|SHAHID, M - ICBA, UAE
|AL MASKRI, A - SULTAN QABOOS UNIV.
Submitted to: International Journal of Food, Agriculture, and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2005
Publication Date: 4/1/2005
Citation: Jaradat, A.A., Shahid, M., Al-Maskri, A.Y. 2005. Biomass production potential in the Batini barley landrace from Oman. Journal of Food, Agriculture, and the Environment. 3(2):249-253.
Interpretive Summary: With the increased interest in indigenous plant resources, particularly for forage production, information is required on the phenology and biomass production potential of barley landraces as a reliable source of forage for livestock production in developing countries. High levels of variation were detected in the Batini barley landrace from Oman for the duration of vegetative and reproductive growth stages. A combination of short, medium and long days to heading, days to maturity and filling period in 2,040 accessions of the Batini landrace identified 14 phenological classes. When combined with diversity in plant height, tillering capacity, and biological and grain yield, the whole collection separated into distinct grain-, dual purpose-, and forage-types. A selection index, based on these traits was developed and was instrumental in selecting parental types and accessions with the desired combination of developmental stages and production potential. Natural variation available in this germplasm collection for phenology and biomass production potential is of tremendous value to breeders, agronomists and farmers in their quest to increase forage productivity and production, especially in irrigated agriculture.
Technical Abstract: Information is required on the phenology and biomass production potential of barley landraces as reliable forage sources in developing countries lacking feed for increasing livestock demands. Our objective was to quantify diversity available in seven subpopulations of the Batini barley landrace for pre- (deg Cd-1H) and post-anthesis (deg Cd-1M) thermal time, filling period (deg Cd-1Fp), biological (BY) and grain (GY) yield, number of tillers (TL) and plant height (PH). We examined whether farmers' and natural selection have altered the mean phenotype among and within subpopulations; identified grain, forage and dual-purpose types; and formulated discriminant functions to help select elite germplasm for breeding purposes. Patterns of phenotypic variation and covariation in the phenological and agronomic traits, measured on 2,040 landrace accessions, subdivided the collection into 14 phenological classes in three (grain, dual-purpose and forage) end-use types, each with distinct phenological trait combinations. The dual-purpose type was more polymorphic and significantly had higher total diversity and differentiation than the grain and forage types. Extensive divergence in the phenotypic covariance matrices among phenological classes suggests that directional selection, especially in the phenological traits, resulted in large, idiosyncratic changes in the principal components' structure, and that some of the changes are attributed to shifts in the mean phenotype. Discriminant loadings indicate that BY, deg Cd-1H, deg Cd-1M, GY, PH and TL, in decreasing order, were most influential in discriminating among phenological classes. Knowledge of genetic covariation of these traits will be useful for plant breeders by targeting traits that have a disproportionately large influence on differences in the mean covariance.