Evaluation and selection of advanced lines rice (Oryza sativa L.) with high Zinc content in Irrigation and rainfed conditions in Nicaragua

Abstract

The bioaccumulation of Zn in the endosperm of popular high consumption crops such as rice has great importance to solve nutritional problems. The present research consisted of different stages of evaluation-selection of advanced rice lines with high zinc content (nursery level, evaluation of advanced lines and multi-environmental evaluation). The experiments were established under irrigation and rainfed conditions in years 2014 and 2015, in the following locations: rice experimental center “TAI-NIC”, Jalapa, Posoltega, Masatepe, San Carlos, Pantasma and Dario. The experimental design was Unbalanced Uncomplete Blocks (Alpha Latice). Agronomic performance data (days to maturity, plant height, tillering, panicle length, grain weight, yield), grain quality and zinc content in the polished grain were measured by X-ray fluorescence (FRX) methodology. Four genotypes that combine desirable agronomic, industrial and nutritional characteristics were selected. A positive relationship was established between the amount of zinc available in the soil and the amount of zinc found in polished grain. Significant differences were determined between genotypes, environments and genotype * environment interaction. Genotypes that exhibit a broad adaptive behavior and genotypes with specific adaptation for each agro climatic and management condition were selected. Two mega-environments with genotypes in common were identifi ed. The first genotype, IR31917-45-3-2-1-1SR-5-M (T4), was formed by Pantasma and Jalapa sites. The second mega-environment was formed by Masatepe and San Carlos sites, with the genotype CT18504-4-5-3Vi-2-3P (T14). In the unique environments of Posoltega and Darío the best genotypes were IR75870-5-8-5-B-2-B- 1SR-8-M (T6) for the first and CT19298- (100) -1-2-3- 1-4MP (T1) for the second. The variable that most influenced the production was days to maturity, confirming the tendency that at a longer cycle, there is higher yield; and panicle length.