Magdi Ahmed Ibrahim Aloufa

Efeitos de citocininas sobre a anatomia foliar e o crescimento de Annona glabra L. durante o cultivo in vitro e ex vitro

The effect of different sources of cytokinins during the in vitro cultivation of A. glabra on anatomical characteristics of leaves and plant growth was evaluated in this work. BAP (6-benzilaminopurine) and KIN (kinetin) induced an increase in leaf mesophyll thickness, while the ZEA (zeatin) promoted an increase in density and stomatic index and development of leaves vascular system. The utilization of KIN and BAP improved higher plant development and survival rate during the acclimatization and rooting phases.

EFEITO DE 6-BENZILAMINOPURINA SOBRE A PROPAGAÇÃO in vitro DE Mimosa caesalpiniifolia Benth. (Fabaceae)

The Mimosa caesalpiniifolia, popularly known as sabia, is a native species belonging to Caatinga forest that due to its countless potentialities has faced a process of exhaustive exploration that makes imminent the need to use sustainable alternatives to its replacement in natural environment and the conservation of its genotype. Accordingly, micropropagation has been considered as a promising technique, since it allows the production of seedlings in large scale and high. The cytokinins, such as 6-benzylaminopurine (BAP), are important in this process, since they influence considerably the growth and morphogenesis in vitro morphogenesis allowing the formation on in vitro germplasm banks. The aim of this study was to investigate the influence of different concentrations of BAP on in vitro budding induction of M. caesalpiniifolia. Cotyledon segments obtained from in vitro germinated seedlings were inoculated in WPM supplemented with six BAP concentrations: 0.0; 4.44; 8.88; 17.76; 26.64 and 35.52 µmol/L. The experimental design was randomized with 6 treatments, 3 replications and each replication consisting of 10 experimental units. After 30 days, the following parameters have been evaluated: number of responsive explants, number of sprouts per explant and presence of callus, oxidation and contamination. The data were statistically analyzed by Correspondence Analysis and through adjusting Regression Equations. It was found that the concentration of 17.76 µmol/L was more responsive with regard to multiplication rate and sprouts number. In this case, is the most suitable concentration for the in vitro propagation of M. caesalpiniifolia.

O efeito do bap (6-benzilaminopurina) sobre a indução de brotos em explantes de pau-brasil

A Mata Atlântica brasileira foi intensamente degradada, restando hoje cerca de 7% a 8% de sua area original, indices que tornaram crescente a preocupacao com a conservacao, principalmente, a dos especimes em extincao. Ao todo, sao 276 especies de arvores e arbustos ameacados e, dentre esses, a pesquisa em questao optou por estudar alternativas de resguarde ao Pau-Brasil (Caesalpinia echinata Lam.). Nesse sentido, a maioria dos estudos desenvolvidos, ou avalia o efeito das citocininas sobre a inducao de calogenese, ou preocupa-se em aperfeicoar metodologias de criopreservacao. Visando a ampliar a gama de conhecimentos em relacao as tecnicas biotecnologicas que viabilizam a conservacao da C. echinata, no presente trabalho avaliou-se o efeito do 6-benzilaminopurina (BAP) e do tipo de explante sobre a inducao de brotacoes em Pau-Brasil. Para isso, os explantes foram inoculados em meio MS basico e em MS suplementado com 2,5; 3,5; e 4,5 µM de BAP e mantidos em sala de crescimento, durante 40 dias sob condicoes controladas de fotoperiodo e temperatura. O delineamento fatorial adotado foi o 2x4, com tres repeticoes. As variaveis analisadas foram o percentual de brotacoes, calogenese e oxidacoes, sendo suas medias comparadas por Tukey a 5% de probabilidade. Os resultados mostraram que houve influencia significativa do BAP apenas na inducao de brotacoes e do tipo de explante nessa e nas demais variaveis. Dessa forma, concluiu-se que, in vitro, o explante do tipo nodal e mais responsivo a acao do BAP e que a concentracao de 2,5 µM e a indicada para induzir brotacoes em Pau-Brasil.

Efeito de diferentes meios de cultura na germinação in vitro de sementes de mangabeira (Hancornia speciosa Gomes)

Mangabeira, belonging to the family Apocynaceae, is a native species of the Cerrado and coastal plains, known for its importance in the social, economic and cultural spheres. This study aimed to evaluate the effect of different culture media on the in vitro germination of seeds of mangabeira, to contribute scientifically with the knowledge related to this species. The treatments used were: T1 - vermiculite (+40 mL of water); T2 - vermiculite + sand (1:1 + 40 mL of water); T3 - vermiculite + clay (1:1 + 40 mL of water); T4 - vermiculite + basic MS (40 mL); T5 - vermiculite + ½ MS (40 mL); T6 - sand (+40 mL of water); T7 - clay (+40 mL of water); T8 - sand + clay (1:1 + 40 mL of water). It was set up an experiment with eight treatments including eight replications with 80 seeds per treatment. The following variables were analyzed: percentage of seedling emergence, seedling emergence average time and speed index of germination. The experimental design was completely randomized and the averages were compared by Tukey test at 5% of significance. There were significant differences for the germination percentage, T3 being statistically superior, and for the GSI, with the best result, treatments T1, T2 and T3. Moreover, the values of average time of germination did not differ significantly. According to our results, we can conclude that the treatments provided with vermiculite and combinations, T1, T2 and T3 exert positive influence on the emergence of Hancornia speciosa Gomes.

Influência da luz na germinação in vitro de sementes de tamareira (Phoenix dactylifera L.)

Date tree (Phoenix dactylifera L.) is a palm (Arecaceae) that produces nutritious fruits and has notable importance for many countries of the North of Africa, the Middle East and Eastern Asia. Due to the botanical characters and for the development in hot and barren regions and diverse types of soil, the date becomes an excellent option for the Brazilian Northeast. This study had as objective to study the seed germination of date palm cv. Khadrawy, being focused the photoblastic behavior of the seeds. The seeds were submitted to continuous dark and photoperiod of 12 hours. The experimental design used was completely randomized with four replicates of 25 seeds. Percentage and speed of germination were evaluated. Seed germination occurred in the presence of light and the dark, however the speed of germination was significantly higher in seeds submitted to continuous dark. The results allowed to classify the date palm seeds cv. Khadrawy as indifferent to light for germination.

Relative planting times on the production components in sesame/cowpea bean intercropping in organic system

Aiming at better land use, small farmers usually plant sesame and cowpea bean intercropped with other crops. The aim of this work was to analyze and quantify the influence of four relative planting times of the cowpea bean in intercropping with sesame from the standpoint of their production components, plant productivity and the index of land equivalent ratio (LER). The field experiment was conducted in a randomized blocks with four treatments and four replicates. The treatments were the sesame and the cowpea bean in intercropping with the cowpea bean planted at the same time, 7, 14 and 21days after than the sesame. A greater part of the production components of both the sesame as well the cowpea bean was affected by the intercropping and significant differences were noted among the treatments in a larger part of the parameters. As the planting of the cowpea bean became more distant from that of the sesame, the yield of the Pedaliaceae increased and the yield of the Fabaceae decreased. The results for LER findings on the other hand suggest that in the sesame/cowpea bean intercropping, when the Fabaceae is planted seven days after the sesame, there is better use of the land and a largest possibility to the producer earning a profit.