scholarly journals Genetic Dissection of Grain Yield Component Traits Under High Nighttime Temperature Stress in a Rice Diversity Panel

2021 ◽  
Vol 12 ◽  
Author(s):  
Anuj Kumar ◽  
Chirag Gupta ◽  
Julie Thomas ◽  
Andy Pereira
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Candidate Genes ◽  
Significant Snps ◽  
The United States ◽  
Yield Component ◽  
Reproductive Stage ◽  
Venn Diagram ◽  
Rice Grain ◽  
Diversity Panel

To dissect the genetic complexity of rice grain yield (GY) and quality in response to heat stress at the reproductive stage, a diverse panel of 190 rice accessions in the United States Department of Agriculture (USDA) rice mini-core collection (URMC) diversity panel were treated with high nighttime temperature (HNT) stress at the reproductive stage of panicle initiation. The quantifiable yield component response traits were then measured. The traits, panicle length (PL), and number of spikelets per panicle (NSP) were evaluated in subsets of the panel comprising the rice subspecies Oryza sativa ssp. Indica and ssp. Japonica. Under HNT stress, the Japonica ssp. exhibited lower reductions in PL and NSP and a higher level of genetic variation compared with the other subpopulations. Whole genome sequencing identified 6.5 million single nucleotide polymorphisms (SNPs) that were used for the genome-wide association studies (GWASs) of the PL and NSP traits. The GWAS analysis in the Combined, Indica, and Japonica populations under HNT stress identified 83, 60, and 803 highly significant SNPs associated with PL, compared to the 30, 30, and 11 highly significant SNPs associated with NSP. Among these trait-associated SNPs, 140 were coincident with genomic regions previously reported for major GY component quantitative trait loci (QTLs) under heat stress. Using extents of linkage disequilibrium in the rice populations, Venn diagram analysis showed that the highest number of putative candidate genes were identified in the Japonica population, with 20 putative candidate genes being common in the Combined, Indica and Japonica populations. Network analysis of the genes linked to significant SNPs associated with PL and NSP identified modules that were involved in primary and secondary metabolisms. The findings in this study could be useful to understand the pathways/mechanisms involved in rice GY and its components under HNT stress for the acceleration of rice-breeding programs and further functional analysis by molecular geneticists.

scholarly journals Response of phytohormone homeostasis to heat stress and the roles of phytohormones in rice grain yield: a review

2019 ◽  
Author(s):  
Chao Wu ◽  
She Tang ◽  
Ganghua Li ◽  
Shaohua Wang ◽  
Shah Fahad ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
Reproductive Organs ◽  
Reproductive Stage ◽  
Grain Weight ◽  
Rice Grain ◽  
Vascular Bundles ◽  
Rice Varieties ◽  
Heat Effects

Rice is highly susceptible to heat stress at the reproductive stage. In this review, we first summarize recent progress in heat effects on rice grain yield during different reproductive stages. Different responses of yield traits of rice to heat stress during different reproductive stages are identified. The number of spikelets per panicle is reduced by heat stress during the early reproductive stage but is not affected by heat stress during the mid-late reproductive stage. Spikelet sterility induced by heat stress can be attributed primarily to physiological abnormalities in the reproductive organs during flowering but attributed to structural and morphological abnormalities in reproductive organs during panicle initiation. The lower grain weight caused by heat stress during the early reproductive stage was due to a reduction in non-structural carbohydrates, undeveloped vascular bundles, and a reduction in grain length and width, while a shortened grain filling duration, reduced grain filling rate, and decreased grain width affect grain weight when heat stress occurs during grain filling. Phytohormones play vital roles in regulating plant adaptations against heat stress. We discuss the processes involving phytohormone homeostasis (biosynthesis, catabolism, deactivation, and transport) in response to heat stress. It is currently thought that biosynthesis and transport may be the key processes that determine phytohormone levels and final grain yield in rice under heat stress conditions. Finally, we prospect that screening and breeding rice varieties with comprehensive tolerance to heat stress throughout the entire reproductive phase could be feasible to cope with unpredictable heat events in the future. Studies in phytohormone homeostatic response are needed to further reveal the key processes that determine phytohormone levels under heat condition.

scholarly journals Response of phytohormone homeostasis to heat stress and the roles of phytohormones in rice grain yield: a review

2019 ◽  
Author(s):  
Chao Wu ◽  
She Tang ◽  
Ganghua Li ◽  
Shaohua Wang ◽  
Shah Fahad ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
Reproductive Organs ◽  
Reproductive Stage ◽  
Grain Weight ◽  
Rice Grain ◽  
Vascular Bundles ◽  
Rice Varieties ◽  
Heat Effects

Rice is highly susceptible to heat stress at the reproductive stage. In this review, we first summarize recent progress in heat effects on rice grain yield during different reproductive stages. Different responses of yield traits of rice to heat stress during different reproductive stages are identified. The number of spikelets per panicle is reduced by heat stress during the early reproductive stage but is not affected by heat stress during the mid-late reproductive stage. Spikelet sterility induced by heat stress can be attributed primarily to physiological abnormalities in the reproductive organs during flowering but attributed to structural and morphological abnormalities in reproductive organs during panicle initiation. The lower grain weight caused by heat stress during the early reproductive stage was due to a reduction in non-structural carbohydrates, undeveloped vascular bundles, and a reduction in grain length and width, while a shortened grain filling duration, reduced grain filling rate, and decreased grain width affect grain weight when heat stress occurs during grain filling. Phytohormones play vital roles in regulating plant adaptations against heat stress. We discuss the processes involving phytohormone homeostasis (biosynthesis, catabolism, deactivation, and transport) in response to heat stress. It is currently thought that biosynthesis and transport may be the key processes that determine phytohormone levels and final grain yield in rice under heat stress conditions. Finally, we prospect that screening and breeding rice varieties with comprehensive tolerance to heat stress throughout the entire reproductive phase could be feasible to cope with unpredictable heat events in the future. Studies in phytohormone homeostatic response are needed to further reveal the key processes that determine phytohormone levels under heat condition.

scholarly journals Green Synthesis of Zinc Oxide Nanoparticles: Fortification for Rice Grain Yield and Nutrients Uptake Enhancement

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 584
Author(s):  
Omnia M. Elshayb ◽  
Khaled Y. Farroh ◽  
Heba E. Amin ◽  
Ayman M. Atta
Keyword(s):  
Zinc Oxide ◽  
Grain Yield ◽  
Field Experiments ◽  
Metal Oxide Nanoparticles ◽  
Foliar Spray ◽  
Yield Component ◽  
Oxide Nanoparticles ◽  
Rice Grain ◽  
Zno Nps ◽  
Agriculture Sector

Applications of metal oxide nanoparticles in the agriculture sector are being extensively included as the materials are considered superior. In the present work, zinc oxide nanoparticle (ZnO NPs), with a developing fertilizer, is applied in the fortification of rice grain yield and nutrient uptake enhancement. To evaluate the role of ZnO NP, two field experiments were conducted during the 2018 and 2019 seasons. ZnO NPs were small, nearly spherical, and their sizes equal to 31.4 nm, as proved via the dynamic light scattering technique. ZnO NPs were applied as a fertilizer in different concentrations, varying between 20 and 60 mg/L as a foliar spray. The mixture of ZnSO4 and ZnO NP40 ameliorated yield component and nutrients (N, K, and Zn) uptake was enhanced compared to traditional ZnSO4 treatment. Nevertheless, the uptake of the phosphorous element (P) was adversely affected by the treatment of ZnO NPs. Thus, treatment via utilizing ZnO NPs as a foliar with a very small amount (40 ppm) with of basal ZnSO4 led to a good improvement in agronomic and physiological features; eventually, higher yield and nutrient-enriched rice grain were obtained.

scholarly journals Identification and allele mining of new candidate genes underlying rice grain weight and grain shape by genome-wide association study

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanan Niu ◽  
Tianxiao Chen ◽  
Chunchao Wang ◽  
Kai Chen ◽  
Congcong Shen ◽  
...  
Keyword(s):  
Grain Yield ◽  
Association Study ◽  
Candidate Genes ◽  
Grain Quality ◽  
Genome Wide Association Study ◽  
Grain Shape ◽  
Grain Weight ◽  
Genome Wide Association ◽  
Rice Grain ◽  
Genome Wide

Abstract Background Grain weight and grain shape are important agronomic traits that affect the grain yield potential and grain quality of rice. Both grain weight and grain shape are controlled by multiple genes. The 3,000 Rice Genomes Project (3 K RGP) greatly facilitates the discovery of agriculturally important genetic variants and germplasm resources for grain weight and grain shape. Results Abundant natural variations and distinct phenotic differentiation among the subgroups in grain weight and grain shape were observed in a large population of 2,453 accessions from the 3 K RGP. A total of 21 stable quantitative trait nucleotides (QTNs) for the four traits were consistently identified in at least two of 3-year trials by genome-wide association study (GWAS), including six new QTNs (qTGW3.1, qTGW9, qTGW11, qGL4/qRLW4, qGL10, and qRLW1) for grain weight and grain shape. We further predicted seven candidate genes (Os03g0186600, Os09g0544400, Os11g0163600, Os04g0580700, Os10g0399700, Os10g0400100 and Os01g0171000) for the six new QTNs by high-density association and gene-based haplotype analyses. The favorable haplotypes of the seven candidate genes and five previously cloned genes in elite accessions with high TGW and RLW are also provided. Conclusions Our results deepen the understanding of the genetic basis of grain weight and grain shape in rice and provide valuable information for improving rice grain yield and grain quality through molecular breeding.

scholarly journals Natural Variation Uncovers Candidate Genes for Barley Spikelet Number and Grain Yield under Drought Stress

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 533 ◽  
Author(s):  
Samar G. Thabet ◽  
Yasser S. Moursi ◽  
Mohamed A. Karam ◽  
Andreas Börner ◽  
Ahmad M. Alqudah
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Candidate Genes ◽  
Agronomic Traits ◽  
Spring Barley ◽  
Functional Characterization ◽  
Reproductive Stage ◽  
Yield Potential ◽  
Grain Number Per Spike

Drought stress can occur at any growth stage and can affect crop productivity, which can result in large yield losses all over the world. In this respect, understanding the genetic architecture of agronomic traits under drought stress is essential for increasing crop yield potential and harvest. Barley is considered the most abiotic stress-tolerant cereal, particularly with respect to drought. In the present study, worldwide spring barley accessions were exposed to drought stress beginning from the early reproductive stage with 35% field capacity under field conditions. Drought stress had significantly reduced the agronomic and yield-related traits such as spike length, awn length, spikelet per spike, grains per spike and thousand kernel weight. To unravel the genetic factors underlying drought tolerance at the early reproductive stage, genome-wide association scan (GWAS) was performed using 121 spring barley accessions and a 9K single nucleotide polymorphisms (SNPs) chip. A total number of 101 significant SNPs, distributed over all seven barley chromosomes, were found to be highly associated with the studied traits, of which five genomic regions were associated with candidate genes at chromosomes 2 and 3. On chromosome 2H, the region between 6469300693-647258342 bp includes two candidate drought-specific genes (HORVU2Hr1G091030 and HORVU2Hr1G091170), which are highly associated with spikelet and final grain number per spike under drought stress conditions. Interestingly, the gene expression profile shows that the candidate genes were highly expressed in spikelet, grain, spike and leaf organs, demonstrating their pivotal role in drought tolerance. To the best of our knowledge, we reported the first detailed study that used GWAS with bioinformatic analyses to define the causative alleles and putative candidate genes underlying grain yield-related traits under field drought conditions in diverse barley germplasm. The identified alleles and candidate genes represent valuable resources for future functional characterization towards the enhancement of barley cultivars for drought tolerance.

scholarly journals Genotyping-by-sequencing based QTL mapping for rice grain yield under reproductive stage drought stress tolerance

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shailesh Yadav ◽  
Nitika Sandhu ◽  
Vikas Kumar Singh ◽  
Margaret Catolos ◽  
Arvind Kumar
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Genotyping By Sequencing ◽  
High Density ◽  
Reproductive Stage ◽  
Linkage Drag ◽  
Rice Grain ◽  
Early Maturity ◽  
Consistent Effect ◽  
Mapping Populations

Abstract QTLs for rice grain yield under reproductive stage drought stress (qDTY) identified earlier with low density markers have shown linkage drag and need to be fine mapped before their utilization in breeding programs. In this study, genotyping-by-sequencing (GBS) based high-density linkage map of rice was developed using two BC1F3 mapping populations namely Swarna*2/Dular (3929 SNPs covering 1454.68 cM) and IR11N121*2/Aus196 (1191 SNPs covering 1399.68 cM) with average marker density of 0.37 cM to 1.18 cM respectively. In total, six qDTY QTLs including three consistent effect QTLs were identified in Swarna*2/Dular while eight qDTY QTLs including two consistent effect QTLs were identified in IR11N121*2/Aus 196 mapping population. Comparative analysis revealed four stable and novel QTLs (qDTY2.4, qDTY3.3, qDTY6.3, and qDTY11.2) which explained 8.62 to 14.92% PVE. However, one of the identified stable grain yield QTL qDTY1.1 in both the populations was located nearly at the same physical position of an earlier mapped major qDTY QTL. Further, the effect of the identified qDTY1.1 was validated in a subset of lines derived from five mapping populations confirming robustness of qDTY1.1 across various genetic backgrounds/seasons. The study successfully identified stable grain yield QTLs free from undesirable linkages of tall plant height/early maturity utilizing high density linkage maps.

scholarly journals Temperature Stress and Turkey Reproduction

2002 ◽  
Author(s):  
Mohamed El Halawani ◽  
Israel Rozenboim
Keyword(s):  
Heat Stress ◽  
Temperature Stress ◽  
Reproductive Performance ◽  
Egg Production ◽  
Detrimental Effect ◽  
The United States ◽  
High Temperature Stress ◽  
Active Immunization ◽  
Reproductive Stage ◽  
Subunit Mrna

High temperature stress is of major concern to turkey producers in Israel and the United States. The decline in the rate of egg production at high environmental temperature is well recognized, but the neuroendocrinological basis is not understood. Our objectives were: 1) to characterize the hypothalamo-hypophyseal axis involvement in the mechanism(s) underlying the detrimental effect of heat stress on reproduction, and 2) to establish procedures that alleviate the damaging effect of heat stress on reproduction. Heat stress (40oC, Israel; 32oC, U.S.) caused significant reduction in egg production, which was restored by VIP immunoneutralization. The decline in egg production did not appear to be entirely related to the expression of incubation behavior due to the rise in circulating PRL in stressed birds. Heat stress was found to increase circulating PRL in ovariectomized turkeys independent of the reproductive stage. Active immunization against VIP was shown for the first time to up-regulate LHb and FSHb subunit mRNA contents. These findings taken together with the results that the heat stress-induced decline in egg production may not be dependent upon the reproductive stage, lead to the suggestion that the detrimental effect of heat stress on reproductive performance may be in part mediated by VIP acting directly on the GnRH/gonadotropin system. Inhibin (INH) immunoneutralization has been shown to enhance FSH secretion and induces ovulation in mammals. It is hypothesized that immunization of heat-stressed turkeys against INH will increase levels of circulating FSH and the number of preovulating follicles which leads to improved reproductive performance. We have cloned and expressed turkey INH-a and INH-bA. Active immunization of turkey hens with rtINH-a increased pituitary FSH-b subunit mRNA and the number of non-graded preovulatory yellow follicles, but no significant increase in egg production was observed.

scholarly journals Identification and Allele Mining of New Candidate Genes Underlying Rice Grain Weight and Grain Shape by Genome-Wide Association Study

2020 ◽  
Author(s):  
Yanan Niu ◽  
Tianxiao Chen ◽  
Kai Chen ◽  
Congcong Shen ◽  
Huizhen Chen ◽  
...  
Keyword(s):  
Grain Yield ◽  
Association Study ◽  
Candidate Genes ◽  
Grain Quality ◽  
Genome Wide Association Study ◽  
Grain Shape ◽  
Functional Characterization ◽  
Grain Weight ◽  
Yield Potential ◽  
Rice Grain

Abstract Background: Grain weight and grain shape are crucial agronomic traitsthat affect grain yield potential and grain quality of rice. Both Grain weight and grain shape are controlled by multiple genes known as quantitative trait locus/loci (QTL).The 3,000 Rice Genomes Project enables the discovery of valuable genetic variants and resources for grain weight and grain shape.Results:2445 rice accessions were classified into 12 sub-populations which showeddiversevariations in grain weight and grain shape.Genome-wide association study (GWAS) revealedthreenovel QTL (qTGW3.1,qTGW9and qTGW11) forgrain weight and four novel QTL(qGL4/qRLW4,qGL10, qGL11andqRLW1) forgrain shape. We finally predicted eightcandidate genes (Os03g0186600, Os09g0544400,Os11g0163600,Os04g0580700, Os10g0399700, Os10g0400100, Os11g0143700 and Os01g0171000) for the seven novel QTL by gene-based association, haplotype and bioinformatics analyses.The accessions with excellent haplotypes at the eight candidate genes and five previously cloned genes were also identified.Conclusion: The identified candidate genes and accessions provided valuable sources for future functional characterization and genetic improvement of rice grain yield and grain quality.

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