INHERITANCE OF THORNLESSNESS FROM TISSUE CULTURE ORIGINATED LOGANBERRIES

1. "Lincoln Loganberry", a tissue culture originated plant from "Thornless Loganberry" /chimerical/ obtained in New Zealand /Hall et al., 1986/;
2. seedlings originated in Italy by selfing micropropageted "Thornless Loganberry" /chimeral/ plants in which tissue culture probably induced the displacement of L2 by L1 /thornless/ layer / ROSATI et al., 1986/.

Progenies derived from selfings and from crosses with different thorny Rubus were observed:

1. all the selfings were closer to 2:1 than 3:1 in segregating for thornlessness. This suggests that the homozigous dominant are missing;
2. crosses with "Tayberry" pollen and other thorny Rubus gave 1:1 ratios but the reciprocal cross with "Lincoln Logan" pollen gave a deficiency of thorny segregates;
3. crosses of the material from source 2 with "Silvan" blackberry pollen gave deficiencies of thorny segregates.

The thornless: thorny ratios suggest that thornless gene of "Thornless Loganberry" is dominant to the thorny allele.

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