Inheritance and combing ability in maize using a 7x7 diallel cross

Abstract

Twenty one F1s produced from 77 diallel mating along with the 7 parents were evaluated to notice the inheritance and combining ability of different traits to obtain high heterotic crosses. Genetic analysis and combing ability were analyzed following Hayman's and Griffing's diallel analyses, respectively. Hybrids projecting positive or negative potency ratio with >1.0 value for those traits is also the sign of incidence of over-dominance in desirable direction, and heterosis breeding is important to improve those traits in maize. Hayman's approach indicated dominance variance and the proportion of +/genes was higher than additive variance in all characters. Griffing's analysis also demonstrated the presence of over-dominance governing the traits. The preponderance of dominant gene action coupled with low heritability observed for days to silking, ear length and grain yield suggests the importance of heterosis breeding. Substantial differences in general combing ability and specific combining ability were noticed in all the studied traits except 1000-grain weight. The parental line CML-509 was found to be the best general combiner for days to tasseling and silking, CML-498 for plant height, ear height and grain yield, CML-395 for ear length and grain yield. The crosses CML-498×CML-376, CML-498×CML-395 and CML-376×CML-247 showed significant positive specific combining ability effect for grain yield along with higher mean values over commercial check varieties.

Genetic Analysis and Heterosis Studies in 5×5 Diallel Crosses of Maize under the Meteorological Conditions of Rawalakot

“…For days to 50% silking minimum heterosis was shown by NCEV-4 × NCEV-1530-11 (-2.08%) and NCEV-4 × EV-70040 (-1.58%). Similar heterosis for days to 50% pollen shed was reported earlier in maize by Karim et al (2018) and Begum et al (2018).…”

“…These crosses showed better plant height than their parents. Karim et al (2018) and Begum et al (2018) also obtained similar results and observed significant positive levels of mid-parent heterosis for plant height in their studies.…”

Diallel analysis and estimation of heterosis in single cross maize hybrids

“…P1×P2, P1×P4, P4×P5, and P6×P7 showed significant negative SCA effects for plant height indicating the better specific combinations of these hybrids for plant height, which is desirable as short-statured plants are mostly lodging tolerant. But Begum et al, (2018) found no significant and negative SCA effects for plant height. Considering yield, seven crosses performed significant and positive SCA effects for grain yield (Table 04) and most of them also possessed high mean values for the trait (Table 01).…”

“…The percent heterosis for grain yield varied from -85.76 to 10.83% (Table 05). Moreover, Karim et al, (2018), Talukder et al, (2016) and Begum et al, (2018) found 5.25%, 12.53 % and 9.9% significant positive heterosis in their studied materials, respectively. Among the 28 F1, three crosses revealed positive heterosis for grain yield.…”

“…P1×P5, P1×P7, P2×P4, P3×P5, P4×P5, P4×P8, and P6×P7 exhibited significant and positive SCA effects for yield. Begum et al, (2018) found 9 significant and positive SCA effects in their crossed materials. The significant and positive SCA effect involved parents where one or both the parents were related to good combiners, indicating GCA of the parental lines plays a vital role for high yield.…”