ABSTRACT
Excavating the quantitative trait locus (QTL) associated with rice cooking quality, analyzing candidate genes, and improving cooking quality-associated traits of rice varieties by genetic breeding can effectively improve the taste of rice. In this study, we used the indica rice HZ, the japonica rice Nekken2 and 120 recombinant inbred lines (RILs) populations constructed from them as experimental materials to measure the gelatinization temperature (GT), gel consistency (GC) and amylose content (AC) of rice at the maturity stage. We combined the high-density genetic map for QTL mapping. A total of 26 QTLs associated with rice cooking quality (1 QTL associated with GT, 13 QTLs associated with GC, and 12 QTLs associated with AC) were detected, among which the highest likelihood of odd (LOD) value reached 30.24. The expression levels of candidate genes in the localization interval were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR), and it was found that the expression levels of six genes were significantly different from that in parents. It was speculated that the high expression of LOC_Os04g20270 and LOC_Os11g40100 may greatly increase the GC of rice, while the high expression of LOC_Os01g04920 and LOC_Os02g17500 and the low expression of LOC_Os03g02650 and LOC_Os05g25840 may reduce the AC. The results lay a molecular foundation for the cultivation of new high-quality rice varieties, and provide important genetic resources for revealing the molecular regulation mechanism of rice cooking quality.
Subject(s)
Quantitative Trait Loci , Oryza/genetics , Plant Breeding , Cooking , Genetic Association StudiesABSTRACT
Cadmium (Cd) is an element that is nonessential and extremely toxic to both plants and human beings. Soil contaminated with Cd has adverse impacts on crop yields and threatens human health via the food chain. Cultivation of low-Cd cultivars has been of particular interest and is one of the most cost-effective and promising approaches to minimize human dietary intake of Cd. Low-Cd crop cultivars should meet particular criteria, including acceptable yield and quality, and their edible parts should have Cd concentrations below maximum permissible concentrations for safe consumption, even when grown in Cd-contaminated soil. Several low-Cd cereal cultivars and genotypes have been developed worldwide through cultivar screening and conventional breeding. Molecular markers are powerful in facilitating the selection of low-Cd cereal cultivars. Modern molecular breeding technologies may have great potential in breeding programs for the development of low-Cd cultivars, especially when coupled with conventional breeding. In this review, we provide a synthesis of low-Cd cereal breeding.
ABSTRACT
Salinity affects more than 6% of the world's total land area, causing massive losses in crop yield. Salinity inhibits plant growth and development through osmotic and ionic stresses; however, some plants exhibit adaptations through osmotic regulation, exclusion, and translocation of accumulated Na+ or Cl-. Currently, there are no practical, economically viable methods for managing salinity, so the best practice is to grow crops with improved tolerance. Germination is the stage in a plant's life cycle most adversely affected by salinity. Barley, the fourth most important cereal crop in the world, has outstanding salinity tolerance, relative to other cereal crops. Here, we review the genetics of salinity tolerance in barley during germination by summarizing reported quantitative trait loci (QTLs) and functional genes. The homologs of candidate genes for salinity tolerance in Arabidopsis, soybean, maize, wheat, and rice have been blasted and mapped on the barley reference genome. The genetic diversity of three reported functional gene families for salt tolerance during barley germination, namely dehydration-responsive element-binding (DREB) protein, somatic embryogenesis receptor-like kinase and aquaporin genes, is discussed. While all three gene families show great diversity in most plant species, the DREB gene family is more diverse in barley than in wheat and rice. Further to this review, a convenient method for screening for salinity tolerance at germination is needed, and the mechanisms of action of the genes involved in salt tolerance need to be identified, validated, and transferred to commercial cultivars for field production in saline soil.
Subject(s)
Gene Expression Regulation, Plant , Genetic Variation , Germination/physiology , Hordeum/physiology , Salt Tolerance/geneticsABSTRACT
Salinity affects more than 6% of the world’s total land area, causing massive losses in crop yield. Salinity inhibits plant growth and development through osmotic and ionic stresses; however, some plants exhibit adaptations through osmotic regulation, exclusion, and translocation of accumulated Na+ or Cl-. Currently, there are no practical, economically viable methods for managing salinity, so the best practice is to grow crops with improved tolerance. Germination is the stage in a plant’s life cycle most adversely affected by salinity. Barley, the fourth most important cereal crop in the world, has outstanding salinity tolerance, relative to other cereal crops. Here, we review the genetics of salinity tolerance in barley during germination by summarizing reported quantitative trait loci (QTLs) and functional genes. The homologs of candidate genes for salinity tolerance in Arabidopsis, soybean, maize, wheat, and rice have been blasted and mapped on the barley reference genome. The genetic diversity of three reported functional gene families for salt tolerance during barley germination, namely dehydration-responsive element-binding (DREB) protein, somatic embryogenesis receptor-like kinase and aquaporin genes, is discussed. While all three gene families show great diversity in most plant species, the DREB gene family is more diverse in barley than in wheat and rice. Further to this review, a convenient method for screening for salinity tolerance at germination is needed, and the mechanisms of action of the genes involved in salt tolerance need to be identified, validated, and transferred to commercial cultivars for field production in saline soil.
ABSTRACT
Cadmium (Cd) is an element that is nonessential and extremely toxic to both plants and human beings. Soil contaminated with Cd has adverse impacts on crop yields and threatens human health via the food chain. Cultivation of low-Cd cultivars has been of particular interest and is one of the most cost-effective and promising approaches to minimize human dietary intake of Cd. Low-Cd crop cultivars should meet particular criteria, including acceptable yield and quality, and their edible parts should have Cd concentrations below maximum permissible concentrations for safe consumption, even when grown in Cd-contaminated soil. Several low-Cd cereal cultivars and genotypes have been developed worldwide through cultivar screening and conventional breeding. Molecular markers are powerful in facilitating the selection of low-Cd cereal cultivars. Modern molecular breeding technologies may have great potential in breeding programs for the development of low-Cd cultivars, especially when coupled with conventional breeding. In this review, we provide a synthesis of low-Cd cereal breeding.
ABSTRACT
ABSTRACT: Soil salinity limits agricultural production and is a major obstacle for increasing crop yield. Common wheat is one of the most important crops with allohexaploid characteristic and a highly complex genome. QTL mapping is a useful way to identify genes for quantitative traits such as salinity tolerance in hexaploid wheat. In the present study, a hydroponic trial was carried out to identify quantitative trait loci (QTLs) associated with salinity tolerance of wheat under 150mM NaCl concentration using a recombinant inbred line population (Xiaoyan 54×Jing 411). Values of wheat seedling traits including maximum root length (MRL), root dry weight (RDW), shoot dry weight (SDW), total dry weight (TDW) and the ratio of TDW of wheat plants between salt stress and control (TDWR) were evaluated or calculated. A total of 19QTLs for five traits were detected through composite interval mapping method by using QTL Cartographer version 2.5 under normal and salt stress conditions. These QTLs distributed on 12 chromosomes explained the percentage of phenotypic variation by individual QTL varying from 7.9% to 19.0%. Among them, 11 and six QTLs were detected under normal and salt stress conditions, respectively and two QTLs were detected for TDWR. Some salt tolerance related loci may be pleiotropic. Chromosome 1A, 3A and 7A may harbor crucial candidate genes associated with wheat salt tolerance. Our results would be helpful for the marker assisted selection to breed wheat varieties with improved salt tolerance.
RESUMO: A salinidade do solo limita a produção agrícola. O trigo mole é uma das culturas mais importantes com característica allohexaploid e genoma altamente complexo. O mapeamento QTL é uma maneira muito útil de identificar genes para traços quantitativos, como a tolerância à salinidade em trigo hexaplóide. No presente estudo realizou-se um ensaio hidropónico para identificar locos de traços quantitativos (QTLs) associados à tolerância à salinidade do trigo sob concentração de NaCl 150 mM, usando uma população de linhagem consanguíneo recombinante (Xiaoyan 54 × Jing 411). Os valores dos traços de mudas de trigo, incluindo comprimento máximo da raiz (MRL), peso seco da raiz (RDW), ponha o peso seco (SDW), peso seco total (TDW) e a proporção das plantas de trigo TDW entre o estresse salgado e o controle (TDWR), foram avaliados ou calculados. Um total de 19QTLs para cinco traços foram detectados através do método de mapeamento de intervalo composto usando a versão 2.5 do cartógrafo QTL sob condições normais e de estresse salino. Estes QTLs distribuídos em 12 cromossomos explicaram a porcentagem de variação fenotípica por QTL individual variando de 7,9% a 19,0%. Entre eles, foram detectados 11 e 6 QTLs em condições de estresse normal e sal, respectivamente, e dois QTLs foram detectados para TDWR. Cromossoma 1A, 3A e 7A podem conter genes que são candidatos cruciais associados à tolerância ao sal de trigo. Nossos resultados seriam úteis para a seleção assistida por marcadores para produzir variedades de trigo com tolerância salina melhorada.
ABSTRACT
The individual variability should be considered in precision medicine-prevention and treatment strategies.Medical research using genomics, proteomics, metabolomics, systems analyses, and other modern tools has made big progress.In 2002, the members of the Complex-Trait Consortium proposed to develop a new mouse genetics resource called the Collaborative Cross (CC).The CC is a genetic reference panel of recombinant inbred lines of mice, designed for the dissection of complex traits and gene networks.It will provide a powerful measure for functional studies of biological networks, which will be essential to understand the intricacies of disease processes.