Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Jason J. Griffin / Heat and drought tolerance make shantung maple (Acer truncatum) and caddo sugar maple (A. saccharum) good candidates for midwestern landscapes. Improving cutting propagation or mound layering techniques could increase the availability of these species. The influence of time of year, cutting position, and auxin concentration, formulation, and solvent on rooting of stem cuttings of shantung maple was investigated. Semi-hardwood cuttings rooted best (55%). Generally, rooting percentage decreased as indole-3-butyric acid (IBA) concentration increased. Cutting position, auxin formulation, and solvent did not affect rooting. Mean root number and mean root length were unaffected by treatments. Results suggest semi-hardwood cuttings and low IBA concentrations [< 2500 ppm (0.25%)] promote rooting. Auxin concentration influenced rooting of caddo and shantung maple mound layered shoots. Rooting peaked at 15,000 ppm (1.5%) IBA for both caddo (71%) and shantung maples (34%). Mean root number for caddo, but not shantung, increased as IBA concentration increased. Differences in mean root length were not significant. Growers may now propagate caddo maple by mound layering. For shantung maple propagation, stem cuttings are recommended. Propagation substrates can strongly influence rooting success of stem cuttings. Eastern redcedar (Juniperus virginiana) chips (ERC) have been suggested as a propagation substrate component. This report investigated ERC as a perlite substitute in a 3 perlite: 1 sphagnum peat moss (v/v) rooting substrate. Stem cuttings of spreading euonymus (Euonymus kiautschovicus), forsythia (Forsythia x intermedia), English ivy (Hedera helix), lantana (Lantana camara), and coleus (Solenostemon scutellarioides) were rooted in substrates containing increasing concentrations of ERC hammer milled to pass a 4.8 mm (0.19 in) screen. All species rooted well (≥95%) in all substrates except forsythia which rooted poorly in all substrates (8% to 36%). ERC did not affect mean root number or mean root length in any species except spreading euonymus where mean root number peaked at 0% and 100% ERC content and mean root length decreased with increasing ERC content. Bulk density, container capacity, and total porosity increased as ERC replaced perlite. Physical properties of all substrates were suitable for cutting propagation. ERC can effectively replace perlite in rooting substrates for many ornamental species.

Synthetic auxin, indole-3-butyric acid (IBA), effectively promoted the rooting in Cinnamomum kanehirae cuttings. The easy-to-root genotype, H107, responded to IBA much earlier than the difficult-to-root genotype, L41. On day 5, the POD activity significantly decreased in the IBA-treated tissues as compared with the control. Similar phenomenon was observed in extract of L41 genotype showing that IBA inhibited POD activity. In addition, the variation in POD activity corresponds to an inverse variation in the concentration of free IAA. The levels of IAA in H107 genotype increased dramatically in IBA-treated tissues on day 5; while, in L41 genotype, the raise of IAA in IBA-treated tissues was observed on day 20. Moreover, the lignin content in IBA-treated H107 cuttings decreased is quite correlated with the decline of the POD activity; yet the lignin content in L41 genotype cuttings was almost unchanged. Hence, we suggest that the inhibition on POD may lead to the redifferentiation processes induced by IBA, then produce the new root primordia during the formation of adventitious roots.

Auxin can induce adventitious rooting. Synthetic auxin, indole-3-butyric acid (IBA), effectively promoted the rooting in Cinnamomum kanehirae. The peroxidase (POX) activity significantly decreased in the IBA-treated tissues as compared with the control. Hence, I suggest that the inhibition on POX activity may lead to the redifferentiation processes induced by IBA, which produces the new root primordia during the formation of adventitious roots. On this investigation, I cloned POX cDNA from the young roots. Degenerate primers were designed from the conservative regions of other published POX to amplify the expectant DNA fragment. Full-length cDNA of the POX gene designated CKPX1 and CKPX3 were cloned by the method of 5'and 3' RACE. The deduced amino acid of CKPX1 and CKPX3 were compared with the previously reported POX and showed between 40% and 60% identity with those plant species. Further studies on the promoter elements of CKPX3 were found out that elements related to auxin response, lignification, pathogen invasion and stress response. The results suggest that CKPX3 may be involved in the regulate process of adventitious rooting and defense against pathogens and environment stress.

Auxin can induce adventitious rooting. Synthetic auxin, indole-3-butyric acid (IBA), effectively promoted the rooting in Cinnamomum kanehirae. In Cinnamomum kanehirae, there are high (H) and low (L) rooting cultivar. The peroxidase (POX) activity significantly decreased in the IBA-treated tissues as compared with the control. The inhibition on POX activity may lead to the redifferentiation processes induced by IBA. In this investigation, we cloned POX cDNA from the young roots. Degenerate primers were designed from the conservative regions of other published POXs to amplify the expectant DNA fragment. We found that the H and L line have similar genes (>99%). The Full-length cDNA of the POX genes were cloned by the method of 5'and 3' Rapid Amplification of cDNA Ends (RACE). The deduced amino acid were compared with the previously reported POX and showed between 40% and 70% identity with other plant POXs. Further studies on the promoter elements of POX in High-rooting cultivar and Low-rooting line show that some elements are related to auxin response, lignification, pathogen invasion and stress response. The regulatory elements of the POX gene in High-rooting line contain sugar repression responsiveness (SRS) elements that might repress the expression of POX gene, causing the lower POX activity.

The nursery/greenhouse industry is innovative. There have been several reports in the popular literature of non-traditional adjuvants used in plant propagation; however, these claims have never been evaluated in a scientific setting. Five studies, conducted at the South Mississippi Branch Experiment Station in Poplarville in 2019 and 2021 determined the impact that adding honey to water-soluble auxin solutions and surfactants to foliar applied auxin solutions on physiological responses associated with adventitious root formation. Treatments in studies presented in chapters two and three included three honey sources (multiflora, local, and Manuka). Honey-infused water-soluble auxin solutions affected plant species but not in the measured physiological responses. Studies presented in chapters four and five examined the impact of water-soluble auxin solutions containing non-ionic surfactants on physiological responses compared to the industry standard basal quick-dip. Like our results for honey, adding surfactants to foliar-applied auxin solutions was species-specific. However, for difficult-to-root species, a foliar auxin application led to similar rooting compared to the current industry standard. For this reason, we recommend a foliar application for rooting Magnolia grandiflora ‘Southern Charm’. Finally, the study presented in chapter six examined the auxin application method, surfactant concentration, and seasonal impacts in rooting challenging to propagate species. The season that cuttings were taken had a significant impact on several of our tested responses. In addition, the auxin application method was also significant. To this end, we can recommend treating fall cuttings with a foliar auxin application for the best results.

Submitted by Marcondes Lopes Leite (marcondesleite@ifma.edu.br) on 2018-07-17T03:02:40Z No. of bitstreams: 1 DISSERTAÇÃO_Marcondes (1).pdf: 855505 bytes, checksum: 87f199a0b3c25e7ac6c9ca3496aaff6b (MD5) / Approved for entry into archive by Karina Gimenes Fernandes null (karinagi@fcav.unesp.br) on 2018-07-17T11:51:19Z (GMT) No. of bitstreams: 1 leite_ml_me.pdf: 825599 bytes, checksum: 98eaa2d4a84e378b555cde009287328e (MD5) / Made available in DSpace on 2018-07-17T11:51:19Z (GMT). No. of bitstreams: 1 leite_ml_me.pdf: 825599 bytes, checksum: 98eaa2d4a84e378b555cde009287328e (MD5) Previous issue date: 2018-05-30 / Outra / PROPAGAÇÃO ASSEXUADA DE FRUTEIRAS DA FAMILIA CLUSIACEA: BACURIZEIRO (Platonia insignis Mart.) E BACUPARIZEIRO (Garcinia gardneriana (Planch & Triana) Zappi). RESUMO As fruteiras bacuri (Platonia insignis Mart.) e bacupari (Garcinia gardneriana (Planch & Triana) Zappi).pertencem à família Clusiaceae e predominam no Norte do Brasil. Estas espécies não são domesticadas e a obtenção de frutos é feita principalmente por meios extrativos sendo raros pomares comerciais. Para à propagação por estaquia do bacurizeiro, ramos jovens foram retirados de uma planta matriz e as estacas foram obtidas como: i. estacas lenhosas, ii. estacas herbáceas com duas folhas e duas gemas na base e iii. estacas herbáceas com duas folhas, sem gemas na base. As estacas foram tratadas com ácido indol butírico (AIB) nas seguintes concentrações: 0.0 (controle), 1.000, 2.000, 3.000 e 4.000 mg.L-1. As estacas lenhosas apresentaram a maior taxa de sobrevivência (95,83%) em relação as estacas herbáceas (70 e 67,5%), sendo que em apenas uma dessas foi observado o desenvolvimento radicular (0,28%). Em relação ao bacuparizeiro, como o estiolamento tem sido utilizado para melhorar o enraizamento em espécies de difícil propagação e como não foram encontrados relatos sobre o uso de estacas estioladas para propagar esta espécie, o objetivo deste estudo foi avaliar a viabilidade dessa técnica de propagação e estudar o efeito de diferentes doses de AIB. As estacas estioladas continham um par de folhas (~12 cm de comprimento) e foram tratadas com AIB por 10 segundos (0 – controle, 500, 1.000 e 2.000 mg.L-1). O estiolamento resultou em 2,5% de estacas enraizadas quando tratadas com 500 e 1.000 mg.L-1 de AIB. O tratamento com IBA afetou a sobrevivência das estacas na fase de propagação, possivelmente ao reduzir a retenção foliar quando estas foram tratadas com concentrações de IBA superiores a 1.000 mg.L-1. Os experimentos foram realizados no outono-inverno, estes devem ser repetidos na primavera-verão, pois espécies neotropicais requerem clima quente e úmido para seu desenvolvimento. / Bacuri (Platonia insignis Mart.) and bacupari (Garcinia gardneriana (Planch & Triana) Zappi.) fruit trees belong to the Clusiaceae family and they predominate in the North of Brazil in the Amazonia basin. These species are not domesticated and fruit are obtained mainly by extractive means due to the inexistence of commercial orchards. To propagate bacuri by cutting, young branches were taken from an matrix bacuri tree and cuttings were obtained as: i. hardwood cuttings, ii. herbaceous stem cuttings with two leaves and two buds on the base, and iii. herbaceous stem cuttings with two leaves without buds on the base. Cuttings were treated with indolbutyric acid (IBA) in the following concentrations: 0,0 mg.L-1 (control), 1,000 mg.L-1 , 2,000 mg.L-1 , 3,000 mg.L-1 , and 4,000 mg.L-1 . The hardwood cuttings presented the biggest survival rate (95.83%) in relation to the herbaceous stem cuttings (70%, 67.50%), and in only one of this cutting was observed root development (0.28%). Regarding bacupari, as etiolation has been used to improve rooting in species which are difficult to propagate and as there is no reports regarding the use of etiolate cuttings to propagate this species, the objective of this study was to evaluate the feasibility of this technique to propagate bacupari and to study the effect of the different doses of IBA. Etiolate cuttings contained on pair of leaves (~12 cm long), and were treated with IBA for 10 seconds (0,0-control, 500, 1,000, and 2,000 mg.L-1 ). Etiolation resulted in 2.5% rooted cuttings when treated with 500 and 1,000 mg.L-1 IBA. The IBA treatment affected the cuttings surviving the propagate phase possibly by reducing the foliar retention when treated with IBA concentrations superior than 1,000 mg.L-1 . The experiments were set during the autumn-winter season, they should be repeated in the spring-summer season as these species require hot and humid climate to develop.