用模式分析。结果表明,HaNAC基因密码子第1(GC1)、第2(GC2)和第3位碱基(GC3)的GC含量表现为GC1>GC3>GC2,且均低于50%,表明向日葵HaNAC基因密码子偏好使用A/T。有效密码子数(effective number of codons,ENC)表明,HaNAC基因密码子偏好性弱。密码子适应指数(codon adaptation index,CAI)表明,HaNAC基因表达水平低。向日葵NAC基因密码子偏好性受自然选择影响较大,突变压力次之。在HaNAC基因密码子中AGA使用频率最高,共有29个高频密码子和20个最优密码子,且最优密码子偏好A/T结尾。综上,向日葵HaNAC基因密码子使用以A/T碱基为主且偏好A/T结尾,其密码子偏好性主要受自然选择驱动,且偏好性较弱、基因表达水平较低。以上结果为向日葵NAC转录因子的密码子优化、偏好机制及遗传进化研究提供了参考。
文摘Despite Morocco's reliance on sunflower as an oilseed crop,little is known about its agronomic performance when sown in autumn or early winter.This knowledge gap is critical,as spring-sown varieties have shown declining performance in recent years under intensifying climate stress.Therefore,targeted breeding strategies could discover genotypes suitable for autumn or early winter sowing,with cold tolerance as a key selection criterion.Currently,‘Ichraq'is the only autumn-planted sunflower variety officially registered in Morocco,although efforts to release additional tolerant varieties are underway.This study evaluated 31 genotypes(MGB1to MGB31)selected from various environments under autumn planting conditions and conserved in the Moroccan Gene Bank.These genotypes were planted in early winter at a mountainous site known for its pronounced winter cold.Eighteen Morphological,physiological and agronomic parameters including initial vigor,leaf area,seed yield,oil content etc.,were assessed using both univariate and multivariate statistical approaches.Analysis of variance revealed significant genotypic differences across most traits,indicating substantial genetic variation.Notably,seed oil content ranged from 23.28%(MGB26)to 43.88%(MGB5),and seed yield from1400 kg/ha(MGB7)to 5400 kg/ha(MGB8).Principal component analysis(PCA)identified that the first principal component,accounting for over 24%of the total phenotypic variance,exhibits a strong positive loading of yield-related traits and chlorophyll content,while displaying a pronounced negative loading for oil content variables.This opposing gradient indicates a clear trade-off between vegetative productivity and oil accumulation across the evaluated genotypes.Hierarchical cluster analysis resolved the germplasm into two principal clusters with high within-group similarity,each further partitioned into relatively homogeneous subgroups.Notably,several genotypes outperformed the control variety Ichraq,underscoring their potential for autumn or early winter cultivation.Nonetheless,essential multi-environment trials remain to validate their phenotypic stability and to ascertain their value as genetic resources for sunflower breeding programs in Morocco and other Mediterranean agro-ecosystems.
