Hayes and Garber - Cucurbit Breeding

RESULTS OF SELECTION WITH SELF-FERTILIZED CROPS 123
studied.
The parental forms were grown with the hybrids for
comparison. Although tobacco is naturally self -fertilized, the
plants were bagged to insure self-fertilization. The behavior
of the parental forms selected in a plus direction is shown. It is
obvious from the data presented that tobacco, like
other selffertilized
crops, does not respond to selection within a pure line;
at least not to a degree which would encourage the plant breeder
to use this method of seeking improvement. (See Table XXII.)
Love and Craig (1918b) recently reported on the effect of
selection for height of plant within a pure line of oats. No evidence
of selective effect was obtained, as is shown in Table XXIII.
TABLE XXIII.
SELECTION FOR HEIGHT WITHIN A PURE LINE OF OATS
Year
Average height of parents
Average height of offspring