title: Stable haploid poplar callus lines from immature pollen culture.
abstract: Embryogenesis and plant regeneration have been obtained from isolated immature pollen of two poplar hybrids (Populus nigra L. x hybrid 'Aue1' and 'Aue2'). In total, 1487 calli or embryos, respectively, larger than 1 mm were generated in a 2-year study. By using a cytokinin containing induction medium, on average 19 calli per responsive immature catkin were formed. Additional supplementation with auxin in 2002 increased the frequency to 72 calli per catkin. Microsatellite marker analyses confirmed haploid origin in most regenerants studied. So far six out of eight obtained regenerative callus lines have maintained their haploid level up to 24 months of development. A number of haploid and doubled haploid plants of different lines are available and have been transferred to soil.
authors.affiliation: Federal Research Centre for Forestry and Forest Products, Institute for Forest Genetics and Forest Tree Breeding, Sieker Landstrasse 2, D-22927 Grosshansdorf, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Deutsch
authors.forename: Jochen
authors.initials: J
authors.lastname: Kumlehn
authors.forename: Birgit
authors.initials: B
authors.lastname: Ziegenhagen
authors.forename: Matthias
authors.initials: M
authors.lastname: Fladung