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“Effects on Red Mangrove’s ( Rhizophora mangle ) growth and foliage development with different salt concentration water treatments”. Presents: Oscar H. Torres University of Arizona Soil, Water, and Environmental Science Department. Course: SWES 574. Introduction.
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“Effects on Red Mangrove’s (Rhizophora mangle) growth and foliage development with different salt concentration water treatments” Presents: Oscar H. Torres University of Arizona Soil, Water, and Environmental Science Department. Course: SWES 574
Introduction • Crops productivity’s improvement or maintenance, has to cope with tolerance of saltier soils and waters today (Boyer, 1982; Epstein et al., 1980). • Key: to make selections under salty conditions found in nature, for genotypes able of exploiting limited resources can be recognized (Boyer, 1982). • With these genotypes, large-scale modification of the environment is less necessary (Boyer, 1982): area for mangrove reforestation.
Salt stress. • Serious factor limiting plant growth and productivity (Boyer, 1982; Zeng et al., 2006). • Outstanding environmental feature in mangroves’ swamps and zonations (Lin and Sternberg, 1993).
Mangroves • Mangroves: woody plants which dominate vegetation in tidal, saline wetlands along tropical and subtropical coasts (Lin and Sternberg, 1993). • The fluctuation in salinity a spp can withstand will be a determinant of the distribution and importance of that spp along salinity gradients(Lin and Sternberg, 1993).
Objective • R. mangle: • Detect optimum water Tx growth and foliage development. • Identify strains with best growth.
Methodology. After Ajmal Khan and Aziz (2001), Hwang and Chen (2001), and Clough (1984).
Discussion. • R. mangle grows in [35/00] (Clough, 1984), vs. growth @ 2 distant [5/00] & [50/00]. • Experiment hints R. mangle can actively accumulate biomass in [ ] & [ ] salty waters. [100/00]
Deionized water • The growth @ [ 0 ] is largely due to the usage of deionized water (0 ions or minerals) Turgid effect. • In all other methodologies reviewed, [ 0 ] Tx was based in regular tap water. • Energy used by plant’s equilibrating osmotic stresses by DI water, could be seized for growth instead.
Lowest growth [20 ppt] plants? • Salt stress: • Causes poor photosynthesis (Hwang & Chen, 2001; Seeman & Critchely, 1985) or causes indirect reaction of ions with C metabolism (Seeman & Critchley, 1985). • Regardless of finding the # in buds & the # of new leaves in the same plant, exemplifies the plant’s need of leaf’s area: photosynthesis & growth.
Freshwater preference • Mangroves growing in high saline ambient preferentially take up fresh water when available (Hwang and Chen, 2001). • This opposes the experiment, where optimal growth was fulfilled at Tx 5 ppt and 50 ppt; freshwater Tx not optimal.
Discrepancies between greenhouse & wild mangroves. • Greenhouse mangroves: optimal growth salinities range from 1.5 ppt to 15 ppt seawater (Hwang and Chen, 2001). • In the field, same mangroves grow well @ salinities ranging from 15 ppt to over 30 ppt (Hwang and Chen, 2001).
Conclusions • 5 ppt & 50 ppt Tx are recommended to grow R. mangle the swiftest in Greenhouse conditions. • 20 ppt Tx is not suggested to grow Red mangroves in the Greenhouse.
Conclusions • Albeit, at 20 ppt Tx, # of leaves & leaf buds were got. • Current results buttress what Boyer (1982) proposed. (Growth reached under unfavorable salt conditions rather in favorable ones).