The nature of gene action for biomass yield and tropane alkaloid content was ascertained
through diallel analysis in Egyptian henbane, Hyoscyamus muticus L. Dominance variation was preponderant over additive genetic variance, dominance
being in the overdominance range for both traits. On an overall basis, recessive alleles
had a positive (i.e. increasing) effect on both the characters. However, the positive
or negative effects of recessive or dominant alleles were genotype-specific. Hence,
transgressive breeding was suggested for isolating segregants with dominant alleles
for herb yield and with recessives for alkaloid content so as to achieve overall high
yields of tropane alkaloid per unit area.
Hyoscyamus muticus
- Solanaceae dominance deviation - gene action - transgressive breeding - tropane
alkaloids - biomass
