Introgression from the secondary gene pools to P' vulgaris

1
Introgression from the secondary gene pools to P.
vulgaris
Chromosome pairing at metaphase I (after D.
Debouck)
Hybrid between P. vulgaris and P. polyanthus
vul P. vulgaris pol P. polyanthus cocc P.
coccineus cos P. costaricensis

• P. polyanthus cross more easily with P.
  coccineus than with P. vulgaris
• P. vulgaris x P. costaricensis seems to be
  easily crossed
• P. coccineus and its allies would represent the
  greatest potential for gene introgression
• Back reversion of the segregants to the
  cytoplasm donor parent reciprocal cross is more
  often difficult