Root architecture variation in Cucurbita

Cucurbita species are employed as rootstocks for melons, watermelons, and cucumbers. The use of one or another species or accession of Cucurbita as a rootstock results from germplasm availability and compatibility with the scion rather than on systematic research of the root characteristics of different taxa. The objectives of the present work were to compare 23 Cucurbita accessions belonging to 10 different species or subspecies (wild and cultivated) for their root architecture and their capacity to form cluster roots under low P and low Fe conditions. Two experiments were conducted, the first consisting of growing the plants in pouches to observe directly root growth in three treatments. One treatment was a full nutrient solution, another was in a P-deficient solution, and the other was a Fe-deficient solution. The second experiment consisted of growing the plants in a hydroponic system with two treatments, full nutrient solution and a nutrient solution without Fe. The results showed variability among the Cucurbita species in their root systems, both in the full nutrient solution, and in their response to the Fe and P deficiency. Some wild species showed root architecture more adapted to exploit deeper soil layers and that responded better to nutrient deficiencies. In the second experiment, the Fe deficiency caused thick and branched root tips in the cultivated species.Cucurbitaceae 2008. IX EUCARPIA Meeting. Avignon (France), May 21-24th, 200