• Title/Summary/Keyword: Pinus rigida${\times}$Pinus x rigitaeda

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Susceptibility of a hybrid (Pinus rigida×P. x rigitaeda) and P. thunbergii Seedlings to Fusarium circinatum Isolated from P. thunbergii in Jeju Island (제주도 해송에서 분리한 푸사리움가지마름병균에 대한 교잡종 (리기다소나무×리기테다소나무) 소나무와 해송 묘목의 감수성 변이)

  • Yoon, Jun-Hyuck;Woo, Kwan-Soo;Shin, Han-Na;Lee, Seong-Kyu
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.420-428
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    • 2009
  • 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${\times}$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${\times}$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${\times}$P. x rigitaeda ($R^2=0.66$) and P. thunbergii (p < 0.0001), respectively. There were significant differences in susceptibility by the age of seedlings in each of P. rigida${\times}$P. x rigitaeda (p < 0.0001) and P. thunbergii (p < 0.0001) based on lesion length.