Combining Ability and Heterosis for Some Agronomic Traits in Crosses of Maize

Abstract

In 2007, five maize inbred lines were crossed in all possible combinations without reciprocals by using a half diallel crosses mating design to obtain 10 single cross. Inbred parents and their F1 single crosses were evaluated through 2008 season to evaluate the role of general and specific combining ability and heterosis for some agronomic traits. Results indicated that mean squares of genotypes were highly significant for all studied traits, i.e., ear diameter, ear length, number of kernels/row, 100-kernel weight, ear yield per plant, grain yield per plant and shelling percentage. General Combining Ability (GCA) and Specific Combining Ability (SCA) mean squares were highly significant for all studied traits. The GCA/SCA ratio was less than unity for all studied traits; this means that these traits are predominantly controlled by non-additive gene action. Significant positive GCA effects were found for all studied traits. Based on GCA estimates, it could be concluded that the best combiners were Rg5 and Rg8 inbred lines for most of studied traits. This result indicated that these inbred lines could be considered as good combiners for improving these traits. Significant positive SCA effects were found for all studied traits. Based on SCA effects, it could be concluded that the best crosses for ear diameter and 100-kernels weigh was G507AxG516; for ear length was G516xRg8; for kernels number/row was G516xG278; for ear yield/plant, grain yield/plant and Shelling percentage was G278xRg5. These crosses could be selected and used in breeding programs for improving these traits. Results showed positive significant heterosis values for all studied traits. The best crosses over both their mid-parents and better-parents for ear diameter and 100-kernel weigh was G507AxG516; for ear length and kernels number/row was G516xG278; for ear yield/plant and grain yield/plant was G278xRg8 and for Shelling percentage was G278xRg5.

Study on combining ability and heterosis for earliness and short statured plant in maize

“…It indicated that all but above mentioned two traits were governed by both additive and non-additive gene action. Similar findings in maize were reported by Aguiar et al (2004), Bhatnagar et al (2004) and Abdel-Moneam et al (2009). The additive gene action played a major role in controlling the character days to tasseling and days to maturity because of non-significant SCA of these characters.…”

Combining ability and heterosis study in maize (Zea mays L.) Hybrids at different environments in Bangladesh

“…Predominance of additive gene action for various quantitative traits in maize was reported by Muraya et al (2006), Ahmed et al (2008) and Amiruzzaman (2010). The current result was in contrast with Abdel-Moneam et al (2009) who observed GCA/SCA ratio was less than unity for 100-kernels weight and ear yield/plant indicating non additive gene action in controlling the traits. Kadir (2010) in his study showed that the non-additive effects (SCA) were more important than additive effects (GCA) for plant height, ear height, days to pollen shedding, days to silking, 1000-seed weight and grain yield/plant.…”

Daya Gabung dan Heterosis Galur Jagung (Zea mays L.) pada Karakter Hasil dan Komponen Hasil

“…Ragam DGU dan DGK yang nyata memberikan indikasi bahwa baik gen aditif maupun non-aditif memberikan pengaruh nyata pada karakter yang diamati. Hasil ini sesuai dengan yang ditemukan oleh Abdel-Moneam et al (2009);Zivanovic et al (2010); Bocanski et al (2010) dan El-Badawy (2012) dimana DGU dan DGK berpengaruh nyata pada karakter hasil biji, panjang tongkol, diameter tongkol, jumlah baris biji, rendemen dan bobot 1,000 biji. Penelitian Iriany et al (2011), DGU dan DGK berpengaruh nyata pada hasil biji dan diameter tongkol.…”

“…Nilai DGK positif menunjukkan bahwa tetua tersebut mempunyai kombinasi hibrida yang tinggi dengan salah satu tetua yang digunakan. Nilai DGK pada karakter hasil biji dan diameter tongkol menunjukkan nilai positif, hal tersebut sejalan dengan penelitian Abdel-Moneam et al (2009), Zivanovic et al (2010 dan Yustiana et al (2013). Nilai DGK yang tinggi pada hasil biji dan diameter tongkol juga dilaporkan oleh Iriany et al (2011) kedua grup penyusunnya.…”

“…Namun demikian terdapat juga hibrida dengan nilai DGK positif berasal dari satu galur saja yang mempunyai DGU positif. Penelitian Alam et al (2008), Abdel-Moneam et al (2009), Kanagarasu et al (2010), Haydar dan Paul (2014) dan Niyonzima et al (2015) menunjukkan bahwa hibrida dengan nilai DGK tinggi biasanya dihasilkan dari persilangan antar kedua tetua mempunyai nilai DGU tinggi, atau paling sedikit salah satu tetuanya mempunyai nilai DGU tinggi, namun hibrida dengan nilai DGK tinggi dapat juga dihasilkan dari pasangan galur dengan nilai DGU yang rendah.…”