Correlations in progeny trials of Cunninghamia lanceolata

Key words: 
• forest breeding /
• Cunninghamia lanceolata /
• seed orchard /
• progeny trial /
• trait correlation /
• rank correlation /
• early selection

Abstract: The objective is to find the regularity of hereditary variations in Cunninghamia lanceolata(Chinese fir)seed orchard and improve the stock breeding efficiency. Data were analyzed from two progeny trials of 17 Cunninghamia lanceolata seed orchards that were surveyed continuously over 6 years for phenotype and genetic correlations among growth traits, age, and rank correlation. Results indicatd a close correlation(P 0.05, rp and rgnear or equal to 1.0) among growth traits of height, diameter, and stem volume. Crown width was significantly correlated to growth traits of height(P 0.01, rp= 0.557 0, rg= 0.699 7), diameter(P 0.01, rp= 0.740 0, rg= 0.881 2), and stem volum(P 0.01, rp= 0.712 5, rg= 0.847 7), whereas two growth ringswas significantly correlated to growth traits of height(P 0.005, rs= 0.461 0), diameter(P0.05, rp= 0.554 6), and stem volum(P 0.01, rp= 0.537 5). Branch number per meter was negatively correlated to growth traits(P 0.01). The correlation coefficients of the growth traits between different years increased with age. The growth sequence tended to be stable when 2- 3 yearsold, and became steady-state after6 years. Within a progeny trial of C. lanceolata, the first selection from the orchard can begin after afforestation at the end of the second year of growth. The selection rate should be twice that of the second selection. With this selection criteria, the accuracy rate of the selection should be close to 100%. Also, when stemvolume is selected indirectly by diameter, accuracy rate of the selection should be close to 100%.[Ch, 7 tab. 30 ref.]