Inheritance of economically valuable traits in f1 hybrids of grain sorghum during saturating crosses

Abstract

Relevance.  The  effect  of  heterosis  is  of  great  importance  in  crop  breeding.  Heterosis  is  defined  as  an increase  in  the  value  of  the  trait  of  F1  hybrids  compared  to  the  average  value  of  both  parents.  In  grain sorghum breeding, heterosis is widely used to increase the yield and expand the adaptive abilities of hybrid plants.Methods.  The  object  of  research  was  13  of  the  most  precocious  F1  combinations  of  grain  sorghum  and their  parent  forms.  The  crossing  scheme  includes  seven  maternal  (Ros,  Zernishko,  Slavyanka,  Ogonek, Premiere, Mercury, Orlovskoye) and 6 paternal (Ros, Zernishko, Slavyanka, Ogonek, Belochka, Mercury) forms grain sorghum. The parameters of heterosis were calculated using the method of D.S. Omarov.Results.  The  greatest  effect  of  true  heterosis  along  the  length  of  the  panicle  was  revealed  in  the combinations:  Slavyanka  —  Ogonyok  (15.6%),  Premiere  —  Mercury  (15.0%),  and  the  highest  value of  hypothetical  heterosis  was  found  in  the  crosses  Ogonyok  —  Ros  (22.2%),  Slavyanka  —  Ogonyok (20.1%) and Premiere — Mercury (20.3%). Also, a high degree of phenotypic dominance was found in the combinations Slavyanka — Ogonyok (5.1) and Premiere — Mercury (4.4). Evaluation of hybrids and parental forms shows that many of them exceeded their parent in terms of grain yield  from  one  plant,  thus  showing  true  heterosis,  which  varied  from  6.1%  in  the  Zernyshko  —  Ogonyok hybrid to 49.5% in Premiera — Ros. The highest values of hypothetical heterosis appeared in combinations Ogonyok — Ros and Premiera — Ros — 62.8% and 51.7%. In hybrid combinations, the degree of dominance varied  from  0.6  to  34.0.  Overdomination  was  noted  for  the  Premiera  —  Ros  combination  (34.0)  and  the Ogonyok — Ros (6,7).