Genetic structure and environmental aptitude of sideoats grama [ Bouteloua curtipendula (Michx.) Torr.] populations in Chihuahua, Mexico

: Research has increasingly centered on selecting outstanding grass genotypes for grasslands restoration, although most focuses on agronomic characteristics. Little importance has been given genotype genetic structure and environmental adaptation. An analysis was done of the genetic structure and environmental suitability of sideoats grama ( Bouteloua curtipendula ) populations in Chihuahua, Mexico. Fifty-one populations were evaluated through AFLP markers and analysis of their genetic structure. In a novel approach, the MaxEnt algorithm, commonly used only at the species level, was used to design models to quantify environmental aptitude of the groups generated by the genetic analysis. The STRUCTURE analysis divided the B. curtipendula populations into two different genetic groups (AMOVA; P <0.0001). Most (89 %) of the Group 1 populations are in the state’s semi-arid region while most (90 %) of the Group 2 populations are in the arid region. The MaxEnt results showed the two genetic groups to have different environmental aptitude. The climatic niche of Group 1 is mainly located in the state’s center and south, while that of Group 2 is in the center, west and northeast. Restoration programs involving B. curtipendula would benefit most from using local ecoregion-specific genotypes in areas for which they have the highest environmental aptitude. The genetic structure of B. curtipendula was analyzed using Amplified Fragment Length Polymorphisms (AFLP) molecular markers. Plant leaves were collected at each site and DNA extracted from them based on the method proposed by Doyle & Doyle (18) . The AFLP analysis was done using the method proposed by Vos et al. (19) . First, 2 µl diluted DNA were digested by the Eco RI and Mse I restriction enzymes and the digested DNA fragments ligated with Eco RI and Mse I adapters. For pre-amplification, an extra nucleotide was added to the primers ( Eco RI + A and Mse I + A). Selective amplification was done using four combinations of fluorescence-labeled primers: Mse I + CTG - Eco RI + AAG, Mse I + CTG - Eco RI + ACT, Mse I + CAG - Eco RI + AGG, Mse I + CAG - Eco RI + AAC. The polymerase chain reaction (PCR) was done in a thermal cycler (Applied Biosystems Veriti 2720), with the following program: one cycle of 94 °C for 30 sec, 65 °C for 30 sec, 72 °C for 1 min; 12 cycles of 94 °C for 30 sec, 65 °C for 30 sec, 72 °C for 1 min; and 23 cycles of 94 °C for 30 sec, 56 °C for 30 sec, 72 °C for 1 min. The selective amplification products (2 µL) were mixed with 8 µl formamide and 1 µL Eco 700 GeneScan label (Applied Biosystems). Separation of the amplified fragments was done in a LI-COR DNA analyzer, loading 0.8 µL sample per well. Fluorescence-marked oligos or primers at different wavelengths (700 nm and 800 nm) were used. With the band pattern produced by the AFLP analysis, a binary band presence (1) / absence (0) matrix was constructed. A genetic structure analysis, based on the Bayesian clustering algorithm, was applied to the binary data using the STRUCTURE version 2.3. 4 software (20,21) . The STRUCTURE program was run 30 times for each K number of