Phenotypic variability in bread wheat root systems at the early vegetative stage
Phenotypic variability in bread wheat root systems at the early vegetative stage
复制标题
DOI：
10.1186/s12870-020-02390-8
复制
发表时间：
2020-04-28
影响因子：
5.3
通讯作者：
Siddique, Kadambot H. M.
中科院分区：
文献类型：
--
作者：
Chen Yinglong;Palta, Jairo;Siddique, Kadambot H. M.
背景了解面包小麦的根系形态对于识别根系性状以培育具有改善资源吸收和更好地适应不利环境的品种至关重要。对来自 37 个国家、在半水培表型系统中种植的 184 个面包小麦基因型进行了检查，了解早期营养阶段根部形态性状的变异性。结果分蘖开始时（Z2.1，移栽后35天），植株芽高达42厘米，根深长158厘米。地上部性状和根性状均存在表型变异，184个基因型中根总长度最大差异为4.3倍，根干质量最大差异为5倍。在41个测量性状中，24个根性状和4个地上部性状的变异系数较大（CV≥0.25）。一些关键根性状（即根质量、根长度和不同深度的这些参数）和芽性状（即芽质量和分蘖数）（P 1）存在强正相关性，占各基因型总变异性的 83.0%。基于同一组根性状，凝聚层次聚类分析将 184 个基因型分为四个（重新调整距离为 15）或七个（重新调整距离为 10）主要组。性能性状（干质量）与特定根长、根长强度和根组织密度等多种功能性状之间的密切关系表明它们与植物生长和适应性策略的联系。结论 使用已建立的半水培表型分析技术，在分蘖期观察到小麦基因型根系形态存在较大的表型变异。一些有趣的根性状之间的表型差异和性状相关性可被考虑用于育种具有高效吸水性和更好地适应非生物胁迫的小麦品种。
Background Understanding root system morphology in bread wheat is critical for identifying root traits to breed cultivars with improved resource uptake and better adaptation to adverse environments. Variability in root morphological traits at early vegetative stages was examined among 184 bread wheat genotypes originating from 37 countries grown in a semi-hydroponic phenotyping system. Results At the onset of tillering (Z2.1, 35 days after transplanting), plants had up to 42 cm in shoot height and 158 cm long in root depth. Phenotypic variation existed for both shoot and root traits, with a maximal 4.3-fold difference in total root length and 5-fold difference in root dry mass among the 184 genotypes. Of the 41 measured traits, 24 root traits and four shoot traits had larger coefficients of variation (CV >= 0.25). Strong positive correlations were identified for some key root traits (i.e., root mass, root length, and these parameters at different depths) and shoot traits (i.e., shoot mass and tiller number) (P 1) capturing 83.0% of the total variability across genotypes. Agglomerative hierarchical clustering analysis separated the 184 genotypes into four (at a rescaled distance of 15) or seven (at a rescaled distance of 10) major groups based on the same set of root traits. Strong relationships between performance traits (dry mass) with several functional traits such as specific root length, root length intensity and root tissue density suggest their linkage to plant growth and fitness strategies. Conclusions Large phenotypic variability in root system morphology in wheat genotypes was observed at the tillering stage using established semi-hydroponic phenotyping techniques. Phenotypic differences in and trait correlations among some interesting root traits may be considered for breeding wheat cultivars with efficient water acquisition and better adaptation to abiotic stress.