ASPECTOS BIOQUÍMICOS E FLUORESCÊNCIA DA CLOROFILA A EM PLANTAS DE MINIMELANCIA HIDROPÔNICA SOB ESTRESSE SALINO*

ASPECTOS BIOQUÍMICOS E FLUORESCÊNCIA DA CLOROFILA A EM PLANTAS DE MINIMELANCIA HIDROPÔNICA SOB ESTRESSE SALINO* LAÍS MONIQUE GOMES DO Ó1, ALIDE MITSUE WATANABE COVA2, PETTERSON COSTA CONCEIÇÃO SILVA3, HANS RAJ GHEYI4, ANDRÉ DIAS DE AZEVEDO NETO5, ROGÉRIO FERREIRA RIBAS6 1Doutoranda em Engenharia Agrícola da Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, s/n, Cruz das Almas, Bahia, Brasil [email protected]. 2Pós-Doutoranda no Programa de Pós-graduação de Engenharia Agrícola da Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, s/n, Cruz das Almas, Bahia, Brasil, [email protected]. 3Doutor em Engenharia Agrícola, Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, s/n, Cruz das Almas, Bahia, Brasil, [email protected]. 4Professor Visitante, Universidade Federal do Recôncavo da Bahia, Cruz das Almas, Bahia, [email protected]. 5Professor Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, s/n, Cruz das Almas, Bahia, Brasil, [email protected]. 6Professor Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, s/n, Cruz das Almas, Bahia, Brasil, [email protected]. *Este artigo é proveniente da tese de doutorado do primeiro autor. 1 RESUMO A salinidade é um dos principais estresses abióticos que induz distúrbios bioquímicos e fisiológicos em diversas culturas. O objetivo do trabalho foi investigar os efeitos da salinidade da solução nutritiva (CEsol) sobre a produção, acúmulo de solutos orgânicos e inorgânicos e fluorescência da clorofila a em plantas de minimelancia cv. Sugar Baby. O delineamento experimental foi o inteiramente casualizado com quatro repetições. As plantas foram cultivadas em sistema hidropônico com cinco níveis de CEsol: 2,5; 3,5; 4,5; 5,5 e 6,5 dS m-1. Foram avaliados: massa do fruto, biomassa da parte aérea, teores de clorofilas a e b, fluorescência da clorofila a e teores de solutos orgânicos e inorgânicos. A massa do fruto e a biomassa seca da parte aérea foram influenciadas negativamente pela CEsol. Houve redução na concentração de carboidratos solúveis totais, aminoácidos livres, proteínas solúveis e prolina livre com o aumento da CEsol. Os íons sódio, cloreto e razão sódio/potássio aumentaram com a salinidade e os teores de potássio foram reduzidos. O incremento da salinidade aumentou linearmente o teor de clorofila b e reduziu linearmente o rendimento quântico da conversão de energia fotoquímica do FSII promovendo um ligeiro aumento no rendimento quântico da perda de energia regulada do FSII. Palavras-chaves: biomassa, carboidratos, íons tóxicos, estresse abiótico. Ó, L. M. G.; COVA, A. M. W.; SILVA, P. C. C.; GHEYI, H. R.; AZEVEDO NETO, A. D. de; RIBAS, R. F. BIOCHEMICAL ASPECTS AND CHLOROPHYLL A FLUORESCENCE IN HYDROPONIC MINI WATERMELON PLANTS UNDER SALT STRESS 2 ABSTRACT Salinity is one of the main abiotic stresses that induce biochemical and physiological disorders in diverse crops. This study investigated the effects of nutrient solution salinity (ECsol) on production, accumulation of organic and inorganic solutes and chlorophyl a fluorescence in mini watermelon plants cv. Sugar Baby. The experimental design was completely randomized with four replications. The plants were grown in a hydroponic system with five levels of ECsol: 2.5; 3.5; 4.5; 5.5 and 6.5 dS m-1. The variables evaluated were the mass of the fruit, the biomass of the aerial parts, contents of chlorophylls a and b, fluorescence of chlorophyll a, and contents of organic and inorganic solutes. The mass of the fruit and dry biomass of the aerial parts was negatively influenced by ECsol. There was a reduction in the concentration of total soluble carbohydrates, free amino acids, soluble proteins and free proline with the increase in ECsol. The sodium, chloride and sodium/potassium ratio increased with ECsol and potassium levels were reduced. The increase in ECsol linearly increased the chlorophyll b content and reduced the quantum yield of the photochemical energy conversion of the PSII promoting a slight increase in the quantum yield of the regulated energy loss of the PSII. Keywords: abiotic stress, biomass, carbohydrates, toxic ions.

Physiological adaptation and photosynthesis characteristics of new hybrid forms of table grapes in summer period

Представлены результаты исследования физиологических особенностей восьми новых перспективных гибридных форм и одного сорта винограда столового направления использования в сравнении с контрольным сортом Ливия. Исследования новых форм, привитых на подвое Берландиери × Рипариа SО4, выполнены в агроэкологических условиях Центральной зоны виноградарства Краснодарского края. Для определения эффективности фотосинтеза использовали два параметра - квантовый выход фотохимической реакции фотосистемы II и содержание хлорофиллов a и b . Определение флуоресценции хлорофилла a проводили согласно методу PAM-флуориметрии. Содержание пигментов в листьях винограда оценивали спектрофотометрическим методом. Степень повреждения клеточных мембран в результате окислительного стресса устанавливали по содержанию малонового диальдегида в модельном опыте. Относительное содержание воды в листьях (RWC) оценивали по степени насыщения клеток водой и способности ее удерживать при высушивании согласно общепринятой методике. Выделены четыре группы гибридных форм винограда: 1) с высоким адаптивным и продукционным потенциалом (низкие значения МДА и высокие значения содержания пигментов, RWC и уровня флуоресценции хлорофилла a ) - сорт Дубовский розовый; 2) с высоким адаптивным потенциалом, но со средними показателями фотосинтеза - гибрид Арабелла; 3) с усредненными показателями, приближенными к контрольному сорту - Агат Дубовский и Гамлет; 4) с разнородными показателями фотосинтеза и относительного содержания воды и высоким уровнем окислительного стресса - Исполин, Кишмиш Дубовский, Пестрый, Тимоти. По содержанию хлорофиллов a и b и малонового диальдегида выявлена наибольшая вариабельность значений среди исследованных форм винограда, а такие показатели как относительное содержание воды в листьях и уровень флуоресценции хлорофилла a характеризовались достаточно однородными величинами. The results of the study of physiological characteristics of eight new promising table hybrid forms and one table grape variety in comparison with the control table variety ‘Livia’ are presented. Analyses of new forms grafted on the rootstock of ‘Berlandieri × Riparia SO4’ were carried out in agroecological conditions of the Central zone of viticulture in the Krasnodar Region. To determine the efficiency of photosynthesis, two parameters were used - the quantum yield of photochemical reaction of photosystem II and the content of chlorophylls a and b . The fluorescence of chlorophyll a was determined according to the PAM-fluorimetry method. The content of pigments in grape leaves was evaluated by spectrophotometric method. The degree of damage to cell membranes as a result of oxidative stress was determined by the content of malondialdehyde in the model experiment. The relative water content in leaves (RWC) was estimated by the degree of saturation of the cells with water and the ability to retain it during drying according to the generally accepted method. Four groups of hybrid forms of grapes are distinguished: 1) with high adaptive and productive potential (low values of MDA and high of pigment content, RWC and the level of fluorescence of chlorophyll a ) - ‘Dubovskiy Rozovyi’ variety; 2) with high adaptive potential, but with average values of photosynthesis - ‘Arabella’ hybrid; 3) with average values similar to the control variety - ‘Agat Dubovskiy’ and ‘Hamlet’; 4) with heterogeneous rates of photosynthesis and relative water content, and high levels of oxidative stress - ‘Ispolin’, ‘Kishmish Dubovskiy’, ‘Pestryi’, ‘Timoti’. According to the content of chlorophylls a and b and malondialdehyde, the greatest variability of values among the studied grape forms was revealed, and such indicators as the relative water content in leaves and the level of chlorophyll a fluorescence were characterized by fairly homogeneous quantities.

Root and Shoot Response to Nickel in Hyperaccumulator and Non-Hyperaccumulator Species

The soil–root interface is the micro-ecosystem where roots uptake metals. However, less than 10% of hyperaccumulators’ rhizosphere has been examined. The present study evaluated the root and shoot response to nickel in hyperaccumulator and non-hyperaccumulator species, through the analysis of root surface and biomass and the ecophysiological response of the related aboveground biomass. Ni-hyperaccumulators Alyssoides utriculata (L.) Medik. and Noccaea caerulescens (J. Presl and C. Presl) F.K. Mey. and non-hyperaccumulators Alyssum montanum L. and Thlaspi arvense L. were grown in pot on Ni-spiked soil (0–1000 mg Ni kg−1, total). Development of root surfaces was analysed with ImageJ; fresh and dry root biomass was determined. Photosynthetic efficiency was performed by analysing the fluorescence of chlorophyll a to estimate the plants’ physiological conditions at the end of the treatment. Hyperaccumulators did not show a Ni-dependent decrease in root surfaces and biomass (except Ni 1000 mg kg−1 for N. caerulescens). The non-hyperaccumulator A. montanum suffers metal stress which threatens plant development, while the excluder T. arvense exhibits a positive ecophysiological response to Ni. The analysis of the root system, as a component of the rhizosphere, help to clarify the response to soil nickel and plant development under metal stress for bioremediation purposes.

The dormant period of the apple tree and its change under the influence of destabilization of weather conditions

The article presents an analysis of the features of weather conditions in 2020 in the Central Black Earth Region. It determines main deviations from the average long-term values of air temperature and humidity, as well as the distribution of precipitation. It shows the influence of climate change in recent decades, the main of which is the destabilization of the water-temperature regime, on the passage of phenophases in the development of fruit plants, including the dormant period. The article studies various methods of determining the dynamic reaction of the photo-system of apple-tree plants of the varieties Lobo, Zhigulevskoe, Melba, Antonovka, Hani Crisp, Ligol on the stock 62-396 deep rest by non-invasive methods based on the analysis of photosynthetic activity and the intensity of photosynthesis of chlorophyll-containing tissues. It shows the prospects of non-invasive registration of photosynthetic activity of tissues of annual branches for monitoring the period of deep dormancy. It was found that the registration of real parameters of changes in the index of photosynthetic activity during the transition to deep dormancy is possible only in the field. Cut branches of plants, placed in favorable laboratory conditions, show smoothed parameters of fluctuations in the level of fluorescence of chlorophyll-a in assimilation tissues, depending on changes in the functional state of the plant organism.

Comparing the effects of different exogenous hormone combinations on seed-derived callus induction in Nicotiana tabacum

Callus from Nicotiana tabacum is used as a model in plant developmental research. We tested several phytohormone (Indoleacetic acid – IAA; 2,4-Dichlorophenoxyacetic acid – 2,4-D; kinetin – KIN; 6-Benzylaminopurine – BAP) combinations to compare different approaches to callus induction directly from the seeds of Nicotiana tabacum. Callus formation was observed up to 4 weeks after sowing and the most effective were 0.5 mg/L of 2,4-D with 0.25 mg/L of BAP and 2 mg/L 2,4-D with 1 mg/L of BAP. The calli were green, photosynthetically active and after 6 weeks of growth, no stress symptoms (estimated on the basis of fluorescence of chlorophyll a in photosystem II) were noticed.

Le voilier OceanoScientific Explorer Boogaloo : Une campagne péri-antarctique en 2017

L'utilisation de voiliers comme pourvoyeurs de données océanographiques et météorologiques de qualité scientifique a été testée dans le cadre du programme OceanoScientific et en particulier lors de la navigation péri-antarctique en solitaire du voilier OceanoScientific Explorer Boogaloo début 2017. Les caractéristiques du système et les données océanographiques recueillies (température, salinité, fluorescence de la chlorophylle A, pression partielle de dioxyde de carbone) sont présentées, illustrant le succès de l'approche, malgré quelques contraintes qui sont évoquées. Using sailing vessels to provide surface oceanographic and meteorological data for operational and scientific use has been promoted in the OceanoScientific programme. It has been tested during the circum-Antarctic sailing of the Explorer OceanoScientific Boogaloo in early 2017. The instrumentation, data acquisition, processing and transmission characteristics are described. Then, the ocean data collected (temperature, salinity, fluorescence of Chlorophyll-A, partial pressure of carbon dioxide) are presented, illustrating the success of the approach, but also some constraints that were encountered.

Silvicultural Potential of Handroanthus heptaphyllus Under Doses of Controlled Release Fertilizer and Container Volume, in Nursery and in the Field

The present study aimed to characterize the growth of Handroanthus heptaphyllus seedlings in a nursery, planted under different container volumes and doses of controlled release fertilizer (CRF), and to verify whether the responses obtained in the nursery are confirmed in the field. For the production of seedlings in the nursery, three volumes of container (180 and 280 cm3 polypropylene tubes and 500 cm3 polyethylene bags) and four CRF doses (0, 4, 8, and 12 g L-1 of substrate) were used. At 180 d after emergence, height (H), stem diameter (SD), H:SD ratio, shoot dry weight, root dry weight, total dry weight, Dickson Quality Index, leaf area, root length, and fluorescence of chlorophyll a were evaluated. The same treatments were evaluated again in the field 540 d after planting, and the survival, increase in H and SD, as well as shoot dry weight, leaf area, chlorophyll fluorescence, and chlorophyll index (a, b and total) were measured. In the nursery, seedlings of H. heptaphyllus responded positively to the volume of the container, as well as the base fertilization using CRF. However, when planted in the field, the plants that received the best nutritional conditions in the nursery showed good performance and was favored in the field. Thus, in the production of quality seedlings, the use of containers of the type polypropylene tubes with 180 cm3, and basic fertilization with 12 g L-1 of CRF conditions that enable growth of H. heptaphyllus in the field are recommended.