Diploid sporophytic tissue in the seed of Cupressus sempervirens L.

Seeds of conifers contain a female megagametophyte (endosperm), which is us ually haploid. Results of biochemical analysis indicate the existence of a nonembryonic tissue in the seeds of Cupressus sempervirens, which expresses at isozyme gene loci the phenotype of the seed tree and is diploid. This p aper presents the genetic verification of the existence of this tissue and discusses its possible origin.