UPDATE ON NEW MANGIFERA SPECIES IN FLORIDA, USA

Abstract

Several Mangifera species have been collected and are under evaluation at Fairchild Tropical Botanic Garden in Soutn Florida, FL, USA over the past 15 years. M. odorata, M. casturi, M. lalijiwa, M. quadrifida, M. laurina and a putative M. odorata/M. foetida hybrid have been grafted successfully on ‘Turpentine’ rootstock and trees have been grown in the field for 14 years. All of these species have bloomed and fruited with reasonable reliability over this time. In addition, many of the species have withstood temperatures as low as 29F for more than 5 hours with only minimal damage. Temperature does not appear to be a reliable inducer of bloom for these species growing in the field. Additional investigation is necessary, but Mangifera species also have shown a high degree of anthracnose tolerance under Florida conditions, but many have shown severe susceptibility to leaf and twig bacteria infection. The fruit of each species is unique in terms of color, appearance and eating quality, and all have potential as fresh fruit given proper selection of clones with superior fruit quality. M. griffithii, M. quadrifida, M. merilli and M. lalijiwa have performed better with M. casturi as an interstock. M. caesia, M. foetida, M. pajang and some unidentified species have not been successfully grafted on M. indica and no successful interstock has been found. INTRODUCTION In Southeast Asia there is a wide diversity of Mangifera species that bear edible fruit, with 69 taxonomically recognized (Kostermans and Bompard, 1993). Among these species, Mangifera indica is the most important commercial fruit crop. Two decades ago Kostermans and Bompard (1993) outlined the potential of Mangifera species as edible fruit crops, rootstocks, and as sources of genetic diversity for the future breeding of disease resistance, and desirable horticultural traits in the modern mango. The importance of conserving these species and their genetic potential has been clearly recognized by the scientific community, but there is almost no practical horticultural information available about their suitability for propagation, their care and domestication. More than 16 Mangifera species from Borneo, peninsular Malaysia, and Thailand have been accessioned into the genetic collections of Fairchild Tropical Botanic Garden since 1994 (Campbell and Ledesma, 2002). These species were introduced as clonal material for each species; however, information about potential graft compatibility of was not readily available in this hemisphere. The process was undertaken by trial and error and there have been many failures in establishment of these species. The objective of this work is to detail the progress made with the establishment of Mangifera species for use in future breeding with M. indica and for the development of new ornamental, home garden, estate and commercial crops. GENERAL METHODOLOGY All collected material was brought to the United States as budwood. The entry of seed material is not allowed due to seed weevil and since many of these species are monoembryonic there would have been no advantage to the introduction of superior selections without clonal material. All species were grafted with cleft of veneer grafts depending on the size of the scion and the rootstocks available. Most grafts were made when nighttime temperatures were 20C or higher. The rootstocks used were ‘Turpentine’ imported from Costa Rica and interstocks of M. casturi and M. odorata. The M. casturi and M. odorata interstocks were from accessions originating in Australia and Brazil, respectively. Proc IX Internationa Mango Symposium