Effects of Low and High Saponin Selection in Alfalfa on Agronomic and Pest Resistance Traits and the Interrelationship of these Traits1

• DOI: 10.2135/cropsci1976.0011183x001600020007x
• Publication Date: 2010-07-29T17:56:03Z
• Authors: M. W. Pedersen; D. K. Barnes; E. L. Sorensen; G. D. Griffin; M. W. Nielson; R. R. Hill; F. I. Frosheiser; R. M. Sonoda; C. H. Hanson; O. J. Hunt; R. N. Peaden; J. H. Elgin; T. E. Devine; M. J. Anderson; B. P. Goplen; L. J. Elling; R. E. Howarth
• Keywords: Phytophthora megasperma; Medicago sativa; Root-knot nematode; Hypera postica

Six alfalfa ( Medicago sativa L.) cultivars, ‘DuPuits,’ ‘Ladak,’ ‘Lahontan,’ ‘Ranger,’ ‘Uinta,’ and ‘Vernal’ were selected for low high saponin concentration tested at various locations seven agronomic traits resistance to six diseases, five insects, two nematodes. Although the selection was effective, none of (yield, foliage color, frost damage, lodging, digestibility, fraction I protein, soluble protein) consistently affected by selection. High retarded in vitro growth southern blight Sclerotium rolfsii Sacc.) but had very little effect on any other disease organisms studied: anthracnose Colletrotrichum trifolii Bain); bacterial wilt Corynebacterium insidiosum (Mc‐Cull.) H. L. Jens.); common leafspot Pseudopeziza medicaginis (Lib.) Sacc.); downy mildew Peronospora trifoliorum deBary); phytophthora root rot Phytoph‐thora megasperma Drechs.). also correlated with pea aphids Acyr‐thosiphon pisum (Harris)) no appreciable chalcids Bruchophagus roddi (Gussakovsky)), clover curculio Sitona hispidulus (F.)), spotted aphid Therioaphis maculata (Buckton)), weevil Hypera postica (Gyllenhal)), northern root‐knot nematode Meloildogyne hapla Chitwood), or stem Ditylenchus dipsaci (Kühn) Filip.). Significant correlations among pest suggest possibility linkages pleiotropic factors.