02004naa a2200301 a 450000100080000000500110000800800410001902400340006010000250009424501610011926000090028050000300028952010700031965000130138965300220140265300320142465300130145665300170146970000160148670000160150270000200151870000240153870000210156270000200158370000180160370000170162177300640163821139022020-08-13       2020    bl uuuu     u00u1 u    #d7 a10.1590/1519-6984.2183912DOI1 aVERONEZE JÚNIOR, V.  aLeaf application of chitosan and physiological evaluation of maize hybrids contrasting for drought tolerance under water restriction.h[electronic resource]  c2020  aPublicado online em 2019.  aIt is a fact that the regions that cultivate the most maize crop do not have fully adequate technologies to measure productivity losses caused by irregularities in water availability. The objective of this study was to evaluate the physiological characteristics of maize hybrids tolerant (DKB 390) and sensitive (BRS 1030) to drought, at V5 growth stage and under water restriction, in order to understand the mechanisms involved in the induction of tolerance to drought by chitosan in contrasting maize genotypes. Plants were cultivated in pots at a greenhouse, and chitosan 100 ppm was applied by leaf spraying. The water restriction was imposed for 10 days and then leaf gaseous exchange and chlorophyll fluorescence were evaluated. The tolerant hybrid (DKB 390) showed higher photosynthesis, stomatal conductance, carboxylation efficiency, electron transport rate, and non-photochemical quenching when chitosan was used. Plants from tolerant genotype treated with chitosan were more tolerant to water stress because there were more responsive to the biopolymer.  aZea Mays  aEstresse hídrico  aFluorescência da clorofila  aTêmpera  aTroca gasosa1 aMARTINS, M.1 aMC LEOD, L.1 aSOUZA, K. R. D.1 aSANTOS FILHO, P. R.1 aMAGALHAES, P. C.1 aCARVALHO, D. T.1 aSANTOS, M. H.1 aSOUZA, T. C.  tBrazilian Journal of Biologygv. 80, n. 3 p. 631-640, 2020.