Skip to main content
ARS Home » Research » Publications at this Location » Publication #166361
Title: THE GENETIC BASIS OF SEX DETERMINATION IN PAPAYA

Author
item LIU, ZHIYONG - HI AG RES CNT
item Moore, Paul
item MA, HAO - HI AG RES CNT
item KIM, MINNA - HI AG RES CNT
item MAKANDAR, RAGIBA - HI AG RES CNT
item PEARL, HEATHER - HI AG RES CNT
item CHARLTON, JOSEPH - HI AG RES CNT
item ACKERMAN, CHRISTINE - HI AG RES CNT
item YU, QINGYI - HI AG RES CNT
item STILES, JOHN - HI AG RES CNT
item Fitch, Maureen
item PATERSON, ANDREW - UNIV OF GEORGIA
item MING, RAY - HI AG RES CNT

Submitted to: Compiled Abstracts for Annual Meeting of American Society of Plant Biologists in Hawaii July 2003
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2003
Publication Date: 7/25/2003
Citation: Liu, Z., Moore, P.H., Ma, H., Kim, M., Makandar, R., Pearl, H., Charlton, J., Ackerman, C., Yu, Q., Stiles, J.I., Fitch, M.M., Paterson, A.H., Ming, R. 2003. The genetic basis of sex determination in papaya. Am. Soc. Plant Physiol. (Abs.) P501, pg. 118. 2003.

Interpretive Summary: Abstract only.

Technical Abstract: Carica papaya is a polygamous plant species with female, male, and hermaphrodite sexes. Sexual polymorphism and available genomic resources make papaya a model plant for studying sex determination and differentiation. Classical genetic analyses led to the conclusion that sex determination in papaya is the result of a single gene with three alleles. We used three hermaphrodite sex-linked markers, W11, T12 and CPBE55 for fine mapping of the sex locus on 991 F2 and 755 F3 plants derived from two cultivars Kapoho and SunUp. No recombination was found between the sex locus and these three markers in either the F2 or F3 populations. Southern hybridization of sex markers to total genomic DNA of the three sex types indicates that the markers are present only in male and hermaphrodite but not in female. We cloned and sequenced 62 hermaphrodite sex-linked AFLP fragments and fourty-three SCAR markers were developed. Twenty-seven of the SCAR markers were used to screen a papaya BAC library. BAC end cloning and chromosome walking have allowed us to construct a 900 kb BAC DNA contig containing the W11, CPBE55, and T12 markers. The physical distances are 500 between W11 and CPBE55, 400 kb between CPBE55 and T12, and 900 kb between W11 and T12. Hybridization of sex markers on BAC contigs reveals multiple DNA duplication events in this genomic region. Overall, our results indicate that the physical length of the non-recombining region containing the papaya sex determination gene is more than 3 Mbp. The large genomic region spaned suggested a yet uncharacterized severe suppression of recombination associated with the sex determination gene. We are currently constructing a fine physical map of the non-recombining region to characterize the genetic basis of sex determination in papaya.