Beta Diversity of Arbuscular Mycorrhizal Communities Increases in Time after Crop Establishment of Peruvian Sacha Inchi (Plukenetia volubilis).

(1) Background: Beta diversity, i.e., the variance in species compositions across communities, has been pointed out as a main factor for explaining ecosystem functioning. However, few studies have directly tested the effect of crop establishment on beta diversity. We studied beta diversity patterns of arbuscular mycorrhizal (AM) fungal communities associated to sacha inchi (Plukenetia volubilis) after crop establishment. (2) Methods: We molecularly characterized the AM fungal communities associated to roots of sacha inchi in plots after different times of crop establishment, from less than one year to older than three. We analyzed the patterns of alpha, beta, and phylogenetic diversity, and the sources of variation of AM fungal community composition. (3) Results: Beta diversity increased in the older plots, but no temporal effect in alpha or phylogenetic diversity was found. The AM fungal community composition was driven by environmental factors (altitude and soil conditions). A part of this variation could be attributed to differences between sampled locations (expressed as geographic coordinates). Crop age, in turn, affected the composition with no interactions with the environmental conditions or spatial location. (4) Conclusions: These results point out towards a certain recovery of the soil microbiota after sacha inchi establishment. This fact could be attributed to the low-impact management associated to this tropical crop.

Mutations Found in the Asc1 Gene That Confer Susceptibility to the AAL-Toxin in Ancestral Tomatoes from Peru and Mexico.

Tomato susceptibility/resistance to stem canker disease caused by Alternaria alternata f. sp. lycopersici and its pathogenic factor AAL-toxin is determined by the presence of the Asc1 gene. Several cultivars of commercial tomato (Solanum lycopersicum var. lycopersicum, SLL) are reported to have a mutation in Asc1, resulting in their susceptibility to AAL-toxin. We evaluated 119 ancestral tomato accessions including S. pimpinellifolium (SP), S. lycopersicum var. cerasiforme (SLC) and S. lycopersicum var. lycopersicum "jitomate criollo" (SLJ) for AAL-toxin susceptibility. Three accessions, SP PER018805, SLC PER018894, and SLJ M5-3, were susceptible to AAL-toxin. SLC PER018894 and SLJ M5-3 had a two-nucleotide deletion (nt 854_855del) in Asc1 identical to that found in SLL cv. Aichi-first. Another mutation (nt 931_932insT) that may confer AAL-toxin susceptibility was identified in SP PER018805. In the phylogenetic tree based on the 18 COSII sequences, a clade (S3) is composed of SP, including the AAL-toxin susceptible PER018805, and SLC. AAL-toxin susceptible SLC PER018894 and SLJ M5-3 were in Clade S2 with SLL cultivars. As SLC is thought to be the ancestor of SLL, and SLJ is an intermediate tomato between SLC and SLL, Asc1s with/without the mutation seem to have been inherited throughout the history of tomato domestication and breeding.

Identificación y selección de Saccharomyces cerevisiae nativas para mejorar el proceso productivo del Pisco a partir de uva Quebranta

El Pisco es el destilado del Perú, elaborado a partir de mostos recientemente fermentados con uvas criollas denominadas "pisqueras". Las levaduras son los microorganismos clave en la fermentación y el uso de cepas nativas seleccionadas presenta ventajas competitivas para la tipicidad del producto, así como también para la estandarización del producto y el control microbiológico del proceso. El objetivo fue identificar y seleccionar las cepas de levaduras nativas para la producción del Pisco de uva Quebranta aisladas de procesos productivos de Pisco en el valle de Ica. Para ello, se emplearon técnicas microbiológicas y moleculares mediante el análisis de ITS1-5.8S-ITS2 PCR-RFLP para la identidad taxonómica. La evaluación de las cepas para producir Pisco consistió en el análisis fisicoquímico y organoléptico del destilado obtenido con las cepas seleccionadas. Se evaluaron 3 aislados para la producción de Pisco identificados como Saccharomyces cerevisiae: UNA SC - 25, UNA SC - 49 y UNA SC - 54, de los cuales la cepa UNA SC-49 destacó por mostrar aptitudes enológicas diferentes a las otras cepas. Este trabajo constituye el primer registro de levaduras nativas del Perú para mostos procedentes de uva Quebranta.

El Pisco stands as Peru's distilled spirit, crafted from recently fermented musts derived from native grape varieties known as "pisqueras". Yeasts serve as decisive microorganisms in the fermentation process, and the utilization of selected native strains confers competitive advantages for product typicity, standardization, and microbiological control within the production process. The aim was to identify and select native yeast strains for Quebranta grape Pisco production, isolated from Pisco production processes in the Ica Valley. Microbiological and molecular techniques were employed, utilizing ITS1-5.8S-ITS2 PCR-RFLP analysis for taxonomic identification. The assessment of yeast strains for Pisco production involved the physicochemical and organoleptic analysis of the distilled product obtained using the selected strains. Three isolates were evaluated for Pisco production, identified as Saccharomyces cerevisiae: UNA SC - 25, UNA SC - 49, and UNA SC - 54. Among these, the UNA SC-49 strain stood out due to displaying oenological characteristics distinct from the other strains. This work is the first documentation of native yeasts in Peru for musts derived from Quebranta grapes.