Phenotyping Systems for Evaluating Saline Stress Response in Lotus

Abstract

Salt stress tolerance is a complex trait which is determined by the additive effects of several genes whose identification is necessary to define improvement strategies. In this sense, the use of model plants genotyped and the availability of massive phenotyping methods are useful to assist breeding programs. Lotus japonicus (Regel) K. Larsen has been adopted as a determined nodulating legume model, which can be used for identification of the genetic determinants in the breeding program of Lotus and other forage legumes. In this work, in order to establish a growth system suitable for massive phenotyping, we compared four experimental systems for evaluating saline stress responses: plates, pouch, hydroponic and pots. Results allow to choose the hydroponic system as the most suitable for evaluating saline stress, since it is able to establish differences in responses based on physiological parameters of growth and development in Lotus japonicus (Gifu) and Lotus burttii genotypes. Moreover, the hydroponic system allowed to discriminate the responses in a population of recombinant inbreed lines (RILs) originated by the crossing of Lotus japonicus Gifu x Lotus burttii. Having a culture system that allows precise and massive phenotyping is necessary for detecting genomic regions involved in the responses to saline stress.