Grain Fe and Zn content, heterosis, combining ability and its association with grain yield in irrigated and aerobic rice

Abstract

Genetic improvement of rice for grain micronutrients, viz., iron (Fe) and zinc (Zn) content is one of the important breeding objectives, in addition to yield improvement under the irrigated and aerobic ecosystems. In view of developing genetic resources for aerobic conditions, line (L) × tester (T) analysis was conducted with four restorers, four CMS lines and 16 hybrids. Both hybrids and parental lines were evaluated in irrigated and aerobic field conditions for grain yield, grain Fe and Zn content. General Combining Ability (GCA) effects of parents and Specific Combining Ability (SCA) effects of hybrids were observed to be contrasting for the micronutrient content in both the growing environments. The grain Fe and Zn content for parental lines were negatively correlated with grain yield in both the contrasting growing conditions. However, hybrids exhibited positive correlation for grain Fe and Zn with grain yield under limited water conditions. The magnitude of SCA mean squares was much higher than GCA mean squares implying preponderance of dominance gene action and also role of complementary non-allelic gene(s) interaction of parents and suitability of hybrids to the aerobic system. The testers HHZ12-SAL8-Y1-SAL1 (T1) and HHZ17-Y16-Y3-Y2 (T2) were identified as good combiners for grain Zn content under irrigated and aerobic conditions respectively.

Molecular Genetic Diversity and Combining Ability for Some Physiological and Agronomic Traits in Rice under Well-Watered and Water-Deficit Conditions

“…Accordingly, the genetic variations that were discovered could be exploited in establishing a successful rice program for breeding high-yielding and drought-tolerant genotypes. In keeping with these findings, high genetic variations have also been observed for different agronomic traits in rice under well-watered and water-deficit conditions by Venuprasad et al [ 49 ], Monkham et al [ 50 ], Khan et al [ 2 ], and Anusha et al [ 17 ]. The significant difference between tested irrigation regimes resulted in dissimilar impacts on the evaluated genotypes.…”

“…They disclosed that the additive gene effects contribute considerably to the inheritance of grain yield and several related traits in rice. On the contrary, other reports have found that non-additive gene action has a major role in the inheritance of agronomic traits in rice [ 17 , 19 , 75 ]. The significant GCA × I and SCA × I interactions for grain yield and most of the other studied traits indicate the differential performance of the parental genotypes and hybrids under distinct conditions.…”

“…Consequently, these parents could transfer their promising alleles to progenies and enhance grain yield under water-stress conditions. Previous studies have also emphasized the significance of using exotic and local parents with positive and high GCA effects for boosting grain yield and related agronomic traits under normal and water-deficit conditions [ 3 , 17 , 21 , 72 ].…”

“…The selection of parental genotypes with good GCA effects and offspring with high SCA effects for eligible traits can be thereby enhanced. Several studies have exploited GCA and SCA to recognize good parents and identify the best crosses for improving stress tolerance in rice [ 3 , 17 , 18 , 19 , 20 , 21 ].…”

Countering elevated CO2 induced Fe and Zn reduction in Arabidopsis seeds

“…This could have negative effects on plant growth and where crops are concerned could impact negatively on human or animal health. This is particularly serious in the case of iron (Fe) and zinc (Zn) where around 60% and 30% of the world population suffer from deficiency of these two minerals (Anusha et al ., 2021). Accordingly, decreased accumulation of these elements in fodder crops or cereals for human consumption could have serious health consequences and are likely to exacerbate what has been referred to as ‘hidden hunger’, prevalent particularly in the countries of sub‐Saharan Africa (Gashu et al ., 2021).…”