COMBINING ABILITY AND GENETIC DIVERSITY OF PROMISING MAIZE (Zea mays L.) INBRED LINES UNDER VARYING WATER REGIMES ASSESSED VIA DIALLEL ANALYSIS AND RAPD MARKERS

Mohamed, Ahmed M. El.; Bakry, Hanaa S.; Soltan, H. A. H.; Asaad, M. R.

doi:10.21608/zjar.2025.445122

COMBINING ABILITY AND GENETIC DIVERSITY OF PROMISING MAIZE (Zea mays L.) INBRED LINES UNDER VARYING WATER REGIMES ASSESSED VIA DIALLEL ANALYSIS AND RAPD MARKERS

Document Type : Original Article

Authors

¹ . Agron. Dept., Fac. Agric., Minia Univ., El-Minia, 61519, Egyptt.

² Genet. Dept., Fac. Agric., Minia Univ., 61519 Minia, Egypt

³ Cent. Lab. of Organic Agric., Agric. Res. Cent. (ARC), 12619 Giza, Egypt

⁴ Agron. Dept., Fac. Agric., Minia Univ., El-Minia, 61519, Egypt

10.21608/zjar.2025.445122

Abstract

: Six white maize inbred lines were used to produce 15 F₁ crosses, which were evaluated under normal and water-stressed conditions. To determine the combining ability, 21 maize genotypes (parental lines and their respective hybrids) were evaluated during 2024 season. The genotypes exhibited highly significant mean squares for all studied traits under both watering regimes, except for anthesis-silking interval (ASI), number of rows (No.R) (under stress). The parental vs. crosses (P.vs.C.) contrast showed significant differences for all studied traits under both conditions, except, ASI and shelling percentage (SH%) under both conditions. P₁ recorded significant negative general combining ability (GCA) effects for ear weight (EW) under both conditions. However, P₃, P₄ and P₆ (under normal conditions) showed significant positive GCA effects. All crosses showed significant positive specific combining ability (SCA) effects for EW and kernel weight (KW) under both conditions, reflecting the importance of its parental combinations in enhancing productivity. Based on the molecular analysis results, it can be concluded that all six RAPD primers used were successful in verifying identity the studied maize genotypes, particularly the four primers (OPL-01, OPK-10, OPM-04 and OPM-05), which generated 6, 5 and 3 unique bands, respectively. These markers can be utilized to distinguish among genotypes. The highest similarity value (0.977) was observed between the two maize hybrids H6 and H12, while the lowest one was (0.414) observed between the two parents P₄ and P₆. The molecular findings based on RAPD marker analysis revealed clear genetic diversity among the maize parents and their hybrids, which is crucial for guiding the selection of parental lines in hybridization programs to enhance heterosis and maintain broad genetic variability in maize improvement efforts.

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