Articles
AN INTEGRATED APPROACH WITH MAPPING, MARKER, BAC LIBRARY AND CANDIDATE GENE CLONING FOR CHILI MOLECULAR BREEDING
Article number
763_1
Pages
15 – 24
Language
English
Abstract
The aim of our research was to construct a molecular linkage map based on RFLP and SSR markers for high resolution mapping and for development of pepper molecular breeding tools.
Consensus maps were constructed using an interspecific and an intraspecific F2 population.
Through the interspecific population from a cross between Capsicum annuum ‘TF68’ and C. chinense ‘Habanero’, 210 markers were developed onto a genetic map.
Based on this molecular linkage map, mature fruit color, determined by carotenoid pigments, was investigated genetically.
The orange fruit color of ‘Habanero’ was shown to cosegregate with PSY encoding phytoene synthase of carotenoid biosynthesis pathway.
For physical analysis, we constructed a 15 X genome size BAC library from C. annuum ‘CM334’. To understand pungency at the molecular level, placenta-specific cDNA clones were isolated from a highly pungent cultivar ‘Habanero’ using the suppression subtractive hybridization (SSH) method and were investigated genetically and biochemically.
One cDNA, SB2–66, was identified as a candidate gene for capsaicin synthetase (CS), and was later found to cosegregate with the C. locus. DNA sequence analysis indicated that non-pungent peppers have a 2,529 bp-deletion at the 5′ upstream region of the CS. Based upon the sequence differences SCAR markers were developed and successfully applied to four pungent and four non-pungent pepper lines.
Cytoplasmic male sterility (CMS) trait is utilized in F1 chili seed production.
The mitochondrial atp6 gene of chili was found to be polymorphic between male fertile or normal (N) and male sterile (S). Further analysis revealed that two copies exist in both cytoplasm types, but in CMS, one copy was a pseudo-atp6 gene.
Consensus maps were constructed using an interspecific and an intraspecific F2 population.
Through the interspecific population from a cross between Capsicum annuum ‘TF68’ and C. chinense ‘Habanero’, 210 markers were developed onto a genetic map.
Based on this molecular linkage map, mature fruit color, determined by carotenoid pigments, was investigated genetically.
The orange fruit color of ‘Habanero’ was shown to cosegregate with PSY encoding phytoene synthase of carotenoid biosynthesis pathway.
For physical analysis, we constructed a 15 X genome size BAC library from C. annuum ‘CM334’. To understand pungency at the molecular level, placenta-specific cDNA clones were isolated from a highly pungent cultivar ‘Habanero’ using the suppression subtractive hybridization (SSH) method and were investigated genetically and biochemically.
One cDNA, SB2–66, was identified as a candidate gene for capsaicin synthetase (CS), and was later found to cosegregate with the C. locus. DNA sequence analysis indicated that non-pungent peppers have a 2,529 bp-deletion at the 5′ upstream region of the CS. Based upon the sequence differences SCAR markers were developed and successfully applied to four pungent and four non-pungent pepper lines.
Cytoplasmic male sterility (CMS) trait is utilized in F1 chili seed production.
The mitochondrial atp6 gene of chili was found to be polymorphic between male fertile or normal (N) and male sterile (S). Further analysis revealed that two copies exist in both cytoplasm types, but in CMS, one copy was a pseudo-atp6 gene.
Authors
Byung-Dong Kim
Keywords
Capsicum, molecular linkage map, molecular markers, fruit color, pungency, BAC library, CMS
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