We developed 18 polymorphic simple sequence repeat (SSR) markers in pineapple (Ananas comosus) by using genomic libraries enriched for GA and CA motifs. The markers were used to genotype 31 pineapple accessions, including seven cultivars and 11 breeding lines from Okinawa Prefecture, 12 foreign accessions and one from a related species. These SSR loci were highly polymorphic: the 31 accessions contained three to seven alleles per locus, with an average of 4.1. The values of expected heterozygosity ranged from 0.09 to 0.76, with an average of 0.52. All 31 accessions could be successfully differentiated by the 18 SSR markers, with the exception of ‘N67-10’ and ‘Hawaiian Smooth Cayenne’. A single combination of three markers TsuAC004, TsuAC010 and TsuAC041, was enough to distinguish all accessions with one exception. A phenogram based on the SSR genotypes did not show any distinct groups, but it suggested that pineapples bred in Japan are genetically diversed. We reconfirmed the parentage of 14 pineapple accessions by comparing the SSR alleles at 17 SSR loci in each accession and its reported parents. The obtained information will contribute substantially to protecting plant breeders’ rights.

We conducted a cold storage test on Okinawan-grown fresh pineapples-'Summer gold,''Soft touch,' 'Bogor,' and 'N６ ７−１ ０'−，to examine varietal differences in internal browning among these varieties and the causes of these differences. Internal browning occurred in 'Summer gold,''Soft touch,' and 'Bogor.' It was particularly notable in 'Summer gold,' progressing at a storage temperature of５℃， and even１ ５℃. During the storage of 'Summer gold,' its polyphenol oxidase activity (PPO) increased, whereas its ascorbic acid content decreased. These results made it clear that the internal browning in ' Summer gold' is one of the symptoms of chilling injury. There was no relationship between polyphenol content and the chilling injury in the fruits during their storage.

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