LINKAGE OF ALLOZYME LOCI IN JAPANESE RED PINE (PINUS-DENSIFLORA)

Linkage relationships among 29 polymorphic loci were investigated in J apanese red pine, Pinus densiflora Sieb. et Zucc. Haploid megagametoph ytes from 12 highly heterozygous plus-tree clones were used. A total o f 217 pairs of two-locus combinations were available for the linkage s tudy. Chi-square and Akaike Information Criterion analyses identified 19 pairs of linkages. Close linkages (r = 0-0. 10) were seen for Est-2 ,3 - Aap-2,3, Dia-1 - Acp, and Shd-1 - Got-1. Strong linkages (r = 0. 10-0.20) were seen for Est-2,3 - Dia-1, Est-2,3 - Acp, Aap-2,3 - Dia-1 , Got-2 - Lap-1, and Pgm - Aap-1. Moderate linkages (r = 0.20-0.30) we re seen for Adh - Sod, Adh - Pgi-1, 2, Adh - Lap-1, G2d - G6p, and Dia -2 - Amy pair of linkages. The remaining six pair combinations, namely 6Pg- 1 - Est-2,3, 6Pg-1 - Acp, Est-1 - Acp, Est-2,3 - Shd-1, Sod - Pg i-1, 2, and Adh - Got-2 were weakly linked (r = 0.30-0.40). In all, 22 loci were classified into five linkage groups by means of three-point mapping methods.