Nitrogen Reserve Pools in Two Miscanthus × giganteus Genotypes under Contrasting N Managements

Abstract

Nitrogen (N) reserves in vegetative tissues contribute N to regrowth of Miscanthus × giganteus 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 Miscanthus × giganteus 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-1 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-1 applied annually rather than semi-annual N applications of 150 kg N-1 ha that depended on N recycling from roots/rhizomes as a supplemental N source.

Miscanthus ×giganteusbiomass yield and quality in the Virginia Piedmont

“…Perhaps the poorer performance of ‘Illinois’ in Iowa indicates lower tolerance to the cooler growing conditions at that site relative to temperatures of Virginia. Dierking et al () also reported a reduction in the growth rate of both shoot and stembase biomass from August through November for ‘Illinois’ in cooler Indiana, USA, but not for an open pollinated tetraploid sibling of ‘Nagara’. Freedom's biomass yields were intermediate to these cultivars both in Virginia and in Iowa.…”

“…The ‘Illinois’ clone is an unlicensed public cultivar obtained in 1988 from the Chicago Botanic Garden as a sterile triploid. ‘Illinois’ is the most common M. ×giganteus cultivar utilized for research and commercial purposes in the United States and Europe (Dierking, Allen, Cunningham, Brouder, & Volonec, ; Głowacka et al, ). ‘Freedom’ M. ×giganteus, the commercial name of the patented MSU‐MFL1 (Baldwin, ), has recently been found to have identical multilocus cultivars and no nuclear or cytoplasmic genetic differences compared with ‘Illinois’ (Głowacka et al, ).…”

“…The 'Illinois' clone is an unlicensed public cultivar obtained in 1988 from the Chicago Botanic Garden as a sterile triploid. 'Illinois' is the most common M. ×giganteus cultivar utilized for research and commercial purposes in the United States and Europe (Dierking, Allen, Cunningham, Brouder, & Volonec, 2017;Głowacka et al, 2015).…”

Improving the Yield and Nutritional Quality of Forage Crops

“…The general fertilizer requirement of maize grown for forage and for grain are the same as that for a biomass crop. N requirements differ greatly for forage crops, and legumes and rhizome crops like Miscanthus have low N requirements ( Dierking et al, 2017 ). Improving NUE using transporter marker genes as indicators of the crop status in the field could be valuable ( Fan et al, 2017 ).…”

Turnover of Minerals and Organics in the Postharvest Herbage of Annuals and Perennials: Winter Wheat and Goldenrod

“…Specific vegetative storage proteins (VSPs) are deposited in late-season taproots of alfalfa (Medicago sativa L.) and white clover (Trifolium repens L.) [65,66] to support regrowth in spring. Non-VSPs N resources formed in red clover (T. pratense L.) and other perennial forage legumes are depleted prior to the next growing season [67,68].…”