RHA Newsletter 9(2):
Henry R. Johnson
Or able co-worker, Joe Winchel, writing in the Spring '78 Newsletter makes some brief mention of a breeding procedure in use at Perdue University which in said to produce sensational results.
The procedure mentioned in In-Breeding; two generations are self-pollinated and subsequently out-crossed. It seems to be similar, with a little modification, to a procedure used by me for some ten years. Thus far the results have been something a little less than "sensational" but have nonetheless been well worth all the time and effort involved by bringing out some interesting colors (plus a few worthwhile variations in foliage and plant characteristics) that otherwise would assuredly have been missed. My experience, albeit limited, suggests that for the hybridist, especially an amateur with ample time and one who is untroubled by monetary expectations who would like to introduce some different and interesting shades (and possibly some increase in vigor, hardiness, disease resistance, etc.) into breeding stock, this might very well be a good course to follow even though the duration may at first seem something akin to taking a slow boat to the Orient.
My method is to begin by selecting a first generation seedling of merit (could be one whose only merit is some interesting or unusual feature) and to manually self-pollinate it. Self-pollination must not be confused with open-pollination. This is done by collecting the anthers from the selected cultivar and preparing the blooms the same as is done in making any cross, being careful to prevent contamination of the stigmas with unwanted pollen through the medium of insects or air currents, from the time of emasculation until a week or ten days following pollination.
Not all stigmas become receptive at the same time and many cultivars are reluctant to accept their own pollen. To enhance the chances of obtaining a better yield of seed and a larger population of siblings, one should not only pollinate as many blooms as possible but the pollination should be repeated on two (preferably three) successive days. The seeds are handled in the usual way. Germination is usually less then when two cultivars are cross-pollinated.
When the progeny came into bloom one is likely to find some unexpected and interesting colors in the population; and once in a while a plant of unusual hybrid vigor may be discovered. They are carefully observed and evaluated throughout the growing season and a selection made of not more than ten of the most meritorious cultivars. Those selected are moved to a separate bed and winter-protected by soil mounding. In the following spring, when they come into bloom, anthers are collected and combined, from each of the selected cultivars. When the anthers have discharged their pollen they are screened out to facilitate thorough mixing of the pollen. The blooms are self-pollinated as was done previously except in this case all will receive pollen from each cultivar in the selected group. Seed set may leave something to be desired and germination may be poor. When germination is poor, the seeds are retained for a second year when it is often found to be improved.
More surprises may be found in the next population of siblings, some of the colors may really be intense. Improved foliage and plant habit has been found but this has not been a frequent occurrence. Careful observation and evaluation is again in order with only The Best of The Best (or something unusual) being selected and retained for out-crossing to other cultivars, either something of one's own origination or to a commercial choice.
Weakness can be expected in the selfed populations, increasing with the repetition, and seemingly more evident with the yellows; but this need not be discouraging because it can be bred out by crossing to vigorous cultivars. The thought of introducing a new shade or other important factor into the breeding stock with which one is working offers an extra measure of pleasure to a hobby with as many rewards.