Genetic characters and polymorphism of chloroplast and mitochondrial DNA in white poplars

The inheritance of chloroplast and mitochondrial DNA of Populus tomentosa, P. tomentosa×P. bolleana and P. alba×P. glandulosa as well as their F₁ progenies were analyzed by PCR-RFLP. The chloroplast trnD-trnT, rps12/7-nadB, trnT-trnF, trnL-trnF3′ and trnL-trnF5′, together with six mitochondrial genes, cox<、i>Ⅲ, ND5/6,orf<、i>25, atp6, nad4/1-2 and ND2-COⅢ, were amplified from these strains respectively; cpDNA and mtDNA polymorphism of these amplified fragments were compared among parental strains by restriction digestion. Restriction fragment length polymorphism (RFLP) analysis revealed that all the chloroplast DNA in F₁ individuals of (P. tomentosa×P. bolleana) ×P. tomentosa,( P. tomentosa×P. bolleana)×(P. alba×P. glandulosa) were the maternal inheritance. Moreover, there are no variations among these four hybrids in the PCR amplification pattern and the restriction pattern, indicating that mitochondrial genes are highly conserved in white poplars.