Abstract

Gherkin (Cucumis anguria L.), also known as West Indian gherkin, burr gherkin, and maxixe, is mainly cultivated and consumed in India, Brazil, and the United States. Marker-assisted selection (MAS) is a highly desirable tool for gherkin breeding, because gherkin cultivation generally requires time, labor, and space. However, few DNA markers for gherkin have been reported. Cross-species amplification of 349 melon (Cucumis melo L.) microsatellite primer pairs was tested on three gherkin accessions. After polymerase chain reaction optimization, 149 (42.7%) microsatellite primer pairs successfully amplified all accessions. Of the amplified primer pairs, 41 (27.5%), 64 (43.0%), and 70 (47%) showed polymorphisms between the accessions PI 147065 and PI 320052, PI 147065 and PI 364475, and PI 320052 and PI 364475, respectively. The remaining 206 primer pairs did not amplify any of the three accessions. In the polymorphic primer pairs, the correlation coefficient between repeat number and polymorphic information content values was low; therefore, it seemed unnecessary to consider it for application of repeat numbers in gherkins. Current polymorphic microsatellite primer pairs would be useful for genetic analysis, landmarks in linkage studies, studying genome structure, MAS and evolutionary ecology of Cucurbitaceae.

Key words: West Indian gherkin, Cucumis spp., simple sequence repeat (SSR), polymorphism, breeding