The inheritance of primin secretion in Primula obconica was determined by s
tudying the F-1, F-2 and BC1 progenies of crosses between primin-secreting
cultivars and primin-free ones.
All plants in a ten-cross combination of F-1 secreted primin; thus, the pri
min-secreting phenotype was dominant over the primin-free phenotype.
In four of ten cross combinations, the factor segregated in F-2 and BC1 as
Mendelian ratios of 3:1 and 1:1, respectively, indicating that primin secre
tion is controlled by a single gene. However, in another six cross combinat
ions, the segregation ratios of F-2 mere significantly different from 3:1,
whereas those of BC1 were 1:1. The results suggested that the distorted seg
regations observed in certain F-2 might have been caused by certation or ga
metic selection.
Given the above findings, the inheritance of primin secretion, which was ch
aracterized by distorted segregations in certain F-2 was found to be contro
lled by a major gene.