Panicle length in grain sorghum hybrids F₁–F₂ compared to parental forms

   In grain sorghum, one of the traits that determines grain productivity is panicle size. Despite its importance for productivity and adaptation, the genetic control of panicle morphology is not fully studied.

   Therefore, knowledge of the genetic basis of sorghum inflorescence architecture and its components can assist breeders’ efforts to improve sorghum. In this regard, the purpose of the current study was to determine the magnitude of heterosis and the types of inheritance of the trait ‘panicle length’, as well as the number of genes controlling this trait, in hybrids of the first- and second-generation in grain sorghum combinations obtained between varieties distant in geographic origin.

   The study was conducted in the conditions of the southern part of the Rostov region (Zernograd) in three crop rotation sequences of the laboratory for sorghum breeding and seed production of the FSBSI “ARC “Donskoy”.

   The objects of the study were parental forms, as well as hybrids of the first and second generation of grain sorghum.

   The hybridization included the varieties ‘Ataman’ and ‘Luchistoye’ developed by the FSBSI “ARC “Donskoy” (Russia), as well as the varieties ‘Seso 1’ and ‘Narosorg 1’ from the Republic of Uganda (East Africa). The conducted study allowed establishing the patterns of inheritance and manifestation of heterosis for the trait ‘panicle length’ in the hybrids F₁ and F₂ obtained on a fertile basis. There has been determined that the values of true heterosis vary from 0 to 30.8 %, and hypothetical heterosis ranges from 14.3 to 33.3 %. The trait is inherited according to the type of overdominance (hp = 1.3–17.0) and complete dominance of large values (hp = 1.0). Hybridological analysis of hybrids in the second generation allowed identifying differences in parental forms for one pair of genes.

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