RESUMEN
Grafting using suitable rootstocks mitigates the adverse effects caused by environmental stresses such as water deficit in the tomato crop. Solanum pennellii and Solanum peruvianum, the wild relatives of tomato, are used as rootstocks due to their tolerance to water deficit and soil-borne diseases. This study focused on evaluating physiological and biochemical responses of tomato plants grafted onto S. pennellii and S. peruvianum rootstocks during water deficit. The commercial tomato cultivar 'HM 1823' (HM) either self-grafted (HM/HM) or grafted onto S. pennellii (HM/PN), S. peruvianum (HM/PR), and 'Multifort' (HM/MU) rootstocks were subjected to water-deficit stress by withholding irrigation for eight days. The performance of the grafted plants under water deficit was evaluated using physiological and biochemical parameters in vegetative tissues of the grafted plants. Plants grafted using S. pennellii (PN) and S. peruvianum (PR) rootstocks showed higher values of water potential (Ψw), relative water content (RWC), net photosynthetic rate (A), and leaf water use efficiencies (WUE) compared to HM, HM/HM, and HM/MU. Plants grafted onto tomato wild relatives showed the lowest malondialdehyde (MDA) and proline content. This study demonstrated that the rootstocks of wild tomato relatives reduced the effect of water deficit to a greater extent through better physiological, metabolic, and biochemical adjustments than self-grafting plants.
RESUMEN
Although intensively studied, few works had looked into S. pennellii's ability to cope with water-deficit conditions from a breeding point of view. In this study, we assessed potential traits of S. pennellii, that had previously been linked to high yields in other plant species, under long-term water-limited conditions and made a parallel with plant yield. For this purpose, the drought-resistant tomato genotypes IL 3-5 and IL 10-1, and the drought-sensitive IL 2-5 and IL 7-1 at seed level, together with both parents the S. pennellii accession LA 716 and the cultivar M82 were kept at 50 and 100% ASW throughout the growing season. Our findings confirm the superiority of LA 716 under water-limited conditions compared to the other S. lycopersicum genotypes in terms of plant water status maintenance. Percentual reduction on plant yield was higher in IL 3-5 and IL 10-1 than in M82 plants, indicating no correlation between drought resistance on germination and plant productive stages. A strong positive correlation was found between fruit yield and A, gs, and Ψleaf at 50% ASW, suggesting these traits as important selection criteria. LT and gmin, LA 716's most promising traits, did not show a linear correlation with fruit yield under low water regimes. This study unravels traits behind tomato performance under water-limited conditions and should work as guidance for breeders aiming at developing drought-resistant tomato cultivars.
Asunto(s)
Fitomejoramiento/métodos , Solanum/anatomía & histología , Solanum/genética , Sequías , Frutas/genética , Genotipo , Solanum lycopersicum/genética , Enfermedades de las Plantas/genética , Hojas de la Planta/genética , Selección Genética/genética , Solanum/crecimiento & desarrollo , AguaRESUMEN
Neste artigo, a autora busca investigar sobre as dimensões psicossociais envolvidas no tratamento da Drogadição em uma fazenda terapêutica de regime interno, identificando seus aspectos positivos e negativos. O sujeito não é reduzido a um estereótipo de drogadicto, sendo compreendido em sua complexidade, enfatizando a rede de relações sociais na qual está inserido. Na pesquisa de campo, foi realizado um grupo focal com sujeitos em tratamento de Drogadição a fim de obter informações acerca da experiência de cada um e das características do tratamento nesta instituição. Com este trabalho, podemos considerar que a análise de diversos tipos de tratamento da Drogadição, assim como das suas dimensões psicossociais, possui grande relevância para o atendimento nesta área. (AU)
In this article, the author investigates the psychosocial dimensions involved in a drug addiction treatment, which is performed at a boarding therapeutic farm, identifying its positive and negative aspects. The individual is not reduced to any stereotype of the drug addicted. Instead, s/he is also understood in his/her own complexity, with the emphasis on the social relationships in which s/he belongs. In the field research, a focal group, composed with drug addiction patients, was chosen to gather data about their own experiences and the characteristics of the treatment in the studied institution. The study of different types of treatments for drug addiction as well as of their psychosocial aspects have a huge importance for this area of professional practice. (AU)
