Genotypic and Phenotypic Variability in Three Prairie Acacia Accessions

Abstract

This sfudy examined three prairie acacia [Acacia angustissima var. hirta (Mill.) Kunfze var. hirta (Nuff.) B.L. Rob.] accessions from Texas for genefic overlap, adapfafion fo a wide range of lafifudes, as well as seed and herbage yieid, nufrifive values, and effecf of forage harvest on seed producfion at Sfephenville, TX. The southernmost accession (Kingsville prairie acacia; KPA) yielded >400% more (P < 0.05) herbage (3483 kg dry matter ha"^ yr^) 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"^ yr^ 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.