Ahmed Anees*(1) Khalid Al-Zubaidy(2) Wajeh AL-Rawi(1) and Sabah Al-Dawody(1)
(1). Faculty of Agriculture, Tikrit University, Tikrit, Iraq.
(2). Faculty of Agriculture and Forestry, Mosul University, Mosul, Iraq.
(*Corresponding author: Ahmed Anees. E-Mail: ahmed75hawas@yahoo.com).
Received: 10/09/2018 Accepted: 19/12/2018
Abstract
The study was carried out to assess the combining ability and nature of gene action in maize genotypes for days to tasseling and silking, plant height, number of rows, grains per ear, 300 grain weight and grain yield per plant using a diallel mating design (without reciprocal crosses) using 7 pure lines namely, Agr183, ZM47W, CML494, IK58, ZP505, ZP670 and ZP197. The experiment was set up at the village of Albu Sabah in the province of Al-Toz using randomized completely block design with three replications during spring and autumn seasons of 2015. Analysis of variance results showed that mean squares of genotypes, parents, crosses, and general and specific combining abilities were highly significant for all characters in the two seasons. General combining ability studies indicated that the two lines CML494 and ZP505 were the best combiners for major traits including grain yield per plant in the two seasons. However, the estimates of specific combining ability showed that the significant desirable effects in the two crosses (Agr183 x ZP505) and (ZM47W x IK58) were for major traits including grain yield per plant in the two seasons. Gene action analysis revealed the importance of both additive and non-additive gene effects in controlling the inheritance of all characters in both seasons with higher preponderance of non-additive one. Narrow sense heritability was high for days to tasseling and silking in both seasons, moderate for plant height, 300 grain weight and grain yield per plant in both seasons and for number of rows and grains per ear in autumn season, while it was low for number of rows and grains per ear in spring season, this is due to the low value of the additive genetic variance and the high value of their non-additive genetic variation.
Kew words: Corn, Diallel cross, Gene action.
Full Paper in Arabic: PDF