Interspecific hybridization to breed the abiotic stress tolerance in Lotus genus. Effect of combined salinity and waterlogging stress.

ANTONELLI C.; ESCARAY F; CAMPESTRE MP; BABUIN M.F.; CALZADILLA PI; RUIZ OA

Simposio; 5 th International Symposium of Forage Breeding; 2015

Waterlogging is an important abiotic stress which often occurs in Flooding Pampa Grassland in Argentina and affects forager species, particularly legumes. The combination between waterlogging and salinity intensifies plant stress and only few forage legumes are able to persist under these conditions. Some species of Lotus genus are capable of producing forage under marginal conditions; nevertheless the tolerance to the mentioned stress could be improved. For this purpose our group studied four Lotus accessions: L. tenuis (Lt), tetraploid L. corniculatus (LcT), diploid L. corniculatus (LcD) and hybrid material L. tenuis x L. corniculatus (LtxLcD). Plants were grown in a chamber with controlled conditions and irrigated with Hoagland 0.5X solution. Treatments imposed during 3 weeks were: saline (NaCl-150, 150 mM NaCl was added to Hoagland), waterlogging (WL, undrained Hoagland solution with reduced levels of O2), saline waterlogging (NaCl-WL) and control (Ctrl). Productions of biomass, photosynthesis, efficiency of PSII and ion accumulation in different plant tissues were evaluated. NaCl-WL and NaCl-150 treatments reduced the shoot weight of Lt, LcT and LtxLcD; only LcD did not differ from control treatment presumably due to its lower growth rate. Similar results were obtained for net photosynthesis. Efficiency of PSII was affected only in LcT under NaCl-WL. In addition, in this condition and for this accession, the highest levels of Na+ and Cl- were recorded. Interestingly the LtxLcD accession showed the best performance under NaCl-WL treatment, demonstrating that interspecific hybridization is an invaluable tool for improving tolerance in legume foragers.