ABSTRACT Peach rootstock and scion cultivars are selected in breeding programs considering resistance to pests and diseases, salt tolerance, drought tolerance, and vigor. However, rootstock tolerance to aluminum (Al), which is markedly present in tropical and subtropical soils of the world, is not considered. Thus, it is essential to define potential markers that can contribute to the selection of Al-resistant or Al-tolerant peach rootstocks. The objective of this study was to identify Al-tolerant peach tree rootstock cultivars and clonal selections using physiological and oxidative stress variables. A completely randomized experimental design was used in a 13 (rootstock cultivars and clonal selections) × 2 (with and without Al) factorial arrangement, with three replications. Nursery peach trees of own-rooted ‘BRS Mandinho’ (without rootstock) and nursery trees of ‘BRS Mandinho’ grafted on different rootstock cultivars and clonal selections were grown in a hydroponic system, consisting of two treatments, with and without 100 mg L-1 of Al. Dry biomass, photosynthetic variables, pigment concentration, hydrogen peroxide content, membrane lipid peroxidation, and activity of the antioxidant enzymes were evaluated. The total dry matter production of the own-rooted ‘BRS Mandinho’ trees and the SS-CHI-09-39 and SS-CHI-09-40 selections is affected by the Al presence, representing a decline of 35.4, 37.2, and 24.4 %, respectively, compared to the treatment with Al. The highest total dry matter production in Al presence was observed for the ‘Sharpe’ rootstock. ‘Capdeboscq’, DB-SEN-09-23, FB-ESM-09-43, JB-ESM-09-13, JAH-MAC-09-77, SAS-SAU-09-71, and VEH-GRA-09-55 rootstock selections are tolerant to Al. The use of physiological and biochemical variables shows potential for the selection of clonal rootstocks tolerant or resistant to Al. diseases vigor However Al, , (Al) world considered Thus Alresistant Altolerant 1 arrangement replications ownrooted own rooted BRS Mandinho system treatments 10 L1 L L- biomass concentration content peroxidation evaluated SSCHI0939 SSCHI SS CHI 09 39 SS-CHI-09-3 SSCHI0940 40 SS-CHI-09-4 354 35 4 35.4 372 37 37.2 244 24 24. % respectively ‘Sharpe Sharpe ‘Capdeboscq, Capdeboscq ‘Capdeboscq ‘Capdeboscq’ DBSEN0923, DBSEN0923 DBSEN DB SEN 23, 23 DB-SEN-09-23 FBESM0943, FBESM0943 FBESM FB ESM 43, 43 FB-ESM-09-43 JBESM0913, JBESM0913 JBESM JB 13, JB-ESM-09-13 JAHMAC0977, JAHMAC0977 JAHMAC JAH MAC 77, 77 JAH-MAC-09-77 SASSAU0971, SASSAU0971 SASSAU SAS SAU 71, 71 SAS-SAU-09-71 VEHGRA0955 VEHGRA VEH GRA 55 VEH-GRA-09-5 (Al SSCHI093 0 3 SS-CHI-09- SSCHI094 35. 37. DBSEN092 DB-SEN-09-2 FBESM094 FB-ESM-09-4 JBESM091 JB-ESM-09-1 JAHMAC097 7 JAH-MAC-09-7 SASSAU097 SAS-SAU-09-7 VEHGRA095 5 VEH-GRA-09- SSCHI09 SS-CHI-09 DBSEN09 DB-SEN-09- FBESM09 FB-ESM-09- JBESM09 JB-ESM-09- JAHMAC09 JAH-MAC-09- SASSAU09 SAS-SAU-09- VEHGRA09 VEH-GRA-09 SSCHI0 SS-CHI-0 DBSEN0 DB-SEN-09 FBESM0 FB-ESM-09 JBESM0 JB-ESM-09 JAHMAC0 JAH-MAC-09 SASSAU0 SAS-SAU-09 VEHGRA0 VEH-GRA-0 SS-CHI- DB-SEN-0 FB-ESM-0 JB-ESM-0 JAH-MAC-0 SAS-SAU-0 VEH-GRA- SS-CHI DB-SEN- FB-ESM- JB-ESM- JAH-MAC- SAS-SAU- VEH-GRA DB-SEN FB-ESM JB-ESM JAH-MAC SAS-SAU

RESUMO Embora o zinco (Zn) seja um micronutriente, quantidades excessivas no solo podem causar efeitos tóxicos às plantas. Fertilizantes, materiais calcários, pesticidas e fungicidas adicionados de Zn têm contribuído para aumentar a concentração deste elemento nos solos agrícolas. Dessa forma, é necessário encontrar espécies de plantas tolerantes ao Zn para serem adequadamente utilizadas em programas de restauração de solos degradados. Assim, o presente estudo tem como objetivo investigar a influência de diferentes concentrações de Zn nas variáveis fotossintéticas, na atividade antioxidante e no crescimento de mudas de I. marginata e A. edulis para determinar seu potencial para serem utilizadas como espécies fitorremediadoras. O experimento foi instalado em esquema fatorial 2×5, sendo o primeiro fator duas espécies (Allophylus edulis e Inga marginata), e o segundo fator: cinco concentrações de Zn (2, 75, 150, 225 e 300μM), com três repetições por tratamento. Cada unidade amostral foi constituída por um vaso com cinco plantas. Foram avaliadas variáveis fotossintéticas, morfológicas da parte aérea e do sistema radicular, fluorescência da clorofila a, pigmentos fotossintéticos, atividade de enzimas antioxidantes, peroxidação lipídica, concentração de peróxido de hidrogênio e Zn acumulado nas raízes e na parte aérea. O estresse por Zn ativou um eficiente sistema antioxidante, que reduziu o dano oxidativo nas folhas de ambas as espécies; consequentemente, não diminuiu a produção de biomassa aérea em mudas de Inga marginata e Allophylus edulis. O alto acúmulo de Zn nos tecidos vegetais e a falta de efeitos negativos na parte aérea de Inga marginata e Allophylus edulis sugeriram que essas espécies de plantas são tolerantes ao Zn e podem ser indicadas para fins de fitorremediação de solos poluídos com Zn. (Zn micronutriente Fertilizantes calcários agrícolas forma degradados Assim fotossintéticas I A fitorremediadoras 25 2 5 2×5 marginata, , marginata) 2, (2 75 150 22 300μM, 300μM μM 300μM) tratamento radicular fotossintéticos antioxidantes lipídica consequentemente 2× ( 7 15 1

ABSTRACT Although zinc (Zn) is a micronutrient, excessive amounts in the soil can have toxic effects on plants. Fertilizers, limestone materials, pesticides, and fungicides added with Zn have contributed to increasing the concentration of this element in agricultural soils. Accordingly, it is necessary to find Zn-tolerant plant species to be properly used in degraded soil restoration programs. Thus, the current study aims to investigate the influence of different Zn concentrations on photosynthetic variables, antioxidant activity, and growth of I. marginata and A. edulis seedlings to determine their potential to be used as phytoremediation species. The experiment was installed in a 2×5 factorial scheme, with the first factor being two species (Allophylus edulis and Inga marginata), and the second factor: five concentrations of Zn (2, 75, 150, 225, and 300 μM), with three replications per treatment. Each sampling unit consisted of a pot with five plants. Photosynthetic, morphological variables of the shoot and root systems, chlorophyll a fluorescence, photosynthetic pigments, antioxidant enzyme activity, lipid peroxidation, hydrogen peroxide concentration, and Zn accumulated in the roots and shoot were evaluated. Zn stress has activated an efficient antioxidant system, which reduced oxidative damage in the leaves of both species; consequently, it did not decrease shoot biomass production in Inga marginata and Allophylus edulis seedlings. High Zn accumulation in plant tissues and lack of negative effects on Inga marginata and Allophylus edulis shoot have suggested that these plant species are tolerant to Zn and may be indicated for Zn-polluted soil phytoremediation purposes. (Zn micronutrient plants Fertilizers materials pesticides soils Accordingly Zntolerant programs Thus activity I A 25 2 5 2× scheme marginata, , marginata) 2, (2 75 150 225 30 μM, μM μM) treatment Photosynthetic systems fluorescence pigments peroxidation evaluated system consequently Znpolluted polluted purposes ( 7 15 22 3 1

RESUMO Solos contaminados com cobre (Cu) são um problema crescente, e o uso da fitorremediação tem evidenciado resultados positivos na redução dos efeitos nocivos desse elemento nos solos. Espécies arbóreas têm sido amplamente utilizadas para esta técnica, pois funcionam como barreira a esse tipo de contaminação. Portanto, é necessário avaliar os limites de tolerância/toxicidade ao Cu, bem como os danos causados por este metal nas plantas. Assim, o presente estudo teve como objetivo investigar a tolerância de plantas de Handroanthus heptaphyllus ao Cu através de análises morfofisiológicas e bioquímicas, bem como a concentração de Cu nos tecidos. Mudas de H. heptaphyllus foram submetidas a diferentes concentrações de Cu adicionadas na solução nutritiva: 0,5, 32, 64, 96 e 128 μM Cu em sistema hidropônico. Foram analisados atributos morfofisiológicos, como altura da parte aérea e comprimento da raiz, massa seca, variáveis morfológicas do sistema radicular, área foliar e variáveis fotossintéticas. Além disso, foram investigados pigmentos fotossintéticos, enzimas antioxidantes, peroxidação lipídica, concentração de peróxido de hidrogênio e Cu acumulado nos tecidos. Os valores registrados para variáveis como massa seca e pigmentos não apresentaram diferença significativa, independentemente das concentrações de Cu. Além disso, as taxas fotossintéticas e transpiratórias foram afetadas negativamente apenas na maior concentração de Cu (128 μM). No geral, a espécie Handroanthus heptaphyllus foi afetada pelo excesso de Cu apenas em 128 μM. O Cu se acumulou principalmente nas raízes, sem registrar diminuição da biomassa, o que pode indicar a tolerância da espécie a esse metal, bem como seu grande potencial para ser utilizado na fitoestabilização de Cu em solos contaminados com este metal. (Cu crescente técnica contaminação Portanto tolerânciatoxicidade toxicidade Assim bioquímicas tecidos H nutritiva 05 0 5 0,5 32 64 9 12 hidropônico morfofisiológicos raiz radicular disso fotossintéticos antioxidantes lipídica significativa (12 . μM) geral raízes biomassa 0, 3 6 1 (1 (

ABSTRACT Copper (Cu)-contaminated soils are becoming more common, and phytoremediation is an effective strategy for reducing the negative effects of Cu on soils. Tree species are commonly used for this technique because they act as a barrier to this type of contamination. It is necessary to evaluate Cu tolerance and toxicity thresholds together with the harm this metal causes to plants. The objective of the current study was to investigate the tolerance of Handroanthus heptaphyllus plants to Cu through morpho-physiological, biochemical, and tissue Cu concentration analyses. H. heptaphyllus seedlings were subjected to nutrient solutions with varying concentrations of copper: 0, 5, 32, 64, 96, and 128 µM Cu in a hydroponic system. We conducted a morpho-physiological trait analysis on shoot height, root length, dry weight, morphological variables of the root system, leaf area, and photosynthetic variables. In addition, we also looked into photosynthetic pigments, antioxidant enzymes, lipid peroxidation, hydrogen peroxide concentration, and Cu accumulation in tissues. The values obtained for variables such as dry weight and pigments did not show significant differences, regardless of Cu concentration. Moreover, photosynthetic and transpiration rates were negatively affected only at the highest Cu concentration (128 µM). Overall, excess Cu had no effect on Handroanthus heptaphyllus below 128 µM. Cu accumulated mainly in the roots without a decrease in biomass, which could indicate the tolerance of the species to this metal as well as its great potential in the phytostabilization of Cu in contaminated soils. Cucontaminated common contamination morphophysiological, morphophysiological morpho physiological, physiological biochemical analyses H copper 0 5 32 64 96 12 system height length area addition enzymes peroxidation tissues differences Moreover (12 . µM) Overall biomass 3 6 9 1 (1 (