PHYTOGENETIC RESOURCES OF THE GENUS LUPINUS IN BAJA CALIFORNIA: EXPLORATION AND IN SITU CHARACTERIZATION STRATEGIES

• DOI: 10.37572/EdArt_2509263217

• Palavras-chave: Biodiversity and biological monitoring, Collected material available, Conservation and protection of species, Ecosystem assessment.

• Keywords: Biodiversity and biological monitoring, Collected material available, Conservation and protection of species, Ecosystem assessment.

• Abstract:

  A comprehensive field expedition was conducted across the Baja California Peninsula from April 26 to May 5, 2023, to locate, document, and collect germplasm of wild Lupinus species. This expedition was critical for updating the knowledge of Lupinus diversity in this biogeographically significant region, as previous systematic collections date back several decades, with most herbarium specimens collected between the 1960s and 1980s. The expedition covered approximately 2,100 kilometers in a circular route starting and ending in La Paz (23°37'N, 109°52'W). The itinerary followed a strategic north-south gradient, beginning in Sierra La Laguna at 789 msnm elevation, proceeding northward through coastal zones (12-73 msnm) near Mulegé and Guerrero Negro (27°37'N-28°57'N), ascending to mid-elevation sites around Loreto and San Ignacio (532-1,078 msnm at 29°24'N-31°27'N), reaching the highest elevations in the Sierra San Pedro Mártir region (1,504-2,628 msnm at 31°02'N-32°10'N), and returning south through the central peninsula (435-1,773 msnm) before completing the circuit back to La Paz. The research team, consisting of four ladies (Minerva, Nancy, Alicia, and Kalina), successfully documented 36 populations and collected 31 accessions representing 10 distinct Lupinus species. The collection prioritized in situ morphological identification, recording of geographic coordinates, and seed collection for subsequent studies and germplasm conservation. Identification was performed by comparison with type specimens and confirmation with the original description. The altitude range where Lupinus species were found varied from 12 msnm to 2621 msnm. The species collected were: Lupinus affinis, L. andersonii, L. arizonicus, L. bicolor, L. concinnus, L. excubitus, L. hirsutissimus, L. latifolius, L. niveus, and L. saxosus. Furthermore, L. excubitus showed the greatest altitudinal range (532 - 2680 msnm), and L. arizonicus showed the greatest ecological versatility by being present from above sea level to submontane elevations. Annual species (L. affinis, L. andersonii, L. arizonicus, L. bicolor, L. concinnus, L. hirsutissimus) have short life cycles (3–5 months) and germinate with the first winter rains. Perennial species (L. excubitus, L. latifolius, L. niveus, L. saxosus) develop persistent woody structures that allow them to survive adverse conditions. L. hirsutissimus is easily distinguished by its dense hairs and large, leaf-like floral bracts. According to the ecoregions of González-Abraham et al. (2010) and our field notes, L. hirsutissimus, the most frequent species in the northern part of the peninsula, occupies three different ecoregions: coastal scrubland towards the Pacific Ocean and the San Felipe Desert and Central Desert towards the Gulf of California. The only species found in both the north and the south was L. niveus. In the north, it occupies the Rosetophyllous Coastal Scrub region, and in the south, the Cape Lowland Forest. This expedition represents a significant contribution to the understanding of Lupinus diversity in the Baja California Peninsula, providing valuable germplasm for conservation and breeding programs. This work establishes a foundation for continued biodiversity assessment and conservation strategies for wild lupins in northwestern Mexico. The collected material is available for public consultation by contacting the authors.