Grafting of cucumber as a means to minimize copper toxicity.pdf

Ai g o D l f T A l s m u c r m c ? K 1 o b o u c l a o p 0 dAvailable online at Environmental and Experimental Botany 63 (2008) 49–58 Grafting of cucumber as a means to minimize copper toxicity Youssef Rouphael a, Mariateresa Cardarelli a, Elvira Rea b, Giuseppe Colla a,? a Dipartimento di Geologia e Ingegneria Meccanica, Naturalistica e Idraulica per il Territorio, Universita? della Tuscia, via S. C. De Lellis snc, 01100 Viterbo, Italy b CRA, Centro di ricerca per lo studio delle relazioni tra pianta e suolo, via della Navicella, 2-4, 00184 Roma, Italy Received 4 December 2006; received in revised form 1 October 2007; accepted 8 October 2007 bstract The aim of the current work was to determine whether grafting could improve copper (Cu) tolerance of cucumber, and to study the changes nduced by the rootstock in the shoot growth at agronomical and physiological levels. A greenhouse experiment was carried out to determine yield, rowth, fruit quality, leaf gas exchange, chlorophyll and carotenoids contents, electrolyte leakage, mineral composition and assimilate partitioning f cucumber plants (Cucumis sativus L. cv. ‘Akito’), either ungrafted or grafted onto the commercial rootstock ‘Shintoza’ (Cucurbita maxima uchesne×Cucurbita moschataDuchesne) and cultured in nutrient film technique (NFT). Plants were supplied with nutrient solutions having three evels of Cu concentration [0.3 (control), 47, or 94 M]. Significant depression of yield, shoot and root biomass production, and fruit quality (low ruit pH, and high Cu content) in Cu treated cucumber plants was observed, and this effect varied as a function of Cu concentration in NFT solution. he relative yield of cucumber decreased by ≈3.4% for each unit of increase in leaf tissue Cu concentrations above the threshold value (7.8 g g?1). t the two higher Cu concentrations (47 and 94 M Cu), the percentages of yield, shoot and root biomass weight reductions were significantly ower in grafted plants in comparison to those o