Purple Lettuce Research Articles

Pest and natural enemy: how the fat bodies of both the southern armyworm Spodoptera eridania and the predator Ceraeochrysa claveri react to azadirachtin exposure.

The effects of biopesticides on insects can be demonstrated by morphological and ultrastructural tools in ecotoxicological analysis. Azadirachtin-based products are widely used as biopesticides, affecting numerous insect populations. Through morphological biomarkers, this study aimed to characterize the fat bodies of both the southern armyworm Spodoptera eridania and the predator Ceraeochrysa claveri after chronic exposure to azadirachtin. Larvae of S. eridania and C. claveri were fed with fresh purple lettuce leaves (Lactuca sativa) and egg clusters of Diatraea saccharalis treated with azadirachtin solution of 6mg active ingredient (a.i.)/L and 18mg a.i./L for 7days, respectively. The biological data showed a significant reduction in survival and body mass in S. eridania and cytotoxic effects in the parietal and perivisceral fat bodies in both species. Ultrastructural cell damage was observed in the trophocytes of both species such as dilated cisternae of the rough endoplasmic reticulum and swollen mitochondria. Trophocytes of S. eridania and C. claveri of the parietal and perivisceral layers responded to those injuries by different cytoprotective and detoxification means such as an increase in the amount of cytoplasmic granules containing calcium, expression of heat shock protein (HSP)70/HSP90, and development of the smooth endoplasmic reticulum. Despite all the different means of cytoprotection and detoxification, they were not sufficient to recover from all the cellular damages. Azadirachtin exhibited an excellent performance for the control of S. eridania and a moderate selectivity for the predator C. claveri, which presents better biological and cytoprotective responses to chronic exposure to azadirachtin.

甘肃河西地区制种紫叶莴笋菌核病的发生与防治

甘肃河西地区制种紫叶莴笋菌核病的发生与防治

Effects of light quality ratio on photosynthetic characteristics and quality of purple lettuce

To explore the effects of different light quality ratios on the growth and development of purple lettuce, we used LED intelligent light control console as light source to study the effects of adding different proportions of red and blue light (1:1, 2:1, 4:1 and 1:2) to the white light on photosynthetic characteristics and commercial quality of purple lettuce (Lactuca sativa L. cv 'Zhongshu Purple Lettuce'). The results showed that when the ratio of red to blue light was 4:1, the chlorophyll content, RuBP carboxylase activity, electron transport efficiency of photosynthesis, net photosynthetic rate and growth were all significantly higher than that in control and other treatments, whereas the nitrate content was the lowest. When the ratio of red to blue light was 1:2, the contents of soluble protein, vitamin C, secondary metabolites such as anthocyanins, flavonoids, total phenolic compounds, and the contents of antioxidant capacity were significantly higher than those in the control and other treatments. We concluded that adding appropriate ratios of red to blue light to the white light could increase photosynthesis and improve commercial quality of purple lettuce.

Production of lettuce with brackish water in NFT hydroponic system

Groundwater reserves in the semi-arid regions, which are mostly brackish, could be used to meet local water demands. Hydroponic cultivation is an alternative of rational use of water. Thus, the objective of this work was to evaluate the technical feasibility of using brackish groundwater in the semi-arid region of Bahia and Recôncavo of Bahia for hydroponic production of curly lettuce cv. ‘Verônica’ and purple lettuce cv. ‘Quatro Estações’. The experiment was conducted in a greenhouse in the city of Cruz das Almas, Bahia State, in a randomized block experimental design, composed of seven treatments [T1- public-supply water; T2- water from the well of UFRB; T3- reject water from the well of Cruz das Almas; T4- water from the well of Sapeaçu; T5- reject water from the well of Sapeaçu; T6- reject water from the well of Conceição do Coité and T7- artificially salinated water (NaCl)] and six replicates in an experimental hydroponic structure using the nutrient film technique (NFT). The following variables were analyzed: number of leaves, shoot fresh matter, shoot length, root length, shoot dry matter, and root dry matter. Relative shoot dry matter production in curly lettuce increased by 1, 5, and 2% in the treatments T2, T3, and T4, respectively, whereas in purple lettuce, the increments were 10, 1, and 20%, respectively, for the same treatments. The use of brackish groundwater from the deep tubular wells of the Federal University of Recôncavo da Bahia and Sapeaçu and desalination reject water from the tubular well of Cruz das Almas proved to be technically feasible for hydroponic lettuce production.

Purple lettuce (Lactuca sativa L.) attenuates metabolic disorders in diet induced obesity

Purple lettuce (Lactuca sativa L.) is a type of low caloric vegetable often consumed freshly, whereas its function in metabolic control has been little studied. To investigate the protective effect of a type of purple lettuce against metabolic risk factors, we treated the C57BL/6J DIO mice with or without purple lettuces for 8 weeks. Results showed that purple lettuce effectively attenuated many metabolic risk factors in DIO mice. Typically, purple lettuce prevented the body weight gain by reducing fat mass accumulation and increasing energy expenditure. Additionally, consumption of purple lettuces enhanced glucose homeostasis, increased insulin sensitivity and improved the lipid profile in the DIO mice. This was, at least partly, attributable to its abundance of bioactive molecules like esculin and chlorogenic acid. High intake of purple lettuces modulated the intestinal microbiota composition like decreased Lachnospiraceae. We conclude that purple lettuce has great potential as functional foods in prevention of metabolic disorders.

ANTHOCYANIN PROFILE AND ITS ANTIOXIDANT ACTIVITY OF WIDELY USED FRUITS, VEGETABLES, AND FLOWERS IN THAILAND

Objective: Anthocyanins are the water-soluble pigments most commonly present in flowers, fruits, and vegetables. Anthocyanins have been reported for is antioxidant, anti-inflammatory, antibacterial properties and other health benefits in human. This study was performed to extract and determine the anthocyanin and to access the antioxidant properties of the most commonly used fruits, vegetables and flowers in Thailand.Methods: Extraction of anthocyanin and its aglycones from the selected samples and determination of anthocyanin and anthocyanidins using reversed-phase HPLC analysis. Determination of total antioxidant ability using ABTS, DPPH and FRAP assay.Results: Maximum distribution of tested anthocyanin and anthocyanidin contents was observed in the extracts of Jambolan plum, Ceylon Spinach, Purple Sweet Potato, Purple Lettuce followed by common plum and Red dragon fruit. The extracts of Ma-Kiang, Purple Eggplant, Red Grape, and Purple Lettuce showed the maximum amount of cyanidin 3-glucoside, delphinidin 3-glucoside, peonidin 3-glucoside, and malvidin 3-glucoside, respectively. Likewise, the maximum concentration of cyanidin, delphinidin, peonidin, and malvidin were found in Common plum, Red Khae, Red Cabbage, and Purple Lettuce, respectively. Ma-Kiang extract exhibited the maximum antioxidant activity followed by Red Cabbage, Common Plum, and Purple Eggplant extract compared to the other extracts.Conclusion: The present study, primarily profiled the anthocyanin content of selected fruits, vegetables, and flowers. Among the tested samples, Ma-Kiang extract showed the high cyanidin 3-glucoside content and antioxidant activity. Further, detailed study on the content of anthocyanins at different climate and geographical conditions and other factors are necessary to develop nutraceutical or cosmetic product with a functional ingredient.Keywords: Anthocyanin, Anthocyanidin, Antioxidant activity.

PHYSICOCHEMICAL CHARACTERISTICS OF PURPLE LETTUCE HARVESTED AT DIFFERENT AGES

ABSTRACT: Lettuce is one of the most produced and consumed leafy vegetables in Brazil. It is harvested when the plant reaches full vegetative growth and the leaves are still tender and there are no signs of bolting. The plant is unsuitable for commercialization after this period, thus, a food that is rich in vitamins, minerals and bioactive compounds such as carotenoid is lost. Therefore, the objective of this work was to assess the purple lettuce quality based on physical-chemical characteristics, in three different ages. The experiment was conducted in an urban community garden in Sete Lagoas MG, Brazil. A completely randomized experimental design was used with three replications. The treatments consisted of three development stages (20, 30 and 40 days after transplanting - DAT). The treatment with 40 DAT presented total carotenoids concentration and soluble solids content significantly higher, lower pH, and darker lettuce, with lower values of the parameter b* (increase in yellow color), and higher values of the parameter a* (increase in red color), compared to the first two treatments. The titratable acidity was statistically equal for the three evaluation periods. Considering the high concentration of carotenoids found at 40 DAT, the harvest can take place at this age.

Características produtivas da alface ‘Piraroxa’ adubada com fertilizante orgânico e mineral

Lettuce (Lactuca sativa L.) is one of the few fresh vegetables consumed exclusively, by possessing it, high added value when produced with organic inputs. This study aimed to evaluate the effect of nitrogen fertilization with different sources on the yield characteristics of purple lettuce, conditions Marechal Cândido Rondon - PR. The experimental design was randomized blocks in factorial 3 x 4 with four replications. The treatments were the combinations of three N sources (swine manure, poultry manure and urea) and four N rates (0, 120, 240 and 360 kg ha-1). The crop was harvested 38 days after transplanting. The results showed quadratic polynomial response to the number of leaves per plant and yield of fresh and dry top of lettuce. The cultivar 'Piraroxa' responds to the dose of 200, 230 and 180 kg ha-1 N in pig slurry, poultry manure and urea, respectively. The use of pig slurry and poultry manure equivalent yield presented the application of mineral fertilizers.