Spread of Sugarcane yellow leaf virus in initially disease-free sugarcane is linked to rainfall and host resistance in the humid tropical environment of Guadeloupe

Abstract

Sugarcane yellow leaf virus, the causal agent of yellow leaf, is transmitted from plant to plant by aphids. Understanding and evaluating the epidemic risks due to spread of yellow leaf by aphids is an important feature for sugarcane production. Four distinct sugarcane trials were set up with disease-free plants to study the relationship between spread of yellow leaf, the vector dynamics and environmental conditions that may favour yellow leaf epidemics. The study was performed by surveys of vector populations and determination of plant infections. Sugarcane cultivar SP71-6163, highly susceptible to yellow leaf, was analyzed spatially at different dates in all four trials and compared to commercial cultivars in two of the four trials. These surveys allowed us to identify a correlation between the aphid dynamics in the field and yellow leaf progress. Additionally, a negative correlation was found between rainfall during the first weeks after transferring sugarcane plants to the field and aphid dispersal within the field. This later result revealed an impact of rainfall on aphid invasion and subsequent plant infection by SCYLV. If aphids are the key factor for disease spread, plant response varied also according to cultivar resistance with high variation depending on rain conditions.

Molecular characterization of genetic basis of Sugarcane Yellow Leaf Virus (SCYLV) resistance in Saccharum spp. hybrid

“…This virus is a Polerovirus (Moonan, Molina, & Mirkov, ) with a single‐stranded positive‐sense RNA genome (Abu Ahmad et al., ; Comstock, Irey, Lockhart, & Wang, ) and can cause severe yield reduction up to 37% in susceptible cultivars (Rassaby et al., ). This virus is transmitted by different aphid species mainly Melanaphis sacchari depending on cultivar susceptibility and weather conditions (Daugrois, Edon‐Jock, Bonoto, Vaillant, & Rott, ). Yellow leaf disease is also spread by infected seed cane used for planting (Debibakas et al., ).…”

“…This virus is transmitted by different aphid species mainly Melanaphis sacchari depending on cultivar susceptibility and weather conditions *These authors equally contributed to this work. (Daugrois, Edon-Jock, Bonoto, Vaillant, & Rott, 2011). Yellow leaf disease is also spread by infected seed cane used for planting (Debibakas et al, 2014).…”

Collapsing of Non‐centred Parameterized MCMC Algorithms with Applications to Epidemic Models

“…In Brown et al (), m = 6 with t = (0,6,10,14,19,23,30) and time units of a week. (Note that in this case t should be (0,6,11,15,19,23,30)Daugrois et al ()).…”

“…In this section, we consider spatial S → I epidemic models where individuals start off susceptible, but once they become infected, they remain so forever. A spatial S → I epidemic model is appropriate for many agricultural diseases, for example, citrus tristeza virus (CTV) in a citrus orchard (Gibson, ; ) and the spread of sugarcane yellow leaf virus (SCYLV) on a sugarcane plantation (Daugrois et al, ; Brown et al, ). In the aforementioned papers, the plants are located on a two‐dimensional rectangular lattice, , although the approach is not limited to this case.…”

“…We highlight the differences and advantages of this approach to that taken in the work of Brown et al () where estimation of both the spatial spread of the disease and the infection rate is performed. Finally, we employ the new MCMC algorithm to the CTV data Gibson () and the spread of SCYLV (Daugrois et al, ; Brown et al, ).…”