Dierking Ryan M, Allen Damian J, Cunningham Suzanne M, Brouder Sylvie M, Volenec Jeffrey J
Actagro, LLC, FresnoCA, United States.
Mendel BioEnergy Seeds, Mendel Biotechnology Inc., HaywardCA, United States.
Front Plant Sci. 2017 Sep 20;8:1618. doi: 10.3389/fpls.2017.01618. eCollection 2017.
Nitrogen (N) reserves in vegetative tissues contribute N to regrowth of × shoots in spring, but our understanding of how N fertilization and plant genotype affect this process is incomplete. Our specific objectives were to: (1) determine how N fertilizer management impacts accumulation of dry matter and N among aboveground and belowground tissues and organs; (2) understand how changes in N management and tissue N concentration influence seasonal fluctuations in concentrations of buffer-soluble proteins and amino acids in putative storage organs including rhizomes and roots; and (3) characterize genotypic variability and genotype × N interactions for N reserve accumulation and use among × genotypes. Established plots of the IL Clone and Nagara-sib population were fertilized with 0-0, 0-150, 75-75, 150-0, and 150-150 kg N ha where the first numeral denotes the N rate applied in 2011 (Year 1) and the second number denotes the N rate applied in 2012 (Year 2). Rhizomes, roots, stembases, and shoots were sampled at 6-week intervals between March and August and then in November at dormancy. Concentrations of N, soluble protein and amino-N increased in all tissues with fertilizer N application. With the exception of rhizome amino-N, concentrations of these N pools in roots and rhizomes declined as plants resumed growth in spring and increased sharply between August and November as growth slowed. Losses in shoot and stembase N mass between August and November were similar to total N accumulation in roots and rhizomes during this interval. Compared to the unfertilized control, specific N managements enhanced growth of above- and belowground tissues. The IL Clone generally had greater biomass yield of all organs than the Nagara-sib; the exception being shoot biomass in November when extensive leaf senescence reduce yield of the IL Clone. High biomass yields were obtained with 75 kg N ha applied annually rather than semi-annual N applications of 150 kg N ha that depended on N recycling from roots/rhizomes as a supplemental N source.
营养组织中的氮（N）储备为春季×茎的再生长提供氮，但我们对氮肥施用和植物基因型如何影响这一过程的理解并不完整。我们的具体目标是：（1）确定氮肥管理如何影响地上和地下组织及器官中干物质和氮的积累；（2）了解氮管理和组织氮浓度的变化如何影响包括根茎和根在内的假定储存器官中缓冲可溶性蛋白质和氨基酸浓度的季节性波动；（3）表征×基因型间氮储备积累和利用的基因型变异性及基因型×氮相互作用。对IL克隆系和长谷川- sib群体的已建立小区分别施用0-0、0-150、75-75、150-0和150-150 kg N/ha的氮肥，其中第一个数字表示2011年（第1年）施用的氮量，第二个数字表示2012年（第2年）施用的氮量。在3月至8月期间，每隔6周对根茎、根、茎基部和茎进行采样，然后在11月休眠期进行采样。随着氮肥的施用，所有组织中的氮、可溶性蛋白质和氨基氮浓度均增加。除根茎氨基氮外，随着春季植物恢复生长，根和根茎中这些氮库的浓度下降，而在8月至11月生长减缓期间急剧增加。8月至11月期间，茎和茎基部氮质量的损失与该时间段内根和根茎中总氮积累量相似。与未施肥对照相比，特定的氮肥管理促进了地上和地下组织的生长。IL克隆系的所有器官生物量产量通常都高于长谷川- sib；唯一的例外是11月的茎生物量，此时大量叶片衰老降低了IL克隆系的产量。每年施用75 kg N/ha比每半年施用150 kg N/ha能获得更高的生物量产量，后者依赖于从根/根茎中回收氮作为补充氮源。
