摘要

To accelerate the breeding and selection of Pinus densiflora Siebold and Zucc. resistance to pine wilt disease, a micropropagation system was established and nematode resistance evaluated in vitro. Cotyledon-hypocotyl explants from 28-day-old seedlings were first cultured on Gresshoff and Doy medium supplemented with 4.0mgL(-1) 6-benzyladenine and 0.2mgL(-1) -naphthaleneacetic acid (NAA) to stimulate the formation of buds. Induced buds were subsequently subcultured on Gupta and Durzan medium supplemented with 0.1% (w/v) activated charcoal for elongation. Stem sections derived from shoots were used as explants for the further multiplication. Roots were formed from shoots transferred to woody plant medium containing 0.2mgL(-1) NAA for 4weeks. The nematode resistance test showed that symptoms in micropropagated shoots after infection with pine wood nematode (PWN) were similar to those in plants infected in the field. The wilting rate varied from 20 to 100% among different clones 18days after inoculation. The most susceptible clone was Clone 6-4 with a 100% wilting rate, while Clone 8-4 showed a relatively high resistance with a 20% wilting rate. The number of nematodes recovered from Clone 8-4 shoots was significantly lower (P=0.05) than from Clones 5-10 and 16-4. This work contributes to the breeding of PWN resistance in P. densiflora.