The allometry and dynamics of carbohydrate and nitrogen in vegetative organs and the relationship to cotton yield

Abstract

Cotton genotypes contrasting in time to maturity are supposed to have different dynamics of carbon (C) and nitrogen (N), which might impose considerable influence on lint yield. The objective of the study was to determine the difference of C N status in cotton plant due to diverse growth period and its relationship to reproductive output. Two Near-isogenic cotton lines differing in growth period (4003-10 and 4003-6) were employed to investigate the allometry and dynamics of total nonstructural carbohydrate (TNC) and total N over roots, stems, and leaves, and reproductive biomass in 2017 and 2018. Compared to the later maturing line (LML 4003-6), the earlier maturing line (EML 4003-10) allocated proportionally more TNC to roots at given leaf TNC per plant, and thus recorded greater starch and TNC concentrations in roots, which can account for greater root to shoot ratio at late reproduction stage. Likewise, proportionally more N was allocated to roots at given leaf N content in EML, and in turn resulted in less nitrogen transport to shoots and smaller N uptake efficiency, but greater internal N use efficiency. Root N content per plant during the reproductive period was a key contributor to the reproductive output of EML.