Combining Ability of White Maize Inbred Lines Via Line X Tester Analysis

Abstract

Combining ability analysis was conducted using line x tester design for seven inbred lines of maize which were crossed to three single crosses as testers at Ismailia Agricultural Research Station during 2016 growing season. In 2017 season, 21 crosses in addition to one check hybrid were evaluated at three locations. Highly significant differences were found between the locations for all studied traits. Mean squares due to crosses, their partitions and their interaction with locations were significant or highly significant for all studied traits, except for lines and lines x testers for number of ears/plant and testers for number of rows/ear. The best inbred lines for general combining ability effects were Gz-8093, Gz-8092 and Gz7253 for earliness and Tep-6240 for grain yield. the tester SC 131 was the best general combiner for days to 50% silking toward earliness, grain yield, number of ears/plant, ear length and ear diameter. The cross Gz-8093 x SC131 had the desirable SCA effects for all traits also. The additive gene effects were more important than the non-additive gene effects in inheritance of days to 50% silking, number of ears/plant, ear length and ear diameter while, the non-additive was more important than additive for grain yield, number of rows/ear and number of kernels/row. The nonadditive gene effects were more affected by environment than additive gene effects for all traits except for number of ears/plant. The cross Gz-8093 x SC131 highly significantly outyielded to the TWC 324, suggesting the use of this cross in maize breeding programs.

Evaluation and Classification of Yellow Maize Inbred Lines Using Line X Tester Analysis Across Two Locations

“…The combined analysis of variance showed highly significant mean squares due to locations (Loc) for all the studied traits (Table 2), indicating the presence of a clear variation between the two locations in climatic and soil conditions for these traits. These results agreed with those reported by El Hosary et al (2018), Gamea et al (2018), El-Shahed et al (2021) and Mousa et al (2021).…”

“…This finding showed that nonadditive type of gene action was more affected by locations than the additive ones. These results are in agreement with the findings of Ibrahim et al (2010), Abd Allah et al (2011, Mousa and Aly (2012), Abdel-Moneam et al (2014) and Mousa et al (2021). They found that the non-additive genetic effects were more sensitive to environmental changes than the additive genetic effects.…”

“…This indicates that the tested inbred lines, testers and their crosses behaved differently from one location to another. These results corroborate the findings of Gamea et al (2018), Abd El-Aty et al (2018, Darshan and Marker (2019), Mohamed (2020) and Mousa et al (2021).…”

“…The estimates of variances due to GCA, SCA and their interactions with locations (Table 3) showed that the SCA variance was higher than GCA variance for all studied traits, indicating that the non-additive effects had an important role in the inheritance of these traits. These results are in harmony with the findings of Abdel-Moneam et al (2020), El-Hosary (2020), Mohamed (2020), El-Shahed et al (2021) and Mousa et al (2021).…”

Combining Ability Variation of some White Maize Inbred Lines via Line X Tester Analysis under Ismailia and Mallawy Locations

“…The significant GCA implies that breeders can exploit the available genetic variability in the identification of elite materials with desirable traits, whereas significant SCA effects suggest that promising single cross combinations may be found. However, each of Mosa (2010), Mostafa (2018) and Mousa et al (2021) reported that the tested genotypes should exhibit enough genetic diversity for an effective breeding program via. Top cross modeling.…”