Semi-Hydroponic Cultivation as a Selection Tool for Aluminum Tolerance in Forage Grasses

Abstract

The constant improvement of selection methods is necessary in order to optimize efficiency of breeding programs for aluminum tolerance. Thus, the aim of this study was to establish a vase volume to the ideal semi-hydroponic cultivation of forage grasses subjected to stress by aluminum in nutrient solution. The experimental design completely randomized, with four replicates, each replicate consisting of one plant per vase. The treatments were arranged in a factorial design 4x5, being the first factor consists of four genotypes of forage grasses Brachiaria Humidicola; Brachiaria brizantha cv. Piatã; Panicum maximum cv. Massai and Panicum maximum cv. Mombaça) and the second consisting of five separate volumes plastics vases where seedlings were grown (0.2; 0.25; 0.3; 0.35 and 0.4 dm³). The grasses grown in a semi-hydroponics system irrigated with nutrient solution rich in aluminum (3 mg L-1). Was measured plant height, dry weight of aereal part and root length. The semi-hydroponic cultivation in aluminum increased nutrient solution is effective in differentiation of forage grasses genotypes in relation to aluminum tolerance. Pots volumes near 0.3 dm3 promote greater development for root and aerial part attributes in forage grasses grown in nutrient solution with aluminum toxicity.

Early Seedling Growth as a Tool to Assess the Tolerance of Urochloa brizantha Cultivars to Free Aluminium

“…Similar decreases in root growth in response to aluminium were found in Jatropha curcas (Rosado et al, 2012), sorghum (Too et al, 2014), and barley (Tamas et al, 2006) in studies that used a similar methodology (e.g., measuring the root growth in seedlings in paper rolls moistened with aluminium solutions). Studies using hydroponic (Giannakoula et al, 2010;Arroyave et al, 2011Arroyave et al, , 2013Matins et al, 2011;Ramos et al, 2012;Roselló et al, 2015), semi-hydroponic (Colombo et al, 2016), and even growth in soil methods (Mutimura & Everson, 2012) have found similar results, but these methods are expensive and time consuming. Hare and Cress (1997) reported that proline accumulation occurred when wheat was exposed to water deficits, and therefore was a function of osmotic regulation and cellular protection.…”

“…Selection has also been done under field conditions (Mutimura & Everson 2012), and using a semi-hydroponic method (Colombo et al, 2016), but these techniques may be expensive, difficult, and time consuming. Other alternatives may include early evaluation using germination tests or early seedling growth under controlled conditions (Custódio et al, 2002;Machado Neto et al, 2004;Custódio et al, 2009;Echer et al, 2010;Rosado et al, 2012), and the evaluation of some effective parameters in the cultivars.…”