Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Molecular Resources for the Improvement of Tropical Ornamental and Fruit Crops

Location: Tropical Plant Genetic Resources and Disease Research

Project Number: 5320-21000-013-00
Project Type: Appropriated

Start Date: Oct 01, 2010
End Date: May 30, 2013

Objective:
Objective 1: Develop the genomics of papaya for producing new knowledge about the regulation of transgenic disease resistance. [NP 301, C4, PS 4B] Objective 2: Develop methods for improved manipulation and expression of transgenes in key tropical/subtropical ornamental and fruit crop species. [NP 301, C4, PS 4A] Objective 3: Evaluate biotechnology risk and develop methods for practical adoption of selected transgenic crops. [NP 301, C4, PS 4C]

Approach:
(1) Fingerprint and end-sequence approximately 40,000 clones from our existing bacteria artificial chromosome (BAC) library for anchoring the whole genome shotgun (WGS) sequence data that will be produced from two WGS libraries of the papaya genome, (2) mine the papaya BAC end and genomic sequences to develop 4,000 microsatellite markers (simple sequence repeats or SSRs) for constructing a high density genetic map of the papaya genome of at least 1,000 SSRs for combining with our amplified fragment length polymorphism (AFLP) map, (3) assemble and annotate the papaya genome sequences, (4) select a core set of evenly distributed SSRs to map major genes controlling fruit size and disease reactions, (5) develop a transient gene silencing system for functional genomic analysis in papaya, (6) characterize novel papaya disease resistance genes with the functional genomic tool, (7) determine the relationship between transgene copy number and gene silencing, (8) characterize the activity of SCYLV P0 and other viral suppressors of post-transcriptional gene silencing (PTGS) in Nicotiana benthamiana as a model system for application to sugarcane, (9) identify papaya genes with tissue-specific expression patterns for developing tissue-specific promoters, (10) use segmented and synthetic gene technology to develop and subsequently characterize transgenic papaya with resistance to wide range of papaya ringspot virus (PRSV) strains, (11) measure the extent, if any, of gene flow from commercial transgenic papaya to adjacent nontransgenic papaya fields, (12) develop and commercialize a transgenic Kapoho with segmented coat protein genes for the Hawaiian papaya industry, (13) develop data that are necessary to have the Rainbow transgenic papaya deregulated in Japan, and (14) develop, transfer, and commercialize transgenic papaya for developing countries with focus on Bangladesh.

Last Modified: 4/16/2014
Footer Content Back to Top of Page