Exogenous application of mixed micro-nutrients improves yield, quality, and 2-acetyl-1-pyrroline contents in fragrant rice

Application of micro-nutrient at low concentrations can play significant roles in yield and quality improvements as well as aromatic characters of fragrant rice.Present study investigated the exogenous mixed application of micro-nutrients on yield quality, 2-acetyle-1-pyrroline (2-AP) and mineral content accumulation in the grains of two aromatic rice cultivars i.e., Xiangyaxiangzhan and Guixiangzhan.Two mixtures containing different proportions of micro-nutrients i.e., mixture-1 (40% zinc sulfate, 6% manganese sulfate, 1% ferric chloride, 50% proline, and 3% sodium selenite) and mixture-II (containing 1% gibberellic acid, 8% zinc sulfate, potassium 76% di-hydrogen phosphate, 8% manganese sulfate, and 7% copper sulfate) were exogenous applied at full heading stage at 1.5 kg hm -2 (T1) and 3 kg hm -2 (T2) diluted in 750 L water while plots with only water application were served as control (CK).Results revealed that exogenous application of mixed micro-nutrients notably increased yield in terms of improved grain numbers per panicle, filled grain (%), 1000-grain weight, grain yield, grain 2-AP, selenium (Se) and zinc (Zn) contents while decreased amylose content, chalky rice percentage and chalkiness degree in both rice cultivars.Furthermore, exogenous application of mixed micro-nutrient enhanced above ground plant dry biomass for both rice cultivars.Significant correlations among 2-AP, Zn and Se (P≤0.05)suggested that these two micro-nutrients have dynamic roles in rice aroma production, however, to unravel the exact mechanisms of micro-nutrient involvement in 2-AP biosynthesis, further research is needed.