2Fisher D V. Spur-type strains of 'McIntosh' for high den- sity planting[J]. British Columbia Fruit Grower's Associa- tion Quartly Report, 1969,14(2) : 3-10.
3Tobutt K R. Breeding columnar apple at East Malling[J]. Acta Horticulture, 1985,159 : 63-68.
4Kesley D F, Brown S K. 'Mclntosh Wijicik' a colum nar- mutation of 'MaIntosh~ apple proving useful in physiology and breeding research[J]. Fruit Varieties Journal, 1992,46 (2) :83-87.
5Wright I I,Reich P B, Westoby M,et al. The world wide leaf economics spectrum[J]. Nature, 2004,428 : 821-827.
