Deficiência hídrica em genótipos de amendoim
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Data
2017-04-12
Autores
Carrega, Willians César [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
No cultivo do amendoim, as plantas estão sujeitas a vários estresses, sejam de natureza biótica ou abiótica. Entre os principais fatores abióticos, a deficiência hídrica é considerada um dos maiores entraves durante o processo produtivo. Diante disso, a compreensão dos mecanismos adaptativos utilizados pelas plantas para tolerar a deficiência hídrica é de suma importância para a tomada de decisão durante a implantação de um sistema de cultivo. Como a cultura do amendoim apresenta determinada tolerância ao estresse hídrico, é necessário saber quais mecanismos estão envolvidos no processo adaptativo dessas plantas, visando selecionar genótipos com maior tolerância a seca e de posse dessas informações, expandir o cultivo para regiões com menor disponibilidade hídrica, bem como fornecer subsídios para o aumento da sua produção nacional. Dessa forma, o presente trabalho teve como objetivo geral, avaliar as respostas de genótipos de amendoim submetidos a condições hídricas. Foram desenvolvidos dois estudos na FCAV/UNESP e dois no INTA, Argentina. Nos estudos realizados na FCAV, objetivou-se (i) avaliar a qualidade fisiológica de sementes de genótipos de amendoim submetidos a deficiência hídrica. Com base nos resultados desse trabalho, concluiu-se que as linhagens ‘506’, ‘599’ e ‘870’ e o cultivar IAC Tatu-ST são os mais tolerantes a deficiência hídrica; (ii) analisar as alterações anatomo-fisiológico de genótipos de amendoim submetidos a deficiência hídrica. Nesse trabalho, verificou-se que para o comportamento anatomo-fisiológico dos genótipos, as linhagens ‘573’ e ‘870’ são as mais tolerantes às condições de deficiência hídrica. Para os trabalhos realizados no INTA, objetivou-se (i) determinar a eficiência no uso da água e da radiação de cultivares com hábitos de crescimento contrastantes (ereto e rasteiro), submetidos a condições hídricas em dois espaçamentos entre linhas. Nesse trabalho, concluiu-se que ocorreu a diminuição da eficiência no uso da água apenas para o cv. ASEM 484 INTA. Para ambos cultivares (ASEM 484 INTA e Blanco Santa Fe), constatou-se que a deficiência hídrica reduz a eficiência no uso da radiação e também verificou-se que o espaçamentos 52 cm entre linhas apresenta maior eficiência no uso da radiação; (ii) avaliar os efeitos da impedância e disponibilidade hídrica na viabilidade dos ginóforos em cultivares de amendoim com hábitos de crescimento contrastantes. Concluiu-se que a deficiência hídrica e os períodos de impedância promovem perdas acentuadas e proporcionais na viabilidade dos ginóforos de amendoim nos cultivares rasteiros, sendo esses, menos afetados pelos períodos de impedância sob deficiência hídrica; (iii) determinar os efeitos da temperatura do solo em combinação com a disponibilidade hídrica sob períodos de impedância visando avaliar a viabilidade dos ginóforos e a fixação de vagens. Para esse trabalho, constatou-se que a deficiência hídrica ou o estresse térmico reduzem a viabilidade dos ginóforos, cujo efeito acentua-se na combinação dos dois fatores. Vale ressaltar que esses estudos são preliminares e há a necessidade de novos estudos, principalmente relacionados a Eficiência no uso da água e da radiação para os genótipos nacionais.
In peanut, plants are subject to various stresses, be they biotic or abiotic. Among the main abiotic factors, water deficiency is considered one of the major obstacles during the productive process. Therefore, the understanding of the adaptive mechanisms used by plants to tolerate water deficiency is of paramount importance for decision making during the implantation of a cropping system. As the peanut crop presents a certain tolerance to water stress, it is necessary to know what mechanisms are involved in the adaptive process of these plants, in order to select genotypes with greater tolerance to drought and of this information, to expand the crop to regions with lower water availability and provide subsidies for the increase the national production. Thus, the present work had as general objective to evaluate the behavior of peanut genotypes submitted to water conditions. Two studies were developed at FCAV/UNESP and two studies at INTA, Argentina. In the studies conducted at FCAV, the objective was to (i) evaluate the physiological quality of seeds of peanut genotypes submitted to water deficiency. Based on the results of this work, it was concluded that genotypes '506', '599', 'Tatu-ST' and '870' are the most recommended for environments with lower water availability; (ii) to analyze the anatomo-physiological behavior of peanut genotypes submitted to water deficiency. In this work, it was verified that for the anatomo-physiological behavior of the genotypes, the lineages '573' and '870' are the most tolerant to the water deficiency conditions. For the work done at INTA, the objective was to (i) determine the efficiency in the use of water and radiation of peanut cultivars with contrasting growth habits, submitted to water conditions and distances between lines. In this work, it was concluded that the WUE only decreased for cv. ASEM 484 INTA. For both cultivars, it was verified that the water deficiency reduces the RUE. There are also differences between the distances between lines; (ii) to evaluate the effects of impedance and water availability on the viability of gynophores in peanut cultivars with contrasting growth habits. It was concluded that the water deficiency and the impedance periods promoted significant and proportional losses in the viability of gynophores in the runner peanut cultivars. These cultivars were less affected by the IP under water deficiency; (iii) to determine the effects of soil temperature in combination with water availability under impedance periods to evaluate the viability of gynophores and fixation of pods. For this work, it was verified that the water deficiency and the thermal stress reduce the viability of the gynophores, whose effect is more accented in the combination of the two factors. It is worth mentioning that these studies are preliminary and there is a need for new studies, mainly related to WUE and RUE for national cultivars.
In peanut, plants are subject to various stresses, be they biotic or abiotic. Among the main abiotic factors, water deficiency is considered one of the major obstacles during the productive process. Therefore, the understanding of the adaptive mechanisms used by plants to tolerate water deficiency is of paramount importance for decision making during the implantation of a cropping system. As the peanut crop presents a certain tolerance to water stress, it is necessary to know what mechanisms are involved in the adaptive process of these plants, in order to select genotypes with greater tolerance to drought and of this information, to expand the crop to regions with lower water availability and provide subsidies for the increase the national production. Thus, the present work had as general objective to evaluate the behavior of peanut genotypes submitted to water conditions. Two studies were developed at FCAV/UNESP and two studies at INTA, Argentina. In the studies conducted at FCAV, the objective was to (i) evaluate the physiological quality of seeds of peanut genotypes submitted to water deficiency. Based on the results of this work, it was concluded that genotypes '506', '599', 'Tatu-ST' and '870' are the most recommended for environments with lower water availability; (ii) to analyze the anatomo-physiological behavior of peanut genotypes submitted to water deficiency. In this work, it was verified that for the anatomo-physiological behavior of the genotypes, the lineages '573' and '870' are the most tolerant to the water deficiency conditions. For the work done at INTA, the objective was to (i) determine the efficiency in the use of water and radiation of peanut cultivars with contrasting growth habits, submitted to water conditions and distances between lines. In this work, it was concluded that the WUE only decreased for cv. ASEM 484 INTA. For both cultivars, it was verified that the water deficiency reduces the RUE. There are also differences between the distances between lines; (ii) to evaluate the effects of impedance and water availability on the viability of gynophores in peanut cultivars with contrasting growth habits. It was concluded that the water deficiency and the impedance periods promoted significant and proportional losses in the viability of gynophores in the runner peanut cultivars. These cultivars were less affected by the IP under water deficiency; (iii) to determine the effects of soil temperature in combination with water availability under impedance periods to evaluate the viability of gynophores and fixation of pods. For this work, it was verified that the water deficiency and the thermal stress reduce the viability of the gynophores, whose effect is more accented in the combination of the two factors. It is worth mentioning that these studies are preliminary and there is a need for new studies, mainly related to WUE and RUE for national cultivars.
Descrição
Palavras-chave
Arachis hypogaea L., Estresse hídrico, Seca, Eficiência no uso da água, Eficiência no uso da radiação, Rendimento