Genetic Analysis on Agronomic Traits Related to Zinc Efficiency in Lowland Rice

Abstract

The hereditary characteristics of plant traits related to zinc (Zn) efficiency in lowland rice (Oryza sativa L.) were analyzed in this study. The plant traits include the relative values of the total plant dry matter, shoot dry matter, root dry matter, leaf number, plant height, and root length of rice seedlings grown at low Zn2+ activity compared to those at sufficient Zn2+ activity. The F1 progeny was obtained by using a diallel cross between Zn-efficient and Zn-inefficient rice genotypes. The results revealed that the variances of dominant effect of all the traits studied were significant or very significant with the ratio being more than 65.4% of total variance. The additive effect variances of other traits except for the root length were also significant or very significant, with the average ratio being 21.85% of total variance. The variance of epistatic effect for root length was significant, with a ratio of 48% of total variance. The relative values of root length at low Zn2+ activity to sufficient Zn2+ activity was found to be governed by dominant and additive effects of hereditary genes. The relative values of leaf number, plant height and dry matter weight of rice seedlings were mainly governed by dominant effects of genes, secondarily by additive effects of genes. As the ability of rice tolerance to Zn deficiency was closely related to these agronomic traits, zinc efficiency in rice was mainly governed by dominant effects of genes, secondarily by additive effects of genes, and might be influenced by its epistatic effects of genes.