Combining ability of tropical × temperate maize inducers for haploid induction rate, R1-nj seed set, and agronomic traits

Abil Dermail; Thomas Lübberstedt; Willy Bayuardi Suwarno; Sompong Chankaew; Kamol Lertrat; Vinitchan Ruanjaichon; Khundej Suriharn

doi:10.3389/fpls.2023.1154905

Combining ability of tropical × temperate maize inducers for haploid induction rate, R1-nj seed set, and agronomic traits

Front Plant Sci. 2023 Apr 11:14:1154905. doi: 10.3389/fpls.2023.1154905. eCollection 2023.

Authors

Abil Dermail¹, Thomas Lübberstedt², Willy Bayuardi Suwarno³, Sompong Chankaew^{1

4}, Kamol Lertrat⁴, Vinitchan Ruanjaichon⁵, Khundej Suriharn^{1

4}

Affiliations

¹ Department of Agronomy, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
² Department of Agronomy, Iowa State University, Ames, IA, United States.
³ Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University, Bogor, Indonesia.
⁴ Plant Breeding Research Center for Sustainable Agriculture, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
⁵ National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Pahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, Thailand.

Abstract

In vivo maternal haploid induction in isolation fields is proposed to bypass the workload and resource constraints existing in haploid induction nurseries. A better understanding of combining ability and gene action conditioning traits related to hybrid inducers is necessary to set the breeding strategy including to what extent parent-based hybrid prediction is feasible. This study aimed to evaluate the following in tropical savanna in the rainy and dry seasons for haploid induction rate (HIR), R1-nj seed set, and agronomic traits: 1) combining ability, line per se, and hybrid performance of three genetic pools; 2) genetic parameters, the modes of gene action, and heterosis; and 3) the relationships of inbred-general combining ability (GCA) and inbred-hybrid performance. Fifty-six diallel crosses derived from eight maize genotypes were evaluated in the rainy season of 2021 and the dry season of 2021/2022. Reciprocal cross effects including the maternal effect barely contributed to the genotypic variance for each trait observed. HIR, R1-nj seed set, flowering dates, and ear position were highly heritable and additive inherited, while ear length showed dominant inheritance. The equal importance of additive and dominance effects was found for yield-related traits. Temperate inducer BHI306 was the best general combiner for the HIR and R1-nj seed set, followed by two tropical inducers, KHI47 and KHI54. The ranges of heterosis were trait-dependent and slightly influenced by the environment, where hybrids in the rainy season consistently had higher heterosis than those in the dry season for each trait observed. Both hybrid groups derived from tropical × tropical and tropical × temperate inducers showed taller plants, larger ear size, and higher seed sets than the corresponding parents. However, their HIRs were still below the standard check of BHI306. The implications of genetic information, combining ability, and inbred-GCA and inbred-hybrid relationships on breeding strategies are discussed.

Keywords: Zea mays L.; diallel analysis; doubled haploid technology; gene action; haploid production; heritability; heterosis; hybrid inducer.

Grants and funding

The National Research Council of Thailand through the Royal Golden Jubilee Ph.D. Program (NRCT5-RGJ63003-070) and the National Science and Technology Development Agency (NSTDA) (Grant Nos. P-20-50493, P-20-52286, and P-21-50610).