Heredity in Gladioli.
G. D. BLACK, GLADIOLUS SPECIALIST, INDEPENDENCE, IA.
(SO. MINN. HORT. SOCIETY.)
As heredity is a comparatively new word, it may be well to define it at the beginning of this paper. Webster says "It is the transmission of mental or physical characteristics or qualities from parent to offspring, the tendency of an organism to reproduce the characteristics of the progenitor."
Most of the species of gladioli are native in the temperate zone of Southern Africa, where they have grown for so long a time that they will reproduce themselves in a marked degree from seeds.
Some have grown in the moist soils of the valleys for so many generations that they have become adapted to these conditions and will not thrive on the elevated plateaus and mountain slopes. Those which are native in the higher and cooler altitudes will not grow well in the lower lands.
A species or variety becomes acclimated when it is grown in one locality for several successive generations, because it is one of nature's laws that it takes on new characteristics that improve it for existence there. These characters are changing more or less during each generation on account of environment.
We can not aid nature in strengthening and improving the desirable qualities unless we follow nature's laws. By crossing two varieties that have certain desirable characters in common we may be able to make these characteristics more dominant.
Much of the crossbreeding of the gladiolus has been done in such an unscientific manner that it is surprising that so much improvement has been made. This improvement is mostly the result of extra care and cultivation, and the selection of the best each generation. In order to retain the benefit of any extra care and cultivation it has to pass on as a heritage to the succeeding generation and is there incorporated among its characteristics. Each generation should be an advance toward the desired ideal.
There is no doubt in my mind that the ruffling and doubling of the petals in flowers that have been under cultivation for several generations is caused by the extra feeding and care that they have received.
Most species of gladioli in their wild state are small and lacking in beauty. Abnormal or freak varieties should not be selected as the best for breeding, because they are usually the result of a violent cross, and are nearly always weak as propagators and sometimes entirely sterile.
Princeps has a very large flower, but the spike is short and only two or three blooms are open at one time. It was originated by Dr. Van Fleet by crossing Mrs. Beecher and Cruentus. Burbank crossed Princeps and America, and quite a number of the seedlings show the markings of Mrs. Beecher, one of their grandparents, but with shorter spikes. In this cross Princeps transmits the undesirable character of short spikes but leaves out the abnormal size of flower, and the best characters of America are lacking. The parentage of America is very much in doubt, as three prominent gladiolus breeders claim the honor of originating it.
There are many characteristics to be considered when making selections for breeding besides the color and size of the flower. The bulbs of some varieties will stand considerable freezing while other varieties will not. This same characteristic is noticed in the foliage. The severe frost that killed our corn crop on August 30th so impaired Panama, Hiawatha and some others that very few blooms of these varieties opened afterwards. The foliage of some varieties remained green after a temperature of twelve degrees below freezing.
A representative of a Holland bulb growing firm who called on me a few days ago says that Niagara is a very weak grower in Holland and Panama is a very vigorous grower. My experience with these varieties is just the reverse. This seems to show that sometimes the difference in climate may cause certain characters in the plant to act differently—if the Hollander is not mistaken.
A few varieties are sometimes subject to blight and rust. Some are only slightly affected, and many others are entirely blight proof.
There are so many characteristics to be considered by the scientific breeder that it is almost impossible to enumerate them all in this paper.
There is yet a great work to be done in breeding out the undesirable traits and incorporating the improvements which we desire.