2018 journal article

Comparison of Root System Morphology of Cucurbit Rootstocks for Use in Watermelon Grafting

HORTTECHNOLOGY, 28(5), 629–636.

co-author countries: United States of America 🇺🇸
author keywords: Citrullus lanatus; Cucurbita maxima; Cucurbita moscbata; Cucurbita pepo; Lagenaria siceraria; scion
Source: Web Of Science
Added: November 19, 2018

Grafting of watermelon ( Citrullus lanatus ) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin ( Cucurbita maxima ), squash ( Cucurbita pepo ), bottle gourd ( Lagenaria siceraria ), and an interspecific hybrid squash ( C. maxima × C. moschata ). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant ( P < 0.05). The main effect of harvest was significant ( P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis.