Research Update:Lettuce or Lactuca sativa

  seminal trace...Lettuce Extract.CAS.NO.084776-66-9.Wild lettuce Extract.Lactuca sativa,common garden lettuce.Lactuca extract; Lettuce extract; Lactuca sativa L. var. capitata.extract...

 


   Phytochemical info of Lettuce or Lactuca sativa

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 Definition:Lettuce or Lactuca sativa are majorly composed of
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   Research Update:Lettuce or Lactuca sativa

  A survey of syrphid predators of Nasonovia ribisnigri in organic lettuce on the central coast of California.:J Econ Entomol. 2007 Feb;100(1):39-48.Smith HA, Chaney WE.University of California Cooperative Extension, Monterey County, Salinas, CA 93901, USA. hasmith@ucdavis.edu

 Organic lettuce, Lactuca sativa L., producers on California's Central Coast rely on endemic syrphid flies (Diptera: Syrphidae) to suppress populations of Nasonovia ribisnigri Mosley (Homoptera: Aphididae) and other aphids affecting lettuce. Growers are using various forms of habitat manipulation to enhance biological control. We surveyed syrphids collected from organic romaine in and around the Salinas Valley from March through September 2005 to gain a better understanding of the species responsible for aphid suppression and to examine possible implications for biocontrol. The primary species of syrphid fly reared were Toxomerus marginatus (Say) (39%), Platycheirus stegnus (Say) (27%), Sphaerophoria sulfuripes (Thomson) (13%), and Allograpta obliqua (Say) (10%). Syrphus opinator Osten Sacken (2%), Toxomerus occidentalis (Curran) (1.3%), and Eupeodes volucris Osten Sacken (1%) were less common. Sphaerophoria pyrrhina Bigot, Scaeva pyrastri (L.), Platycheirus obscurus Say, Allograpta exotica Wiedemann, and Eupeodes americanus Wiedemann each made up <1% of the syrphids reared. T. marginatus and Sphaerophoria sulfuripes were commonly collected from romaine plants with few or no detectable aphids. P. stegnus was observed to deposit in clusters of eggs, and was only reared in significant numbers from highly infested fields. Approximately 5% of syrphid larvae overall were parasitized by either Diplazon sp. (Hymenoptera: Ichneumonidae) or Pachyneuron sp. (Hymenoptera: Pteromalidae).

  Lettuce, lactuca sp., as a medicinal plant in polish publications of the 19th century.:Kwart Hist Nauki Tech. 2005;50(3-4):123-34. Polish.Trojanowska A.Instytut Historii Nauki PAN Warszawa.

 Mentions of lettuce Lactuca sp. that have appeared since antiquity contained similar information on its curative properties, but such properties were ascribed to different species or varieties. Apart from the wild and poisonous lettuce, also garden or common lettuce were identified as having curative action, and some publications lacked information enabling the precise identification of the lettuce in question. In the 19th century, attempts were made to put some order into the knowledge of lettuce as a medicinal plant. Information contained in Polish medical studies of the 19th century on lettuce points to the poisonous species, Lactuca virosa, and the common or garden lettuce, Lactuca sativa v. Lactuca hortensis, as being used as a medicinal plant. In that period, lettuce and especially the the desiccated lactescent juice obtained from it, lactucarium, were considered to be an intoxicant, and were used as a sedative and an analgesic. The action of the substance was weaker than that of opium but free of the side-effects, and medical practice showed that in some cases lactucarium produced better curative effects than opium. To corroborate those properties of lettuce and its lactescent juice, studies were undertaken to find the substance responsible for the curative effects of the juice. However, such studies failed to produce the expected results, and the component responsible for the curative properties of letuce was not identified. Medical practice thus had to restrict itself to the uses of the desiccated lactescent juice and extracts obtained from it. The possibility of obtaining lactucarium from plants cultivated in Poland caused Polish pharmacists and physicians to take an interest in the stuff and launch their own research of lettuce and the lactescent juice obtained from it. Results of research on lettuce were published in 19th-century journals by, among others, Jan Fryderyk Wolfgang, Florian Sawiczewski and J¨®zef Orkisz.

  Chryseobacterium formosense sp. nov., isolated from the rhizosphere of Lactuca sativa L. (garden lettuce).:Int J Syst Evol Microbiol. 2005 Jan;55(Pt 1):423-6.Young CC, K?mpfer P, Shen FT, Lai WA, Arun AB.College of Agriculture and Natural Resources, Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung, 402, Taiwan, Republic of China.

 A yellow-pigmented bacterial strain (CC-H3-2T), isolated from the rhizosphere of Lactuca sativa L. (garden lettuce) in Taiwan, was investigated using a polyphasic taxonomic approach. The cells were Gram-negative, rod-shaped and non-spore-forming. Phylogenetic analyses using the 16S rRNA gene sequence of the isolate indicated that the organism belongs to the genus Chryseobacterium, with the highest sequence similarity to the type strains of Chryseobacterium indoltheticum (97.7 %), Chryseobacterium scophthalmum (97.5 %), Chryseobacterium joostei (97.2 %) and Chryseobacterium defluvii (97.2 %). The major whole-cell fatty acids were iso-C(15 : 0) (52.2 %) and iso-C(17 : 0) 3-OH. DNA-DNA hybridization experiments revealed levels of only 27.4 % to C. scophthalmum, 27.1 % to C. indoltheticum, 14.1 % to C. joostei and 7.8 % to C. defluvii. DNA-DNA relatedness and biochemical and chemotaxonomic properties demonstrate that strain CC-H3-2T represents a novel species, for which the name Chryseobacterium formosense sp. nov. is proposed. The type strain is CC-H3-2T (=CCUG 49271T=CIP 108367T).

  Mechanism of Selective Phytotoxicity of L: -3,4-Dihydroxyphenylalanine (L: -Dopa) in Barnyardglass and Lettuce.:J Chem Ecol. 2007 Sep 26;

 L: -3,4-Dihydroxyphenylalanine (L: -dopa) is one of the few allelochemicals in which the phytotoxic action mechanism has been studied. Excess exogenous L: -dopa suppresses root elongation in some plant species, and the inhibitory action is species-selective. The main factor of phytotoxicity of L: -dopa is considered to be oxidative damage by reactive oxygen species (ROS) and/or free radical species (FRS). This study was performed to elucidate the mechanism of species-selective phytotoxicity. The involvement of ROS/FRS and polyphenol oxidase (PPO) in species-selective phytotoxicity was examined with barnyardgrass (Echinochloa crus-galli L.) and lettuce (Lactuca sativa L.), tolerant and susceptible species, respectively. Lipid peroxidation and melanin accumulation correlated with growth inhibition by L-dopa. Antioxidants, ascorbic acid and alpha-tocopherol, decreased lipid peroxidation and melanin accumulation and rescued lettuce root from growth inhibition. The oxidation of L-dopa by PPO was much greater in lettuce than in barnyardgrass. From these results, the phytotoxicity of L-dopa is considered due to the oxidative damage caused by ROS/FRS generated from the melanin synthesis pathway. PPO activity might be involved in the mechanism of species-selective phytotoxicity between barnyardgrass and lettuce.

  A high-density, integrated genetic linkage map of lettuce (Lactuca spp.).:Theor Appl Genet. 2007 Oct;115(6):735-46. Epub 2007 Sep 8.Truco MJ, Antonise R, Lavelle D, Ochoa O, Kozik A, Witsenboer H, Fort SB, Jeuken MJ, Kesseli RV, Lindhout P, Michelmore RW, Peleman J.The Genome Center and The Department of Plant Sciences, University of California, Davis, CA, 95616, USA, mjtruco@ucdavis.edu.

 An integrated map for lettuce comprising of 2,744 markers was developed from seven intra- and inter-specific mapping populations. A total of 560 markers that segregated in two or more populations were used to align the individual maps. 2,073 AFLP, 152 RFLP, 130 SSR, and 360 RAPD as well as 29 other markers were assigned to nine chromosomal linkage groups that spanned a total of 1,505 cM and ranged from 136 to 238 cM. The maximum interval between markers in the integrated map is 43 cM and the mean interval is 0.7 cM. The majority of markers segregated close to Mendelian expectations in the intra-specific crosses. In the two L. saligna x L. sativa inter-specific crosses, a total of 155 and 116 markers in 13 regions exhibited significant segregation distortion. Data visualization tools were developed to curate, display and query the data. The integrated map provides a framework for mapping ESTs in one core mapping population relative to phenotypes that segregate in other populations. It also provides large numbers of markers for marker assisted selection, candidate gene identification, and studies of genome evolution in the Compositae.


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  1.Research Update:Lettuce or Lactuca sativa