Performance, Heterosis, and Combining Ability for Some Important Traits of Maize (Zea mays L.) Under Low Addition of Nitrogen

Combining Ability for Some Important Traits of Maize (Zea mays L.) Under Low Addition of Nitrogen

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Ahmad A. ElAli ElKhalf*(1) and Abed El Karim El Gasem(2)

(1). Raqqa Research Center, General Commission for Scientific Agricultural Research, Damascus, Syria.

 (2). Corporative Society for Cereal Marketing and Store, Raqqa, Syria.

(*Corresponding author: Dr. Ahmed Al-Ali Al-Khalaf. E-Mail:

Received 05/11/2021                     Accepted 15/12/2021


Seven inbred lines of maize were crossed in half diallel system (7×7) to give a set of 21 F1 crosses following method 2 (parents and crosses), model 1 (fixed) of Griffing (1956) at the Scientific Agricultural Research Center in Raqqa, Syria. RCBD lay out was applied and arranged in split plot design where the main factor was the nitrogen level while the secondary factor was the genotypes with three replications during the growing seasons 2013 and 2014, to evaluate the performance of maize genotypes under three levels of nitrogen (40, 80, and 130 N kg/ha), to assess the general combining ability (GCA) and specific combining ability (SCA) effects, and to study heterosis (%) for days to tasseling, 100 kernels weight (g) and grain yield (ton/ha). Analyses of variance for combining ability (GCA and SCA) variance was significant for all studied traits, which indicated that these traits were controlled by additive and non-additive gene actions. P1, P3 and P4 were considered as desirable inbred lines for days to tasseling and grain yield, this is a clear indication that these parents have the largest number of genes that had additive effect which play an important role in the inheritance of these traits. The best crosses namely (P1xP3, P1xP2, P1xP4, P3xP4 and P2xP3) showed highest significant SCA effects and heterosis, this refers to the possession of these crosses largest number of genes that show dominance in inheritance those traits, which means deterioration of quality value due to continues genetic isolations under the influence of low nitrogen levels.

Key words: Maize, Heterosis, GCA, SCA, Low Nitrogen addition, Crosses.

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