Relationships between yield and agronomic traits among geographic groups of barley landraces grown under high yielding conditions

Abstract Future crop production needs to deliver sustained yield increase in important crops such as barley. Although significant progress has been made over the last century in improving yields, in the last few decades yield improvement has stagnated. Morphological traits related to yield from a wide genetic base can be explored to identify novel variation to support future plant breeding. This includes exploitation of traits and yield association for developing varieties with more consistent yield. We investigated the strength of the association between yield (grain yield, thousand grain weight) and related agronomic traits (seed number, height, ear number, flag leaf width and length, ear length). This was done among groups of European barley landrace from different geographic origins and Harlan composite cross populations compared to modern cultivars grown under a common high yield test protocol. Relationship of agronomic traits and yield were assessed for each group across environments and years. There were significant relationships between yield and morphological traits among landrace and other groups and between 2 and 6 rowed ear habit. Traits most strongly associated with grain yield were number of ears, plant height, flag leaf width and seeds per ear. Grain size as thousand grain weight was correlated with number of ears, ear length, seeds per ear, flag leaf width and plant height. We conclude that phenotypic relationships between yield and agronomic traits among barley landraces could be exploited for enhancing yield and sustainable production in future barley breeding.