Cultural Characteristics of Rhizoctonia cerealis Isolated from Diseased Wheat Fields and Evaluation of the Resistance of Korean Winter Cereal Crops

Abstract

It was identified as a sharp eyespot (Rhizoctonia cerealis) that the isolates from abnormal symptoms in wheat that showed yellowing leaves, necrotic spot on stem base and dead tillers. These isolates have slower growth property and fewer mycelia than Rhizoctonia solani AG-1(1A) (KACC 40106). They showed binuclear cell, same media cultural and DNA characteristics to R. cerealis. They caused same symptoms on leaves and stem base appeared in artificial inoculation test, comparing to diseased wheat fields and also affect to maturing of kernels. They have optimal growth temperature and acidity on the artificial media as 20~25 o C and pH 5~7, respectively. In the investigation of varietal resistance of Korean winter cereal crops to sharp eyespot, there was no resistant in wheat cultivars that all materials infected over 20% diseased ratio. 12 cultivars including 'Anbaekmil', however, considered to moderate resistance with 20 to 30% infection ratio. The others crops using in feeding, whole crop barley, oat, rye and triticale were resistant below 15% diseased degree except the rye that showed over 50% infection rate. It was the first evaluation to sharp eyespot resistance for the Korean feeding crop cultivars. Most tested Korean barley cultivars for malting and food were moderate and susceptible to the sharp eyespot. Only 3 hulled barley, 'Tapgolbori', 'Albori' and 'Seodunchalbori', showed resistance with less than 10% diseased ratio. All tested naked barley cultivars showed susceptible response to the disease.

Effects of Different Seeding Rates on Disease Incidences of Wheat Sharp Eyespot and Selection of Fungicides

“…The same letter within columns means no significant differences between the treatments by Duncans multiple range test (P<0.05). Inoculation method referred toLee et al (2011). 리에서도 무처리에 비해 약 14%의 발병률 억제 효과를 보였으나, 유의성 있는 차이로 나타나지는 않았다.…”

“…Post-treatment effects of chemicals on the disease incidences after artificial inoculation of Rhizoctonia cerealis Disease incidence : Percentage of diseased stems among the total inoculated seedlings. Inoculation method refrred toLee et al (2011).…”