Investigation of the Self Incompatibility Mechanism in Clementine (Citrus clementina Hort. ex Tan.) Using cDNA-AFLP

In this study the pollen-pistil interaction was investigated to understand which genes are involved in the self-incompatibility mechanism of Clementine mandarins. Pollen tube growth of clementine 'Algerian Tangerine' (self-incompatible) was analyzed using the complementary DNA-amplified fragment length polymorphism technique to identify genes putatively involved in self-incompatibility. The transcript profiles of unpollinated and self-pollinated (for 1, 2, 3, 4, 5, 6, 7th days) styles and stigmas of 'Algerian Tangerine' were compared. Complementary DNA profiles showing transcriptional differences between unpollinated and self-pollinated stigmas and styles were excised from the gels and directly sequenced. Some unigenes were determined from the results of direct cDNA sequencing. Selected gene tags showed transcriptional differences between unpollinated and self-pollinated styles and stigmas during pollen germination and pollen tube elongation. The differential expression of some sequences was confirmed with the quantitative reverse transcription-polymerase (RT PCR) chain reaction.