CHARACTERIZATION OF A WIDE LEAF MUTANT OF RICE ORYZA SATIVA L. WITH HIGH YIELD POTENTIAL IN FIELD

Abstract

A new wide leaf rice mutant with high yield in the field was identified which has the leaf width about 1.5-2 folds more than that of wild-type. It possesses fewer, larger, upright leaves per plant. The chlorophyll contents of leaves were significantly higher than those of wild-type. The maximal PSII (Photosystem II) photochemistry (Fv/Fm), the electron transfer rate (ETR) and photochemical quenching (qP) were lower than those of wild-type, respectively. Because of great decrease of non-photochemical quenching (NPQ), the efficiency of excitation energy trapping by open PSII reaction centers in the light–adapted state (Fv’/Fm’) was higher than that of wild-type. Low temperature fluorescence analysis showed that wide leaf mutant assigned more excited energy to PSI than to PSII. These results indicated that wide leaf mutant was better in the distribution of energy among 2 photosystems, and increase the efficiency of light utilization because of increase of chlorophyll contents. Furthermore, the SOD enzyme activities and MDA content of wide leaf mutant were nearly 44.4%, and 50.8% of those of wild-type, respectively. The low SOD and MDA contents indicated that this wide leaf mutant had high photosynthetic efficiency and its membrane structure did not probably affected(delete) by oxidation stress.