Submitted to: Soybean Bio-Active Compounds
Publication Type: Book / Chapter
Publication Acceptance Date: September 5, 2012
Publication Date: February 20, 2013
Citation: Morris, J.B., Wang, M.L., Tonnis, B.D. 2013. Variability of phenotype, anthocyanin indexes, and flavonoids in accessions from a close relative of soybean, Neontonia wightii (Wright & Arn. J.A. Lackey) in the U.S. germplasm collection for potential use as a health forage. In: El-Shemy, Hany A., editor.Soybean Bio-Active Compounds. Rijeka,Croatia:Intech. p.375-386. Interpretive Summary: Neonotonia wightii is used as pasture, hay, and silage in tropical areas worldwide. Little information for producing N. wightii is known. Variability for branching and foliage characteristics, plant height, plant width, plant maturity, seed number, leaf anthocyanin index, leaflet weight, and genisten content occurred. Neonotonia wightii produced quality plants and more than 2,000 seeds in the greenhouse at Griffin, GA indicating that N. wightii has potential for use in the tropical southeastern U.S.
Technical Abstract: A close relative of soybean, Neonotonia wightii (Wright & Arn. J.A. Lackey), is used as a ruminant feed and restores soil productivity in Brazil and Zimbabwe, respectively. Neonotonia wightii accessions were grown in a greenhouse at Griffin, Georgia, characterized for various phenotypic traits, and the leaflets were evaluated for anthocyanin indexes as well as flavonoids. Significant variation for phenotypic traits, anthocyanin indexes, and genistein were observed among these N. wightii accessions. The accession, PI 213256 matured the earliest and produced the most seeds (2214). The accessions, PI 213257 and PI 612241 produced a significantly higher anthocyanin index (7.5) and genistein content (90 µg/g of leaflet tissue), respectively than all other accessions. Several significant correlations were detected, including branching with foliage (r2 = 0.84***), foliage with plant width (r2 = -0.28*), plant width with maturity (r2 = 0.57***), and maturity with seed number (r2 = -0.39**). However, there were no correlations detected among the phytochemical traits. Variability among accessions for phenotypic traits, anthocyanin indexes, and genistein were observed based on principal component analysis. Cluster analysis grouped 14 N. wightii accessions into two maturity groups and one outlier. Interestingly, the average distance cluster analysis also grouped 7 N. wightii accessions into three genistein producing accessions and one outlier. Several of these N. wightii accessions could be used in the development of superior cultivars, since variability for phenotypic traits, maturity, seed reproduction, and genistein has been determined.