Drought escape can provide high grain yields under early droughtin lentils

摘要

In the current context of climate change, evaluation of intraspecific genetic and phenotypic variability of lentil (Lens culinaris Medik) in response to early droughts is fundamental to gain novel insight on the adaptive potential of lentil to water deficit. Here we studied in the field the variability of functional traits, leaf biochemical composition and yield components of three Spanish lentil cultivars submitted to an atypically dry spring. The genetic variability was also studied using amplified fragment length polymorphisms based on 156 polymorphic bands. The vulnerability of the cultivars to future drier scenarios was assessedandwe identified potential traits related with lentil's tolerance to early water deficit. Inter-cultivar variability was found in the response pattern of stomatal conductance to water availability but also in other functional traits and yield components. The small-seeded commercial cultivar PAR had the highest harvest index, grain yield, maximum stomatal conductance, stomatal density and specific leaf area while the lowest root-to-shoot ratio. PAR also had early flowering and the shortest life cycle as well as high leaf polyphenol and carotenoid contents. Therefore,the drought escape strategy exhibited by PAR could be beneficial under dry springs in Mediterranean environments. In contrast, despite the big-seeded non-commercial traditional cultivar MAN displayed drought tolerant traits and high genetic and phenotypic variability, it had the lowest grain yield, suggesting that MAN is less valuable than PAR as a source of early drought resistance for the genetic improvement of lentils.