ORIGINAL RESEARCH article

Front. Plant Sci.

Sec. Plant Breeding

Volume 16 - 2025 | doi: 10.3389/fpls.2025.1618054

Genetic Analysis of Ear, Husk, and Tassel Traits in Tropical Maize under Diverse Environments

Provisionally accepted
Dan  MakumbiDan Makumbi1*Titus  KosgeiTitus Kosgei1Edna  K MagetoEdna K Mageto1Hilda  Musula KavaiHilda Musula Kavai1George  O OchiengGeorge O Ochieng1Carolyne  A AdhiamboCarolyne A Adhiambo1Joseph  S KasangoJoseph S Kasango1Joan  J C KimutaiJoan J C Kimutai1Rachael  M KamauRachael M Kamau1Julius  Pyton SserumagaJulius Pyton Sserumaga2
  • 1International Maize and Wheat Improvement Center (Mexico), Texcoco, Mexico
  • 2National Agricultural Research Laboratories, National Agricultural Research Organization (NARO), Kampala, Uganda

The final, formatted version of the article will be published soon.

Grain yield (GY) in maize (Zea mays L.) is influenced by multiple component traits, with ear-and tassel-related traits playing a significant role. Despite their importance, these traits receive less emphasis in tropical maize breeding. This study aimed to: (i) assess the inheritance and heterosis of ear and tassel traits, and (ii) investigate their genetic correlation with GY. Thirty tropical maize inbred lines were used to develop 150 hybrids, which were evaluated under artificial Striga hermonthica infestation, managed drought stress, and rainfed conditions over two years. General (GCA) and specific (SCA) combining ability mean squares were significant (P < 0.05) for most traits, indicating the contribution of both additive and nonadditive gene action. GCA sums of squares predominated over SCA, suggesting that additive gene action controlled the inheritance of ear, husk, and tassel traits. Broad-sense heritability was high for husk (H 2 = 0.59-0.89), ear (H 2 = 0.71-0.93), and tassel (H 2 = 0.78-0.95) traits. Fifteen inbred lines exhibited significant positive GCA effects for ear traits, suggesting the presence of favorable alleles associated with increased ear length (ERL) and circumference (ERC). Additionally, 23 inbred lines exhibited favorable GCA effects for reduced tassel size. Mid-parent heterosis for ERL (41%) and ERC (22%) was greater under managed drought stress. Both ERL and ERC were strongly correlated with GY (rg = 0.58-0.96), suggesting their suitability for inclusion in a selection index. Path analysis identified ERL and ERC as having significant positive direct effects on GY, while ear aspect had a negative direct effect on GY across all conditions. Selection for ear and tassel traits in tropical maize is recommended to develop more efficient inbred lines for higher grain yield.

Keywords: Combining ability, Ear length, Ear circumference, heritability, heterosis, Path analysis, Tassel traits, Striga hermonthica

Received: 25 Apr 2025; Accepted: 07 Jul 2025.

Copyright: © 2025 Makumbi, Kosgei, Mageto, Musula Kavai, Ochieng, Adhiambo, Kasango, Kimutai, Kamau and Sserumaga. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Dan Makumbi, International Maize and Wheat Improvement Center (Mexico), Texcoco, Mexico

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