Impacts of Fungal Stalk Rot Pathogens on Physicochemical Properties of Sorghum Grain

Abstract

Stalk rot diseases are among the most ubiquitous and damaging fungal diseases of sorghum (Sorghum bicolor (L.) Moench) worldwide. Although reports of quantitative yield losses to stalk rots are available, the impact of stalk rot on grain quality attributes is unknown. This study was conducted to test whether stalk rot diseases could affect grain mineral (N, P, K; Ca, Mg, Cu, Fe, Mn, and Zn) and macronutrient (protein, fat, and starch) content, ash content, and physical traits (unit grain weight, hardness, and diameter). A field experiment was conducted in 2013 and 2014 with four sorghum genotypes (two hybrids and two lines). Plants from each genotype were inoculated with four stalk rot pathogens (Fusarium andiyazi, F. proliferatum, F. thapsinum, and Macrophomina phaseolina) and mock-inoculated with phosphate-buffered saline (control). Grains collected from infected and control plants were analyzed for macronutrient and ash content using near-infrared reflectance spectroscopy, grain hardness and diameter using the single-kernel characterization system, and mineral content using the Rapid Flow Analyzer (Model RFA-300 for N) and inductively coupled plasma spectrometer (for P, K, Ca, Mg, Cu, Fe, Mn, and Zn). Although stalk rot pathogens significantly reduced unit grain weight, they did not significantly affect grain hardness and diameter and, therefore, may not affect milling quality. Pathogens significantly reduced all macronutrient and most mineral contents across genotypes and environments on a per-unit-grain basis, except N and Mg, which were affected in a genotype- and environment-specific manner, and Fe, which was not significantly affected. Most minerals tested were significantly and negatively correlated with disease severity (lesion length) and total grain weight per panicle. The hybrid tested (Pioneer 84G62) exhibited reduced mineral and macronutritional changes after stalk rot infection, providing insights into the possibility of producing high-yielding, nutritionally stable hybrids under stalk rot disease pressure through dedicated breeding efforts.

Virome Identification and Characterization of Fusarium sacchari and F. andiyazi: Causative Agents of Pokkah Boeng Disease in Sugarcane

“…The FFSC species F. sacchari is associated with both PBD and sugarcane wilting (Viswanathan et al, 2017) as well as fruit rot disease in bananas (Abd Murad et al, 2017), spear rot of oil palm (Suwandi et al, 2018), and even mycotic keratitis among sugarcane farmers (Bansal et al, 2016). The FFSC species F. andiyazi has been reported to cause wheat head blight (Wang et al, 2015), ear rot of maize (Bandara et al, 2017), and stalk rot of sorghum (Zhang et al, 2014). Recently, our team found F. sacchari and F. andiyazi strains with various phenotypes in Guangxi, Fujian, and Yunnan, which are the major sugarcane producing provinces in China (Wang J. et al, 2018;Meng et al, 2020).…”

Dynamics of host glutathione and glutathione related enzymes in Macrophomina phaseolina-sorghum bicolor interaction

“…Charcoal rot is a high priority fungal disease in sorghum [ Sorghum bicolor (L.) Moench], causing tremendous crop losses where ever sorghum is grown (Tarr, 1962, Tesso et al ., 2012). Recent reports revealed the M. phaseolina ’s ability to negatively affect the physicochemical properties of sorghum grain (Bandara et al, 2017 a), sorghum yield components (Bandara et al, 2017 b), leaf greenness (Bandara et al, 2016) and sweet sorghum biofuel traits such and juice yield and biomass (Bandara et al, 2017 c). Our recent genes expression and functional investigations provided exciting insights into induced charcoal rot disease susceptibility in grain sorghum through up-regulated host oxidative stress after M. phaseolina infection (findings have been submitted for publication).…”

Host lipid alterations afterMacrophomina phaseolinainfection contribute to charcoal rot disease susceptibility in grain sorghum: Evidence from transcriptomic and lipidomic data

“…Charcoal rot is a high priority fungal disease in sorghum [ Sorghum bicolor (L.) Moench], causing tremendous crop losses wherever sorghum is grown (Tarr, 1962, Tesso et al ., 2012). Recent studies have shown that charcoal rot can negatively affect the grain sorghum physical and chemical properties (Bandara et al, 2017a), yield parameters (Bandara et al, 2017b), and leaf greenness (Bandara et al, 2016), as well as the key biofuel traits of sweet sorghum (Bandara et al, 2017c). There are limited options available to control charcoal rot disease.…”