Genotypic and Phenotypic Variability in Three Prairie Acacia Accessions

This study examined three prairie acacia [Acacia angustissima var. hirta (Mill.) Kuntze var. hirta (Nutt.) B.L. Rob.] accessions from Texas for genetic overlap, adaptation to a wide range of latitudes, as well as seed and herbage yield, nutritive values, and effect of forage harvest on seed production at Stephenville, TX. The southernmost accession (Kingsville prairie acacia; KPA) yielded >400% more (P ≤ 0.05) herbage (3483 kg dry matter ha−1 yr−1) at Stephenville, TX, than the other entries the third year after establishment. Herbage removal negatively (P ≤ 0.05) affected seed yield, which was as much as 2590 kg ha−1 yr−1 for unharvested Plains germplasm prairie acacia (PPA) the second year after establishment. Final percent plot cover differed (P ≤ 0.05) among locations (Knox City, TX, 50%; Stephenville, TX, 100%; Nacogdoches, TX, 99%; Homer, LA, 61%). Differences (P ≤ 0.05) in leaf:stem ratios, some nutritive values, and crude protein yields were measured among accessions, with KPA showing the most promise where there were differences. Genetic analysis of inter–simple sequence repeat markers indicated the least within accession difference between two north Texas accessions (91 and 92% similarity) and the most difference between these two and KPA (79% similarity), which also presented a taller, woodier growth habit. Genetic variation within prairie acacia germplasm collected in Texas is expressed primarily in herbage production.