Osmotic stress influence on heterosis events of maize hybrids from different maturity groups
Penka Vulchinkova • Stefan Vulchinkov
Maize Research Institute – Kneja, 5835, Bulgaria
Резюме
Four (4) maize hybrids from different maturity FAO groups and their parent
forms (P1 and P2) are studied at normal (H2O control) and osmotic stress (1μ
sucrose solution). The emerging of seeds (emerge and root) was carried out at lab
conditions for every studied genotype. The degree depression of emerge and roots is
determined by Blum et al. (1980). MPH and BPH are calculated according Omarov
(1975) and degree of dominance in F1 by Romero and Frey (1973). A high heterosis
was established at normal emerging (in water) for lenght of the emerge and root and
positive overdominance of studied hybrids. The osmotic stress changes heterosis
events of hybrids Kn-461 and Kn-560 witch are with negative values of root, merge and root, respectively by hybrids. A negative better parent heterosis (BPH)
was observed also at hybrids Kn-442 (merge) and Kn-310 (root). The degrees of
dominance at stress conditions point out that the inheritance is due to positive
overdominance of the emerge of hybrids Kn-310 and Kn-461, intermediate one
at Kn-442 and a negative overdominance for Kn-560. Specific events are present
for root dominance – incomplete positive dominance for Kn-310, overdominance
for Kn-442, a negative overdominance for Kn-461 and a negative intermediate
inheritance for Kn-560. About the total depression negative heterosis events are
found out for hybrids Kn-442 and Kn-461, and a negative intermediate inheritance
and overdominance and a positive incomplete dominance for Kn-560 was observed.
Key words: Osmotic stress, Maize hybrids degree of root and merge depression,
Total depression, MPH (Middle parent heterosis), BPH (Better parent heterosis)
