Study of inbreeding and heterosis in sunflower has been taking place for
over 80 years now. Practical application of the phenomenon of heterosis in this
species began after the discovery of a suitable source of cytoplasmic male sterility
in
1969
and that of
restorer genes.
Many authors have reported significant manifestation of heterosis for
seed yield and yield components as well. Also, the mode of inheritance of agronomically
important
traits
in
the
F
1
and F
generations has been thoroughly
examined. Positive correlations for yield have been established between parental
lines
and
F
1
2
hybrids. The GCA and SCA for yield and yield components
have been well studied. Solutions have been suggested on how to increase the
harvest index and sink capacity as well as the contributions of individual physiological
parameters
in
the
process
of yield
augmentation.
In order to increase heterotic effects for seed yield and oil yield and direct
and indirect yield components, it is necessary to increase the genetic variability
of pre-breeding materials, achieve improved efficacy at the inbreeding stage,
and streamline and accelerate the process of GCA and SCA evaluation using molecular markers and other biotechnology methods in order to achieve
breeding goals.
