Name: PRISCILA DA CONCEIÇÃO DE SOUZA BRAGA
Type: PhD thesis
Publication date: 28/02/2019
Advisor:

Name	Role
Antelmo Ralph Falqueto	Advisor *
João Paulo Rodrigues Martins	Co-advisor *
Robson Bonomo	Co-advisor *

Examining board:

Name	Role
Andreia Barcelos Passos Lima Gontijo	External Examiner *
Antelmo Ralph Falqueto	Advisor *
Camilla Rozindo Dias Milanez	Internal Examiner *
Diolina Moura Silva	Internal Examiner *
Elisa Mitsuko Aoyama	External Alternate *
Fábio Luiz Partelli	External Examiner *
João Paulo Rodrigues Martins	Co advisor *
Luis Fernando Tavares de Menezes	Internal Alternate *

Summary: Title: Physiological changes of Crambe abyssinica Hochst. submitted to water déficit
Abstract
Crambe (Crambe abyssinica Hochst, Brassicaceae) is an annual crop native to the Mediterranean region of Ethiopia and cultivated in some tropical and subtropical regions. Because it does not compete with oilseeds used in human consumption, it has been an innovative crop in the Brazilian agribusiness sector with potential supply of insulating vegetable oil. Currently, new genotypes have been tested in order to expand the culture and improve crop productivity in Brazil. The objective of this study was to evaluate the tolerance of different crambe genotypes to water deficit in different development phases. The results obtained will contribute to the crop expansion to regions characterized by low precipitation, such as the State of Espírito Santo. Four experiments were installed: First – the objective of this study was to compare the germination and initial growth of five crambe genotypes (FMS Brilhante, FMS CR 1203, 1307, 1312 and 1326) submitted to the water deficit induced by polyethylene glycol. In this experiment, the germination and vigor index of crambe seeds were hampered by the reduction in the potential to -0.4 MPa. The genotype FMS CR 1203 is the most tolerant to water stress, WHEREas FMS CR 1307 and
1312 are the most sensitive (Chapter 1). Second - conducted in a greenhouse, this study investigated and compared the effects of water deficit on vegetative growth on photosynthetic characteristics using kinetic analysis of transient chlorophyll a fluorescence in two crambe genotypes: FMS CR 1307 and 1326. Under water deficit, the crambe genotypes showed differentiated photochemical responses. The FMS CR 1326 genotype presented greater advantage in terms of stability and energy efficiency under water suppression, WHEREas the FMS CR 1307 genotype appears to have higher FSI photoprotection (Chapter 2). Third - conducted in a greenhouse, this experiment evaluated the performance of crambe (FMS Brilhante, FMS CR 1307 and 1326) under water limiting conditions by previous exposures to water deficit. The repeated exposures to the water deficit in the crambe plants resulted in morphophysiological changes of the plants, reflecting in a better photochemical performance coupled with moderate anatomical adjustments, indicating memory to the water deficit. The FMS CR 1307 genotype presented better photochemical performance, confirming the existence of water deficit memory in FSII (Chapter 3). Fourth - carried out in a greenhouse, this experiment investigated the effect of the intense water deficit applied at the beginning of the flowering stage on the physiological characteristics and production of crambe grains (FMS CR 1307 and FMS CR 1326) as well as possible dormancy of the progeny due to water deficit. The water deficit resulted in negative effects on the photochemical apparatus of plants, as well as reductions in stomatal conductance. Furthermore, these changes in the physiological responses of crambe plants reflected reduced grain yield and mild dormancy in the progeny. The FMS CR 1307 genotype presented better photochemical adjustment during the period of water deficit and recovery, confirming photochemical tolerance under water deficit.
Keywords: chlorophyll a fluorescence, photosystem II, drought tolerance, germination, water deficit memory, flowering.

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