Molecular Studies to Evaluate Variegation of Philodendron var. Birkin

Kryzsko Commons Ballroom, Winona, Minnesota

Plant tissue culture and molecular genetic techniques were used to analyze the instability of the genome in philodendron var. ‘Birkin’. This plant has variegated, white, and greenish-red leaves (that have lost their variegation) on the same plant. Did genetic mutations occur in meristematic sectors of variegated leaves that have reverted to green coloration, or is it an epigenetic change? PCR and sets of plastid primers were used to determine if the presence or absence of a PCR product correlated with differences in leaf color and variegation (white, green-white variegated, reddish green or green leaves). A DNA isolation procedure was first optimized to extract PCR quality DNA. The Zymo Quick DNA Plant/Seed Miniprep Kit resulted in no DNA, but a modified DNA extraction procedure (BABEC) used to isolate insect genomic DNA also resulted in a high yield of PCR-quality DNA from Philondendron leaves - as measured by the Nanodrop system. PCR was performed with 3 different sets of plastid primer pairs (1F/724 R, 390F/1326 R and trnH/psbA) using 3 different thermocycling conditions. Differences in PCR products were observed for the three sets of primers. This indicated that genetic mutations resulted in differences in leaf color and variegation. We are, however, not excluding the possibility that epigenetic changes also play a role in variegation. While a number of factors can influence epigenetic variegation in a plant, the influence of varying hormone concentration has yet to have been studied. Plant tissue culture is being optimized as a way to vary environmental conditions and examine genetic and epigenetic changes. These results could provide useful information in terms of breeding for ornamental traits and introducing improvements to the genus Philodendron.