SLIIT International Conference on Advancements in Sciences and Humanities [SICASH] 2021

Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/318

Browse

Filters

20212

Advanced Search

Filter by

Settings

End date: 2021Subject: search.filters.subject.Dracaena sanderiana

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    PublicationEmbargo
    Biomonitoring of HgCl2 with Dracaena sanderiana under Two Different Irradiance Levels: Effects on the Photosynthetic Apparatus
    (Faculty of Humanities and Sciences,SLIIT, 2021-09-25) Jayasooriya, L. S. H; Wijethunga, W. M. U. D; Kumarihami, H. M. P. C; Attanayake, U; Beneragama, C. K
    Heavy metals such as Hg are phytotoxic. Interference of heavy metals with photosynthesis has been a topic of intensive research during the last few decades. Some plants can be used in biomonitoring and the remediation of such pollutants. It is important to assess the biomonitoring potential in ornamental plants as they do not enter into the food chain. This experiment was conducted to examine the effect of HgCl2 on the photosynthetic apparatus in Dracaena sanderiana to assess its potential to use in biomonitoring. D. sanderiana cuttings were subjected to heavy metal stress (100 μM HgCl2), along with control (distilled water) under two contrasting irradiance levels (High light-: 22,500±2,000 lux and Low light-: 750±200 lux). OJIP chlorophyll fluorescence measurements were conducted using a fluorometer (FluorPen, FP-110). The measurements were recorded four times a day (9 am, 12 noon, 3 and 6 pm) continuously for four days after imposing the treatments. Specific energy fluxes per reaction center, flux ratios and Performance Index (PI) were recorded. There was a significant reduction in PI, maximum quantum yield of primary photochemistry (φPo) and quantum yield of electron transport (φEo) with the time in HgCl2 treatment compared to the control. This indicates the negative effects of Hg+ on the photosystem II. However, the visual rating of the foliage quality was at a satisfactory level. Moreover, there was a significant increase/progress/growth in effective antenna size (ABS/RC) and maximum quantum yield of nonphotochemical de-excitation (φDo) in HgCl2 with time. Except in electron transport efficiency (ψo), a clear unimodal circadian variation was observed in all OJIP parameters under high light condition. Photosynthetic apparatus of D. sanderiana is affected by the Hg+. However, the plant was able to cope up with the heavy metal stress during the experimental period indicating that, it can successfully be employed in short-term biomonitoring of mercury. In the experiment, the temperature effect could not be eliminated, thus future experiments for studying that might be crucial.
  • Thumbnail Image
    PublicationEmbargo
    A Successful Surface Sterilization Technique for in vitro Establishment of Dracaena sanderiana Sander ex Mast. Nodal Explants
    (Faculty of Humanities and Sciences,SLIIT, 2021-09-25) Seneviratne, K. L; Malwattage, G; Weerakkody, G. K; Peiris, S. E; Peiris, C. N
    Dracaena sanderiana Sander ex Mast. is the number one cut foliage exported from Sri Lanka and it is also a popular potted plant. In order to promote dracaena cultivation, micropropagation techniques can be employed to produce high quality large number of clones as planting materials. However, severe microbial contaminations in the in vitro establishment stage mitigate the micropropagation application on this species. Therefore, this study was undertaken with the objective of using silver nitrate (AgNO3) to eliminate surface adhered microorganisms to obtain high amount of contamination free cultures at the in vitro establishment stage. Investigations also carried out to explore reusability of AgNO3 after the first wash in surface sterilization. Apical parts of about 8 cm of D. sanderiana cv ‘White’ were used in this study. Silver nitrate solution in 200 mg/L and Clorox™ in 10% concentrations were used for the surface sterilization of the nodal explants. Results revealed that 200 mg/L AgNO3 produced 90% and 10% Clorox produced 20% contamination free cultures after 8 weeks of establishment in vitro. Also, in the experiment of investigation of reusability of AgNO3 it was observed that the second and third washings of AgNO3 produced 80 and 70% non-contaminated cultures, respectively. Results of this study suggest that AgNO3 is a highly effective low-cost non-toxic material which can be used in surface sterilization of D. sanderiana nodal explants. With this promising results it can be suggested that 200 mg/L AgNO3 solution can be considered to replace toxic heavy metals such as mercuric chloride frequently used in Micropropagation.