Genetic evaluation of haploid clonal lines of a single donor plant of Populus maximowiczii.

Haploid clonal lines derived from anthers of a single donor plant of Populus maximowiczii were evaluated for several quantitative traits. In a nursery test, variances due to clonal lines ranged from 8% to 12% of the phenotypic variance in growth cessation and flushing date, respectively. No variance in relative shoot growth rate was associated with clonal lines. In a greenhouse study, gametoclonal variance in several leaf morphology traits ranged from 9% to 37% of the total variance. In relative wood density, variation due to haploid lines accounted for 25% of the total variance. In an isozyme analysis of 20 haploid and dihaploid plants, significant non-Mendelian segregation in isocitrate dehydrogenase was detected. The implications of these results for tree breeding are discussed.