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Nutritive Quality of Foliar Disease Resistant and Susceptible Strains of Intermediate Wheatgrass
Author(s) -
Karn J. F.,
Krupinsky J. M.,
Berdhal J. D.
Publication year - 1989
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1989.0011183x002900020040x
Subject(s) - biology , pyrenophora , cultivar , germplasm , plant disease resistance , agronomy , poaceae , cochliobolus sativus , horticulture , botany , biochemistry , gene
Intermediate wheatgrass [ Elytrigia intermedia (Host) Nevski] including the pubescent subspecies [ E. intermedia subsp, barbulatum (Schur) A. Löve], is an important introduced cool‐season grass the plains of northern USA and southern Canada. It is susceptible, however, to foliar diseases, primarily those caused by Cochliobolus sativus , Pyrenophora tritici‐repentis , and Leptosphaeria nodorum . The primary objective of this study was to evaluate the effect of naturally occurring foliar diseases on the nutritive quality of a diverse group of intermediate wheatgrass germplasm selected for resistance or susceptibility to these diseases. A secondary objective was to examine the effect of plant height on nutritive quality and the development of foliar diseases. Herbage samples were collected from resistant and susceptible plants selected from 12 cultivars or strains on 29 July 1983 and 2 July 1985. Susceptible plants infected with foliar diseases (2‐yr means) were lower in N, and higher in neutral‐detergent fiber (NDF) ( P < 0.05) than resistant plants. In 1985, susceptible plants had higher concentrations of acid‐detergent fiber (ADF), but there was no significant ( P > 0.05) difference between resistant and susceptible plants with respect to cellulose and hemicellulose expressed on an NDF basis, indicating the affect of foliar diseases was on the cell contents, not on the cell walls. Correlation coefficients between disease ratings and in vitro digestible organic matter, N, and NDF were r = −0.27, −0.71, and 0.76, respectively, in 1983. Correlation coefficients involving these entities were lower in 1985. Plant height did not not affect the plants' resistance or susceptibility to foliar diseases. Results from this study demonstrate over a representative germplasm base that nutritive quality of intermediate wheatgrass is diminished by leaf spot diseases, and that leaf spot resistant plants maintain a higher nutritive quality in the presence of disease.