Adaptive changes of seminal root and coleoptile length in wild barley (Hordeum vulgare subsp. spontaneum (C. Koch) Thell.) over a period of 23 years in Jordan

In the context of climate change, drought is a critical challenge that drastically limits the growth and productivity of crops. Seminal roots and coleoptile play an important role in crop establishment and growth. This study assessed the adaptive changes at an early stage of development using a resurrection approach on 40 populations of wild barley [Hordeum vulgare subsp. spontaneum (C. Koch)] that were collected in 1991 and recollected from the same sites in 2014. Significant genetic variability (P < 0.001) was detected for seminal shoot and root traits assessed based on collection sites and with collection-time interactions. All traits except root length showed an increase in broad-sense heritability (h2) and diversity in the population collected in 2014, with root number and first leaf length showing the highest values (68% and 57%, respectively). The two populations diverged into two distinctive structure categories: a conserved structure and an evolved structure. Moreover, the study revealed a trend in adaptative changes of the populations by grouping them according to their eco-geographical pattern, such as a better shoot and seminal roots traits expression that allows the plant to respond to increases in drought from the north to the south over time. These results provide useful information on the responses of crop wild relatives to environmental pressures and highlight the importance of in-situ conservation in the context of climate change adaptation and sustainability of crop improvement.