El potencial de agua del sustrato en la germinación de maíces con tolerancia y sensibilidad a la sequía

the objective of this study was to characterize seed germination of drought sensitive and tolerant maize in laboratory conditions. cafime o, qpm (quality protein maize) h519, tuxpe？o sequia c0 and zacatecas 58 o, drought sensitive, and cafime sm16 sequia, tuxpe？o sequia c8 and zacatecas 58 sm19 sequia, drought tolerant cultivars, were evaluated. the seeds were germinated in vermiculite with ψw of-0.03 mpa (well watered), -1.28, -1.41, -1.58 y -2.05 mpa (with 6% of humidity), were weighted every 12 h and the percentage of water absorbed and germination was calculated. the maximum imbibition (up to germination) in the ψw of -0.03 mpa of all cultivars was significantly major compared with the other ψw evaluated and it reached between 40% and 70%, in variable times between the cultivars, from 48 h (cv. caf. seq.) untill 170 h (cv tux. seq. c8). the cafime sm16 and zac. 58 sm19 cultivars reached maximum germination four times higher with the ψw of -2.05 mpa compared with their respective drought sensitive cultivars. the drought tolerance of some drought tolerant cultivars, like cafime sm16, is expressed since the germination stage; even though this respond contrasts between cultivars. some drought tolerant cultivars react negatively at the high substrate ψw and reach germination percentages significantly higher when the substrate ψw is significantly lower, between -1.28 and -1.58 mpa.