scholarly journals Genetic Dissection of Hybrid Performance and Heterosis for Yield-Related Traits in Maize

2021 ◽  
Vol 12 ◽  
Author(s):  
Dongdong Li ◽  
Zhiqiang Zhou ◽  
Xiaohuan Lu ◽  
Yong Jiang ◽  
Guoliang Li ◽  
...  
Keyword(s):  
Grain Yield ◽  
Recombinant Inbred ◽  
Fixed Effects ◽  
Prediction Accuracy ◽  
Genetic Architecture ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Hybrid Performance

Heterosis contributes a big proportion to hybrid performance in maize, especially for grain yield. It is attractive to explore the underlying genetic architecture of hybrid performance and heterosis. Considering its complexity, different from former mapping method, we developed a series of linear mixed models incorporating multiple polygenic covariance structures to quantify the contribution of each genetic component (additive, dominance, additive-by-additive, additive-by-dominance, and dominance-by-dominance) to hybrid performance and midparent heterosis variation and to identify significant additive and non-additive (dominance and epistatic) quantitative trait loci (QTL). Here, we developed a North Carolina II population by crossing 339 recombinant inbred lines with two elite lines (Chang7-2 and Mo17), resulting in two populations of hybrids signed as Chang7-2 × recombinant inbred lines and Mo17 × recombinant inbred lines, respectively. The results of a path analysis showed that kernel number per row and hundred grain weight contributed the most to the variation of grain yield. The heritability of midparent heterosis for 10 investigated traits ranged from 0.27 to 0.81. For the 10 traits, 21 main (additive and dominance) QTL for hybrid performance and 17 dominance QTL for midparent heterosis were identified in the pooled hybrid populations with two overlapping QTL. Several of the identified QTL showed pleiotropic effects. Significant epistatic QTL were also identified and were shown to play an important role in ear height variation. Genomic selection was used to assess the influence of QTL on prediction accuracy and to explore the strategy of heterosis utilization in maize breeding. Results showed that treating significant single nucleotide polymorphisms as fixed effects in the linear mixed model could improve the prediction accuracy under prediction schemes 2 and 3. In conclusion, the different analyses all substantiated the different genetic architecture of hybrid performance and midparent heterosis in maize. Dominance contributes the highest proportion to heterosis, especially for grain yield, however, epistasis contributes the highest proportion to hybrid performance of grain yield.

scholarly journals RIL-StEp: epistasis analysis of rice recombinant inbred lines (RILs) reveals candidate interacting genes that control seed hull color and leaf chlorophyll content

2021 ◽  
Author(s):  
Toshiyuki Sakai ◽  
Akira Abe ◽  
Motoki Shimizu ◽  
Ryohei Terauchi
Keyword(s):  
Chlorophyll Content ◽  
Recombinant Inbred ◽  
Complex Traits ◽  
Genetic Architecture ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Gene Interactions ◽  
Leaf Chlorophyll Content ◽  
Leaf Chlorophyll ◽  
Seed Hull

Abstract Characterizing epistatic gene interactions is fundamental for understanding the genetic architecture of complex traits. However, due to the large number of potential gene combinations, detecting epistatic gene interactions is computationally demanding. A simple, easy-to-perform method for sensitive detection of epistasis is required. Due to their homozygous nature, use of recombinant inbred lines (RILs) excludes the dominance effect of alleles and interactions involving heterozygous genotypes, thereby allowing detection of epistasis in a simple and interpretable model. Here, we present an approach called RIL-StEp (recombinant inbred lines stepwise epistasis detection) to detect epistasis using single nucleotide polymorphisms in the genome. We applied the method to reveal epistasis affecting rice (Oryza sativa) seed hull color and leaf chlorophyll content and successfully identified pairs of genomic regions that presumably control these phenotypes. This method has the potential to improve our understanding of the genetic architecture of various traits of crops and other organisms.

scholarly journals Quantifying the Effects of Fusarium Head Blight on Grain Yield and Test Weight in Soft Red Winter Wheat

2015 ◽  
Vol 105 (3) ◽  
pp. 295-306 ◽  
Author(s):  
Jorge David Salgado ◽  
Laurence V. Madden ◽  
Pierce A. Paul
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Fusarium Head Blight ◽  
Fixed Effects ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Test Weight ◽  
Head Blight ◽  
Soft Red Winter Wheat ◽  
Red Winter Wheat

Fusarium head blight (FHB), caused by the fungus Fusarium graminearum, is known to negatively affect wheat grain yield (YLD) and test weight (TW). However, very little emphasis has been placed on formally quantifying FHB–YLD and FHB–TW relationships. Field plots of three soft red winter wheat cultivars—‘Cooper’ (susceptible to FHB), ‘Hopewell’ (susceptible), and ‘Truman’ (moderately resistant)—were grown during the 2009, 2010, 2011, and 2012 seasons, and spray inoculated with spore suspensions of F. graminearum and Parastagonospora nodorum to generate a range of FHB and Stagonospora leaf blotch (SLB) levels. FHB index (IND) and SLB were quantified as percent diseased spike and flag leaf area, respectively, and YLD (kg ha−1) and TW (kg m−3) data were collected. Using IND as a continuous covariate and cultivar (CV) and SLB as categorical fixed effects, linear mixed-model regression analyses (LMMR) were used to model the IND–YLD and IND–TW relationship and to determine whether these relationships were influenced by CV and SLB. The final models fitted to the data were of the generic form y = a + b (IND), where a (intercept) or b (slope) could also depend on other factors. LMMR analyses were also used to estimate a and b by combining the studies from these 4 years with an additional 16 experiments conducted from 2003 to 2013, and bivariate random-effects meta-analysis was used to estimate population mean b ([Formula: see text]) and a (ā) for the IND–YLD relationship. YLD and TW decreased as IND increased, with b ranging from −3.2 to −2.3 kg m−3 %−1 for TW. For the IND–YLD relationship, [Formula: see text] was −51.7 kg ha−1 %IND−1 and ā was 4,426.7 kg ha−1. Neither cultivar nor SLB affected the IND–YLD relationship but SLB affected a of the IND–TW regression lines, whereas cultivar affected b. Plots with the highest levels of SLB (based on ordinal categories for SLB) had the lowest a and Hopewell had the highest b. The level of IND at which a 50-kg m−3 reduction in TW was predicted to occur was 19, 16, and 22% for Cooper, Hopewell, and Truman, respectively. A yield loss of 1 MT ha−1 was predicted to occur at 19% IND. The rate of reduction in relative TW or YLD per unit increase in IND was between −0.39 and −0.32%−1 for TW and −1.17%−1 for YLD. Results from this study could be integrated into more general models to evaluate the economics of FHB management strategies.

scholarly journals Correlation and path analysis in recombinant inbred lines (RILs) of wheat (Trticum aestivum L.)

2016 ◽  
Vol 8 (2) ◽  
pp. 826-832
Author(s):  
Ramesh Ramesh ◽  
Shailesh Marker ◽  
S. Muniswamy ◽  
Yamanura Yamanura
Keyword(s):  
Grain Yield ◽  
Recombinant Inbred ◽  
Recombinant Inbred Lines ◽  
Flag Leaf ◽  
Correlation Coefficients ◽  
Grain Filling ◽  
Inbred Lines ◽  
Spike Length ◽  
Grain Filling Period ◽  
Selection Of

Correlation and path coefficient analysis were studied in 22 heat tolerant Recombinant Inbred Lines (RILs) of wheat. Analysis of variance revealed the significant difference among genotypes for all the characters. Suggested that there was ample scope for selection of promising RILs for yield improvement. A wide range of variability was exhibited by most of the traits. The results of correlation studies indicated that genotypic correlation coefficients were higher in magnitude than their corresponding phenotypic correlation coefficients for all the traits which indicated that association among these characters was under genetic control and indicating the preponderance of genetic variance in expression of characters. Grain yield per plant had high, significant and positive association with number of grains per spike, spike weight, spike length, canopy temperature depression, tillers per plant, grain filling period and chlorophyll content both at genotypic and phenotypic levels indicating that these traits were main yield attributing traits. Path analysis revealed that grains per spike, tillers per plant, spike length, had the highest positive direct effect on grain yield followed by flag leaf length, flag leaf width, days 50% heading, plant height, grain filling period, membrane stability and days to maturity at genotypic level. The selection of characters such as grains per spike, tillers per plant, spike length and spike weight would be helpful for further improvement in RILs of wheat.

scholarly journals Genetic variabiity and character association for quality traits in recombinant inbred lines derived from inter sub-specific crosses of rice (Oryza sativa L.)

2014 ◽  
Vol 43 (1) ◽  
pp. 97-99
Author(s):  
AH Madakemohekar ◽  
SS Bornare ◽  
AS Chavan
Keyword(s):  
Grain Yield ◽  
Recombinant Inbred ◽  
Amylose Content ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
High Yield ◽  
Gelatinization Temperature ◽  
Kernel Length ◽  
Seed Width ◽  
Positive Direct

The investigation was carried out to study the genetic parameters for quality and nutritional characters in 60 recombinant inbred lines (RIL’s) of rice. Analysis of variance revealed significant differences for all the traits. It was observed that grain yield per plant was positively significant associated with seed width, milling per cent, gelatinization temperature, amylose content and kernel breadth before cooking. Kernel length after cooking, seed width, milling per cent, amylose content and gelatinization temperature had positive direct effect on grain yield. Comprehensive examination of result revealed that the recombinant inbred lines tested for high yield in rice viz., RIL-77, 08, 99, 75, 10 and 13 were identified as superior. DOI: http://dx.doi.org/10.3329/bjb.v43i1.19756 Bangladesh J. Bot. 43(1): 97-99, 2014 (June)

scholarly journals RIL-StEp: epistasis analysis of recombinant inbred lines (RILs) reveals candidate interacting genes that control rice seed hull color

2020 ◽  
Author(s):  
Toshiyuki Sakai ◽  
Akira Abe ◽  
Motoki Shimizu ◽  
Ryohei Terauchi
Keyword(s):  
Recombinant Inbred ◽  
Complex Traits ◽  
Genetic Architecture ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Gene Interactions ◽  
Rice Seed ◽  
Nucleotide Polymorphisms ◽  
Control Seed ◽  
Seed Hull

SummaryStudying epistatic gene interactions is important in understanding genetic architecture of complex traits in organisms. However, due to an enormous number of gene combinations to be analyzed, detection of epistatic gene-gene interactions has been computationally demanding. Here, we show a simple approach RIL-StEp, specialized to Recombinant Inbred Lines (RILs), to study epistasis using single nucleotide polymorphisms (SNPs) information of the genome. We applied the method to reveal epistasis affecting rice seed hull color phenotype, and successfully identified gene pairs that presumably control seed hull color. This method has a potential to enhancing our understanding of genetic architecture of various traits.

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