A new look at incompatibility relationships in higher plants uri icon

abstract

  • Pollen tube growth was evaluated using an 18-step scale after both intra- and interspecific pollinations of genotypically widely differing diploid potato species and potato dihaploids expressing monofactorial gametophytic incompatibility. The results obtained account for a wide array of types of pollen tube growth resulting from crossing partners with distinct incompatibility behavior. Based on the assumption that inhibition of pollen tubes is the rule and solely prevented by the pollen itself, a model proposing one common cause underlying different mechanisms for both intraspecific self-incompatibility and interspecific incompatibility in diploids is put forward. Data supporting the model are presented from the experimental results of this study and from the literature. The strength of pollen-style interaction depends on particular S-alleles in combination with recognition and activity properties of the basic S-genotypes. The model is suitable to explain all former observations on incompatibility in diploids with a gametophytic system of incompatibility and, with modifications of the manner of phenotypic expression, also in plants with sporophytic incompatibility. The proposed scheme of pollen tube growth phenotypes permits prediction of pollen tube growth behavior in an intended cross combination. The model is based on both classical Mendelian genetics and recent molecular genetic insight.

publication date

  • 1993
  • 1993