Haploid trees: Their production in vitro and use in forest tree improvement [including 4 manuscripts]

antera anther culture anthere anthers arbre forestier cal callo callus citogenetica cultivo de anteras cultivo in vitro culture in vitro culture media cytogenetics desarrollo embrionario embryonic development fitomejoramiento forest trees haploidia haploidie haploidy haplomethods hybride hybrids in vitro culture larix decidua medio de cultivo milieu de culture picea sitchensis plant breeding populus trichocarpa