Identification of self-incompatibility alleles in Quince (Cydonia oblonga Mill.)

TL;DR

This study identifies new self-incompatibility alleles in quince, revealing genetic diversity that affects self-pollination and could improve breeding strategies.

Contribution

The discovery of two novel self-incompatibility alleles (S4 and S5) in quince expands our understanding of its reproductive genetics.

Findings

Two new S alleles, S4 and S5, were identified in quince genotypes.

S4 was the most prevalent allele among the tested genotypes.

Behta showed self-incompatibility, while Ardabil2 showed self-compatibility.

Abstract

The Quince (Cydonia oblonga Mill.), typically known for its self-compatibility, surprisingly presents a degree of self-incompatibility. This research focused on exploring the diversity within the self-incompatibility gene locus (S) in various C. oblonga genotypes. Through meticulous DNA sequencing, the study sought to unearth potential novel S alleles. In the process of genotyping the S gene across multiple quince genotypes, not only were the previously documented S1 and S2 alleles identified, but this investigation also uncovered two previously unrecognized alleles, termed S4 and S5. These alleles, particularly S4, emerged as the most prevalent among the tested genotypes. To corroborate the findings derived from DNA sequencing, the study employed pollen tube growth germination assays. These assays elucidated a higher pollen germination rate in the Ardabil2 genotype in contrast to Behta. Additionally, the study involved assessing pollen tube growth in both Ardabil2 and Behta through cross-pollination techniques, meticulously tracking the development of pollen tubes at various stages. Remarkably, the outcomes demonstrated that the Behta genotype possesses self-incompatibility, whereas the Ardabil2 genotype showcases a notable degree of self-compatibility. This groundbreaking discovery of new S alleles in quince not only affirms the species’ self-compatibility but also sheds light on the complexities of allelic diversity and its impact on self-incompatibility. Such insights are invaluable for enhancing the yield of quince orchards through strategic breeding programs.

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