Cucurbita pepo L. can be transformed by Agrobacterium rhizogenes

Two-week-old in vitro grown Cucurbita pepo L. intact plants and cotyledons (detached and undetached from the mother-plant) were transformed by Agrobacterium rhizogenes strain NCPPB 1855, grown for 48 h at 25 degrees C on YMB medium. All infected material formed vigorous hairy roots in about seven days. The transformed roots were successfully grown in liquid MS medium without plant growth regulators for an indefinite number of transfers. Genetic transformation of root DNA was proven by Southern analysis performed with a rolABC probe and a vir probe. Our results demonstrate that, in contrast with previous literature, A. rhizogenes could represent an efficient and reproducible system to transform C. pepo plants. Furthermore, we verified that plant age and incubation times/temperatures of bacterial strain influence transformation efficiency.