In this study，32 germplasm resources of rootstock-used Lagenaria siceraria collected from
China and Japan were selfed，crossed，and their resistance heterosis was analyzed．Through comparison，this
paper studied on the seedling character of rootstock-used Lagenaria siceraria germplasm resources and their
graft compatibility with watermelon，and the effects of different stock on the growth and fruit characters，so as to
evaluate the grafting applicability of rootstock-used Lagenaria siceraria．The result showed that H04，H10，
H12 and H13 were highly resistant to watermelon Fusarium wilt（Fusarium oxysporum f．sp．niveum）．Their
F₁ expressed heterosis on resistance，and had good graft compatibility and symbiotic compatibility with watermelon
scion．The single fruit weight of the grafted watermelon was increased，and the fruit quality remained unchanged．
The general performance of disease resistance and grafting applicability was excellent．They could be great
resources for watermelon stock breeding．H05 and H04 could be used as backbone parent of cross breeding to
resist Fusarium wilt，and H04 was suitable for being male parent．