Burton Amy L, Johnson James, Foerster Jillian, Hanlon Meredith T, Kaeppler Shawn M, Lynch Jonathan P, Brown Kathleen M
Department of Plant Science, The Pennsylvania State University, 110 Tyson Building, University Park, PA, 16802, USA.
Theor Appl Genet. 2015 Jan;128(1):93-106. doi: 10.1007/s00122-014-2414-8. Epub 2014 Oct 19.
Root anatomical trait variation is described for three maize RIL populations. Six quantitative trait loci (QTL) are presented for anatomical traits: root cross-sectional area, % living cortical area, aerenchyma area, and stele area. Root anatomy is directly related to plant performance, influencing resource acquisition and transport, the metabolic cost of growth, and the mechanical strength of the root system. Ten root anatomical traits were measured in greenhouse-grown plants from three recombinant inbred populations of maize [intermated B73 × Mo17 (IBM), Oh43 × W64a (OhW), and Ny821 × H99 (NyH)]. Traits included areas of cross section, stele, cortex, aerenchyma, and cortical cells, percentages of the cortex occupied by aerenchyma, and cortical cell file number. Significant phenotypic variation was observed for each of the traits, with maximum values typically seven to ten times greater than minimum values. Means and ranges were similar for the OhW and NyH populations for all traits, while the IBM population had lower mean values for the majority of traits, but a 50% greater range of variation for aerenchyma area. A principal component analysis showed a similar trait structure for the three families, with clustering of area and count traits. Strong correlations were observed among area traits in the cortex, stele, and cross-section. The aerenchyma and percent living cortical area traits were independent of other traits. Six QTL were identified for four of the traits. The phenotypic variation explained by the QTL ranged from 4.7% (root cross-sectional area, OhW population) to 12.0% (percent living cortical area, IBM population). Genetic variation for root anatomical traits can be harnessed to increase abiotic stress tolerance and provide insights into mechanisms controlling phenotypic variation for root anatomy.
描述了三个玉米重组自交系群体的根系解剖性状变异。针对解剖性状呈现了六个数量性状位点（QTL）：根横截面积、活皮层面积百分比、通气组织面积和中柱面积。根系解剖结构与植物性能直接相关，影响资源获取和运输、生长的代谢成本以及根系的机械强度。对来自三个玉米重组自交群体[B73与Mo17杂交系（IBM）、Oh43与W64a杂交系（OhW）以及Ny821与H99杂交系（NyH）]温室种植的植株测量了十个根系解剖性状。这些性状包括横截面积、中柱、皮层、通气组织和皮层细胞的面积，通气组织占皮层的百分比以及皮层细胞列数。每个性状均观察到显著的表型变异，最大值通常比最小值大七至十倍。OhW和NyH群体所有性状的均值和范围相似，而IBM群体大多数性状的均值较低，但通气组织面积的变异范围大50%。主成分分析表明这三个家系具有相似的性状结构，面积和计数性状聚类。皮层、中柱和横截面积性状之间观察到强相关性。通气组织和活皮层面积百分比性状与其他性状无关。针对其中四个性状鉴定出六个QTL。QTL解释的表型变异范围为4.7%（根横截面积，OhW群体）至12.0%（活皮层面积百分比，IBM群体）。可以利用根系解剖性状的遗传变异来提高非生物胁迫耐受性，并深入了解控制根系解剖表型变异的机制。
