Alocação de fotoassimilados em tomateiro marcados com isótopos estáveis
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Data
2018-04-24
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Universidade Estadual Paulista (Unesp)
Resumo
O trabalho teve como objetivo avaliar a partição de fotoassimilados em tomateiro de crescimento indeterminado, utilizando isótopo estável do 13C como marcador na relação fonte-dreno nos diferentes órgãos, bem como, saber em que órgão se encontraria o 13C, visando encontrar o ramo com maior participação no fornecimento de fotoassimilados para os drenos, ou seja, para o crescimento dos frutos de tomateiro. Os experimentos foram conduzidos na estação experimental da Sakata Seed Sudamérica localizada no município de Bragança Paulista (SP). O experimento I foi conduzido em delineamento inteiramente casualizado em esquema fatorial com 2 fatores: avaliação do tempo de chegada do 13C a partir do 13CO2 no racemo (6; 12; 18 e 24 horas) e duas folhas de aplicação do 13CO2, em relação ao racemo (folha acima ou abaixo do racemo) com quatro repetições. O experimento II foi conduzido em delineamento inteiramente casualizado, com quatro repetições, e após verificar o tempo de chegada do 13C no racemo (18 horas), as folhas enriquecidas com 13C referentes ao racemo foram analisadas em diferentes estádios fenológicos: fase vegetativa; fase de inflorescência; fase de início da frutificação e racemo com frutos no ponto de colheita, observando a mudança de 50-60% da coloração do fruto. Os tratamentos de aplicação do 13CO2 marcado nesse experimento foi realizada em diferentes posições das folhas em relação ao racemo e nas fases fenológicas: folha entre dois racemos do mesmo lado do racemo; folha abaixo e oposta ao racemo e folha acima e oposta ao racemo. Na fase vegetativa, como ainda não havia racemo formado foi medida a taxa de assimilação de CO2 das três folhas presentes e definiuse a aplicação do 13CO2 na folha fotossinteticamente mais ativa, que foi a 2ª folha. A partir dos resultados verificou-se que na particição de fotoassimilados a folha abaixo e oposta ao racemo apresentou maior presença de 13C, na fase de inflorescência e início de frutificação
The objective of this work was to evaluate the partition of photoassimilates in an indeterminate growth tomato using the 13C stable isotope as a source-drain marker in the different organs, as well as to know in which organ the 13C would be found, in order to find the branch with the largest participation in the supply of photoassimilates to the drains, that is, for the growth of tomato fruits. The experiments were conducted at the Sakata Seed Sudamérica experimental station located in the city of Bragança Paulista (SP). The experiment I was conducted in a completely randomized design in a factorial scheme with 2 factors: evaluation of the arrival time of 13C from 13CO2 in racemic (6; 12, 18 and 24 hours) and two application leafs of 13CO2, in relation to racemus (leaf above or below the racemus) with four replicates. Experiment II was conducted in a completely randomized design with four replicates, and after checking the time of arrival of the 13C in the racemic (18 hours), the leaves enriched with 13C racemes were analyzed in different phenological stages: vegetative phase; inflorescence phase; phase of beginning of fruiting and racemes with fruits at harvest point, observing the change of 50-60% in the color of the fruit. The application treatments of 13CO2 marked in this experiment were carried out in different positions of the leaves in relation to the racemic and in the phenological phases: leaf between two racemes of the same side of the racemic; leaf below and opposite the racemus and leaf above and opposite the racemus. In the vegetative phase, as there was no racemic formed, the CO2 assimilation rate of the three leaves present was measured and the application of 13CO2 on the photosynthetically active leaf, which was the second leaf, was measured. From the results it was verified that in the photoassimilates, the leaf below and opposite to the racemic showed a greater presence of 13C, in the inflorescence phase and the beginning of fruiting.
The objective of this work was to evaluate the partition of photoassimilates in an indeterminate growth tomato using the 13C stable isotope as a source-drain marker in the different organs, as well as to know in which organ the 13C would be found, in order to find the branch with the largest participation in the supply of photoassimilates to the drains, that is, for the growth of tomato fruits. The experiments were conducted at the Sakata Seed Sudamérica experimental station located in the city of Bragança Paulista (SP). The experiment I was conducted in a completely randomized design in a factorial scheme with 2 factors: evaluation of the arrival time of 13C from 13CO2 in racemic (6; 12, 18 and 24 hours) and two application leafs of 13CO2, in relation to racemus (leaf above or below the racemus) with four replicates. Experiment II was conducted in a completely randomized design with four replicates, and after checking the time of arrival of the 13C in the racemic (18 hours), the leaves enriched with 13C racemes were analyzed in different phenological stages: vegetative phase; inflorescence phase; phase of beginning of fruiting and racemes with fruits at harvest point, observing the change of 50-60% in the color of the fruit. The application treatments of 13CO2 marked in this experiment were carried out in different positions of the leaves in relation to the racemic and in the phenological phases: leaf between two racemes of the same side of the racemic; leaf below and opposite the racemus and leaf above and opposite the racemus. In the vegetative phase, as there was no racemic formed, the CO2 assimilation rate of the three leaves present was measured and the application of 13CO2 on the photosynthetically active leaf, which was the second leaf, was measured. From the results it was verified that in the photoassimilates, the leaf below and opposite to the racemic showed a greater presence of 13C, in the inflorescence phase and the beginning of fruiting.
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Palavras-chave
Solanum lycopersicum L, Carbono-13, Relação Fonte-Dreno, Posição da Folha