BOGLER, DAVID1,2*, ALEXANDRA MARRACCINI1, and JAVIER FRANCISCO-ORTEGA1,2. 1Fairchild Tropical Garden, Research Center, 11935 Old Cutler Road, Miami FL 33156; 2Florida International University, University Park Campus, Miami FL 33199. - Conservation genetics of Microcycas calocoma, a rare cycad endemic to Cuba: preliminary data from RAPD and AFLP markers.
Microcycas is a genus with one species, M. calocoma,
endemic to Pinar del Río Province in Cuba. Morphology and DNA sequence
data indicate a close relationship between Microcycas and
Zamia, although Microcycas has many unique molecular
characters which suggests a long period of isolation. There are
approximately 500-600 individuals left in the wild, occurring in 17
scattered populations. The plants have suffered a decline due to
habitat clearing, overcollecting, and destruction of young plants by
pigs. The natural insect pollinator may have become extinct due to
fires and pesticides. There is little natural regeneration in the
wild, and juveniles are uncommon. Major efforts to preserve
Microcycas have been initiated in Cuba. Preserves have been
established, plants are pollinated manually, and studies are underway
to improve propagation techniques and reintroduce plants to the wild.
It would be very useful to find molecular markers to measure genetic
variation within and between populations. This would help establish
conservation priorities and be useful in breeding and reintroduction
efforts. Towards this goal, we have screened an ex situ
population at Fairchild Tropical Garden and Montgomery Botanical
Center with 80 RAPD primers and 18 AFLP primer pairs. We will
eventually include samples from wild populations in Cuba. A secondary
goal was to explore the possibility of using molecular techniques to
screen young plants for sex determination. All cycads are dioecious,
with separate sexes that can be recognized only by their reproductive
structures (cones). The mechanism of sex determination control in
cycads is unknown. Sex markers will be useful to determine the sex of
nursery propagated Microcycas seedlings prior to replanting in
wild populations to restore balanced sex ratios to wild populations,
and may be useful in other aspects of cycad horticulture.
Key words: AFLP, conservation genetics, cycad, Microcycas, RAPD, sex determination