Hayes and Garber - Cucurbit Breeding

110 BREEDING CROP PLANTS
Time of culm formation was carefully studied by Hoshino
(1915), who crossed an early with a late variety. The parents
averaged 83.8 and 113.2 days, respectively, from time of planting
to jointing, the parental average being 98.5 days, while the Fi
gave an average of 94 days from planting to jointing. The F z
generation equalled the combined range of the parents. Some
forms bred true to the parental types in F 3 . One form which
segregated in F 3 was much less variable than the F 2
. This line
could be explained by the presence of a single heterozygous factor
for time of shooting. The author suggests that three multiple
factors will explain the results.
Kock (1917) crossed Karang Serang, an early maturing good
quality rice, with Skrivimankotti, a variety of high yielding
ability. Results were not easily explained on a factor basis.
After seven years some hybrids showed considerable uniformity.
Improvements in quality and quantitjr of yield were obtained as
shown by a comparison of the parents and the better of these
hybrid lines.
These facts show that correct methods of breeding rice are
similar to those of the other small grains.