03072nam a2200205 a 450000100080000000500110000800800410001910000170006024501680007726000980024552023930034365300110273665300240274765300120277165300120278370000140279570000180280970000230282770000160285010597292019-04-16       2019    bl uuuu     u00u1 u    #d1 aDO CANTO, J.  aDoes endophyte-association improve productivity in tall fescue? The case of the novel AR584 strain in a non-limiting environment. [Resumen].h[electronic resource]  aIn: International Forage & Turf Breeding Conference,  24-27 March, Lake Buena Vista, FLc2019  aIn the symbiotic relationship between tall fescue (Festuca arundinacea SHREB.) and the endophytic fungus Epichloë coenophialum, the compounds produced by the later offers survival benefits to the infected grass. Novel endophyte strains offer such advantages, with no toxicity associated to cattle. However, whether both the biotic and abiotic stress tolerance attributed to the endophyte infection result in an increase in dry matter productivity remains unclear. Thus, the objective of this study was to determine if tall fescues infected with the novel endophyte strain AR584 performed better than its endophyte-free counterpart in the temperate region of Uruguay. From 2010 to 2017 two cultivars, INIA Aurora and INIA Fortuna, with and without the AR584 endophyte (E+ and Nil respectively) were sowed in the tall fescue field trials of INIA?s breeding program. These cultivars along with other breeding lines were sowed in 6.25 m2 plots, with 4 reps in randomized complete block design, and were evaluated for 3 years periods. Both, seasonal and annual dry matter (DM) production of the swards were evaluated under cuts. Analysis of the data shows that Cultivar INIA Aurora E+ had higher annual DM yields than INIA Aurora Nil in swards of all 1st, 2nd and 3rd years, but differences were not significant (P>0.05). The seasonal DM yields were also higher in INIA Aurora E+ in all but one season, although the difference was significant only in spring of the 1st year (P<0.05). On the other hand, cultivar INIA Fortuna E+, had higher annual DM yields in swards of 1st and 2nd years and lower yield in 3rd year than INIA Fortuna Nil but differences were never significant (P>0.05). Except for the 3rd winter and spring, seasonal DM yields were higher for INIA Fortuna E+, but again the differences were not significant (P>0.05). For the total DM production over 3 years of evaluation, INIA Aurora E+ produced 4.9% and INIA Fortuna E+ produced 1.4% more than their respective Nil versions. Levels of infection measured by blotting test averaged 91±5.5 for INIA Aurora E+, 3±2.2 for INIA Aurora Nil, 93±3 in INIA Fortuna E+, and 25±7.9 in INIA Fortuna Nil. Although data can be further analyzed, these preliminary analysis suggests that the novel endophyte AR584 provides a small, but not significant advantage, in DM production to, infected tall fescue cultivars in mild environments.  aFESCUE  aFESTUCA ARUNDINACEA  aPASTURA  aPASTURE1 aREYNO, R.1 aGUTIERREZ, F.1 aCIBILS-STEWART, X.1 aSTEWART, A.