A genetic linkage map of the sweet pepper (Capsicum annuum L.) using an intraspecific doubled-haploid (DH) population was primarily constructed by amplified fragment-length polymorphism (AFLP) using the high efficiency genome scanning (HEGS) system and random amplified polymorphic DNA (RAPD). Linkage analysis was done using a total of 518 molecular markers that consisted of 382 AFLP, 122 RAPD, 3 RFLP, 7 SCAR and 4 CAPS markers. The linkage groups consisted of 11 large linkage groups (56.7 to 118.5 cM) and 5 small linkage groups (1.8 to 33.1 cM), covering a total distance of 1043.1 cM with an average distance between 224 framework markers of 4.6 cM. AFLP markers could be developed quickly using HEGS, even in an intraspecific DH population in which it is generally difficult to detect polymorphisms in comparison with interspecific crossing populations. The map was constructed essentially in two months. Linkage analysis also provided three AFLP markers and an RAPD marker linked to PMMoV resistance (L 3 ), and an AFLP marker linked to C that was required for expression of pungency. A closer marker linked to C, Plastid-lipidAssociated Protein-simple sequence repeat (PAP-SSR), a microsatellite marker linked to C, was found at a distance of 0.6 cM. We examined the usefulness of PAP-SSR with three species in Capsicum using fragment analysis and nucleotide sequences, many alleles were found at this locus. The results suggested that these markers could be effective in marker-assisted selection (MAS) programs for sweet pepper breeding purposes.

A doubled-haploid (DH) population (n = 176) obtained by anther culture of an F 1 hybrid between a line susceptible to Phytophthora capsici 'K9-11' (Capsicum annuum L.) and a line resistant to P. capsici 'AC2258' (C. annuum L.) was inoculated with P. capsici. QTL analysis of the resistance was performed using a linkage map consisting of 16 linkage groups (LGs), covering a total distance of 1100.5 cM. Three QTLs were detected on LG1, LG6 and LG7. The QTL with the highest LOD score, detected on LG7, explained 82.7% of the phenotypic variance with a LOD score of 67.02. This QTL was designated as Phyt-1. The nearest marker was an AFLP marker, M10E3-6. The second QTL, designated as Phyt-2, was found on LG1. It explained 6.4% of the phenotypic variance with a LOD score of 2.54. The nearest RAPD marker was RP13-1. The other QTL, designated as Phyt-3, which was found on LG6, explained 5.6% of the phenotypic variance with a LOD score of 2.20. The nearest AFLP marker was M9E3-11. It was confirmed that the lines with a high resistance could be efficiently selected by using two markers, M10E3-6 and RP13-1, simultaneously. The presence of both Phyt-1 and Phyt-2 under homozygous conditions may enable to breed resistant cultivars of sweet pepper. The molecular markers identified in the present study could be useful for marker-assisted selection (MAS) in order to breed sweet pepper cultivars with a high resistance to P. capsici using 'AC2258' as a source of resistance genes.

Random amplified polymorphic DNA (RAPD) markers linked to the L 3 locus were developed by applying the bulked segregant analysis method to two doubled haploid (DH) populations in Capsicum. The codominant RAPD markers, E18 272 and E18 286 , were converted into sequence-characterized amplified region (SCAR) markers by molecular cloning and nucleotide sequencing. A PCR analysis using DH (n = 176) and backcross (n = 190) populations revealed that all the SCAR markers, PMFR11 269 , PMFR11 283 and PMFR21 200 , co-segregated with the original RAPD markers, and were mapped at a distance of 4.0 cM from the L 3 locus. Furthermore, after confirmation of their validity in 18 accessions of Capsicum spp. using the codominant SCAR marker pair, PMFR11 269 and PMFR11 283 , it was suggested that the SCAR markers developed here could become effective in marker-assisted selection programs for the introduction of the L 3 gene derived from PI159236 (C. chinense) into sweet pepper for breeding purposes.

Although Japanese mango is produced under a fairly unique cultivation system and fetches high prices at market, further growth of the mango industry in Japan requires the development of new cultivars. However, since individual mango flowers are quite small, no more than 1 cm in diameter, a large number of skilled workers is necessary for artificial pollination, thus making it difficult to obtain a sufficient number of progenies for breeding. We therefore evaluated a methodology whereby progenies were obtained by open pollination and their male parent was subsequently determined by DNA markers. Two mango cultivars ('Irwin' and 'Beni-Keitt') were arranged in a plastic house and honeybees were released as a pollen vector for open pollination. Harvested fruits were characterized and their seeds were sown in a bed. The male parent of the germinated seedlings was then identified by five simple sequence repeat (SSR) markers. As a result of SSR genotyping, the male parents of 185 of 239 'Irwin' seedlings were revealed; 79 were obtained by self-pollination and 106 from out-crossing. For 'BeniKeitt', the male parent of 14 of the 20 seedlings was determined with two self-pollinated and 12 out-crossed. Preferential out-crossing in 'Irwin' was revealed using the chi-square test, although the considerable number of self-pollinated fruit obtained shows that a sufficient number of fruit can be set in a single-planted orchard. The effect of the male parent on fruit characteristics was subsequently examined, revealing that in 'Irwin' the Brix value of self-pollinated fruits was significantly higher than that of cross-pollinated fruits. Certain color values were, however, lower in self-pollinated 'Irwin' fruits.

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