Susceptibility of a hybrid (Pinus rigida×P. x rigitaeda) and P. thunbergii Seedlings to Fusarium circinatum Isolated from P. thunbergii in Jeju Island
제주도에서 푸사리움가지마름병의 자연감염목으로 추정되는 해송에서 분리된 균을 분자생물학적 기법을 이용하여 기존의 푸사리움가지마름병균과 비교하고, 분리된 균을 리기다소나무× 수식 이미지리기테다소나무 2, 4년생과 해송 2, 3, 6년생 묘목에 인공 접종하여 수종 및 수령별 감수성을 파악하고자 본 실험을 수행하였다. Site 1(FT)에서는 총 샘플 14 개체 중 13 개체에서 푸사리움균이 분리되었으며, Site 2(FS)에서는 9 개체 중 7
In this study, the variation of 20 Pinus thunbergii isolates of F. circinatum from 2 damaged sites in Jeju-Island were compared with a known Fusarium circinatum using molecular biological techniques. Two- and four-year-old seedlings of Pinus rigida×Pinus x rigitaeda and two-, three- and six-year-old seedlings of P. thunbergii were inoculated with one of the most virulent isolates, FT-7, to determine differences in susceptibility. In site 1 (FT), 13 isolates of F. circinatum were isolated from 14 individuals and in site 2 (FS), 7 isolates of F. circinatum were isolated from 9 individuals. No difference was found in the sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genes in the FS and FT isolates, and also even in the known isolate of F. circinatum, FE 1-1. However, the ITS sequences of the FS and FT isolates differed from those of a fungus, Botrytis cinerea. Two-year-old seedlings of P. rigida×P. x rigitaeda showed higher susceptibility (93.3% of mortality) than four-year-old ones. Three-year-old seedlings of P. thunbergii showed the highest susceptibility (66.7% of mortality) compared to those at other ages in the same species. We found a positive correlation between basal diameter and lesion length in the seedlings of P. rigida×P. x rigitaeda (R2 = 0.66) and P. thunbergii (p < 0.0001), respectively. There were significant differences in susceptibility by the age of seedlings in each of P. rigida×P. x rigitaeda (p < 0.0001) and P. thunbergii (p < 0.0001) based on lesion length.