LINE-SELECTION WORK WITH POTATOES 



By O. B. Whipple 



Horticulturist, Montana Agricultural Experiment Station 



The data and discussions presented here have to do with the subject of 

 potato-seed improvement through tuber selection. As such it deals 

 with the improvement of existing varieties and may be contrasted with 

 another type of potato breeding which, through the mediums of fer- 

 tilization, production of seed, and growing of seedlings, aims at the 

 origin of new varieties. 



In the language of the plant breeder potato varieties are termed clons 

 or clonal varieties. To him they differ from varieties of wheat, barley, 

 or corn in that they are propagated from vegetative parts. Sexual 

 reproduction or the use of seeds is resorted to only as a means of orig- 

 inating new varieties, not as a means of perpetuating existing ones. 

 Varieties of wheat, barley, or corn reproduce true from seed, while 

 clonal varieties do not. In other words, if we plant pure seed of yellow 

 corn or blue barley, we harvest yellow corn or blue barley, but if we 

 should plant seeds of red apples or red potatoes it is very doubtful if 

 we should harvest either red apples or red potatoes. Few, if any, will 

 doubt the value of potato-breeding work which has for its object the 

 origin of new varieties from seed. Most of our potato varieties have 

 originated as seedlings, either chance seedlings or those resulting from 

 carefully planned breeding work. This phase of potato breeding is still 

 attracting the attention of both scientific and amateur plant breeders, 

 and new seedlings are constantly being introduced for trial. Some of 

 these are real additions to potato culture, and others prove of only local 

 and passing interest. 



The improvement of clonal varieties through bud selection has been 

 the subject of much discussion and the basis for much experimental 

 study. In propagation, the horticulturist deals largely with clons or 

 varieties which must be perpetuated by transplanting vegetative parts. 

 Fruit trees, small fruits, many ornamental plants, nut trees, bulbous 

 and tuberous plants, and many flowers, particularly greenhouse special- 

 ties, fall in this class. This line of plant breeding is of just as vital im- 

 portance as the other which aims at improvement through crossing and 

 hybridization and the growing of new seedlings. Potatoes have been 

 the subject of much study along this line, the work of East,^ Eustace,^ 



' East, Edward M. a study of the factors influencing the improvement of the potato. III. 

 Agr. Exp. Sta. Bui. 127, p. 375-456, 10 fig. 1908. Bibliography, p. 450-456. 



THE transmission of variations in the potato in asexual reproduction. In Conn. Agr. 



Exp. Sta. Rpt. 1909/10, p. 119-160, 5 pi. 1910. 



' Eustace, H. J. an experiment on the selection of "seed" potatoes: productive vs. unpro- 

 ductive HILLS. In Proc. Soc. Hort. Sci., 1903/04, p. 60-62. 1905. 



Journal of Agricultural Research, Vol. XIX, No. 11 



Washington, D. C. Sept. i, 1920 



uw Key No. Mont. - 7 



(543) 



