Rice is the staple food for half of the world"s population, however, its edible grain part is deficient in essential micronutrients, especially Fe and Zn. Breeding for micronutrient dense rice demands exploration of available genetic diversity for grain Fe, Zn and β-carotene contents. In this study, we analysed brown and polished grain samples of 26 traditional rice genotypes for Fe and Zn concentration. Fe concentration varied from 13.23 ppm to 45.83 ppm and 1.10 ppm to 36.45 ppm in brown and polished rice, respectively. Whereas, Zn concentration in brown and polished rice ranged from 18.67 ppm to 38.01 ppm and 5.86 ppm to 23.88 ppm, respectively. The landraces had higher Fe and Zn contents than improved varieties and advance uniform lines. Significant positive correlation was present between Fe and Zn concentration in brown (r = 0.694, P < 0.01) and polished rice (r = 0.533, P < 0.01). Fe concentration was greatly reduced by the polishing process than Zn concentration and approved varieties lost less Fe and Zn contents than advance uniform lines. Minimal levels of beta-carotene were detected in rice genotypes indicating need for genetic modifications to enhance pro-vitamin A contents in rice endosperm.

Rice is critical for sustainable food and nutritional security; however, nominal micronutrient quantities in grains aggravate malnutrition in rice-eating poor populations. In this study, we evaluated genetic diversity in grain iron (Fe) and zinc (Zn) contents using trait-linked simple sequence repeat (SSR) markers in the representative subset of a large collection of local and exotic rice germplasm. Results demonstrated that aromatic fine grain accessions contained relatively higher Fe and Zn contents in brown rice (BR) than coarse grain accessions and a strong positive correlation between both mineral elements. Genotyping with 24 traitlinked SSR markers identified 21 polymorphic markers, among which 17 demonstrated higher gene diversity and polymorphism information content (PIC) values, strongly indicating that markers used in current research were moderate to highly informative for evaluating the genetic diversity. Population structure, principal coordinate and phylogenetic analyses classified studied rice accessions into two fine grain specific and one fine and coarse grain admixture subpopulations. Single marker analysis recognized four ZnBR and single FeBR significant marker-trait associations (MTAs) contributing 15.41-39.72% in total observed phenotypic variance. Furthermore, high grain Fe and Zn contents linked marker alleles from significant MTAs were also identified. Collectively, these results indicate a wide genetic diversity exist in grain Fe and Zn contents of studied rice accessions and reveal perspective for marker-assisted biofortification breeding.

Rice is critical for sustainable food and nutritional security; however, nominal micronutrient quantities in grains aggravate malnutrition in rice-eating poor populations. Here, we assessed genetic diversity in grain iron (Fe) and zinc (Zn) contents using trait-linked simple sequence repeat (SSR) markers in 56 fine and coarse grain rice accessions of different geographical origin. Aromatic fine gain accessions contained relatively higher Fe and Zn contents in brown rice (BR) than coarse grain accessions. Genotyping with 24 SSR markers identified 21 polymorphic markers, among which seventeen demonstrated higher gene diversity and polymorphism information content (PIC) values, strongly indicating that markers used in current research were moderate to highly informative for evaluating genetic diversity. Population structure, principal coordinate and phylogenetic analyses classified studied rice accessions into two fine grain specific and one fine and coarse grain admixture subpopulations. Single marker analysis recognized four ZnBR and single FeBR significant marker-trait associations (MTAs), contributing 15.41-39.72% in total observed phenotypic variance. Furthermore, high grain Fe and Zn contents linked marker alleles from significant MTAs were also identified. Collectively, these results indicate availability of wide genetic diversity in rice germplasm and perspective for marker-assisted biofortification breeding.

U pland cotton (Gossypium hirsutum L.) is a real cash crop in Pakistan and is called white gold in the true sense. It provides lint to the textile sector, the main national export source. Approximately two per cent of our grand domestic product (GDP) is dependent on cotton (Sial et al., 2014). Its economic Abstract | An ideal genotype must possess yield constancy under erratic environments to become a popular cultivar. The genotypes contributing least towards genotype by environment interaction (GEI) are considered stable ones. The present experiment was carried out at five locations viz.