Study On Hybridization Between Abies Fabri And American Firs And The Verification Of The Putative Hybrids

China is one of the distribution centre of the genus Abies, and the firs species play an important role in the improving entironment in China. Interspecific hybridization has been a technique of forest tree improvement and has been commonly practiced in many tree species, but there have been few attempts on China fir species. The researches on fir interspecific hybridization conducted by others show that there are two striking different views of the crossability of the Abies species. One is that there are few barriers to interspecific crossability in Abies, and the other is that the compatibility is higher when crossing between species within section and lower, even no compatibility, between species intersections.To breed new species for the west of China and to further explore the crossability of firs, the interspecific hybridization of Abies were carried out in Sichuan province in the spring of 2002 and 2003. In 2002. A. fabri as female parent, four America fir species (A.concolor, A.procera, A.grandis, A.bracteata) and A.holophylla as male parents, five hybrid combinations were made and 182 cones were obtained. In 2003, two hybrid combination (A. fabriXA.concolor, A. fabriXA.procera) were undertook and 80 female strobili were controlled pollinations.The seeds germination tests of all combinations and of A. fabri and of bagged but unpollinated cones were made before the hybrids verification, and the rate of bagged but unpollinated cones' seeds germination is 7% in Mount Jiajin forestry center and 8% in 511 forestry center in 2002. The results suggest that accidental pollinations occurred and the lagged time of bagged may be the main cause of pollen contamination, However, DNA marker from paternally inherited chloroplast DNA (cpDNA) was used to futherly verify theseeds of 2002 crossing. A PCR-SSCP (single strand conformation polymorphism)analysis of the trnL-trnF intergenic spacer shows that the artificial hybrids from 2002 firs hybridizations all exhibit the profile of A.fabri. It is also shown that all crossing combinations in 2002 were contaminated by A.fabrfs pollen.A. fabriXA.concolor and A. fabriXA.procera have produced only empty seeds in 2003 and we concluded that it is difficult to cross in that two combinations. The results of hybridization experiments have confirmed the view that crosses among groups are relatively difficult and sometimes impossible in the genus Abies, and the same time, it is at odds with the long-held view that it is easy to hybridize fir species.