Agriculture in the Andean region is mainly small-scale and rainfed, especially in Peru where almost 80% of its population depends on agriculture-related activities. Climate change in addition to social factors threatens the food security of this region. The forecast of more frequent dry spells would especially affect potato crops, domesticated centuries ago in the Andes, where there remains a great genetic diversity. This study aimed to characterize the response to drought stress of 79 potato landraces traditionally grown in the Central Andes of Peru (Pasco region) as a first selection for future breeding evaluations. The used indices were mean productivity (MP), geometric mean productivity (GMP), stress tolerance (STI), stress susceptibility (SSI), and tolerance index (TOL), and a scoring methodology that integrates all of them into a single descriptor in a simple and fast way. The varied responses showed a wide genetic diversity within the assessed landraces, where at least nine of them own high resilience and productivity qualities, and many others are highly vulnerable to drought. It is recommended to complement these studies with physiological and molecular evaluations in stress situations, especially in those with tolerance qualities highlighted in this study, and thus promote the conservation of the biodiversity of this region.

The diversity of native potatoes cultivated above 3500 masl in the Pasco region (Central Andes of Peru) has not been fully characterized. It is currently subject to constant genetic erosion caused by biotic and abiotic factors. The research aimed to characterize phenotypically and genotypically 40 native potato landraces representative of 4 Solanum species. Twenty phenotypic descriptors and 10 microsatellites were used for genetic evaluation. Likewise, the ploidy level was evaluated based on the number of chloroplasts in the stomata. The clustering analysis was performed using the Infostat software and the R program with the Adegenet and Polysat libraries. The phenotypic characterization allowed to obtain five groups with a distance coefficient of 9.5. The molecular characterization found seven groups and 58 alleles in total. The average number of alleles per microsatellite was 5.5. 13.2 % of duplicates were identified. The microsatellites STG001, STM1106, ST0032, and STM5127 with an average He of 0.8 and a polymorphism information content (PIC) of 0.5 - 0.8 were the most informative. Finally, the ploidy results were 13 % diploid, 35 % triploid, and 52 % tetraploid. It was evidenced low diversity when using a set of 10 SSR markers, which indicates limited applicability for studying the genetic diversity of local potato landraces. It is necessary to involve a broader range of markers and a more diverse set of genotypes from the Pasco region for further studies.

Los trabajos agronómicos para la obtención de semillas homogéneas de seis morfotipos de maca (Lepidium meyenii) en estudio en su segunda generación, utilizando el método de la selección individual; así como una aproximación de los costos de producción en las dos fases del cultivo para el cálculo de su rentabilidad económica, tuvieron lugar en la Provincia de Pasco, durante los años 2018 y 2019. Los resultados indican que aún no se ha podido determinar los fundamentos científicos y/o técnicos que dan coloración a los hipocotilos de maca; es decir, aún no se puede afirmar científicamente que los colores homogéneos de los hipocotilos buscados se debe a razones genéticas o a las condiciones ambientales y/o a los tipos de suelos. Los morfotipos en investigación son: negro, blanco, rojo, amarillo, plomo y rosado. La productividad de maca por unidad de superficie cultivada en su hábitat natural sobre los de 4000 msnm, es 50 por ciento más respecto a la productividad lograda a una altitud de 3300 msnm. Con los análisis de costos y productividad, se encontró que la producción de hipocotilos frescos no debe ser inferior a 4400 kilogramos por hectárea para evitar pérdidas económicas al agricultor.