Phenotyping for Grain Mineral Contents (Iron and Zinc) in PAU201 × Palman 579 F₅ and BC₁F₄ Populations in Rice (Oryza sativa L.)

Rice (Oryza sativa L.) occupies an enviable prime place among the food crops cultivated around the world. Biofortification refers to the development of micronutrient-dense staple crops using the best traditional breeding practices and modern biotechnology. F₅ (278) and BC₁F₄ (212) plants derived from the cross between PAU201 (high yielding) and Palman 579 (Iron rich) were phenotype during 2013–14 crop season. The results showed 17.14% plants in F₅ and 5.60% plants in BC₁F₄ populations perform higher than Palman 579 for zinc content. Likewise, 1.07% F₅ and 31.30% BC₁F₄ populations performed higher than PAU201 for grain yield/plant and 17.14% F₅ population and 61.21% BC₁F₄ population performed higher than PAU201 for 1000-grain weight. Plants showed large variation for various grain yield related traits for iron and zinc contents. Pearson's correlation coefficients showed Iron, zinc content and grain yield/plant were positively correlated to all the studied traits in both the populations except plant height in BC₁F₄ population. 1000-grain weight showed significant positive correlation in both the population with panicle length, grain yield/plant, iron content and zinc content. Notably, one F₅ plant (plant number 48-14-3-2) had exceptionally high iron content (296.5 μg/g). The distribution curves showed normal parabolic distribution for effective number of tillers/plant and zinc content. Frequency distribution curves for iron content were skewed towards Palman 579 in F₅ and BC₁F₄ populations. This indicated that available populations is feasible to plan a breeding program to develop high-yielding, mineral rich rice genotypes and to identify genomic location for micronutrients content.

The mean performance of the parent PAU201 showed higher grain yield/plant and 1000-grain weight than Palman 579, while it performed lower for remaining traits. The result indicated that Palman 579 has higher iron and zinc content however PAU201 has higher grain yield. Performance of both the parents showed that they were contrasting for grain yield and micronutrients content. The contrasting behavior of these parents was also identified by the variation observed among F₅ and BC₁F₄ population. These F₅ and BC₁F₄populations could be utilized in identifications and introgression of QTL for iron and zinc content.