|Belamkar, Vikas - Iowa State University|
|Wenger, Alex - Goddard College|
|Bhattacharya, Gautam - Retired Non Ars Employee|
|Blackmon, William - Retired Non Ars Employee|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2014
Publication Date: 2/3/2015
Citation: Belamkar, V., Wenger, A., Kalberer, S.R., Bhattacharya, G.V., Blackmon, W.J., Cannon, S.B. 2015. Evaluation of phenotypic variation in a collection of Apios americana: an edible tuberous legume. Crop Science. 55(2):712-726. DOI: 10.2135/cropsci2014.04.0281.
Interpretive Summary: Reliance on a small number of plant species for our major food sources increases our vulnerability to failures in the food system. Therefore, new crops should be of great interest to farmers and consumers. A native North American bean relative, Apios americana (sometimes called "potato bean" or "ground nut"), was once a staple crop of Native American Indians. This plant produces high-protein, potato-like tubers, which grow along underground stolons. This paper describes selected lines from an Apios breeding program that began in the 1980s, and reports several high-yielding cultivars. The plant is also able to grow in some challenging soil conditions, including wet or waterlogged soil. The selected varieties show good promise as a new crop -- one which is nutritious, disease resistant, high-yielding, easy to cook, and pleasing to eat. The plant shows good promise as a crop that can help diversify our food system.
Technical Abstract: Apios americana, sometimes called “potato bean,” is native to the central and eastern parts of the United States and southeastern Canada. Apios is a nitrogen-fixing legume with a vining habit that produces protein rich tubers at nodes along below-ground stolons originating from a “mother tuber.” A breeding program initiated in the 1980s, in which wild germplasm was collected from throughout the native range and hybridized, yielded ~2,500 genotypes. From these, a core collection of 53 phenotypically diverse genotypes of interest were selected for further evaluation. This study reports a two-year evaluation of this collection, using 20 phenotypic descriptors. The genotypic effect was significant for all but two of the measured traits, and the broad-sense heritability (H2) was generally high, ranging from 32% to 85%. Four above-ground traits (internode length, plant vigor, and stem diameter at 2 and 5 months) showed strong correlations (r > 0.57) with below-ground yield. Hierarchical clustering and principal component analyses group the genotypes into approximately four clusters, from which we have identified six high-yielding genotypes that may be suitable as the first “cultivars” in this new crop species. The average yield of these genotypes across both years ranged from 404.9 to 537 g/plant, with an estimated 14.5 to 19.3 Mg ha-1 and an average of 16.7 Mg ha-1 - on par with the yields reported for cassava and yam (Dioscorea), suggesting a promising future for this new crop.