López-Álvarez Diana, Zubair Hassan, Beckmann Manfred, Draper John, Catalán Pilar
Department of Agriculture and Environmental Sciences, High Polytechnic School of Huesca, University of Zaragoza, Ctra. Cuarte Km 1, 22071 Huesca, Spain.
Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EB, UK.
Ann Bot. 2017 Mar 1;119(4):545-561. doi: 10.1093/aob/mcw239.
Morphological traits in combination with metabolite fingerprinting were used to investigate inter- and intraspecies diversity within the model annual grasses Brachypodium distachyon, Brachypodium stacei and Brachypodium hybridum .
Phenotypic variation of 15 morphological characters and 2219 nominal mass ( m / z ) signals generated using flow infusion electrospray ionization-mass spectrometry (FIE-MS) were evaluated in individuals from a total of 174 wild populations and six inbred lines, and 12 lines, of the three species, respectively. Basic statistics and multivariate principal component analysis and discriminant analysis were used to differentiate inter- and intraspecific variability of the two types of variable, and their association was assayed with the rcorr function.
Basic statistics and analysis of variance detected eight phenotypic characters [(stomata) leaf guard cell length, pollen grain length, (plant) height, second leaf width, inflorescence length, number of spikelets per inflorescence, lemma length, awn length] and 434 tentatively annotated metabolite signals that significantly discriminated the three species. Three phenotypic traits (pollen grain length, spikelet length, number of flowers per inflorescence) might be genetically fixed. The three species showed different metabolomic profiles. Discriminant analysis significantly discriminated the three taxa with both morphometric and metabolome traits and the intraspecific phenotypic diversity within B. distachyon and B. stacei . The populations of B. hybridum were considerably less differentiated.
Highly explanatory metabolite signals together with morphological characters revealed concordant patterns of differentiation of the three taxa. Intraspecific phenotypic diversity was observed between northern and southern Iberian populations of B. distachyon and between eastern Mediterranean/south-western Asian and western Mediterranean populations of B. stacei . Significant association was found for pollen grain length and lemma length and ten and six metabolomic signals, respectively. These results would guide the selection of new germplasm lines of the three model grasses in ongoing genome-wide association studies.
结合形态学特征与代谢物指纹图谱，研究模式一年生禾本科植物短柄草、斯氏短柄草和杂种短柄草种间和种内的多样性。
分别对来自174个野生种群和6个自交系以及12个品系的三种植物个体，评估15个形态特征的表型变异以及采用流动注射电喷雾电离质谱法（FIE-MS）生成的2219个标称质量（m/z）信号。运用基本统计、多变量主成分分析和判别分析来区分这两类变量的种间和种内变异性，并用rcorr函数分析它们之间的关联。
基本统计和方差分析检测到8个表型特征[（气孔）叶保卫细胞长度、花粉粒长度、（植株）高度、第二片叶宽度、花序长度、每个花序的小穗数、外稃长度、芒长度]和434个初步注释的代谢物信号，这些显著区分了这三个物种。三个表型性状（花粉粒长度、小穗长度、每个花序的花数）可能是遗传固定的。这三个物种表现出不同的代谢组学特征。判别分析通过形态测量和代谢组特征显著区分了这三个分类群以及短柄草和斯氏短柄草的种内表型多样性。杂种短柄草的种群分化程度要低得多。
具有高度解释性的代谢物信号与形态特征揭示了这三个分类群一致的分化模式。在短柄草的伊比利亚半岛北部和南部种群之间以及斯氏短柄草的东地中海/西南亚和西地中海种群之间观察到种内表型多样性。分别发现花粉粒长度和外稃长度与10个和6个代谢组信号存在显著关联。这些结果将指导在正在进行的全基因组关联研究中选择这三种模式禾本科植物的新种质系。
