The different response of sugarcane genotypes in multiple stress

Abstract

Research focused on identify abiotic stress-tolerant genotypes is highly desirable since their use may reduce costs of soil and crop management and productivity losses. The aim of this study was to determine the behavior of 24 sugarcane genotypes under high levels of Al 3+ and Mn 2+ associated with low availability of mineral nutrients. The experiment was carried out under greenhouse condition in a 24 × 2 factorial scheme (24 genotypes × 2 treatments: with and without stress), and four replications in completely randomized design. In the treatment without stress plants were grown in a complete nutrient solution whereas in the treatment with stress a nutrient solution with a high acidity (4.0 ± 0.1) and 5% of its original concentration, as well as a high concentration of aluminum (60 mg L -1 ) and manganese (700 mg L -1 ) was used. The genotypes RB966928, RB855443, IACSP96-3060, SP81-3250, RB867515, CTC 21, RB965902, and IAC91-1099 had their biometric characteristics less affected by the stress, possibly due to the ability to continue the process of cell division and elongation and to maintain meristematic viable regions, hence they were considered as the most tolerant. On the other hand, the genotypes RB965917, CTC 15, CTC17, RB855536, CTC 2, CTC 20, and CTC99-1906 were the most sensitive to stress. Root system was the most affected by stress, with most genotypes showing more than 70% reduction in root biomass. No relationship was observed between tolerance level of genotypes and the maturation cycles. RESUMOPesquisas científicas focadas em identificar genótipos tolerantes a estresse abiótico são altamente desejáveis, pois, o uso desses genótipos permite reduzir custos de manejo do solo, da cultura e perdas de produtividade. O objetivo desse trabalho foi determinar o comportamento de 24 genótipos de cana-de-açúcar sob elevados teores de Al 3+ e Mn 2+ , associado a baixa disponibilidade de nutrientes. O ensaio foi instalado e conduzido em casa de vegetação em delineamento inteiramente casualizado, num esquema fatorial 24x2, correspondendo a 24 genótipos, dois tratamentos (com e sem estresse), com quatro repetições. No tratamento sem estresse, as plantas foram cultivadas em solução nutritiva completa e no com estresse foi utilizada solução nutritiva com elevada acidez (4,0 ± 0,1) e com 5% da sua concentração original, além da elevada concentração de alumínio (60 mg L -1 ) e manganês (700 mg L -1 ). Os genótipos RB966928, RB855443, IACSP96-3060, SP81-3250, RB867515, CTC 21, RB965902 e IAC91-1099 foram os que tiveram suas características biométricas menos afetadas pelo estresse, possivelmente devido a capacidade de continuarem o processo de divisão e elongação celular e manterem regiões meristemáticas viáveis, dessa forma, foram considerados os mais tolerantes. Por outro lado, os genótipos RB965917, CTC 15, CTC17, RB855536, CTC 2, CTC 20 e CTC99-1906 foram os mais sensíveis ao estresse. O sistema radicular foi o mais afetado pelo estresse sendo que a maioria dos genótipos apresentaram mais de 70% de redução da biomas...

Aluminum toxicity reduces the nutritional efficiency of macronutrients and micronutrients in sugarcane seedlings

“…The fact that aluminum content increased only in the root confirms the observations that this element has preferential accumulation in the root system, with a small amount translocated to the shoot, thus showing its low mobility in the plant (Yan et al, 2018;Li et al, 2018). Thus, symptoms of Al toxicity in the aerial part are not always easily identifiable (Souza et al, 2016;Sousa;Cazetta;Nascimento, 2018) and, unlike the root system, it has little direct effect on that part of the plant, mainly in a relatively short period of time (Rossiello;Jacob-Netto, 2006). The high availability of Al in the growing environment can also induce nutrient deficiency due to its interference in the solubilization/precipitation processes in the solution, uptake by roots, transport, and use of nutrients in the plant.…”

“…The reduction in the root and shoot dry matter found in this study was also observed by Sousa, Cazetta and Nascimento, (2018) in 24 sugarcane genotypes, Barbosa et al (2017) with wheat and Riaz et al (2018) with trifoliate orange. Therefore, the increased aluminum contents lead to a decrease in root and shoot dry matter production (Wang et al, 2016;Sousa;Cazetta;Nascimento, 2018). Root ends are the most affected, and their response to Al occurs very quickly, which indicates that at first, Al inhibits root cell expansion and elongation, and then cell division is inhibited (Ecco;Santiago;Lima, 2014).…”

“…Macronutrients and micronutrients were supplied provided through a Hoagland and Arnon (1950) nutrient solution. The nutrient solution was provided by an alternative hydroponic system adapted for sugarcane (Sousa;Cazetta;Nascimento, 2018). The experiment was conducted for 30 days.…”

“…Sugarcane cultivation areas have been increasing in Brazil in recent years due to its importance (Caldarelli;Gilio, 2018). Regions to which sugarcane has migrated are characterized by acid soils, generalized nutrient deficiency, and high contents of toxic elements, such as Al (Schultz et al, 2017;Sousa;Cazetta;Nascimento, 2018). About 70% of the areas cultivated with sugarcane have acid soils (Nogueirol et al, 2015;Schultz et al, 2017).…”

“…Toxicity occurs through a series of symptoms that demonstrate the continuous Al effect on the root system and shoot growth, probably due to the limited absorption and use of nutrients (Guo;Chen;Yang, 2018;Sousa;Cazetta;Nascimento, 2018). Root ends are most affected by aluminum toxicity (Sousa;Cazetta;Nascimento, 2018;Maia et al, 2018), which reduces root system volume and increases plasma membrane permeability (Yu et al, 2011), consequently hindering the water and nutrient absorption mechanism (Maia et al, 2018;Riaz et al, 2018). In this context, the harmful effect of aluminum on plants has deserved the attention of the scientific community (Ecco;Santiago;Lima, 2014;Barbosa et al, 2017;Zhu et al, 2019).…”