ARS | Publication request: Modeling seed weight under environmental resource limitations as a function of C, N, and C:N allocation

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 11, 2008
Publication Date: July 11, 2008
Citation: Jaradat, A.A. 2008. Modeling seed weight under environmental resource limitations as a function of C, N, and C:N allocation [abstract]. Polish Journal of Natural Sciences. Supplement No. 5. p. 79.

Technical Abstract: The carbon (C) and nitrogen (N) contents and C:N ratio in seed of two genotypes each of five crops with different resource allocation patterns were assessed under normal growing degree days (GDD) and normal population density (NN) for each crop; normal GDD and 25%>normal population density (NL); short GDD (~100 GDD <NN) and normal population density (SN); and short GDD and large population density (SL). Carbon, N, and C:N ratio discriminated between the five crops with 100% correct classification irrespective of the significant differences between their seed weights. Nitrogen content was significantly impacted by crops and their interaction with population density; whereas C and C:N were significantly impacted by crops and their two-way interaction with GDD and population density. Most genotypes within crops differed significantly in their allocation of N, C, and C:N per unit seed weight. On average, the C:N ratio was negatively correlated with protein content (r=-0.91, p<0.001), but not with seed weight (r=0.21, p=0.2) with large differences among crops. Average seed weight for all crops under NN was 0.183 mg; it was 0.184 under NL; 0.185 under SN, and 0.191 under maximum resource limitation (SL); the latter seed weight differed significantly from the rest. A model predicts seed weight for all crops and GDD-population density combinations with large and significant fit (R2 range from 0.70 to 0.84) and is based on N, C, and C:N allocation per unit seed weight.