Browsing by Person "Chen, Shaojiang"

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Genetic dissection of hybrid performance and heterosis for yield-related traits in maize
(2021) Li, Dongdong; Zhou, Zhiqiang; Lu, Xiaohuan; Jiang, Yong; Li, Guoliang; Li, Junhui; Wang, Haoying; Chen, Shaojiang; Li, Xinhai; Würschum, Tobias; Reif, Jochen C.; Xu, Shizhong; Li, Mingshun; Liu, Wenxin
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.
Genetic dissection of phosphorus use efficiency and genotype-by-environment interaction in maize
(2022) Li, Dongdong; Li, Guoliang; Wang, Haoying; Guo, Yuhang; Wang, Meng; Lu, Xiaohuan; Luo, Zhiheng; Zhu, Xintian; Weiß, Thea Mi; Roller, Sandra; Chen, Shaojiang; Yuan, Lixing; Würschum, Tobias; Liu, Wenxin
Genotype-by-environment interaction (G-by-E) is a common but potentially problematic phenomenon in plant breeding. In this study, we investigated the genotypic performance and two measures of plasticity on a phenotypic and genetic level by assessing 234 maize doubled haploid lines from six populations for 15 traits in seven macro-environments with a focus on varying soil phosphorus levels. It was found intergenic regions contributed the most to the variation of phenotypic linear plasticity. For 15 traits, 124 and 31 quantitative trait loci (QTL) were identified for genotypic performance and phenotypic plasticity, respectively. Further, some genes associated with phosphorus use efficiency, such as Zm00001eb117170, Zm00001eb258520, and Zm00001eb265410, encode small ubiquitin-like modifier E3 ligase were identified. By significantly testing the main effect and G-by-E effect, 38 main QTL and 17 interaction QTL were identified, respectively, in which MQTL38 contained the gene Zm00001eb374120, and its effect was related to phosphorus concentration in the soil, the lower the concentration, the greater the effect. Differences in the size and sign of the QTL effect in multiple environments could account for G-by-E. At last, the superiority of G-by-E in genomic selection was observed. In summary, our findings will provide theoretical guidance for breeding P-efficient and broadly adaptable varieties.
Genetic dissection of phosphorus use efficiency in a maize association population under two P levels in the field
(2021) Li, Dongdong; Wang, Haoying; Wang, Meng; Li, Guoliang; Chen, Zhe; Leiser, Willmar L.; Weiß, Thea Mi; Lu, Xiaohuan; Wang, Ming; Chen, Shaojiang; Chen, Fanjun; Yuan, Lixing; Würschum, Tobias; Liu, Wenxin