Estimating numbers of embryonic lethals in conifers

Abstract

Conifers have recessive lethal genes that eliminate most selfed embryos during seed development. It has been estimated that Scots pine has, on average, nine recessive lethals which act during seed development. Such high numbers are not consistent with the level of outcrossing, about 0.9-0.95, which has been observed in natural populations. Correcting for environmental mortality or using partial selfings provides significantly lower estimates of lethals. A similar discordance with numbers of lethals and observed outcrossing rates is true for other species. © The Genetical Society of Great Britain.