Genetic Modification of Ornamental Shrubs

The phrase genetically modified has come to mean that the DNA of a plant or animal has been modified using recombinant DNA technology; gene splicing by means of a gene gun and a gene transporting viruse. To many it is a frightening prospect that man should play God, but people have been genetically modifying plants and animals since the dawn of agriculture, if not before. The simple act of collecting seeds for replanting has given us new and improved strains of heavier fruiting plants. For years we have been selecting, culling, isolating and transferring pollen, all which have changed the world in ways we rarely think about. 

Plant breeding using tradition methods, and the principles first developed by Gregor Johann Mendel, have served human-kind well. Our stomachs are full and our gardens are more colorful because man has genetically modified thousands of organisms. This is especially true in the world of ornamental garden plants.    

There is an orange forsythia, but I created these with Photoshop

Sure, there have been a few forays into transgenic ornamentals. I once saw an orange flowered forsythia in France. Beet genes had been inserted into its DNA, but not to worry, the plant is under lock and key and will never be released. The Japanese used gene transfer to created a blue rose, but It's only sold as a cut flower and not as a garden plant. These are rare examples of transgenic ornamentals. The truth be told, traditional breeding is easier and plenty powerful. We have just seen the tip of the iceberg when it comes to the potential of traditional plant breeding. 

Take a look at the picture below. While most people would not recognize that it's a hydrangea, it is or native form of Hydrangea arborescens or smooth hydrangea. This is a plant I saw while hiking in the Smoky Mountains in Tennessee. Not too spectacular, is it?

This unassuming plant is the starting point for many popular garden hydrangeas that you know and love. Through traditional breeding, it has been turned into a wide array beautiful garden plants. Just look at what has been has done with this shrub.

White Dome has very large lacy flowers
'Hayes Starburst'  was selected for its highly doubled flowers 

'Annabelle' is one of the most well known hydrangeas. It has large round blooms

Incrediball hydrangea is an improved 'Annabelle' with larger flowers and stronger stems 

Once in a while nature lends a hand in the breeding process. Annabelle was discovered in the wild as a naturally occurring mutation. There are three pink flowered variants of Hydrangea arborescens and I believe all were discovered in nature. 'Pink Pincushion', 'Eco Pink Puff' and 'Wesser Falls' all resemble the wild-type I showed you in the first picture, except that each has a bit of pink coloration in their flowers. While none of these selections are all that attractive, they were exactly what plant breeders needed to make the next big step.

Here are the crosses that lead to the creation of Invincibelle Spirit Hydrangea

Two of these pink variants along with 'Annabelle' were used to create the plant labeled here a F1B. The breeder then crossed siblings in this generation to create the first ever pink Annabelle hydrangea called called Invincibelle 'Spirit'.  

Invincibelle 'Spirit' 
All of this genetic modification resulted by selecting, culling, isolating and traditional plant breeding techniques. Toss in a bit of natural occurring mutation and an unassuming shrub is changed in ways we could hardly image. And the great thing about this is that we have only just begun to see the power of traditional plant breeding.