Summary Candidatus Liberibacter solanacearum (CLs) is a bacterium associated with the psyllid yellows disease in tomato (PY), that causes great damage to tomato (Solanum lycopersicum L.) production in México. The use of resistant genotypes is the most sustainable alternative for disease management in plants; however, there are currently no reports of commercial tomato cultivars resistant to CLs. Therefore, the objective of this study was to evaluate the response to infection with CLs in cultivars Rio Grande®, Moctezuma®, Marmande, DRK2180®, La Roca®, Bonny Best® and the advanced line UAS 2016. The evaluation was carried out in Culiacan, Sinaloa, Mexico, in greenhouse conditions through a randomized complete block design with four replications. Inoculation of CLs was carried out by means of its vector and the expression of the disease in the plant was recorded for seven weeks. Genetic variability of the genotypes was analyzed by using of 15 microsatellites (SSR). Results indicated that the damage by PY in UAS 2016 and Marmande was significantly lower than in Rio Grande® and Moctezuma® while DRK2180®, La Roca® and Bonny Best® showed significant difference in relation to the last cultivar. The total genetic diversity presented a value of 0.58 and a GST of 0.30, indicating that the genotypes presented similar genetic variability.

Resumen Candidatus Liberibacter solanacearum (CLs) es una bacteria asociada a la enfermedad “Permanente del Tomate” (PT) que ocasiona grandes daños a la producción de tomate (Solanum lycopersicum L.) en México. El uso de genotipos resistentes es la alternativa más sustentable para el manejo de enfermedades en plantas; sin embargo, actualmente no hay reportes de cultivares comerciales de tomate resistentes a CLs. Por lo anterior, el objetivo del presente estudio fue evaluar la respuesta a la infección con CLs en los cultivares Río Grande®, Moctezuma®, Marmande, DRK2180®, La Roca®, Bonny Best® y la línea avanzada UAS 2016. La evaluación se desarrolló en Culiacán, Sinaloa, México en condiciones de invernadero mediante un diseño de bloques completos al azar con cuatro repeticiones. La inoculación de CLs se llevó a cabo mediante su vector y la expresión de la enfermedad en la planta se registró durante siete semanas. La variabilidad genética de los genotipos fue analizada con el empleo de 15 microsatélites (SSR). Los resultados indicaron que la expresión de PT en UAS 2016 y Marmande fue significativamente menor que en Río Grande® y Moctezuma®, sin que DRK2180®, La Roca® y Bonny Best® mostraran diferencia significativa con respecto a esta última variedad. La diversidad genética total presentó un valor de 0.58 y un GST de 0.30, lo que indica que los genotipos presentaron variabilidad genética similar.

ABSTRACT The objective of our study was to assess the apparent digestibility of plant ingredients in diets for juvenile (50 g) and adult (220 g) Nile tilapia (Oreochromis niloticus). Dietary dry matter and protein apparent digestibility coefficients of four plant-derived feedstuffs (chickpea, maize, high-quality maize protein, and beans) were tested. The beans diet had the lowest apparent digestibility coefficient of dry matter (ADCDM) (69.41%), while no significant differences were detected in ADCDM among the other diets; ADCDM was significantly higher in adults compared with juveniles (77.02 vs. 73.76%). Apparent dry matter digestibility coefficient of ingredients (ADCI) was significantly higher in the chickpea (70.48%) and high-quality protein maize (71.09%) ingredients, and lower in the beans (52.79%) ingredient. Apparent dry matter digestibility coefficient of ingredients was significantly higher in juveniles compared with adults (72.56 vs. 56.80%). The protein digestibility of diet (ADCCP) was significantly higher in the reference diet (93.68%), while the lowest corresponded to the maize (87.86%) and beans (87.29%) diets. Significantly lower apparent digestibility coefficient of protein (ADCICP ) was obtained with the high-quality maize protein (59.11%) and maize (49.48%) ingredients, while higher ADCICP was obtained with the chickpea and beans ingredients (71.31 and 63.89%, respectively). The apparent digestibility coefficient of ingredient crude protein ADCICP was significantly higher in juveniles compared with adults (67.35 vs. 53.46). Digestibility is generally higher in juveniles, and we recommend using chickpea as an ingredient in diets for Nile tilapia.