Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones

Abstract

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

Genetic Variation for and Correlations Among Seed Yield and Seed Components in Tall Fescue

“…These results were in agreement with previously published reports on tall fescue (Veronesi and Falcinelli, 1988;Moutray and Frakes, 1973;Ibrahim, 1980;Griffiths et al, 1980, Nguyen and Sleper, 1983b) and other grasses (Jafari, 2003;Araujo and Coulman, 2004). According to our results, selection for higher seed yield by increasing the fertility index seemed possible.…”

“…Clonally propagated parents and their half-sib family seeds were grown as individual spaced plants using a randomized completeblock design with two replications in Alborz Research Center, Karaj, Iran, during 2002-2004. The estimates of broad-sense heritability (h b 2 ) were moderate to high for all traits (h b 2 = 0.46-0.82), except harvest index, seed number and seed weight per panicle.…”

Productivity, persistence and traits related to drought tolerance in smooth bromegrass

“…The heritability for a particular trait will enable calculation of expected genetic gain (ΔG) that will provide the basis for designing an effective breeding programme to maximize genetic improvement (Falconer , Kearsey and Pooni ). Estimation of genetic variance and heritability has been carried out in many of forage grasses through different biometrical methods and designs (Araujo , Ebrahimiyan et al. , Amini et al.…”

Half-sib progenies evaluation in velvet grass

“…In meadow bromegrass (Bromus riparius Rehm. ), Araújo and Coulman (2004) have found broad-sense heritabilities of 90% for height and 58% for diameter.…”