REPRODUCTIVE ALLOCATION AND NUTRIENT RELATIONSHIPS IN CUPHEA: A SEMI-DOMESTICATED OILSEED CROP |
| |
| Authors: | Abdullah A Jaradat |
| |
| Institution: | United States Department of Agriculture (USDA) , Agricultural Research Service (ARS) , Morris , Minnesota , USA |
| |
| Abstract: | Interrelationships between ontogeny, allometric mass, and carbon (C): nitrogen (N): phosphorus (P) ratios were quantified in Cuphea, a semi-domesticated indeterminate and phenotypically plastic potential oilseed crop. Relative growth rate and net assimilation rate were estimated as functions of growth stages, phenotypic traits and C:N:P ratios. Ontogenically, N:P ratios in reproductive and metabolic tissues were least variable and were mainly affected by allometric leaf mass and relative growth rate. Reproductive mass is best predicted by allometric stem mass and C:N ratio in structural and metabolic tissues; whereas, net assimilation rate is best predicted by allometric total branch length and relative growth rate. The conservative N:P ratios found in reproductive and metabolic tissues are important in determining reproductive allocation in Cuphea. Large antagonistic effects of C:N on N:P ratios found in different plant tissues suggest that maximum reproductive allocation can be attained by manipulating N:P ratio during ontogeny. A greater investment of resources in reproduction may be possible for this semi-domesticated crop if nutrient and mass allocation to supporting stems and roots can be altered for the benefit of reproductive biomass. |
| |
| Keywords: | allometry Cuphea C:N:P ratios ontogeny reproductive mass stoichiometry |
|
|
