December 22, 2012
Sports — baseball, football, tennis, basketball and more — they all have passionate followers. While I'm not much of a fan of athletic sports, I am hooked on the kind of sports that appear in the garden.
No, not competitive pumpkin growing or flower arranging. Sports you might encounter if you look closely at your plants; and if you're really lucky (and it is all about luck), you might discover a new sport and make yourself a pile of money. Hm, got your interest?
The sports that grab my attention are those mysterious botanical anomalies — naturally occurring, spontaneous mutations found in a wide range of plants. The term "sport" is used by gardeners to describe changes that cause a portion of a plant to be distinct from its parent in appearance. The mutation may appear as a different shape, form or color of the plant's foliage, flowers, fruit or branch structure.
Also referred to as chimeras (a word defined in part as "an imaginary monster made up of grotesquely disparate parts"), the terms are often used interchangeably. Botanically speaking, a chimera is where two or more genetically distinct tissues are present, while a sport is a part of a plant that shows unusual or singular deviation from the normal or parent plant.
The changes to the plant can be of inferior quality such as "witches' broom" — a symptom in woody plants where many twigs are densely clustered together resulting in a mass of shoots that resemble a broom; you might see it on California live oaks afflicted with powdery mildew. The mutation also may result in a significant improvement to the plant — in aesthetics, health or productivity.
Many commercially successful fruit cultivars have developed from a sport — a branch of fruit that was different and better than the rest of the original tree. Popular varieties of grapefruit, oranges, lemons and apples originated from sports.
Virtually all variegated plants started life as ordinary green plants; at some point a genetic hiccup produced a bit of foliage in shades of white, yellow, orange, red or lighter green coloring, producing multicolored foliage. Plants like chrysanthemums, roses, dahlias and African violets are prone to producing chimeral flowers, with sectors of blooms having different colors.
Most of these mutations are random and a result of a change within the cells of the plant, but can sometimes be triggered by cold weather, temperature fluctuations or insect damage.
"Spontaneous mutation occurs for no apparent reason, it just happens." notes Dr. Malcolm Manners, environmental horticulture professor at Florida Southern College in Lakeland, Fla. "Induced mutation is a kind of mutation that occurs when there are external factors that stimulate the plant/animal to change form, due to changes in its genetic makeup. The external factor could be chemicals, radioactive rays such as gamma rays, etc."
The sports we might be fortunate enough to find are generally the result of spontaneous mutation.
If a sport is discovered and determined to be desirable from a commercial perspective, it is propagated by cuttings. Sports that are genetically unstable may not make good candidates for propagation as they are prone to reversion — where the anomalous appearing trait returns back to its original form.
I was ecstatic when I came across an amazing sport growing in my garden. The shrub rose "Blushing Pink Knockout" with its iridescent pink five-petaled rose, produced a spray of extraordinary bicolored blooms; nearly every individual petal of the flower had one half the original soft baby pink color while the other half a deep cerise pink! I took oodles of pictures and shared them with nationally renowned rose hybridizer Tom Carruth, then of Weeks Roses, who said he'd be interested in the rose if it were genetically stable.
"Watch the rose over a season or two and if the plant keeps producing those awesome blooms, get back to me," he said.
Alas, the plant did revert back to its solid color, though periodically producing that same unique pattern.
Another example of a rather unstable but very attractive rose variety is "Brilliant Pink Iceberg," a sport of the popular porcelain-white rose "Iceberg." Throughout the growing season, this plant will don the carmine-colored blossoms it's named for as well as the bright white of the parent plant and a burgundy-toned one of the sport sibling "Burgundy Iceberg." Three distinctive flower colors growing on the same bush — makes for an interesting looking plant!
So, next time you're strolling through your garden, take a closer look and just maybe, you'll get hooked on sports.