Introduction:

Magnolia mexicana DC. is a threatened species according to NOM-059-SEMARNAT-2010, a situation attributed to the fragmentation and destruction of its habitat. There are no studies on the genetic diversity of M. mexicana, even though it is endemic to our country.

Objective:

To evaluate genetic variability in two M. mexicana populations using ISSR molecular markers.

Materials and methods:

The collections come from Amatitla and Zapotla in Zongolica, Veracruz. The DNA was extracted from the young leaves. A total of 55 ISSR primers were tested; the 10 that produced the highest number of polymorphic bands were selected and amplified by PCR.

Results and discussion:

The ISSR primers showed 86 % polymorphism. Cluster analysis, using Ward's minimum variance method, was able to separate the collections by their geographical origin. Analysis of molecular variance showed that the greatest variability (90.88 %) is found within each population. The Shannon-Weaver diversity index was 0.47 and 0.41 for Amatitla and Zapotla, respectively.

Conclusion:

The M. mexicana populations have not undergone changes in their genetic structure; there is no evidence at genetic level of alterations caused by population reduction or habitat fragmentation.

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