Phenotypic and Molecular Analyses of Rhizoctonia spp. Associated with Rice and Other Hosts

Abstract

Forty-two Rhizoctonia isolates were collected from rice, mung bean, and grasses from Laguna, Philippines. Sixteen isolates were binucleate Rhizoctonia (BNR), while 26 were multinucleate Rhizoctonia (MNR). BNR isolates produced white to brown, small sclerotia (<1.0 mm) except for mung bean isolates. Twenty MNR isolates produced big (>1.0 mm), light to dark brown sclerotia, three produced salmon-colored masses in the medium, and three did not produce sclerotia. Twenty-three MNR isolates were identified as R. solani AG1-IA using specific primers. Deduced Internal Transcribed Spacer (ITS) sequences of BNR isolates D1FL, NVL, and ScNL shared 100, 97, and 100% identity with R. oryzae-sativae, respectively, while MNR isolates BMgL, IbMgL, and MaSL that produced salmon-colored masses shared 100, 90, and 100% identity with R. oryzae, respectively. Preliminary analysis of the DNA fingerprint patterns generated by repetitive-element PCR (rep-PCR) clustered the 42 isolates into three: R. solani, R. oryzae-sativae, and R. oryzae, together with Ceratobasidium sp. R. solani isolates were pathogenic on rice (TN1), barnyard grass, mungbean (Pagasa 3), and tomato (Athena), while R. oryzae and R. oryzae-sativae isolates were only pathogenic on rice, Echinochloa crus-galli, and tomato. R. solani and R. oryzae were found to be more virulent than R. oryzae-sativae.

Diversity Analysis of Rhizoctonia solani Kuhn Isolates Causing Sheath Blight of Rice in Eastern Uttar Pradesh, India

“…The R. solani isolates were grouped into 4 groups based on the distribution pattern of sclerotia viz., sclerotia at the periphery (11), center as a ring (1), both centered and periphery ring (4), and scattered pattern (5) (Table 3). The similar results agree with Sandoval et al, [39], who categorized the formation of the sclerotic body as central, peripheral, scattered, and ring pattern. Among thirty-eight isolates, twenty-eight isolates had scattered distribution, five had centered sclerotia, three isolates had a peripheral pattern, and two isolates had a ring pattern.…”

First Report of Rhizoctonia solani Associated with Black Scurf of Potato Tubers in Lesotho

“…The most commonly used include those that identify the pathogen nuclear status and their anastomisis groups (Kareem and Hassan, 2018). More frequently, Rhizoctonia species classification is based on cytomorphology of the hyphae and the culture morphology (Sandoval and Cumagun, 2019). Depending on the nuclear status of the young vegetative hyphae, Rhizoctonia isolates can be divided into binucleate and multinucleate groups (Yang, 1994;Kareem and Hassan, 2018).…”

Hydrogel capsules as new delivery system for Trichoderma koningiopsis Th003 to control Rhizoctonia solani in rice (Oryza sativa)

“…The sheath blight disease caused by Rhizoctonia solani (R. solani JG Kuhn) [teleomorph Thanatephorus cucumeris (Frank) Donk] has been the second most damaging in rice crops in supplying countries (Sandoval and Cumagun 2019). The management of sheath blight is currently based on plant breeding and chemical fungicides, but other alternatives such as formulations based on bene cial microorganisms, are also effective.…”