Crescimento de híbridos e variedades porta-enxerto de citros sob salinidade

Abstract

RESUMO.A salinidade da água e do solo afeta o crescimento, o desenvolvimento e a produção de espécies frutíferas, dentre as quais os citros. O uso de porta-enxertos tolerantes pode garantir a sustentabilidade do agronegócio citrícola em tais condições. Assim, estudou-se a sensibilidade à salinidade durante a fase de formação de portaenxertos compreendendo variedades e híbridos selecionados. O experimento foi realizado em casa-de-vegetação, considerando cinco níveis de salinidade da água de irrigação [testemunha, irrigação com água de abastecimento local, condutividade elétrica da água (CE a ) de 0,41 dS m -1 e água com CE a de 1,0; 2,0; 3,0 e 4,0 dS m] e sete genótipos, utilizando delineamento em blocos casualizados, com cinco repetições em esquema fatorial e quatro plantas úteis por parcela, durante o período de 150 dias. Avaliaram-se variáveis de crescimento e fisiológicas. A redução mais expressiva foi observada na fitomassa seca total da parte aérea com aumento unitário da CE a . Observou-se redução linear no crescimento com aumento da salinidade nos híbridos LVK x LVA-009 e TSK x TRENG-256. Dentre os genótipos avaliados, o limoeiro 'Volkameriano' foi o menos sensível ao estresse salino.Palavras-chave: Citrus spp., mudas, estresse abiótico. ABSTRACT. Growth of hybrids and rootstock varieties of citrus under salinity.Water and soil salinity affects the growth, development and production of fructiferous species, such as citrus. The use of tolerant rootstocks can guarantee the agribusiness of citrus under such conditions. Thus, the sensibility to salinity during the phase of rootstock formation of varieties and selected hybrids was studied. The experiment was carried out in a greenhouse, with five levels of irrigation water salinity [control, tap water with electrical conductivity (EC w ) of 0.41 dS m ] and seven genotypes, in a randomized block design and five replications each consisting of four plants, during 150 day period. Growth and physiologic variables were evaluated. Significant effects of genotypes and salinity in the variables were observed. The most expressive reduction was found for total dry matter with unit increase of EC w . A linear reduction was observed in hybrids LVK x LVA-009 and TSK x TRENG-256. Among the evaluated genotypes 'Volkamer' lemon was the least sensitive to saline stress.

Growth and physiology of citrus rootstocks under salt stress

“…V. S. et al thereby avoiding toxicity by specific ions. This is because a greater root growth, besides favoring a higher exploration of the environment in search for nutrients under saline conditions, may also lead to a greater absorption of Na + and Cl -ions until toxic levels and its consequent transport to the shoot, damaging plant growth as a whole (BRITO et al, 2008;FERNANDES et al, 2011;GONZÁLEZ;ETXEBERRIA, 2012;BRITO et al, 2014a;BRITO et al, 2014b;GARCIA-SANCHEZ, 2014). …”

“…It results in the need to use sources of water for irrigation, whit high concentration of salts (MEDEIROS et al, 2010). This is a condition that contributes the most to reduced growth and physiological disorders in plants ( BRITO et al, 2008;FERNANDES et al, 2011;NASCIMENTO et al, 2012;SILVA et al, 2012;BRITO et al, 2014a;BRITO et al, 2014b), especially citrus plants, considered sensitive to salinity (SYVERTSEN; GARCIA-SANCHEZ, 2014). 908 Growth and physiology… SÁ, F. V. S. et al…”

Morphophysiology of Tahiti lime grafted onto Sunki mandarin hybrids under salt stress

“…Studies have reported genetic materials used as rootstocks with potential tolerance to salinity (Fernandes et al, 2011;Silva et al, 2014;Barbosa et al, 2017;Brito et al, 2008Brito et al, , 2016Brito et al, , 2017. Thus, the use of salinity-tolerant rootstocks can allow the use of water with high salt levels or even saline soils (Grieve et al, 2007;Prior et al, 2007;Brito et al, 2014Brito et al, , 2015.…”

Growth and fluorescence of ‘Tahiti’ acid lime/rootstock on Sunki mandarin hybrids under salinity

“…Despite that, the literature has reported genotypes used as rootstocks with potential tolerance to salinity (FERNANDES et al, 2011HUSSAIN et al, 2012SILVA et al, 2012;HUSSAIN et al, 2015;BRITO et al, 2016). However, to identify salt-tolerant citrus genotypes, successive evaluations must be conducted and need to encompass the entire crop production system.…”

“…However, to identify salt-tolerant citrus genotypes, successive evaluations must be conducted and need to encompass the entire crop production system. For citrus, firstly, it is necessary to identify tolerant materials during the stages of rootstock growth (BRITO et al, 2008;FERNANDES et al, 2011), Growth and photochemical… SILVA, L. A. et al grafted seedling growth (BRITO et al, 2014;BRITO et al, 2015). Then, these materials with potential need to be taken to the field to consolidate the recommendation, based on growth and physiological variables, which are of great importance.…”