LINKAGE OF RAPD MARKERS TO NESTUR, A STEM GROWTH INDEX IN RADIATA PINE-SEEDLINGS

Needle-to-stem unit rate (NESTUR) is a stem growth index of conifer se edlings that measures the efficiency of stemwood production per unit o f foliage growth. The random amplified polymorphic DNA (RAPD) techniqu e was applied to haploid DNA from the megagametophytes of a full-sib r adiata pine cross to fmd markers linked to factors controlling the NES TUR trait. Using the bulked segregant analysis approach, 23 of 933 pri mers displayed putative linkage to factors controlling NESTUR. Based o n the genotypic analysis of 174 individuals, two quantitative trait lo ci (QTLs)controlling NESTUR were identified at ANOVA P-levels of 0.01- 0.001. The QTLs were identified by RAPD markers OPE-06(450) and OPA-10 (1200), which were linked to each other (r = 7%), and UBC-333(550), wh ich was not linked to the other two. Linkage to components of NESTUR ( increments in stem diameter and stem volume) was demonstrated for UBC- 333(550), while the others were not linked to NESTUR components.