2.4-Dichlorophenoxyacetic acid and sucrose in rhizogenesis maintenance and induction in cuttings of cagaita and mangabeira from cerrado

Abstract

The Cerrado has a vast diversity of fruit plant species. Among them, the cagaita and mangabeira trees stand out because of their fruits nutritional potential. They propagate through seeds, a method that generates genetically distinct plants. Thus, it would be of interest to propagate these plants through vegetative propagation techniques aiming to select superior and identical genotypes from the mother plant. Therefore, the objective was to establish a methodology for maintenance, survival, and rooting induction of Eugenia dysenterica and Hancornia speciosa var. pubescens in nutrient solution with different sucrose concentrations added with 2.4-dichlorophenoxyacetic auxin (2.4-D). In the cagaita and mangabeira tree cuttings, five sucrose concentrations were evaluated: 0, 5, 10, 15, and 20% for the first; and 0, 10, 20, 30, and 40 % for the second species. In addition to these, the control was deionized water. To the sucrose solution was added 190 g L-1 NH4NO3, Ca3ClO, K2SO 4, and 3.00 mg L -1 of 2.4-D. We also performed a second test for cagaita tree, which was evaluated different doses of 2.4-D: 0, 0.5, 1.0, 1.5, and 2.0 mg L-1; and control (deionized water). In all experiments, the completely randomized design was used. We collected data on survival, contamination, cuttings with permanent leaves, base oxidation, callus formation, and root starts. In the first cagaita tree experiment, cuttings survival was higher than 80%. In the second trial, the use of 2.4-D did not favor the survival of the cuttings, nor did it promote the formation of root starts. For mangabeira was observed survival values of 100% in all treatments evaluated, and root starts were also found in its herbaceous cuttings.

2,4-Diclorofenoxiacético no enraizamento de estacas lenhosas de figueira

“…Por outro lado, Ferreira e Ferrari (2010) obtiveram enraizamentos médios próximos dos 90% em estacas de atemoieira (Annona cherimola Mill. x A. squamosa L.) tratadas tanto com AIB quanto 2,4-D nas concentrações de 0, 500, 1000, 2000, 3000, 4000 e 5000 mg L -1 durante 5 s. Vieira et al (2020) avaliaram o enraizamento de estacas de mangabeira (Hancornia speciosa var. pubescens) tratadas com soluções de sacarose (0, 10, 20, 30 e 40%) acrescidas de 3 mg L -1 de 2,4-D e constataram que o uso do 2,4-D auxiliou na formação das raízes adventícias, embora tenham sugerido o uso de concentrações mais diluídas deste regulador de crescimento devida a alta taxa de mortalidade de estacas obtida.…”

“…É importante destacar os resultados inferiores promovidos pelo 2,4-D nas características número de raízes e massas fresca e seca de raízes (Tabela 1), pois reforça a teoria de que esta substância pode ter realmente provocado efeito herbicida nas estacas de figueira. Vieira et al (2020) também relataram o possível efeito herbicida do 2,4-D em estacas de mangabeira quando foram tratadas com soluções de sacarose (0, 10, 20, 30 e 40%) acrescidas de 3 mg L -1 deste regulador de crescimento. Tofanelli et al (2014) estudaram o efeito da aplicação do 2,4-D e AIB em estacas de porta-enxertos de videira (Vitis ssp) nas concentrações de 0, 1000, 2000 e 3000 mg L -1 e obtiveram queda no número de raízes por estaca à medida que se aumentava as concentrações de 2,4-D. Já Uyoh et al (2016) destacaram que as concentrações de AIB e 2,4-D (10.000, 30.000 e 50.000 mg L -1 ) quando aplicadas em estacas de inhame da Índia (Dioscorea alata L.) não promoveram os mesmos resultados em relação às também testadas soluções naturais promotoras do enraizamento a base de água de coco ou cinzas de folha de neem nas mesmas concentrações provavelmente porque, conforme os mesmos autores, as concentrações de ambos reguladores de crescimento não favorecerem a formação de raízes no mesmo nível dos enraizadores naturais.…”

Advances and perspectives in the propagation of mangabeira (Hancornia speciosa Gomes) - review on a tropical fruit tree with socioeconomic importance

“…Regarding staking, the study by Soares et al (2020) revealed total mortality of the cuttings, but no anatomical impediments were found for the rooting of the cuttings. Vieira et al (2020) observed a 100% survival of the cuttings, but only with the emission of root primordia. No scientific articles on the propagation of mangabeira by air layering were found in the review.…”

“…• Both herbaceous and woody stem cuttings presented total mortality and lack of rooting, independently of the high concentrations of IAB (indol butyric acid) and the origin of the cuttings. (Vieira et al, 2020;Soares et al, 2020)…”