Breeding for Mg, Ca, K, and P Content in Tall Fescue¹

Abstract

Diseases such as hypomagnesaemia (grass tetany) have been associated with deficiencies of certain minerals in tall fescue (Festuca arundinacea Schreb.) and in other forage species. To overcome these deficiencies through breeding, information is needed on the inheritance of accumulation of these minerals. Objectives of our investigation were to measure the heritability of the accumulation of Mg, Ca, K, P, and a ratio, K/(Ca+Mg), and their interrelationships in tall fescue. Two diallel mating sets, each with six parents, were randomized and planted in one experiment. Forage was analyzed for Mg, Ca, K, P, and K/(Ca+Mg) for three harvest dates in 1974 and in 1975. Parents and progenies differed significantly for all minerals studied except that progenies were not significantly different for K in one of the diallel sets for the first harvest date. Estimates of general combining ability were more important than estimates of specific combining ability in the inherited uptake of these minerals. Heritability values calculated by the progeny‐parent regression and standard unit method indicated that progress can be made in breeding for higher mineral levels of most minerals at most harvest dates. Since the K/(Ca+Mg) ratio was highly heritable, progress in breeding a tall fescue with low hypomagnesaemia potential should be possible. Correlation of Mg between years was highly significant in one diallel but not in the other. Correlation of K/(Ca+Mg) between years was highly significant at all sampling dates for both diallels. Correlations coefficients between years for Ca, K, and P were more erratic.

Prospects for improving the nutritive value of temperate, perennial pasture grasses

“…Heritable variation in concentration of minerals has been demonstrated for most elements [sodium (Na) and potassium (K), Digitaria milianjiaa (Hacker et al 1985); magnesium (Mg), calcium (Ca), K, Agropyron spp. ; Na, Ca, Mg, S, phosphorus (P), iron (Fe), manganese (Mn), zinc (Zn), iodine (I), silicon (Si), but not K, chlorine (Cl), total N, NO 3 -N, or copper (Cu) (Rumball et al 1972); Mg, Ca, K, P, Festuca arundinacea (Sleper et al 1977Brown & Sleper 1980;Nguyen & Sleper 1981); K, Ca, Mg, Zn, Cu, Mn, P. arundinacea (Hovin et al 1978); Mg, L. multiflorum (Crush 1983;Moseley & Griffith 1984;Hides & Lovatt 1988)]. …”

“…Selections for low K/(Ca+Mg) ratio (Sleper et al 1977) or high Mg concentration (Reeder et al 1986) have been proposed to decrease the incidence of hypomagnesaemia associated with grass tetany. Both are highly heritable (see also Currier et al 1983 andCasler et al 1987).…”

Genetic Variability for Elements Associated with Grass Tetany in Russian Wildrye

“…), Sleper et al (1977) concluded that substantial progress should be possible in breeding for low hypomagnesemia potential in this species. This conclusion was later confirmed by Sleper and Mayland (Unpublished).…”

Genetic Variability of Mg, Ca, and K in Crested Wheatgrass

“…Such control has already been shown for Ca, Mg, and K in perennial ryegrass (Lolium perenne, Cooper 1973), Italian ryegrass (Lolium multiflorum, Hides and Thomas 1981), Lolium-Festuca hybrids (Buckner et al 1981), reed canarygrass (Phataris arundinacea, Hovin et al 1978), orchardgrass (Dactylic glamerata, Mika et al 1988 andStratton andSleper 1979), and tall fescue (Festuca anusdinacea, Nguyen and Sleper 1981). Sleper et al (1977) (Mayland 1986). To test this potential, we determined the magnitude of genetic variability and broad-sense heritability in Mg, Ca, and K uptake by crested wheatgrass.…”