Temperature and Soil Moisture Stress Modulate the Host Defense Response in Chickpea During Dry Root Rot Incidence

Abstract

Dry root rot caused by the necrotrophic phytopathogenic fungus Rhizoctonia bataticola is an emerging threat to chickpea production in India. In the near future, the expected increase in average temperature and inconsistent rainfall patterns resultant of changing climatic scenarios are strongly believed to exacerbate the disease to epidemic proportions. The present study aims to quantify the collective role of temperature and soil moisture content (SMC) on disease progression in chickpea under controlled environmental conditions. In our study, we could find that both temperature and soil moisture played a decisive role in influencing the dry root rot disease scenario. As per the disease susceptibility index (DSI), a combination of high temperature (35°C) and low SMC (60%) was found to elicit the highest disease susceptibility in chickpea. High pathogen colonization was realized in chickpea root tissue at all time-points irrespective of genotype, temperature, and SMC. Interestingly, this was in contrast to the DSI where no visible symptoms were recorded in the roots or foliage during the initial time-points. For each time-point, the colonization was slightly higher at 35°C than 25°C, while the same did not vary significantly with respect to SMC. Furthermore, the differential expression study revealed the involvement of host defense-related genes like endochitinase and PR-3-type chitinase (CHI III) genes in delaying the dry root rot (DRR) disease progression in chickpea. Such genes were found to be highly active during the early stages of infection especially under low SMC.

Efficiency of some Organic Matter on Suppression of Soil-Borne Diseases of Tomato Plants under Organic Agriculture System

“…Finally, all organic matters improved the fruit quality and the results in the 2020/21 growing season were higher than in 2019/20 growing season. The obtained results are in harmony with those obtained by (Ahmed et al, 2017;Barthod et al, 2018;Sharath Chandran et al, 2021 andMohammed et al, 2021), who explained That instead of the increment in physical and chemical quality attributes may be due to the increase of macronutrient of plant tissues which affect photosynthetic assimilation rate and in turn increased accumulation of total soluble solids in fruit and ascorbic acid, total acidity and carbohydrate, which was intermediate products during the photosynthetic assimilation process. It is also contributed to increasing the aeration capacity of the soil, which improves and increases the quality, quantity, dry matter, vitamin C and sugars of vegetable crops.…”

“…These soluble nutrients in turn support the growth of bio microbes to control pathogens. The use of organic matter to tomato plants as soil amendments (Tables , 1 and 2) resulted in a better soil quality and greater plant disease suppressiveness (Sullivan (2004); Martina and Brathwaite (2012); Ahmed (2013) andSharath Chandran et al, 2021); however, in this study it depended on the type of organic fertilizer. These data are in agreement with those obtained by Sullivan (2004);Zmora-Nahum et al (2008) and Deeksha et al (2009) who stated that different organic matters improve soil properties due to their ammonium-fixing, nitrifying, and cellulose-destroying bacteria content, enrich the soil's macro-and microelement composition.…”

“…Fusarium spp., Phytophthora spp., Alternaria solani, Rhizoctonia solani, Sclerotium rolfsii and Pythium spp. are the most popular pathogens causing severe yield losses and quality of tomato all over the world and disease control is difficult (Hamza et al, 2016;Sharath Chandran et al, 2021 andMergawy et al, 2022).…”

Combined Drought and Heat Stress Influences the Root Water Relation and Determine the Dry Root Rot Disease Development Under Field Conditions: A Study Using Contrasting Chickpea Genotypes

“…Extensive evidence on DRR incidence and its increased severity under deficit soil moisture conditions has been reported ( Sharma and Pande, 2013 ; Sinha et al, 2019 , 2021 ; Sharath Chandran et al, 2021 ). Our results further confirm that drought-induced plant water reductions may aggravate DRR infection in chickpea.…”

“…Likewise, high temperature predisposes chickpea to DRR ( Sharma and Pande, 2013 ; Sharma et al, 2015 ). High temperature leads to enhanced proliferation of M. phaseolina in chickpea roots, as indicated by increased fungal DNA in infected roots of plants grown at 35°C as compared to those growing at ambient temperature ( Sharath Chandran et al, 2021 ). Furthermore, elevated temperatures improved microsclerotia production ( Marquez et al, 2021 ).…”