Selection of maize top-crosses for different nitrogen levels through specific combining ability

Abstract

An alternative to increase yield without raising the production costs and minimizing the dependence of agricultural inputs is the development of maize genotypes presenting high nitrogen (N) use efficiency under low N level conditions. Thus, the objective of this study was to estimate the specific combining ability of maize topcrosses under high and low nitrogen (N) conditions and to select highyielding hybrids for both conditions. The grain yield of 110 top-cross hybrids was evaluated in 2012 in two locations in the Brazilian Midwest. Partial diallel analysis was performed with the adjusted means of each PLANT BREEDING -Article of the individual top-cross analyses. Specific combining ability (SCA)of the hybrids and their interaction with N levels was estimated for each location. The mean grain yield of the 11 hybrids selected by the highest SCA estimates for high and low N was higher than the controls mean in approximately 330 and 241 kg•ha -1 . These results demonstrate that the selection for each environment was efficient and reveals the possibility of developing new hybrids for the Brazilian Cerrado region.

Maize topcrosses for yield performance by additive main effects and multiplicative interaction analysis

“…The MlP102, AG8025 and 60.h23.1 testers held most of the interaction, suggesting that they are not the most suitable for topcross, as they influence the relative merit of the evaluated inbred lines. Regarding tester 70.h26.1, in addition to high stability, a wide adaptability to most of the inbred lines evaluated can be verified considering both the additive and multiplicative effects of the interaction (CANDIDo et al, 2020;hEINZ et al, 2019).…”

“…When the iLxT interaction is verified in topcross evaluations, in most cases through the analysis of variance and the use of the additive model, this one is only mentioned without considering the analysis of the partition or the respective contribution of each genitor for a significant effect of the interaction (CANDIDo et al, 2020;hEINZ et al, 2019). Given the above, the AMMi analysis can enable a more efficient interpretation by allowing the partition of the effect of the interaction and; consequently, its study and analysis in more detail (ChARCoSSET et al, 1993).…”

“…It is not possible to determine a suitable tester for all crosses when there is a large number of inbred lines, mainly due to the fact that some inbred lines are eliminated because the tester used has low combining ability, influences heterogeneously with dominant or epistatic alleles (vencovsky & BArrigA, 1992). Another aggravating factor is that when the iLxT interaction is verified in topcross evaluations, in most cases through the analysis of variance and the use of the additive model, this one is only mentioned without considering the partition, multiplicative effects or the respective contribution of each parent to a significant effect of the interaction (CANDIDo et al, 2020;hEINZ et al, 2019).…”

Assessment of Nitrogen Use Efficiency in Algerian Saharan Maize Populations for Tolerance under Drought and No-Nitrogen Stresses

“…Drought also affects fertilization, particularly nitrogen (N) uptake by the plant, which is a paramount macronutrient for plant growth, development, and production. The high and relatively rapid nutrient requirement is an important characteristic of maize, and its production consumes over one-fifth of all nitrogen produced [20], resulting in marked increases in yield [21]. In addition, as a C4 plant, maize accumulates biomass efficiently under abundant N supply with high photosynthetic efficiency [22,23].…”

“…The breeding goal for high NUE is to maintain or increase productivity with less N applied [39]. Then, the alternative to increase yield without raising the production cost and minimizing the dependence on agricultural inputs is the development of maize genotypes presenting high NUE under low N level conditions, allowing the development of sustainable agriculture [21,30,31,33,40]. Moreover, compared to inefficient cultivars, a nitrogen-efficient cultivar may produce a higher yield at low N and/or at high N applications.…”