Tolerance of cultivars and clonal selections of peach rootstocks to excess aluminum

Abstract

Forms of aluminum (Al) present in the solution of tropical and subtropical soils can cause toxicity in rootstocks and peach cultivars, impairing growth and productivity. This can be minimized by growing Al-tolerant rootstocks and cultivars. However, this is not sufficiently known, especially because plant breeding programs do not always consider tolerance as a selection variable for genetic materials. The study aimed to (a) select cultivars and clonal selections of Al-tolerant peach rootstocks, (b) identify variables that confer Al tolerance for use in genetic improvement programs, and (c) propose critical levels (NC) and ranges of toxicity (TF) of Al in relation to morphological variables of the root system. The experimental design was completely randomized, comprising a factorial of 13 (cultivars and clonal selections) x 2 (with and without Al) with three replications. Own-rooted ‘BRS Mandinho’ peach seedlings (without rootstock) and grafted seedlings of ‘BRS Mandinho’ on different cultivars and clonal rootstock selections were cultivated in a hydroponic system, composing two levels for the Al factor (absence and presence at 100 mg L−1). The morphological variables of the canopy and root system, Al accumulation in tissues, translocation factor, and the critical level (NC) and toxicity range (TF) of Al in the roots were evaluated. Rootstocks FB-SM-09-43, JB-ESM-09-13, SAS-SAU-09-71, SS-CHI-09-40, ‘Sharpe’ and VEH-GRA-09-55 were tolerant at high Al concentrations. The NC of Al in the roots in relation to the root surface area of peach rootstocks was 1400 mg Al kg−1, and the FT was between 1200 and 1500 mg Al kg−1.

Root system and antioxidant mechanisms of Eugenia uniflora plants promote greater tolerance to aluminum stress

“…As a result, there was also a possible maintained of secondary roots emitted by E. uniflora seedlings in the presence of Al, indicating a root system with greater adaptability to Al stress. Plants without toxic effects of Al on the root system tend to absorb more water and nutrients and consequently contribute to maintained production of root and leaf biomass (Aguilar et al, 2023a), as observed in this experiment (Table 1). This is evidence of the tolerance potential of E. uniflora seedlings to Al stress.…”

“…Aluminum in the solution can impair cell division and elongation, increasing root diameter, decreasing growth and consequently root volume and surface area (Aguilar et al, 2023a). As a result, roots will likely reduce water and nutrient uptake, which may decrease plant growth and biomass production (Mayer & Ueno, 2021).…”