Elucidating the intricate interplay between microorganisms and crops, mainly maize (Zea mays), holds promise for devising agronomic interventions to augment yield, inducing defense mechanisms against pests and pathogens, and alleviating abiotic stresses. In pursuit of comprehending the composition of the maize root microbiomes across different genotypes, we conducted a thorough characterization of the root and rhizosphere microbiome of three indigenous Ecuadorian Andean maize cultivars, UCE-Amarillo, INIAP-122, and UCE-Pepa grown in a native soil, employing high-throughput DNA sequencing targeting the 16S rRNA gene. Root tissues and rhizosphere were collected from 18 plants from each cultivar, plus 18 bulk soil samples. Alpha diversity metrics, such as the Chao and Shannon indices, were employed to assess microbial richness and evenness, revealing a notably lower diversity within the root microbiome than the rhizosphere and bulk soil compartments. Furthermore, discernible plant genotype-driven microbiome assembly patterns were observed across all compartments. Taxonomic profiling unveiled a conspicuous absence of Actinobacteria and an elevated abundance of Proteobacteria within the root microbiome. Moreover, 34 amplicon sequence variants (ASVs) were present in all the root and rhizosphere samples (100% occupancy) from the three cultivars, making these the core microbiome of the indigenous Ecuadorian Andean maize. The highly consistent root and rhizosphere colonization across cultivars make these 34 ASVs great candidates as bioinoculants for maize in the Andean region of Ecuador. Target isolation and functional characterization of these microbes are necessary for future applications to enhance their resistance to biotic and abiotic stresses.

The Passifloraceae family is one of the most representative in tropical America, with food, pharmaceutical, and ornamental importance. This study evaluated seed morphometry and germination of eight accessions of four Passiflora edible species, P. edulis; P. ligularis; P. quadrangularis; and P. tripartita var. mollissima, by studying accessions conserved several years in the gene bank (−15 °C) and recently collected accessions. Four experimental phases were carried out as follows: (1) morphometric characterization of seeds with qualitative and quantitative variables; (2) evaluation of germination under two thermal regimes (20 °C/30 °C and 25 °C); (3) application of six pre-germination treatments to overcome dormancy; and (4) tetrazolium tests. In phase 1, P. quadrangularis stood out for its unique morphological characteristics according to multivariate analysis. In phase 2, the alternating thermal regime (20 °C/30 °C) promoted the highest germination. In phase 3, the germination response was specific to each species: mechanical scarification in P. edulis (85.7%), KNO₃ (0.5%) in P. ligularis (35.7%), control in P. quadrangularis (71.1%), and gibberellic acid (GA₃ 400 ppm) in P. tripartita (71.4%). The tetrazolium phase 4 identified the viability status of the seeds. It is concluded that the differences in morphometry and germination reflect the intrinsic characteristics of each species, highlighting the importance of specific protocols for their germination. This study provides tools to optimize the conservation and regeneration of Passiflora spp. germplasm under ex situ conditions, as a genetic base to be utilized in the future.

Los sistemas de inmersión temporal (SIT) complementados con el autotrófico hidropónico (SAH), se ensayaron, con el objetivo de acelerar el proceso de propagación de semilla prebásica de papa (Solanum tuberosum L.) de las variedades Superchola y Diacol-Capiro. Los resultados de los datos técnicos evaluados en las plántulas en los dos sistemas bajo las condiciones del sitio de implementación, presentaron varias ventajas en el incremento vegetativo, sobre el total de número de segmentos nodales obtenidos por biorreactor, que fueron de 322 y 264 para Superchola y Diacol-Capiro respectivamente, estos valores corresponden a la obtención de 81 tubos de ensayo (1,8 x 14 cm), que ocupan una área de 2041.2 cm2 y con reducción en el ciclo de producción comparado con el sistema tradicional de cultivo en agar in vitro en quince días. Las tasas de multiplicación en los biorreactores para Superchola y Diacol-Capiro fueron 1:9 y 1:8, respectivamente. En invernadero la tasa de producción por área fue > 366 minitubérculos por m2 en la variedad Superchola y en Diacol-Capiro fue de 225 minitubérculos por m2. El rendimiento promedio de 3.75 kg. m2 es superior a los obtenidos en plántulas in vitro en el sistema convencional y semihidropónico. Al comparar las dos variedades, Superchola alcanzó la mejor respuesta con rendimientos superiores en el número de tubérculos del 20% con respecto a Diacol-Capiro. El análisis financiero determinó una relación Beneficio/Costo para Superchola de 1.27 con una ganancia de 0.27 USD por cada dólar invertido. Este sistema puede proveer un método conveniente que puede ser adaptado para la propagación in vitro comercial.