RESUMEN

The adaptive potential of plants is commonly used as an indicator of genotypes with higher breeding program potential. However, the complexity and interaction of plant metabolic parameters pose a challenge to selection strategies. In this context, this study aimed to explore phenotypic plasticity within the germplasm of Hybrid Timor coffee. Additionally, we assessed the utility of the multivariate phenotypic plasticity index (MVPi) as a promising tool to predict genotype performance across diverse climatic conditions. To achieve this, we evaluated the performance of seven accessions from the Hybrid Timor germplasm in comparison to the Rubi and IPR 100 cultivars, known for their susceptibility and resistance to drought, respectively. The experiment took place in a greenhouse under two conditions: one with normal soil moisture levels near maximum capacity, and the other with a water deficit scenario involving a period of no irrigation followed by rehydration. Data on physiological and biochemical factors were collected at three stages: before applying the water deficit, during its imposition, and after rehydration. Growth data were obtained by the difference between the beginning and end of the experimental period Furthermore, field evaluations of the productivity of the same genotypes were carried out over two consecutive seasons. Based on physiological and biochemical assessments, the MVPi was computed, employing Euclidean distance between principal component multivariate analysis scores. Subsequently, this index was correlated with growth and productivity data through linear regressions. Our findings reveal that the plastic genotypes that are capable of significantly altering physiological and biochemical parameters in response to environmental stimuli exhibited reduced biomass loss in both aerial and root parts. As a result, this positively influenced their productivity. Enhanced plasticity was particularly prominent in accessions from the MG Germplasm Collection: MG 311-Hybrid Timor UFV 428-02, MG 270-Hybrid Timor UFV 377-21, and MG 279-Hybrid Timor UFV 376-31, alongside the Rubi MG 1192 cultivar. The MVPi emerged as a valuable instrument to assess genotype adaptability and predict their performance under varying climatic scenarios.

RESUMEN

The population dynamics, life cycle and feeding of Argyrodiaptomus furcatus and Notodiaptomus iheringi, were studied in Broa reservoir from August 1988 to August 1989, period when a replacement of A. furcatus by N. iheringi was observed. Some abiotic factors such as temperature, dissolved oxygen, pH and conductivity were measured to characterize the limnological conditions of the reservoir. Also, phytoplankton composition was analyzed and related to the feeding of the two species. Experimental data on developmental time and reproduction of A. furcatus and N. iheringi under different temperatures showed that lower temperatures were responsible for density decreasing of both populations in the reservoir during the dry season. Chlorophyta and Chrysophyta smaller than 20 mum were the most abundant phytoplankton groups in the reservoir as well as in the gut content of A. furcatus and N. iheringi, representing an important food source for both species. The temporary disappearance of Argyrodiaptomus furcatus, observed between 1988 and 1989 and its replacement by Notodiaptomus iheringi was related to mining activities upstream, modifying the water turbidity, pH and conductivity. However, the reappearance and maintenance of A. furcatus for another ten years and a recent replacement re-incidence indicates that these two calanoids do not coexist in this environment. Adaptive strategies of both species, related to changes in environmental conditions, are discussed. Probably, Argyrodiaptomus furcatus is an indicator of less eutrophic environments, while Notodiaptomus iheringi of more eutrophic systems.

A dinâmica da população, o ciclo de vida e a alimentação de Argyrodiaptomus furcatus e de Notodiaptomus iheringi foram investigados na represa do Broa, durante o período de agosto de 1988 a agosto de 1989, quando houve a substituição da primeira espécie pela segunda. Alguns fatores abióticos, como temperatura, oxigênio dissolvido, pH e condutividade, foram medidos para caracterizar as condições limnológicas do reservatório. A composição fitoplanctônica também foi analisada para ser relacionada à alimentação das duas espécies. Dados experimentais sobre o tempo de desenvolvimento e a reprodução de A. furcatus e N. iheringi sob diferentes temperaturas mostraram que baixas temperaturas foram responsáveis pelo decréscimo de ambas as populações durante a estação de seca. Chlorophyta e Chrysophyta, grupos de organismos de fitoplâncton menores do que 20 mim, foram os mais abundantes tanto no reservatório quanto no conteúdo estomacal de A. furcatus e de N. iheringi, constituindo importante fonte de alimento para ambas as espécies. O desaparecimento temporário de Argyrodiaptomus furcatus, observado entre 1988 e 1989, e sua substituição por Notodiaptomus iheringi coincide com a atividade mineradora instalada na cabeceira do reservatório nesse período, alterando a turbidez, o pH e a condutividade. Entretanto, o reaparecimento e a manutenção de A. furcatus por mais dez anos, e a recente reincidência da substituição, indicam que essas duas espécies de Calanoida não coexistem nesse ambiente. Estratégias adaptativas de ambas as espécies em relação às condições ambientais são discutidas. Provavelmente, Argyrodiaptomus furcatus seja uma espécie indicadora de ambientes menos eutróficos, enquanto Notodiaptomus iheringi sobrevive bem em sistemas eutróficos com freqüentes florescimentos de cianofíceas.

RESUMEN

The population dynamics, life cycle and feeding of Argyrodiaptomus furcatus and Notodiaptomus iheringi, were studied in Broa reservoir from August 1988 to August 1989, period when a replacement of A. furcatus by N. iheringi was observed. Some abiotic factors such as temperature, dissolved oxygen, pH and conductivity were measured to characterize the limnological conditions of the reservoir. Also, phytoplankton composition was analyzed and related to the feeding of the two species. Experimental data on developmental time and reproduction of A. furcatus and N. iheringi under different temperatures showed that lower temperatures were responsible for density decreasing of both populations in the reservoir during the dry season. Chlorophyta and Chrysophyta smaller than 20 mum were the most abundant phytoplankton groups in the reservoir as well as in the gut content of A. furcatus and N. iheringi, representing an important food source for both species. The temporary disappearance of Argyrodiaptomus furcatus, observed between 1988 and 1989 and its replacement by Notodiaptomus iheringi was related to mining activities upstream, modifying the water turbidity, pH and conductivity. However, the reappearance and maintenance of A. furcatus for another ten years and a recent replacement re-incidence indicates that these two calanoids do not coexist in this environment. Adaptive strategies of both species, related to changes in environmental conditions, are discussed. Probably, Argyrodiaptomus furcatus is an indicator of less eutrophic environments, while Notodiaptomus iheringi of more eutrophic systems.

A dinâmica da população, o ciclo de vida e a alimentação de Argyrodiaptomus furcatus e de Notodiaptomus iheringi foram investigados na represa do Broa, durante o período de agosto de 1988 a agosto de 1989, quando houve a substituição da primeira espécie pela segunda. Alguns fatores abióticos, como temperatura, oxigênio dissolvido, pH e condutividade, foram medidos para caracterizar as condições limnológicas do reservatório. A composição fitoplanctônica também foi analisada para ser relacionada à alimentação das duas espécies. Dados experimentais sobre o tempo de desenvolvimento e a reprodução de A. furcatus e N. iheringi sob diferentes temperaturas mostraram que baixas temperaturas foram responsáveis pelo decréscimo de ambas as populações durante a estação de seca. Chlorophyta e Chrysophyta, grupos de organismos de fitoplâncton menores do que 20 mim, foram os mais abundantes tanto no reservatório quanto no conteúdo estomacal de A. furcatus e de N. iheringi, constituindo importante fonte de alimento para ambas as espécies. O desaparecimento temporário de Argyrodiaptomus furcatus, observado entre 1988 e 1989, e sua substituição por Notodiaptomus iheringi coincide com a atividade mineradora instalada na cabeceira do reservatório nesse período, alterando a turbidez, o pH e a condutividade. Entretanto, o reaparecimento e a manutenção de A. furcatus por mais dez anos, e a recente reincidência da substituição, indicam que essas duas espécies de Calanoida não coexistem nesse ambiente. Estratégias adaptativas de ambas as espécies em relação às condições ambientais são discutidas. Provavelmente, Argyrodiaptomus furcatus seja uma espécie indicadora de ambientes menos eutróficos, enquanto Notodiaptomus iheringi sobrevive bem em sistemas eutróficos com freqüentes florescimentos de cianofíceas.