field HortTechnology. 1 78 81 Penaloza, P. Ramirez-Rosales, G. McDonald, M.B. Bennett, M.A. 2005 Lettuce ( Lactuca sativa , L.) seed quality evaluation using seed physical attributes, saturated salt accelerated aging, and the seed vigor imaging system
cultivars of lettuce ( Lactuca sativa ) ( Koontz and Prince, 1986 ; Soffe et al., 1977 ), as well as for other vegetable species ( Soffe et al., 1977 ) and strawberry ( Fragaria × ananassa) ( Tsuruyama and Shibuya, 2018 ). Plant growth generally increases
Lettuce ( Lactuca sativa L.) is one of the most valuable vegetables in the world. The United States ranks as the second largest lettuce producer after China, harvesting ≈105,000 ha worth $3.5 billion in 2019 [ Food and Agriculture Organization of
photochemical performance of a greenhouse-grown crop of a romaine-type lettuce cultivar ( Lactuca sativa L. ‘Green Towers’) under growing conditions comparable to a commercial production environment. Specific hypotheses tested were whether the current ETR is
year-round ( Abbey et al., 2019 ). However, there were several production issues that needed careful management to have yields comparable to hydroponic greenhouse or field-grown types. Lettuce, Lactuca sativa , is the most commonly grown leafy green in
. Ryder, E.J. 2004 Identification of lettuce ( Lactuca sativa L.) germplasm with genetic resistance to drop caused by Sclerotinia minor J. Amer. Soc. Hort. Sci. 129 70 76 Koopman, W.J.M. Guetta, E. van de
‘Black Seeded Simpson’, ‘Buttercrunch’, and ‘New York 12’ lettuce.(Lactuca sativa L.), Plant Introductions (PI) 261653 of Lactuca saligna L., and Acc. No. 500–4 of L. serriola L. regenerated plants from cell suspensions originated from leaf callus. Liquid cultures of these Lactuca spp. in either B5 or Murashige and Skoog (MS) basic medium amended with alpha-naphthaleneacetic acid (NAA) and 6-benzylamino purine (BA) developed roots, shoots, and complete plants when transferred to agar plates of B5 with several concentrations of BA under 16 hr of fluorescent illumination. Shoots were induced to produce a root system when cultured in B5 agar medium amended with NAA. Variation in response between cultivars and between species was observed, with L. serriola and ‘Black Seeded Simpson’ responding best to treatments.
Analysis of tissues of lettuce, Lactuca sativa L., seedlings failed to reveal the presence of anthocyanin, pheophytin or phenolic compounds as the cause of red cotyledons (physiological necrosis). Electron microscope study showed that the cells in the necrotic tissues were completely disintegrated with only the mitochondria identifiable.
In greenhouse and field plantings, necrotic seedlings that survived produced heads equal in size and total yield to those from normal seedlings. Seedlings with slight spotting were a few days behind normal seedlings in establishment, whereas those which were badly necrotic were about 2 weeks delayed. After 8 weeks in the greenhouse or field there was no differences in plant sizes. Seedlings with only slight necrosis appeared to be satisfactory for field seeding but badly necrotic ones would probably not give a satisfactory stand.
's ability to cope with water stress in specific/localized environments will lead to better-informed decisions on the suitability of irrigation management practices. Lettuce ( Lactuca sativa L. var. capitata), a member of the Asteraceae family, is cultivated
Lettuce (Lactuca sativa L.) were transformed using microparticle bombardment with two different genes, alpha-glucuronidase (GUS) gene and Chinese cabbage Glutathione Reductase (GR) gene. The adventitious shoots of cotyledonary explant from 4-day-old seedlings were formed (46.7%) in MS basal media supplemented with 5.0 μm IAA and 1.0 μm 2ip. When 1100 psi helium pressure, 9 target distance, and coating with tungsten 10 microparticles were used and explants were treated with osmoticum-conditioning medium (0.6M sorbitol/mannitol), 4 h prior to and 16 h after bombardment, it was identified by GUS assay that these conditions were the most efficient for transformation of foreign genes into cotyledon tissue of lettuce with particle bombardment. PCR confirmed that the band observed in the transgenic plants were originated from T-DNA tranfer with strong hybridization. The genomic Southern analysis showed that the 1.5-kbp fragment was hybridized with radiolabeled 1.5-kbp GR probe. To know whether the expression of the GR gene can be stably maintained in the next generation, when T2 selfing seeds that were obtained from the transformed mother plants were sowed on MS medium supplemented with 200 μm kanamycin, 70% of seedlings were revealed resistance to kanamycin.