Comparative assessment of einkorn and emmer wheat phenomes: III. Phenology

Authors: Jaradat, Abdullah

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2019
Publication Date: 9/25/2019
Citation: Jaradat, A.A. 2019. Comparative assessment of einkorn and emmer wheat phenomes: III. Phenology. Genetic Resources and Crop Evolution. 66:1727-1760. https://doi.org/10.1007/s10722-019-00816-3.
DOI: https://doi.org/10.1007/s10722-019-00816-3

Interpretive Summary: Landraces and old varieties of einkorn and emmer are composed of different genotypes with different growth patterns that may contribute to better resource-use than modern wheat. Different growth and development patterns of these species resulted from long-term environmental and farmer selection under a wide range of environments. Documentation of these patterns may provide guidelines for their improvement and for the development of newly adapted and high-yielding varieties. Reliable relationship was established between visual scoring and color measurements of plants based on digital images at different growth stages. This relationship may become useful for research and crop management in resource-limited areas. Accurate estimation of growth stages of einkorn and emmer is needed for the establishment of a cottage industry to benefit small-scale farmers, and to improve and maintain high-quality end products from these underutilized wheat genetic resources.

Technical Abstract: In-depth information on plant phenology of einkorn (Triticum monococcum L. subsp. monococcum) and emmer, (Triticum turgidum subsp. dicoccun (Schrank) Thell) germplasm, as underutilized crops, is essential for better utilization of available genetic resources of these wheat species, especially under biotic and abiotic stresses. Whereas, optimization of phenology is one of the most effective strategies to achieve this goal as it is a key factor for crop adaptation to such environments. The objectives of the study were to integrate several quantitative phenotyping methods to describe and explain phenotypic and genotypic differences or similarities in phenological development between einkorn and emmer germplasm; identify discriminating trait combinations between einkorn and emmer germplasm at successive phenological growth stages; and estimate multivariate distances between einkorn and emmer germplasm based on geographical sources and stage of genetic improvement of the germplasm. The evaluated germplasm represented a wide range of geographical origins in the Fertile Crescent of West Asia, East Africa, West and East Europe, and North America. It also represented different stages of development including landraces, old cultivars and improved germplasm. The study developed a method for accurate estimation of synchrony and duration of phenological growth stages of diverse germplasm of hulled wheat; and presented a "sliding" scale capable of discriminating between different "maturity classes" of einkorn and emmer wheat species on the basis of growing degree days in conjunction with plant height, normalized deviation vegetative index, color space coordinates, and green gradient-based canopy segmentation as phenology indicators. Accurate prediction of phenological growth stages of einkorn and emmer wheat is essential, not only for ideotype development through simulation and modeling of weather and management effects, but also to improve and maintain high-quality end products from these underutilized wheat genetic resources.