INHERITANCE OF BIOMASS YIELD AND TROPANE ALKALOID CONTENT IN HYOSCYAMUS-MUTICUS

The nature of gene action for biomass yield and tropane alkaloid conte nt was ascertained through diallel analysis in Egyptian henbane, Hyosc yamus muticus L. Dominance variation was preponderant over additive ge netic variance, dominance being in the overdominance range for both tr aits. On an overall basis, recessive alleles had a positive (i.e. incr easing) effect on both the characters. However, the positive or negati ve effects of recessive or dominant alleles were genotype-specific. He nce, transgressive breeding was suggested for isolating segregants wit h dominant alleles for herb yield and with recessives for alkaloid con tent so as to achieve overall high yields of tropane alkaloid per unit area.