Soursop (Annona muricata L.) is a tropical fruit tree highly valued for its organoleptic characteristics, and is the most important Annonaceae species in Mexico. This study aimed to generate maps of the natural geographic and eco-climatic distribution where soursop grows in Mexico, and to model potential zones according to climate change scenarios estimated for 2050. The natural distribution model showed that this species is found in most tropical and some subtropical areas of Mexico. This fruit tree grows in three different eco-climatic regions (two tropical and one temperate): A_w1 (found on the edges of the Balsas basin, and in the south, southeast and central north of the Veracruz region, as well as in the center of the Mexican Pacific coast), Am (north and central south of the Veracruz region, and the Yucatán peninsula) and C_(w0) (east of the Trans-Mexican Volcanic Belt). Modelling of suitable climate adaptation zones showed that the Pacific coast of Mexico and Veracruz, as well as some areas of the Balsas basin and the Yucatán peninsula, have potential for soursop cultivation. Likewise, in the scenario of global climate change, beneficial effects on the adaptation of this species are predicted.

Polyembryony is a common trait in most citrus varieties. The level of polyembryony has the potential to be used as a descriptor in the characterization of varieties or to select parents in conventional hybridization work. The aim of this research was to find an efficient methodology to detect, count and estimate the potential number of embryos per seed, the percentage of polyembryonic seeds and the level of polyembryony in the varieties ‘Colimex’ and ‘Lise’ of Mexican lime, and the variety ‘Rosenberger’ of true lemon. Four methodologies were evaluated: 1) direct counting of embryos in mature seeds (DCEMS), 2) direct counting of embryos in immature seeds (DCEIS), 3) counting of seedlings derived from mature seeds germinated in vitro (CSMSGV) and 4) counting of seedlings derived from mature seeds germinated in substrate (CSMSGS). The highest averages of embryos per seed and percentage of polyembryonic seeds were recorded with the DCEMS and CSMSGV methods (P ≤ 0.01), so it was concluded that they are adequate to estimate these variables in the genotypes studied. The varieties ‘Colimex’ and ‘Lise’ had 80.65 and 78.27 %, respectively, of seeds with two or more embryos, resulting in a high level of polyembryony, while ‘Rosenberger’, with 18.37 %, was slightly polyembryonic (P ≤ 0.01).