© 2002 Heron Publishing—Victoria, Canada
Annual shoot growth components related to growth of Pinus brutia
Fikret Isik (1, 2), Kani Isik (3), Tolga Yildirim (3) and Bailian Li (1)
1. North Carolina State University, College of Natural Resources, Department of Forestry, Campus Box 8002, Raleigh, NC 27695,
USA / 2. Author to whom correspondence should be addressed (fisik@unity.ncsu.edu) / 3. Akdeniz University, Faculty of Arts and Sciences, Department of Biology, 07058 Antalya, Turkey / Received April 26, 2001; accepted August 18, 2001; published online December 1, 2001
Summary
Shoot elongation patterns of Pinus brutia Ten. were studied in six natural populations and 10 open-pollinated families within each population. The data were collected
from a provenance-progeny trial that was thinned at Ages 13 and 17 years. Annual height increment was partitioned into first
flush (spring shoot) and subsequent flushes (summer shoots) and the contribution of each to annual height increment was measured
from Ages 7 to 17.
Spring shoot elongation patterns were similar in all populations and families for 9 out of 10 years. In contrast, at all ages,
populations differed significantly in total summer shoot growth and number of summer flushes. Families within populations
differed in number of summer flushes in 7 out of 10 years. Summer shoot growth was the major cause of the differences in annual
height growth among the six populations. Significant and high correlations were observed between summer shoot growth at Ages
7 to 12 and height at Age 13. A population from near the middle of the species' altitudinal range had more summer flushes
than populations from higher or lower elevations, indicating an opportunistic growth pattern. Compared with mid-elevation
populations, low- and high-elevation populations had more conservative growth patterns that depended mainly on growth of spring
shoots. We conclude that summer shoot growth can serve as an explanatory variable to predict height growth of populations.
Differences in shoot elongation patterns among Pinus brutia populations may be useful for selecting seed sources and for gene conservation programs.
Keywords:
adaptation, first flush, growth cycles, shoot elongation.
