Field survival and growth of clonal, micropropagated Eucalyptus marginata selected for resistance to Phytophthora cinnamomi

Clones of jarrah (Eucalyptus marginata), micropropagated from glasshouse-grown seedlings selected for resistance or susceptibility to Phytophthora cinnamomi, were planted in a former bauxite mine-site in the jarrah forest and inoculated with P. cinnamomi. Mortality after 13 years in resistant clones was 0–30%, while that of susceptible clones was 40–100%. Mean heights of resistant clones after 13 years were 7.8–13.6 m, while heights of surviving susceptible clones were 0.9–6.7 m. The resistance character of the seedling ortets was transmitted consistently to the clones. The field mortality of clones of some rare, apparently resistant seedlings selected from susceptible half-sib families was low after 1 year, but approached that of the susceptible clones after 2 years. The results show that Phytophthora-resistant jarrah ortets can be selected using stem-inoculation of glasshouse-grown seedlings; the resistance of the resulting clones has been validated in the field in an inoculation trial.

[1]  M. Stukely,et al.  Selection and propagation of jarrah for dieback resistance. A progress report , 1990 .

[2]  M. Stukely,et al.  Genetically based resistance of Eucalyptus marginata to Phytophthora cinnamomi , 1994 .

[3]  D. Ingram,et al.  Plant tissue culture , 1976 .

[4]  M. Stukely,et al.  Genetic variation in resistance of Pinus radiata to Phytophthora cinnamomi , 1984 .

[5]  J. McComb,et al.  Vegetative propagation of Eucalyptus using tissue culture and its application to forest improvement in Western Australia , 1982 .

[6]  P. H. Tsao.  Inhibition of Mortierella and Pythium in a Phytophthora-isolation Medium Containing Hymexazol , 1977 .

[7]  F. Podger.  Phytophthora cinnamomi, a Cause of Lethal Disease in Indigenous Plant Communities in Western Australia , 1972 .

[8]  J. McComb,et al.  Phytophthora in forests and natural ecosystems : 2nd International IUFRO Working Party 7.02.09 Meeting, Albany, W. Australia 30th Sept.-5th Oct 2001 , 2003 .

[9]  D. Cahill,et al.  A comparison of changes in phenylalanine ammonia-lyase activity, lignin and phenolic synthesis in the roots of Eucalyptus calophylla (field resistant) and E. marginata (susceptible) when infected with Phytophthora cinnamomi , 1992 .

[10]  J. McComb,et al.  Inoculation of Eucalyptus marginata Donn ex Sm. (jarrah) clones with Phytophthora cinnamomi Rands in vitro and under glasshouse conditions , 1993 .

[11]  B. Dell,et al.  The Jarrah Forest: A Complex Mediterranean Ecosystem. , 1991 .

[12]  J. Bartle,et al.  Mining and rehabilitation , 1989 .

[13]  D. Cahill,et al.  Resistance of micropropagated Eucalyptus marginata to Phytophthora cinnamomi , 1992 .

[14]  D. Cahill,et al.  Mechanisms of resistance to Phytophthora cinnamomi in clonal, micropropagated Eucalyptus marginata , 1993 .