PRELIMINARY SURVEYS FOR THE GENETIC VARIABILITY OF RICE ASSOCIATION WITH PLANT GROWTH PROMOTING BACTERIA

The root endophytic microbiota can enhance plant tolerance to biotic an abiotic environmental challenges in several plant species, including th rice crop. It is possible that during plant domestication and varie selection the aptitude of rice roots to associate with be microbiota has been modified, since this aptitude was not a direct target of selection and because the human input for plant nutrition and defenc have lowered the importance of the microbiota contribution for traits. To verify whether there is genetic variability in the level of rice root association with selected endophytic plant growth promoting bacteria (PGPB), we evaluated such aptitude in a range ofOryza sativa ssp. japonica accessions and in a wild ricOeryza( rufipogon) accession. Results highlighted a variability in both the germplasm pools, in particular, the rice variety Baldo and the wild riOc.e rufipogon accession showed an aptitude to associate with a nitrogen fixing endophytic strain at least ten and sixty times, respectively, higher than Vialone Nano. Availability o segregating populations derived from crossing Baldo x Vialone (recombinant inbred lines, RILs) and Vialone Nano xO. rufipogon accession (BC3F4 introgression lines) are allowing preliminary evaluations of t segregation of the association aptitude in these rice genotypes and the identification of lines with enhanced aptitude to associate with PBPG.