Performance of vertical and horizontal treatment wetlands planted with ornamental plants in Central Chile: comparative analysis of initial operation stage for effluent reuse in agriculture.

This study comparatively evaluated effluent reuse from two TWs-a horizontal subsurface flow (HF) and a vertical subsurface flow (VF)-used for rural wastewater treatment in Central Chile during the initial operation stage. The two TWs were planted with Zantedeschia aethiopica and were operated for 10 months at a pilot scale. The water quality of the influent and effluents was measured and compared with reuse regulations. The results showed similarities in the behavior of the effluents from the two TWs, presenting differences only in the chemical oxygen demand (COD) and different forms of nitrogen, suggesting the necessity of complementary treatment stages or modifications to the operation. The effluents from the HF better fulfilled the reuse standards for irrigation, as the VF faced problems associated with its size. However, a complementary disinfection system is necessary to improve pathogen removal in the effluents coming from the two TWs, especially to be reused as irrigation water for crops. Finally, this work showed the potential for applying subsurface TWs for wastewater treatment in rural areas and reusing their effluents as irrigation water, practice that can contribute to reducing the pressure on water resources in Chile, and that can be used as an example for other countries facing similar problems.

Exogenous applications of gibberellic acid modulate the growth, flowering and longevity of calla lily.

Calla lily (Zantedeschia aethiopica (L.) Spreng.) is an important ornamental crop used in garden landscapes, floral arrangements, and medicinal applications. Gibberellic acid (GA3) is actively involved in cell elongation, growth, physiology, and flowering. In addition, it is an environmentally-friendly compound which can be applied to plants to increase the ornamental production. Therefore, the present study was designed with three GA3 spray times viz., single, double and triple spray and five exogenous applications of gibberellic acid concentrations viz., 0, 25, 50, 100, and 200 mg L-1 with factorial randomized block design. Results revealed that the interaction effect of combinations of two time applications of GA3 at 100 mg L-1 induced higher growth parameters over control. Significantly higher physiological parameters viz., photosynthetic rate (14.3 µmol m-2s-1), number of stomata (26.5 mm-2), stomatal conductance (0.28 mmol m-2s-1), and transpiration rate (3.6 mmol m-2s-1) were reported when plants were treated twice with 100 mg L-1 GA3. Similarly, among flowering traits, days to flower were significantly low in plants treated two-time spray at GA3 100 mg L-1 (169.8 days). The number of flowers in the double spray at GA3 100 mg L-1 treatment increased by 11.3 and 23.7% over triple spray and control, respectively. Vase life was also significantly higher in plants treated with double spray at GA3 100 mg L-1 (6.3 days). The regression equation and correlation matrix indicated a strong relationship between growth, flowering and GA3 concentrations up to 100 mg L-1. The PCA analysis revealed that the calla lily crop is positively affected by spray timing and GA3 treatments. In the context of vegetative, reproductive, and longevity parameters of the crop, a dual spray of 100 mg L-1 GA3 can be recommended to small scale farmers and commercial growers as an alternative technique for promoting growth, yield and improving the ornamental value for commercial level production.

Root-Associated Microbiomes, Growth and Health of Ornamental Geophytes Treated with Commercial Plant Growth-Promoting Products.

The microbial community inhabiting a plant's root zone plays a crucial role in plant health and protection. To assess the ability of commercial plant growth-promoting products to enhance the positive effects of this environment, two products containing beneficial soil bacteria and a product containing plant extracts were tested on Zantedeschia aethiopica and Ornithogalum dubium. The products were tested in two different growing media: a soil and a soilless medium. The effects of these products on Pectobacterium brasiliense, the causal agent of soft rot disease, were also evaluated in vitro, and on naturally occurring infections in the greenhouse. The growing medium was found to have the strongest effect on the microbial diversity of the root-associated microbiome, with the next-strongest effect due to plant type. These results demonstrate that either a single bacterial strain or a product will scarcely reach the level that is required to influence soil microbial communities. In addition, the microbes cultured from these products, could not directly inhibit Pectobacterium growth in vitro. We suggest density-based and functional analyses in the future, to study the specific interactions between plants, soil type, soil microbiota and relevant pathogens. This should increase the effectiveness of bio-supplements and soil disinfestation with natural products, leading to more sustainable, environmentally friendly solutions for the control of bacterial plant diseases.

A systemic response of geophytes is demonstrated by patterns of protein expression and the accumulation of signal molecules in Zantedeschia aethiopica.

In geophyte plants, such as Zantedeschia, individual leaves are directly connected to a specialized underground storage organ (rhizome/tuber), raising a question regarding systemic resistance as a mechanism of defense. A systemic response requires a transfer of a signal through the storage organ which has been evolutionary adapted to store food, minerals and moisture for seasonal growth and development. We have characterized the nature of induced defense responses in Zantedeschia aethiopica, a rhizomatous (tuber-like) ornamental plant by the application of local elicitation using two well-known defense elicitors, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) and methyl jasmonate (MJ). The system consisted leaves in which local responses were directly induced, and systemically responsive leaves in which defense molecules were detected, demonstrating a transported vascular signal. Using anatomical and biochemical tools and local elicitation with MJ, the systemic nature of the response was verified in adjacent leaves by unique protein expression patterns; similarly polyphenol oxidase (PPO) activity was found to increase systemically in all parts of the locally induced plants, including the rhizome, and adjacent leaves; finally, significant accumulation of defense signal molecules such as salicylic and jasmonic acids was recorded in local and systemic leaves following elicitation with BTH. Anatomical sections through the leaves and the rhizome revealed that to be transferred from one leaf to its neighbor, signal molecules must have been transferred through the storage organ. The collected data strongly support our hypothesis that defense signals may and are transferred through the storage organ in monocot geophytes.

Calla lily inflorescences postharvest: pulsing with different sucrose concentrations and storage conditions / Conservação pós-colheita de inflorescências de copo-de-leite: pulsing com diferentes concentrações de sacarose e condições de armazenamento

Calla lily is an appreciated specie used for flower arrangements. In spite of its commercial importance, there is little information on calla lily postharvest conservation. Thus, this study aimed to determine the best sucrose concentration for pulsing and cold storage conditions to extend calla lily postharvest durability. Flower stalks were submitted to a pulsing pre-treatment using 2, 4, 8, 12 and 16 percent sucrose in the solution, for one hour, plus a treatment with direct storage in cold chamber (4ºC), without a prior-treatment. Dry storage or storage in solution with the commercial product Flower® was also tested. A completely randomized design was used with four replicates and three inflorescences per plot. Spathe length and width were daily measured from which the opening and wilting processes were analyzed. It was observed that pulsing with sucrose was efficient in extending calla lily inflorescences opening process and durability. Dry storage for short periods (less than six days) can also be used, but a prior-treatment with 12 percent sucrose pulsing for one hour or with a water supply for the same period was required. For storage in solution, a pulsing with 5 percent or 7.5 percent sucrose was recommended.

Copo-de-leite é uma espécie apreciada para uso em arranjos florais. Apesar da sua importância comercial, há pouca informação sobre a conservação pós-colheita de copo-de-leite. Dessa forma, neste estudo, objetivou-se determinar a melhor concentração de sacarose para pulsing e condições de armazenamento a frio para estender a durabilidade pós-colheita de copo-de-leite. Hastes florais foram submetidas a pré-tratamento (pulsing), usando 2, 4, 8, 12 e 16 por cento de sacarose na solução, por 1 hora, mais um tratamento de armazenamento direto em câmara fria, sem pré-tratamento. Armazenamento a seco ou em solução com produto comercial Flower® foram também testados. Foi utilizado o delineamento experimental inteiramente casualizado com quatro repetições e três inflorescências por parcela. O comprimento e largura da espata foram medidos diariamente, sendo a partir desses, analisado o processo de abertura e senescência floral. Foi observado que o pulsing com sacarose foi eficiente para estender o processo de abertura e durabilidade de inflorescências de copo-de-leite. O armazenamento a seco por curto período (inferior a 6 dias) pode também ser utilizado, mas um pré-tratamento (pulsing) com 12 por cento de sacarose por 1 hora ou manutenção em água pelo mesmo período é necessário. Para armazenamento em solução, é recomendado o pulsing com 5 por cento ou 7,5 por cento de sacarose.

Development and dry mass accumulation in callalily at the initial cultivation stage / Desenvolvimento e acúmulo de massa seca em copo-de-leite em fase inicial de cultivo

The cultivation of the calla lily, despite its importance in the floriculture sector, is still limited due to the lack of knowledge of basic production techniques such as development and dry mass accumulation. These techniques facilitate more appropriate management, especially regarding the application of fertilizers, providing better nutrients utilization and greater yields. Thus, this study was aimed at evaluating the growth and development of calla lily plants, establishing growth curves according to dry mass accumulation. Acclimatized and micropropagated calla lily plantlets were grown in plastic pots containing coconut fiber as a substrate and fertilized with a modified formula of Malavolta. Treatments consisted of assessments at intervals of 30 days for 7 months. The design was in randomized blocks with four replications, in a total of 28 plots. Plants were evaluated by observing their growth characteristics and development of shoots, rhizome, roots, as well as production and flower quality. Development of the plants increased throughout the experimental period, with the maximum dry mass accumulation occurring at the end of the experimental period. Blooming was constant with the length of flower stalks increasing with along with the age of the plant.

O cultivo de Zantedeschia aethiopica, apesar de sua importância no segmento da floricultura, ainda é limitado pelo reduzido conhecimento em técnicas básicas de produção, como o desenvolvimento e acúmulo de massa seca. Essas informações permitem um manejo mais adequado, sobretudo referente à aplicação de fertilizantes, proporcionando melhor aproveitamento de nutrientes e maiores produções. Dessa forma, neste estudo, objetivou-se avaliar o crescimento e desenvolvimento de plantas de copo-de-leite, estabelecendo curvas de crescimento, considerando o acúmulo de massa seca. Para tanto, mudas micropropagadas e aclimatizadas de copo-de-leite foram cultivadas em vasos plásticos contendo como substrato fibra de coco e adubadas com a formulação modificada de Malavolta. Foram realizadas avaliações com intervalos de 30 dias, durante 7 meses, nos quais consistiram os tratamentos. O delineamento utilizado foi em blocos casualizados, com 4 repetições, totalizando 28 parcelas. As plantas foram avaliadas quanto às características de crescimento e desenvolvimento da parte aérea, rizoma, raízes, além de produção e qualidade das inflorescências. O desenvolvimento das plantas de copo-de-leite foi crescente ao longo do período experimental, sendo que o máximo acúmulo de massa seca total ocorreu ao final do período analisado. O florescimento foi constante com aumento do comprimento das hastes florais proporcional à idade das plantas.

Doses de boro no desenvolvimento de copo-de-leite em solução nutritiva / Boron doses in the development of calla lily in nutrient solution

O boro desempenha funções importantes em processos biológicos das plantas, como a síntese e estruturação da parede celular, lignificação, metabolismo e transporte de carboidratos, além de participar da divisão e diferenciação celular em tecidos meristemáticos. No entanto, as necessidades nutricionais para o cultivo de copo-de-leite, especialmente de boro, ainda são pouco conhecidas. Assim, objetivou-se avaliar os efeitos de diferentes doses de boro no crescimento e desenvolvimento, teor e acúmulo desse nutriente em plantas de copo-de-leite cultivadas em solução nutritiva. Mudas micropropagadas foram submetidas aos tratamentos com as doses de 0,05; 0,25; 0,50; 0,75; 1,00 e 2,00 mg L-1 de boro em solução nutritiva de Hoagland & Arnon diluída a 30 por cento de sua força iônica. O delineamento experimental foi o inteiramente casualizado, com dez repetições. As plantas não manifestaram sintomas visuais de deficiência ou de toxidez de boro, no entanto, o sistema radicular das plantas cultivadas na dose de 0,05 mg L-1 de boro apresentou-se com o crescimento reduzido. A melhor dose para o desenvolvimento adequado de plantas de copo-de-leite em solução nutritiva é de 1,20 mg L-1 de boro.

Boron has essential functions in plant biological processes such as cell wall synthesis and structuralization, lignification, carbohydrates metabolism and transport. This element also acts in cell division and differentiation in meristematic tissues. However, the nutritional needs for calla lily cultivation, and especially boron needs, are still poorly known. Thus, the objective of this work was to evaluate the effects of different boron doses on growth and development, content and accumulation of boron in calla lily plants grown in a nutrient solution. Micropropagated seedlings were submitted to treatments with the doses 0.05; 0.25; 0.50; 0.75; 1.00 and 2.00 mg L-1 boron in Hoagland & Arnon nutrient solution diluted to 30 percent of its ionic force. The experimental design used was completely randomized blocks with ten replicates. Plants showed no visual deficiency or toxicity symptoms, however, the root system of plants cultivated in 0.05 mg L-1 boron showed reduced growth. The best development of calla lily plants was observed in 1.20 mg L-1 boron in nutrient solution.

Multiplicação in vitro de copo-de-leite: espectros de luz e sacarose / Calla lily in vitro multiplication: spectrum of light and sucrose

O espectro luminoso pode alterar a morfogênese das plantas por meio de uma série de processos mediados por receptores de luz, principalmente na região do vermelho e azul. O objetivo deste trabalho foi determinar um possível tipo de luz mais ativo que a luz branca, de forma a aumentar a eficiência da multiplicação in vitro de copo-de-leite e obter um nível ótimo de sacarose. Para isso, os tratamentos consistiram em quatro diferentes tipos de luz, sob os quais os explantes cresceram (branca, vermelha, azul e verde), fornecidos pelo espectro luminoso das lâmpadas fluorescentes coloridas T8 20W Ecolume 05/1 e sacarose (0; 15; 30; 45 e 60g L-1). O meio de cultura constituiu-se dos sais e das vitaminas de MS, adicionado de 5mg L-1 de BAP e 5,5g L-1 de ágar. O tipo de luz não influencia a multiplicação in vitro de copo-de-leite, e o maior número de brotos (2,0) é obtido em 45g L-1 de sacarose. Observou-se maior número de folhas em luz branca (3,8) e azul (2,9), com 15 e 60g L-1 de sacarose, respectivamente. Maior comprimento dos brotos (3,7cm) foi observado em 60g L-1 de sacarose, e maior fitomassa fresca da parte aérea (1,07g) foi observada com a utilização de 60g L-1 de sacarose.

Light spectrum can modify plant morphogenesis through a number of processes mediated by light receptors, mainly in the red and blue region. The aim of this work was to determine a possible light type more active than the white light, and an optimized sucrose concentration, in order to increase the efficiency of the calla lily in vitro multiplication . To that end, the treatments consisted of four different light types (white, red, blue and green), under which the explants grew, supplied by colored T8 20W Ecolume 05/1 fluorescent lamps and various sucrose concentrations (0; 15; 30; 45 and 60g L-1). The culture medium contained MS salts and vitamins, added of 5mg L-1 BAP and 5.5g L-1 agar. The light type did not influence in vitro propagation of calla lily and there were a higher number of sprouts (2.0) in 45g L-1 of sucrose. There was higher number of leaves in white (3.8) and in blue light (2.9) with 15 and 60g L-1 of sucrose, respectively. Higher length of sprouts (3.7cm) was observed in 60g L-1 of sucrose and higher fresh weight of the aerial part (1.07g) in 60g L-1 of sucrose.

Pós-colheita de copo-de-leite: efeito de diferentes conservantes comerciais e armazenamento a frio / Calla lily postharvest: effect of different commercial preservative solutions and cold storage

As inflorescências de copo-de-leite, apesar de bastante utilizadas na composição de arranjos florais, apresentam pequena durabilidade. Com o objetivo de analisar a qualidade e o processo de abertura e murcha de inflorescências de copo-de-leite após a colheita, avaliaram-se o efeito de diferentes conservantes florais e sistemas de armazenamento. Para o experimento estudaram-se duas condições de armazenamento em câmara fria a 4ºC: a seco ou em solução com os conservantes comerciais Crystal Clear®, Flower®, Original Floralife® e o pré-tratamento com Hydraflor-100®. O armazenamento em solução, com os conservantes estudados, não influenciou o processo de abertura e murcha das inflorescências de copo-de-leite, dentro e fora da câmara fria. Também não houve diferença, entre os produtos testados, para melhorar a conservação das inflorescências, quando estas foram retiradas da câmara fria. O período de armazenamento por 10 dias com os tratamentos utilizados não foi eficiente, pois apesar da qualidade das inflorescências, observada dentro da câmara fria, quando estas foram retiradas, não apresentaram durabilidade para comercialização. O armazenamento a seco foi eficiente quando se realizou o pré-tratamento com Hydraflor-100®, entretanto, as inflorescências apresentaram maior longevidade total quando armazenadas em solução.

Inflorescences of calla lily have reduced durability after harvest despite their constant use in the composition of floral arrangements. With the objective to analyze the postharvest quality and the process of opening and wilt of calla lily, the effect of different floral conservers and storage systems were evaluated. Two storage conditions in a cold chamber at 4º C, dry or solution containing the commercial preservative Crystal Clear®, Flower®, Original Floralife® and pre-treatment with Hydraflor-100® were studied. The storage in solution with conservers had no influence on the opening and closure of inflorescence, despite its maintenance inside or outside the cold chamber. No difference was observed on the inflorescence conservation when their removal from the cold chamber regarding the different products tested. Inflorescences stored for 10 days on all tested treatments presented no commercial durability, after their removal, despite their quality inside the cold chamber. Dry storage was efficient using the pre-treatment with Hydraflor-100®; however, the inflorescences presented higher longevity when stored in solution.