Are the agronomic performance and grain quality characteristics of bread wheat Mediterranean landraces related to the climate prevalent in their area of origin?

This study analyses the relationship between the climate of the countries where wheat landraces are specifically adapted, and their agronomic and grain quality characteristics. Regions with similar climate within the Medi-terranean Basin were identified based on long-term climatic data of the 23 countries origin of a collection of 153 bread wheat landraces. The panel was genotyped with 13177 SNP markers and was grown on field experiments for two years under rainfed conditions in north-east Spain and 14 agronomic and 11 grain-quality traits were assessed. Great phenotypic variability was found in the collection. The agronomic performance of the landraces varied according to the climate of the four climatic regions identified within the Mediterranean Basin (south-east, south-west, north coast and north-Balkan), which gradually varies from warm and dry to wet and cold. Cycle length, grain-filling rate and yield increased, but grain-filling duration decreased from south-eastern landraces to north Balkan ones. Grain weight accounted for 25% of yield variations and was lowest in landraces from the south-eastern region. Grain quality showed no geographical pattern related to the climatic region. Landraces from Bosnia-Herzegovina, Bulgaria and Romania differed from the rest in their high gluten strength (W), loaf volume (LV), mixing time (MT) and grain hardness, while opposite attributes were found in accessions from Jordan, Lebanon and Cyprus. Landraces from south-western Mediterranean countries had low MT, alveograph-peak, W and LV. Genotypes suitable for use in breeding programmes may be identified. Molecular analyses revealed that genetic structure was mostly influenced by high temperatures before anthesis and rainfall, solar radiation and sunshine after anthesis.This study was partially funded by the research project AGL201565351-R and PID2019-109089RB-C31 of the Spanish Ministry of Science and Innovation (https://www.ciencia.gob.es/), the CERCA Programme/Generalitat de Catalunya (http://cerca.cat/), and CGIAR Research Program on Wheat lead by CIMMYT. Thanks are given to IPK, ISC, Suceava GenBank, VIR, CRF-INIA, CGN-WUR and NSGC-USDA for providing accessions for this study. The skilled technical assistance of the staff of the Sustainable Field Crops Programme of IRTA and the Wheat Quality and Chemistry Laboratory of CIMMYT are gratefully acknowledged. Carlos Guzm ' an gratefully acknowledges the European Social Fund and the Spanish State Research Agency (Ministry of Science and Innovation) for financial funding through the Ramon y Cajal Program (RYC-201721891)