In vitro effects of regulators on growth and morphogenesis of Ocimum basilicum L. ‘Alfavaca Green’ stem apexes

Large-scale cultivation of contamination free plants requires a good standardization protocol and production methods. Basil is widely used for cosmetics, food and pharmaceutical industries as it is rich in many bioactive compounds. This present study aimed to evaluate the growth and in vitro anatomical aspects of apical buds of basil grown under different concentrations rowth regulators like: NAA (Naphthalenoacetic Acid), BAP (6-benzylaminopurine), and KIN (Kinetin). The in vitro establishment was evaluated every 20 days to calculate the, the percentage of plants with calluses, appearance of the roots, any abnormal seedlings, any oxidized seedlings, and the number of sprouts per plant. Growth, physiological, and morpho-anatomical evaluations were performed at 80 days. Basal callogenesis was observed when cytokinin’s and auxins are used in combination. Auxin treatments caused hyperhydricity in the stems and leaves. Medium A2 (0.05 mg L -1 of NAA and 0.1 mg L -1 of BAP), and A3 (0.05 mg L -1 of NAA and 0.1 mg L -1 of KIN) resulted in the best development of basil plants, cultivar ‘Alfavaca Green’. The A2 produced plants with greater numbers of leaves, an average bud length of 59.81 mm, and the best root properties. A2 and A1 have a higher percentage of hyperhydricity (83 and 67%). The A3 resulted in an acceptable number of leaves (range: 21–39), and this treatment produced the best shoot properties as well as fewer plants with hyperhydricity. In addition, the A3 treatment produced plants with a shoot length, high shoot fresh and dry mass (2.82 and 0.23 g), high chlorophyll index and leaf anatomy that was similar to the control. Excluding the control, the other treatments presented more than 90% of the explants with calluses in their bases

Copper modulates the biochemical and enzymatic activity and growth of tomato cultivars grown in vitro

Received: August 25th, 2020 ; Accepted: December 17th, 2020 ; Published: February 09th, 2021 ; Correspondence: [email protected] (Cu) is a micronutrient that is neglected for tomato growth. This study sought to identify the effects of exposure to Cu on the growth and biochemical activity of two tomato cultivars. Tomato seeds of ‘Carolina’ and ‘Cereja’ cultivars were disinfected and inoculated in MS medium plus copper sulfate concentrations (CuSO4) (default MS, 25, 50, and 100 µm) and had their growth monitored for 30 days. It was estimated that the growth and biomass accumulation of tomato plants ‘Carolina’ and ‘Cereja’, both from the aerial part and the roots, were benefited by 25 e 50 µm of CuSO4. However, it was observed that these concentrations were inefficient in controlling hyperhydricity and leaf deformation. There was a reduction of these phenomena in the treatment with 100 µm, in both cultivars. Tomato of ‘Carolina’ cultivar subjected to 100 µm showed an increase in anthocyanins and superoxide dismutase (SOD) activity in the root system. There was a reduction of catalase (CAT) activity in shoots exposed to Cu. ‘Cereja’ tomatoes subjected to 100 µm showed an increase in CAT and SOD activity in shoots and roots, respectively. It was concluded that the ‘Carolina’ and ‘Cereja’ tomatoes have their growth impaired when exposed to 100 µm CuSO4. Concentrations higher than 50 µm of CuSO4 cause an increase in the antioxidant activity in the shoot of tomato plants from the ‘Carolina’ cultivar. Concentrations higher than 50 µm CuSO4 increase SOD activity in the root system of tomato plants from the ‘Cereja’ cultivar

Embryonic dormancy in seeds of Bactris gasipaes Kunth (peach-palm)

Bactris gasipaes is a domesticated palm whose fruits are of great importance for the Amazonian people and whose heart of palm is also receiving economic interest in other brazilian and Latin America regions. The aim of this study was verify embryonic dormancy and its correlation with first cataphyll emergence in B. gasipaes seeds collected from four plants at Manaus city and four others at Coari city, both in the Amazonas state, Brazil. After extraction and cleaning, some of the seeds (4 replications of 25 per plant) were sown in a seedbed with a sawdust and sand mixture as substrate, and embryos (4 replications of 10 per plant), after extraction, were inoculated into half strength Murashige and Skoog cultures. Were used 100 seeds and 40 embryo per treatment. Whole seed and embryo germination varied between the different source plants and locations, with the greatest difference observed for the emergence of first cataphyll from seeds in the seedbed. For the most part of variables, results of seed and embryo were positively associated, namely, as one went up the other also, and vice versa. These results suggesting that, at least in part, seed dormancy in Bactris gasipaes is associated with embryonic dormancy. © 2017, Associacao Brasileira de Tecnologia de Sementes. All rights reserved

Avaliação da embebição e do desenvolvimento inicial das estruturas embrionárias de sementes de milho submetidas a diferentes potenciais hídricos

Substrates with water potentials between O and -12atm, were used to evaluate the behavior of corn seeds during the germination process. Water deficiency treatments were compared with the control (adequate available water) using seeds with and without fungicide treatment. The analysis and the interpretation of the results permitted to conclude that the absorption of water, the emergency and the initial development of the embryonic structures are interdependent and vary with the water deficit. For these cases the reduction of water potential promotes difficulties in the evolution of the processes. The presence of fungicide treatment may not influence quantitatively the processes occurring in the beginning of the germination.Empregando substratos com potenciais hídricos variáveis entre 0 e -12atm, o presente trabalho objetivou avaliar o comportamento das sementes de milho postas a germinar. As situações de deficiência hídrica foram diretamente comparadas à testemunha (plena disponibilidade de água), usando sementes com e sem tratamento fungicida. A análise e a interpretação dos resultados permitiram concluir que a absorção de água, a emergência e o desenvolvimento inicial das estruturas embrionárias são interdependentes e reagem no mesmo sentido ao déficit hídrico; para esses casos, a redução do potencial hídrico promove dificuldades na evolução dos processos. Paralelamente, a presença de tratamento fungicida pode não influenciar, quantitativamente, os fenômenos envolvidos no início da germinação

Development of corn seedlings after a period of exposition to various water potential

Fungicide treated and untreated corn seeds were sets to germinate under varying water availability conditions (0 to -12atm water potential). The seedlings obtained on each individual treatment were subsequently grown under ideal available water conditions. The results permitted to conclude that the occurrence of a water deficit during the on set of the germination process results in reductions on the length of the embryonic structures, particularly the epicotil. This effect attenuates with times due to the increase in growth velocity in environments where water potential is lower. Fungicid treated seeds, did not appear to be consistently vantageous in environments with water stress.Submetendo sementes de milho com e sem tratamento fungicida, a ambientes de germinação variáveis quanto à disponibilidade de água (0 a -12atm), o presente trabalho avaliou o desenvolvimento posterior das plântulas postas em ambientes sem limitações hídricas. Os resultados obtidos permitiram concluir que a ocorrência de déficit hídrico, durante o início do processo de germinação, promove reduções posteriores no comprimento das estruturas embrionárias e, de forma mais acentuada, do epicótilo; apesar disso, esse efeito se atenua com o passar do tempo pela elevação progressiva na velocidade de crescimento em ambientes que oferecem menores potenciais hídricos. Paralelamente, o tratamento fungicida das sementes pode não trazer vantagens em ambientes hidricamente deficientes; esta afirmação, contudo, considera o papel toalha como meio fornecedor de água o que, em contrapartida, exige cautela na sua extrapolação para as condições proporcionadas pelo solo