RESUMEN
Objective To investigate the dormancy reason of the seeds by studying on intrinsic inhibitor in the seed of Paeonia lactiflora.Methods Biological methods and embryo culture were carried out to study the activity of intrinsic inhibitor in the testa and endosperm of the P.lactiflora seeds.ResultsThe Activity of intrinsic inhibitor exists in the testa and endosperm,and both of the intrinsic inhibitors showed stronger inhibitory effect on the growth of younger roots of Brassica pekinensis than that on their seed germination.The Rf 0.5 section of the ether extract of endosperm showed the strongest inhibition on the growth of younger roots of B.pekinensis(relative rate: 36.36%).All embryos that inoculated on different culture medium could root,but the epicotyls of embryos that inoculated on culture medium without GA3 could not elongate,which showed that the embryo in vitro also exists the dormancy of epicotyl,or embryo with inhibitor.Conclusion Intrinsic inhibitor in the seed of P.lactiflora is the main factor that results in its dormancy.