Comparative analysis of telomeric restriction fragment lengths in different tissues of Ginkgo biloba trees of different age.

Ginkgo trees of four different ages were selected as experimental material. Telomeric restriction fragment (TRF) lengths, as an indicator of telomere length, were determined for different tissues by Southern hybridization analysis. Statistical analysis was performed to compare two aspects of TRF length. By determining TRF lengths for different tissues for each age, a latent tendency was found. TRF length varied from short to long in these tissues in the order microspore < embryonal callus < leaf < branchlet. TRF lengths for leaf tissue and branchlet tissue were dissimilar for female and male mature trees, although this difference between TRF lengths for the two sexes was not statistically significant. Evaluation of TRF lengths for each tissue for trees of all four ages revealed TRF lengths increased with age to some extent. Different rates of change were found for leaf tissue and for branchlet tissue, although tendencies to increase were not linear for either. Finally, a simple mathematical model was formulated to describe the relationship between telomere length and age for Ginkgo biloba L.