2017 ASHS Annual Conference

Tropical fruit improvement is hindered by long breeding cycles, poorly characterized germplasm, challenging funding scenarios, and a lack of diverse germplasm in general. The tropical fruit industry in southern Florida is composed of many species for diverse markets, and thus presents multiple challenges often requiring disparate solutions. Program solutions to these challenges range from genomics-assisted plant breeding of new cultivars to the adoption of existing varieties. Optimized cultural practices, increased efficiencies, effective collaborations, creative forward strategies and the adoption of powerful technologies create novel opportunities for the tropical fruit industry. The long-term vision of the University of Florida Tropical Fruit Breeding and Genetics program is to enhance the viability and sustainability of subtropical and tropical crops via cultivar development and the use of plant genomics to optimize crop genes. Scholarly research and extension components ensure the long-term viability and utility of the program. The end goal is to provide a superior product guided by a deep understanding of the end consumer, the grower/industry, and the limitations and strengths of each target tropical fruit species.

Modern consumers are increasingly looking for novel sensory experiences from their fresh produce. New shapes, color, taste, aroma, and functionality delight consumers and command premium prices. A tropical fruit industry that is sluggish in responding to consumers’ needs will miss lucrative markets unless tropical fruit improvement can efficiently meet evolving and yet timeless consumer needs. The apple industry is an example of this process. Today, grocery stores in developed nations offer multiple varieties of apples suited for different consumer tastes and needs. Conversely, only a few geographies are fortunate enough to have access to multiple (and superior) types of mangos or bananas. Growers can be supportive of producing these novel, niche and economically viable crops, but often lack essential information for establishing, maintaining and maximizing new tropical fruit plantings. This information is vital to guide long-term investments and planting decisions. Improving tropical fruits also requires a deep understanding of each species’ limitations and strengths. These include the availability of optimized cultural practices, genetic variability and technical information like genomics resources.

The scale of the tropical fruit market in southern Florida necessitates a broad program to meet diverse needs. No single crop can monopolize the entire program, and no single technological solution will be suitable for the entire program. Therefore, each opportunity is carefully measured for its costs, appropriateness and value. These concepts are exemplified by mango, papaya and Vanilla tropical fruit industries for production in southern Florida.

Mango

Background: Few tropical fruit species excite as much consumer passion as the mango. Mango trees are a long-term investment for new plantings.

Consumer needs: Mango imports are subjected to heat treatments that reduce consumer quality. Additionally, consumer quality in domestic markets is lacking for aroma, texture, and sweetness.

Grower/industry needs: Domestic production is limited, but southern Florida has a strong mango industry. Grower needs include disease resistant and high yielding varieties.

Challenges: A formal mango plant improvement program is hindered by extended mango juvenility ranging from 5-10 years.

Opportunities: International popularity creates opportunities for collaboration and adapting research findings to local needs. Diverse mango collections are available for study, and mango is quickly moving into the genomics age. Methods like Rapid Cycle Breeding could be an appropriate solution for many tropical fruit species with long juvenile periods. The ultimate objective is to combine the rapid flowering trait with genomic selection. This would improve the efficiency of the breeding program.

Papaya

Background: Papaya has international appeal, but lacks the genetic diversity of many other tropical fruit species. Papaya has a sequenced genome, rapid breeding cycle, and quicker return on investment for growers.

Consumer needs: Sweet, aromatic fruits of acceptable size are highly desired by consumers.

Grower/industry needs: Papaya Ringspot Virus (PRSV) resistance, increased winter productivity, and higher quality winter fruit.

Challenges: PRSV is the major constraint to papaya production, and transgenic solutions have attracted much media attention. A viable papaya improvement program and industry will rely on the transgenic solution, intense use of pesticides to control the vector, increased costs from frequent replanting, or surrendering the land from current plantings to other purposes.

Opportunities: The deregulated PRSV-resistant papaya is a suitable scaffold for a papaya breeding program in southern Florida. Attention can now be focused on yield, fruit quality, and various consumer needs.

Vanilla

Background: Vanilla orchid-based vanillin represents ~1% of global vanillin, but many industries are removing artificial flavorings and ingredients from their products.

Consumer needs: Consumers can currently find limited options for vanillin extract including artificial, natural, and natural-niche (V. x tahitensis vanillin).

Grower/industry needs: There is currently no Vanilla industry in southern Florida, but the crop is attractive to many growers looking for new economic opportunities.

Challenges: Obtaining diverse Vanilla accessions is challenging, but most species being poorly characterized for their agronomics or other beneficial traits. The cost of vanillin fluctuates in response to output from the major production area in Madagascar.

Opportunities: Vanillin is a premium, niche product that could be economically viable for southern Florida. Much of the required infrastructure for growing Vanilla is currently in place for various ornamental production facilities. Further, there are four native Vanilla species that could be leveraged for adaptation traits possibly including pod set without manual pollination.

Establishing a new tropical fruit breeding program requires tight interactions between research, teaching and extension. Networking with growers and industry representatives helps establish a consensus (or majority opinion) defining the greatest needs. These needs are then given perspective based on the potential economic benefit, effort required to provide a solution, the viability of the solution and the biological limitations of the crop system. With the end goals in mind, projects are then designed to meet all outcomes and scholarly objectives as research progresses. Balance between short- and long-term projects is critical for maintaining productivity in a public sector breeding program. Finally, the longer the project’s duration, the greater the need for timeless objectives.