Novel S. pennellii × S. lycopersicum Hybrid Rootstocks for Tomato Production with Reduced Water and Nutrient Supply

Abstract

Drought stress and nutrient deficiency are limiting factors in vegetable production that will have a decisive role due to the challenges of climate change in the future. The negative effects of these stressors on yield can be mitigated by crop grafting. The increasing demands for resource-use efficiency in crop production, therefore, require the development and phenotyping of more resilient rootstocks, and the selection of appropriate scions. We tested the effect of combined drought stress and nutrient deficiency on yield and fruit quality of the two tomato cultivars ‘Lyterno’ and ‘Tastery’ in the greenhouse, grafted onto different rootstock genotypes. The use of four different rootstocks, including two novel S. pennellii × S. lycopersicum hybrids and the proven-effective use of ‘Beaufort’, as well as self-grafted plants, allowed conclusions to be drawn about the differential stress mitigation of the rootstocks used. The stress-induced yield reduction of the scion ‘Lyterno’ can be mitigated more significantly by the novel hybrid rootstocks than by the commercial rootstock ‘Beaufort’. At the same time, however, the individual fruit weight and the lycopene content of the fruits were significantly reduced when grafted onto the hybrid rootstocks. In contrast, the cultivar ‘Tastery’ showed a weak stress response, so that a generally positive influence of the rootstocks independently of the scions could not be demonstrated. We conclude that, particularly for more sensitive cultivars, the selection of more resilient rootstocks offers the potential for sustainable and resource-efficient production not competing with the overall quality of tomatoes.

Managing the Product Quality of Vegetable Crops under Abiotic Stress

“…The majority of the contributions deal with pre-harvest conditions and investigate whether cultivation practices can modulate the yield and nutritional value of vegetable crops and herbs under abiotic stresses. Among these publications, several deal with nutrient supply [2][3][4][5], salinity [6,7], water supply [2,3,8] or lighting conditions [6]. Two manuscripts describe either the effects of applying chemical substances such as gibberellic acid [9] or seaweed extract [10] on the yield and quality of vegetable crops.…”

“…Two manuscripts describe either the effects of applying chemical substances such as gibberellic acid [9] or seaweed extract [10] on the yield and quality of vegetable crops. Grafting as a method to mitigate the impacts of abiotic stress in vegetables was elucidated by a research paper by Ellenberger et al [3] and in a review by Devi et al [11]. Elevated CO 2 levels were either used as pre-harvest conditions in combination with different nitrogen forms [5] or as post-harvest treatment combined with different methods of packaging [12].…”

“…In general, a large quantity of the contributions in this Special Issue present data on fruit vegetables such as watermelons, bitter gourd and tomatoes [2][3][4]9,11], with the latter being the focus of three publications. These crops were mostly grown in greenhouses [2][3][4], but some were grown in an open field [9] or under rain-out shelters [8].…”

“…In general, a large quantity of the contributions in this Special Issue present data on fruit vegetables such as watermelons, bitter gourd and tomatoes [2][3][4]9,11], with the latter being the focus of three publications. These crops were mostly grown in greenhouses [2][3][4], but some were grown in an open field [9] or under rain-out shelters [8]. Leafy vegetables and herbs-such as arugula [5], purslane [6] and basil [7]-were used in three experiments and were cultivated in growth cabinets [5,6] or in greenhouses [7].…”

“…Three contributions to this Special Issue deal with yield and quality aspects of tomatoes under different nutritional conditions that are regarded as "stressful" for the plants. Specifically, Ellenberger et al [3] addressed the question of how grafting two commercial tomato varieties may affect the yield and fruit quality when exposed to a combination of nutrient deficiency and drought stress. They used the commercial rootstock 'Beaufort', two novel hybrid rootstocks of S. pennellii × S. lycopersicum, which are expected to be drought tolerant, and self-grafted plants.…”