Growth, yield, and metabolic responses of temperature-stressed tomato to grafting onto rootstocks differing in cold tolerance.
Tomato (Solanum lycopersicum cv. Kommeet) plants were either self-grafted, grafted onto the coldsensitive
cultivar Moneymaker or onto LA 1777, a cold-tolerant accession of Solanum habrochaites . Plants were
grown at three different temperatures (T): optimal (19.4 8C), intermediate (17 8C), or low (14.6 8C). Grafting
tomato ‘Kommeet’ onto LA 1777 increased shoot growth at intermediate and optimal T and root growth at low or
intermediate T in comparison with self-grafting or grafting onto ‘Moneymaker’. Reducing T significantly
suppressed fruit yield as a result of reduced fruit number per plant without any interaction with grafting
treatments. Grafting ‘Kommeet’ onto LA 1777 remarkably restricted fresh and dry fruit mass in comparison with
self-grafting of ‘Kommeet’ as a result of a reduction in the fruit number per plant while not influencing flower
number per plant and mean fruit mass, regardless of T regime. Negative effect of LA 1777 on fruit setting points to
impairment of pollen fertility indicating signals originating from the root. At low and intermediate T, plants
grafted onto LA 1777 were capable of increasing soluble carbohydrates, total amino acids, and guaiacol peroxidase
activity in roots to higher levels than those grafted onto S. lycopersicum rootstocks whilemaintaining a significantly
lower malondialdehyde content. These differences point to a much weaker oxidative stress in roots of plants
grafted onto S. habrochaitis than those grafted onto S. lycopersicum rootstocks when exposed to low and
intermediate T. Furthermore, plants grafted onto LA 1777 exhibited significantly higher levels of soluble
carbohydrates, total amino acids, and guaiacol peroxidase activity in leaves and fruit and superoxide dismutase
in fruit at low and intermediate T, which indicates that LA 1777 improved the level of antioxidant compounds in
tomato shoots, thereby enhancing its adaptation to lower T than optimal.
Ntatsi, G., Savvas, D., Klaering, H.-P., Schwarz, D. 2014. Growth, yield, and metabolic responses of temperature-stressed tomato to grafting onto rootstocks differing in cold tolerance. Journal of the American Society of Horticultural Science 139 (2), 230–243.