（1Vegetable Research Institute，Guangdong Academy of Agricultural Sciences，Guangzhou 510640，Guangdong，China；
2School of Life Sciences，South China Normal University，Guangzhou 510631，Guangdong，China；3Guangdong Key
Laboratory for New Technology Research of Vegetables，Guangzhou 510640，Guangdong，China）
Abstract：In order to find out the relation between ACC synthase and female chieh-qua，this study took
female inbred line（A36）and normal monoacious inbred line（SX）as material，gained CqACS gene through
coloning，then conducted homologous sequence comparative analysis with the known CqACS gene；and
constructed evolutionary tree．The expression profile of CqACS in seedling leaf blades of A36 was analyzed
after treatment with gibberellin（GA3）by qRT-PCR on CqACS gene．The female flower rate within 20 nodes
was carried out statistic analysis before and after gibberellin treatment．The results showed that the length of CqACS gene in A36 of female inbred line was 1 318 bp and that in normal monoecism selfing line in SX was
1 637 bp．After comparative analysis，we found that SX in 3 bp base element：91，97 bp and 117 bp were
more than detected in A36，and only 2 basic group differences were found between them．The homologous
sequence comparison revealed that CqACS gene in A36 had the highest homology with Cit-ACS1 gene in
watermelon，reaching 95.31%．And the homology with cucumber Cs-ACS1 was 91.31%．CqACS gene in SX
had the homology with Cit-ACS1 gene in watermelon，reaching 78.04%，and the homology with cucumber Cs-ACS1 was 76.06%．After GA3 treatment，the average female flower rate（within 20th node order）of GA3
treatment group in A36 was 45%．While，that of the contrast group was 90%．qRT-PCR analysis discovered
that the expression quantity of CqACS gene after GA3 treatment was significantly up-regulated．Compared with
the contrast group．Moreover，4 h after the third time treatment the up-regulated range was the largest．
