Improving maize (Zea mays L.) genotypes for higher productivity and tolerance to
drought stress depends mainly on physiological and molecular markers. Therefore,
this study aims at breeding maize for drought tolerance and high potentiality by selection based on molecular markers, photosynthetic parameters; and easy graphic methods that help in selecting elite genotypes across diverse environments. An 8 × 8 half
diallel analysis was used at two locations involving drought and normal irrigation
treatments to study parental genetic diversity (GD) and combining ability (general
combing ability [GCA] and specific combining ability [SCA]) in F1 of maize. Fingerprinting of parents was made using simple sequence repeat (SSR) markers. Fiftyeight alleles were ranged from two to five alleles per locus with an average of 0.63
alleles per locus. The average of polymorphic information content (PIC) was 0.63.
Cuvette temperature (oc) was lowest by the cross L14 × L36. The cross L8 × L34
expresses the highest value for Quantum sensor (μmol m–2 s–1), net CO2 assimilation rate and chlorophyll content. As for leaf diffusive resistance (LDR) four crosses
exhibited significant desirable LDR values. Concerning rate of leaf transpiration
(LTR) (μg cm−2 S−1) the cross (L5 × L104) gave the lowest value. Most hybrids
exhibited desirable values for drought susceptibility index. For grain yield plant–1,
five F1 crosses, that is, L5 × L34, L8 × L14, L8 × L14, L30 × L104, and L36 ×
L104 expressed the most desirable SCA effects. These crosses are promising in maize
breeding programs. Based on GGE biplot analysis, genotype nos. 8 and 10 exhibited
the highest grain yield plant−1 and ranked the first across all environments. |
