Genotypic variation for root traits of maize (Zea mays L.) from the Purhepecha Plateau under contrasting phosphorus availability
Genotypic variation for root traits of maize (Zea mays L.) from the Purhepecha Plateau under contrasting phosphorus availability
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DOI：
10.1016/j.fcr.2011.01.001
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发表时间：
2011-04-03
影响因子：
5.8
通讯作者：
Lynch, Jonathan P.
中科院分区：
文献类型：
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作者：
Bayuelo-Jimenez, Jeannette S.;Gallardo-Valdez, Marin;Lynch, Jonathan P.
在许多低投入农业生态系统中，缺磷是玉米生产的主要制约因素。本研究在墨西哥中部高地的两个地点研究了玉米地方品种适应缺磷安迪索尔的根系(根构型和形态，包括根毛)和植物生长性状的遗传变异。来自米却肯州珀尔佩查高原的242份材料在Ponzomaran种植，在雨水灌溉的田间条件下，施低磷(23 kg P_2O_5 ha(-1))和高磷(97 kg P_2O_5 ha(-1))，然后在接下来的作物周期中在Bonilla种植50份对照材料。不同供试材料在植株生长、根系形态和磷效率上差异很大，被定义为磷有效性次优的生长。通过主成分分析和聚类分析，将供试材料分为3类磷效率类型，根据保留的主成分及其在各类型中的相对重量，结合生长或产量潜力，将材料分为4类。三个磷效率等级的材料在不同地点的分布是稳定的。磷高效材料的生物量、根冠比、节根数、节根侧枝数、节根毛密度和节根主轴长度、一级侧枝数在缺磷条件下均较高。利用异速生长分配系数(K)量化的生物量分配到根的分配不受磷有效性的影响，但低效材料在低磷条件下K较低。增强节根和侧根的材料在低磷条件下生长较快，节根主轴和一级侧根上密集的根毛在低磷条件下表现出明显的效益，表现为植株生物量的增加。晚熟促进了低磷条件下的生长和产量。这些结果表明，墨西哥中部高地的地方品种在几个根系性状上表现出变异，这些变异可能有助于玉米磷效率的遗传改良。(C)2011爱思唯尔B.V.保留所有权利。
Phosphorus (P) deficiency is a major constraint for maize production in many low-input agroecosystems. This study was conducted to evaluate genotypic variation in both root (root architecture and morphology, including root hairs) and plant growth traits associated with the adaptation of maize landraces to a P-deficient Andisol in two locations in the Central Mexican highlands. Two hundred and forty-two accessions from the Purhepecha Plateau, Michoacan were grown in Ponzomaran with low (23 kg P2O5 ha(-1)) and high (97 kg P2O5 ha(-1)) P fertilization under rain-fed field conditions, and subsequently a subset of 50 contrasting accessions were planted in the succeeding crop cycle in Bonilla. Accessions differed greatly in plant growth, root morphology and P efficiency defined as growth with suboptimal P availability. The accessions were divided into 3 categories of P efficiency using principal component and cluster analyses, and 4 categories according to the retained principal component and their relative weight for each genotype in combination with growth or yield potential. The distribution of accessions among three phosphorus efficiency classes was stable across locations. Phosphorus-efficient accessions had greater biomass, root to shoot ratio, nodal rooting, nodal root laterals, and nodal root hair density and length of nodal root main axis, and first-order laterals under P deficiency. Biomass allocation to roots, as quantified by the allometric partitioning coefficient (K) was not altered by P availability in the efficient accessions, but inefficient accessions had a lower K under low P conditions. Accessions with enhanced nodal rooting and laterals had greater growth under low P. Dense root hairs on nodal root main axes and first-order laterals conferred a marked benefit under low P. as evidenced by increased plant biomass. Late maturity improved growth and yield under low P. These results indicate that landraces of the Central Mexican highlands exhibit variation for several root traits that may be useful for genetic improvement of P efficiency in maize. (C) 2011 Elsevier B.V. All rights reserved.