JIP TEST ANALYSIS OF FLAG LEAF SENESCENCE IN RICE

JUAN MANUEL VILAS; MARIA FLORENCIA BABUIN; RODOLFO BEZUS; ANDRES ALBERTO RODRIGUEZ; SANTIAGO JAVIER MAIALE

Congreso; XXXI Reunion Argentina de Fisiologia Vegetal; 2016

Introduction: Rice (Oryza sativa L),  is a very important crop in Argentina which undergoes episodes of cold weather during the implementation period. Low temperatures cause stunted growth in seedling rice and affects grain yield by affecting tillering, spikelet formation and ripening in adult plant . Cold stress cause damage in photosynthetic apparatus , particularly  in the photosystem II (PSII). The aim of this work  was to analyze the behavior  of PSII  in the flag leaf  and their relationship  whit growing under low temperature in seedling plants.We used  a  F2 panel population from crossing sensitive and tolerant varieties. We assess growth at low temperatures  in seedling  and   behavior of the photosynthetic apparatus in flag leaf. the seedlings of F2 population were grouped according the distribution of net leaf elongation under ST, 30 plants with highest and lowest net leaf elongation (Hereafter, groups H and L, respectively). We observed a smaller drop in PS II   functionality in group H compared with the group L. Among the parameters that explain the differential behavior they may be mentioned the size of the antenna, the dissipated energy and the probability that a photon trapped an electron move beyond Qa.In conclusion, these results suggested that there was an association between growth at low temperatures in seedling stage and the PSII performance in flag leaf of rice.