01944naa a2200265 a 450000100080000000500110000800800410001902200140006002400570007410000180013124501060014926000090025552011430026465000200140765300150142765300120144265300220145465300230147670000160149970000210151570000240153670000200156070000240158077300740160419692422023-05-15       2013    bl uuuu     u00u1 u    #d  a1806-92907 ahttps://doi.org/10.1590/S1516-359820130011000012DOI1 aSANTOS, P. M.  aResponse mechanisms of Brachiaria brizantha cultivars to water deficit stress.h[electronic resource]  c2013  aTwo cultivars of Brachiaria brizantha (Hochst ex. A. Rich) Stapf. (Syn. Urochloa) were evaluated for their adaptation to water deficit and the stress response mechanisms in a greenhouse experiment. The experimental design was in completely randomized blocks with a 2 × 2 × 4 factorial arrangement. The Marandu and BRS Piatã cultivars were evaluated under two water availability conditions, with or without water restriction. The harvests were carried out 0, 7, 14 and 28 days after the start of water restriction. For both cultivars, the water deficit stress caused a reduction in shoot biomass and leaf area and an increase in the percentage of roots in the deeper soil layers. The B. brizantha cv. Marandu reached critical levels of leaf water potential in a shorter period of water restriction than did the B. brizantha cv. BRS Piatã. The osmoregulation and deepening of the root system are mechanisms of adaptation to water stress observed in both Marandu and BRS Piatã cultivars. Besides that, the Marandu cultivar also increases its leaf senescence and, consequentially, decreases its leaf area, as a response to water deficit.  awater potential  aBRS Piatã  aMarandu  aOsmotic potential  aWater availability1 aCRUZ, P. G.1 aARAUJO, L. C. de1 aPEZZOPANE, J. R. M.1 aVALLE, C. B. do1 aPEZZOPANE, C. de G.  tRevista Brasileira de Zootecniagv. 42, n. 11, p. 767-773, nov. 2013.