Abstract: Two dormancy-associated MADS-box genes（PpMADS1 and PpMADS2）were obtained
from transcriptome library constructed Pyrus pyrifolia white pear group‘Suli’. To understand sequence
characteristics of two genes，bioinformatics analysis was carried out. Furthermore the gene expression
patterns in lateral flower buds of both pear cultivars‘Cuiguan’and‘Wonhwang’were analyzed during the
period of dormancy by quantitative real-time PCR. The results showed that PpMADS1 and PpMADS2
contained well-conserved MIKC-motifs of MADS-box. A phylogenetic analysis revealed that PpMADS1
was closely related to PpMADS13-1 of Japanese pear（P. pyrifolia‘Kosui’），whereas PpMADS2 was
similar to PpMADS13-2 of Japanese pear. The pear DAM genes formed an independent subclade and were
closely related to those of Prunus spp. The expression patterns of PpMADS1 and PpMADS2 were similar
with one peak in two cultivars during the period of dormancy. However，the timing of gene expression
peak differed between two cultivars. The PpMADS1 and PpMADS2 expression peak occured on the
November 15th in‘Cuiguan’pear，while the PpMADS1 expression peak on the December 30th，and the
PpMADS2 expression peak on the December 15th in‘Wonhwang’pear. The PpMADS1 and PpMADS2
expression peak appeared prior to the release of endodormancy，and their expression levels were gradually
down-regulated after the turn over of endodormancy and kept at a lower level during the period of
ecodormancy. These results indicated that PpMADS1 and PpMADS2 might play an important role in the
regulation of bud endodormancy-release in pear.

Key words: pear, bud, dormancy, MADS-box gene, expression analysis