Resistencia varietal al ataque por Diatraea spp. (Lepidoptera: Crambidae) en caña de azúcar

Abstract

Los barrenadores del tallo, Diatraea spp., constituyen las plagas más importantes de la caña de azúcar en Colombia. En el país, el proceso de obtención de variedades no involucra la selección con respecto a la resistencia a insectos plaga, pero en la etapa final de selección se evalúa el porcentaje de entrenudos barrenados (intensidad de infestación) y se asigna una calificación de daño relativa al daño promedio obtenido en cada prueba, que luego de al menos tres pruebas da lugar a un promedio de calificación de daño denominado índice de resistencia (I.R.). En este trabajo se identificaron los genotipos según su caracterización de resistencia al ataque de la plaga, en tres localidades y bajo condiciones fenológicas de dos cosechas (plantilla y primera soca). Mediante una tabla de contingencia se analizaron 16 variedades con respecto a la frecuencia en su calificación de daño y se analizó estadísticamente la proporción de entrenudos barrenados y el I.R. Consistentemente la mayor estabilidad ambiental y fenológica fue para las variedades susceptibles CC 93-3826 y CC 93-3803, la resistente CC 93-3811 y la moderadamente resistente CC 93-3895; se propone que estas variedades con caracterización de resistencia contrastante sean utilizadas como testigos para el establecimiento de un protocolo en condiciones controladas que permita determinar de forma precisa el componente genético de la resistencia frente a los barrenadores del tallo.

Resistance to Diatraea (Lepidoptera: Crambidae) stem borers in sugarcane is independent of species

“…In general, CC 93-3826 and CC 93-3895 have exhibited contrasting responses to insect attacks (proportion of bored internodes) both under field conditions (Echeverri-Rubiano et al 2017) and under uniform infestation, as reported in the present study. Studies using controlled infestation, such as those under screen house and/or laboratory conditions, enable homogeneous pest populations per experimental unit (i.e., plants), thus enhancing precision in assessing the impact of genotypes on borer biology, as well as in reducing the prevalence of variables affecting survival such as harsh weather, cannibalism, parasitism, predation, and disease (Rodríguez-Del-Bosque et al 1989, Knutson and Gilstrap 1990).…”

“…The applicability of our results from screen house experiments to commercial sugarcane production fields is reinforced by the findings of Echeverri-Rubiano et al (2017), as the authors also found more pest injury on CC 93-3826 (susceptible) in comparison to other varieties, including CC 93-3895 (resistant), on regional trials in three different locations in the Cauca River Valley (CRV) of Colombia. Additionally, an increase in pest injury has been observed in association with an increase in susceptible cultivars plantings in the CRV region (Echeverri-Rubiano et al 2018).…”

“…However, differences in magnitude were found between species due to biological characteristics and preferences (Echeverri-Rubiano et al 2022); this requires further study. In general, pest injury exhibited by sugarcane varieties under field conditions are related to levels of resistance or susceptibility (White 1993, Echeverri-Rubiano et al 2017); however, as it has been found that the magnitude of pest injury can be affected by environmental conditions, such as a species complex overlapping in time or spatial distribution (Rossi 2004, Smith 2005). In addition, it is also important to determine whether external lesions are entrance or emergence holes (Bessin et al 1990b).…”

“…Even though recent sugarcane stem borer pest outbreaks in Colombia are possibly associated with D. busckella and D. tabernella population increases and due to the fact that genotypes with greater resistance have been replaced by less resistant genotypes (Echeverri-Rubiano et al 2018), thus far it is not clear whether sugarcane varieties exhibit differential host-plant resistance responses to different Diatraea species. In addition, most studies focus only on D. saccharalis, while only a few have focused on D. indigenella (Pastrana et al 1993) and D. tabernella (Atencio et al 2017(Atencio et al , 2018.…”

“…In Colombia, field studies have allowed for a preliminary characterization of the resistance of some varieties to sugarcane stem borers, finding that CC 93-3826 is susceptible, while CC 93-3811 is resistant (Gómez and Vargas 2014, Echeverri-Rubiano et al 2017). However, under field conditions, it is impossible to discriminate the relationships between different sugarcane varieties and the Diatraea species most abundant in this crop in Colombia, such as D. saccharalis (Fabricius, 1794) , D. busckella Dyar & Heinrich, 1927; D. indigenella Dyar & Heinrich 1927, and D. tabernella Dyar, 1911 (Lepidoptera: Crambidae) (ICA, 2017), since their presence overlaps in both time and space within the same sugarcane crop (Leyton-Flor et al 2018), as well as across different hosts (e.g., rice and corn) grown in neighboring areas (Reay-Jones et al 2007, Joyce et al 2016).…”