Submitted to: Tropical Grasslands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 11, 2010
Publication Date: January 13, 2011
Repository URL: http://hdl.handle.net/10113/49566
Citation: Morris, J.B. 2011. Morphological, phenological, and peproductive trait analysis for the pasture species, Siratro [Macroptilium atropurpureum (DC.) Urb.]. Tropical Grasslands. 44:266-273. Interpretive Summary: Siratro is used as a forage, hay crop, and cover crop in tropical and sub-tropical areas. More than 147 accessions are conserved at the Plant Genetic Resources Conservation Unit in Griffin, GA. Limited information for producing siratro in Georgia is known. Variability for branching, foliage, plant height, plant width, days to maturity, and seed number occurred. Siratro produced quality plants and more than 4,400 seeds at Griffin indicating that siratro has potential for use in the southeastern U.S.
Technical Abstract: Agronomic traits among 66 siratro (Macroptilium atropurpureum) accessions were characterized for variability and regeneration in Byron and Griffin, GA, U.S.A. At 50% maturity, siratro accessions were evaluated for branching, foliage, height, width, days to maturity (DTM), and seed numbers between May through June 2000, 2005, and 2007 - 2008. Most of the accessions produced many branches and foliage. The best accessions for early maturity (96 DTM) and seed production (averaging 2,429 seeds per accession) included PI 451726, PI 543331, and PI 543380. The Australian accession, PI 543332 produced slightly smaller plants maturing later (121 DTM) and the highest number of seeds (4,480). The coefficient of variation was 109% for DTM and 169% for seed number indicating high variability for these traits. Potential exists to develop cultivars with improved early maturity and high seed yield. Analysis indicated that accessions clustered in group 1 revealed closer genetic relationships than those in groups 2 and 3. These accessions require further field evaluations in the southeastern U.S.A. for pasture value under grazing conditions.