PRELIMINARY STUDY ON THE PROPAGULE DEPENDENCY OF Rhizophora SEEDLINGS

N.P. DISSANAYAKE, S.K. MADARASINGHE, K.A.S. KODIKARA, L.P. JAYATISSA, A.J.D. PERERA, N. KOEDAM, F. DAHDOUH -GUEBAS

Abstract


Early life of viviparous mangroves merely depends on the propagule and it can be assumed that the period and the degree of dependency could depend on the size and the intrinsic factors of the propagule as well as on the edaphic and environmental factors in which the seedlings are growing. However scientific studies on the propagule dependency of mangrove seedlings is poorly studied, irrespective to the fact that such information is vital particularly in mangrove restoration programs.  However, propagule dependency of mangrove seedlings is poorly studied scientifically, irrespective to the fact that such information is vital particularly in mangrove restoration programs. 

This study was carried out to investigate the growth performances of seedlings and the variations in the content of carbohydrate foods (starch content) in the propagule during the first 20 weeks period of the seedling growth of  two viviparous species, Rhizophora apiculata and Rhizophora mucronata, which are having larger propagules and commonly used in replanting programs. The experiment was conducted, under three salinity regimes (i.e. 5psu; 15psu; 30psu) in a planthouse. A separate set of propagules was planted within the mangrove forest of Pambala lagoon under natural conditions and subjected to the same investigation as above.

Growth performances of both species grown under high salinity regime were significantly lower than those grown in low and moderate salinity regimes. Total leaf area of the seedlings of R. mucronata increased in higher order compared to that of the R. apiculata during the study period. After an initial drop in the content of starch in the propagules of both species, it started to increase slowly in the propagule of R. mucronata seedlings whilst the reduction was continued in R. apiculata propagules during the study period. However, the initial starch concentration of R. apiculata was remarkably higher than that of R. mucronata and hence, the starch content in R. apiculata, even after continued decreasing, was higher at the end of the study period. It can be hypothesized that the higher concentration of the stored food in smaller propagule of R. apiculate, compared to lower concentration of the stored food in propagules of R. mucronata, might lead to a similar longevity of viviparous mangrove seedlings of the two species allowing more or less the same chance to survive and establish in the same habitat as observed in many mangrove ecosystems.

 

KEYWORDS: Mangroves, Restoration, Starch content, Propagule dependency, Rhizophora, Sri Lanka


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References


Alongi, D.M., (2002). Present state and future of the world’s mangrove forests. Environ. Conserv.29:331–349

Aziz, I. and Khan, M.A., (2001). Effect of seawater on the growth, ion content and water potential of Rhizophora mucronata Lam. J. Plant Res., 114:369–373

Bewley, J.D. and Black, M., (1994). Seeds – physiology of development and germination, 2nd edn. New York, NY, USA: Plenum Press.

Chapman, M.G., Underwood A.J., (2000). The need for a practical scientific protocol to measure successful restoration.Wetlands (Australia).19(1).

Dahdouh-Guebas, F., Zetterstro, T., Ronnba, P., Troell, C.K., Wickramasinghe, A. and Koedam, N., (2002). Recent changes in land-use in the Pambala–Chilaw lagoon complex (Sri Lanka) investigated using remote sensing and GIS: conservation of mangroves vs. development of shrimp farming. Environment, development and sustainability.4:185–200.

De Block, M., Verduyn, C., De Brouwer, D. and Cornelissen, M., (2005). Poly(ADPribose) polymerase in plants affects energy homeostasis, cell death and stress tolerance. Plant J. 41:95–106.

Drexler, J.Z., (2001).Maximum Longevities of Rhizophora apiculata and R. Mucronata Propagules.Pac Sci.55:17–22.

Elmqvist, T. and Cox, PA., (1996).The evolution of vivipary in flowering plants.OIKOS.77: 3-9

Elster, C., (2000). Reasons for reforestation success and failure with three mangrove species in Colombia.Forest Ecol. Management.131: 201–214.

Erftemeijer, P.L.A. and Lewis III, R.R., (2000). Planting mangroves on intertidal mudflats: habitat restoration or habitat conversion? – In: Enhancing Coastal Ecosystem Restoration for the 21st Century. Proceedings of Regional Seminar for East and Southeast Asian Countries: Ecotone VIII, Ranong and Phuket Provinces, Southern Thailand. pp. 1–11.

Farnsworth, E., (2004). Hormones and shifting ecology throughout plant development. Ecology85:5–15.

Filed CD., (1996).Restoration of mangrove ecosystems.International society for mangrove ecosystems. Okinawa, Japan. pp. 250

Hogarth, PJ. (2007). The Biology of Mangroves and Seagrasses. Oxford University Press, Oxford, U.K..

Jayatissa, L.P., Dahdouh-Guebas F. andKoedam N., (2002).A review of the floral composition and distribution of mangroves in Sri Lanka. Bot J Linn Soc, 138:29–43.

Jayatissa, L.P., Wickramasinghe, W.A.A.D.L., Dahdouh-Guebas, F. and Huxham, M., (2008).Interspecific variation in response of mangrove seedlings to two contrasting salinities Intern. Rev. Hydrobio. 93:700–710.

Kasawani, I., Sulong, I., and Mohd-Suffian Khzirani, A., (2006). Mangrove forest classes, distribution and changes using remote sensing techniques and ground truth data in Kelantan delta, Kelantan. In (Shazil, NAM.,Abol-Munafi, AB. eds) proceeding of the Kusten. 5 th annual seminar on sustainability science and management, Kuala Terenggana, Malaysia, pp. 115-118.

Lewis,III RR., (2005). Ecological engineering for successful management and restoration of mangrove forests – Ecol. Engin.24:403–418.

Parida, A,K. and Das, A.B., (2005). Salt tolerance and salinity effects on plants: a review. Ecotoxicol Environ Saf., 60:324–349.

Primavera, J.H. and Esteban J.M.A., (2008). A review of mangrove rehabilitation in the Philippines: successes, failures and future prospects. WetlEcolManag.16:173–253.

Rizhsky, L., Liang, H., Mittler R., (2002) The combined effect of drought stress and heat shock on gene expression in tobacco. Plant Physiol.130:1143–1151

Smith, S.M. andSnedaker, S.C., (1995). Salinity responses in two populations of viviparous Rhizophora mangle L.

seedlings. Biotropica, 27:435-440

Tiwari B.S., Belenghi B., Levine, A., (2002) Oxidative stress increased respiration and generation of reactive oxygen species, resulting in ATP depletion, opening of mitochondrial permeability transition, and programmed cell death. Proc. Natl Acad. Sci. USA.128:1271–1281.

Wang, F., Sanz, A., Benner, M.L., and Smith, A., (1993). Sucrose synthase, starch accumulation, and tomato fruit sink strength. Plant Physiol. 101:321-327.

Ye, Y., Tam, N.F.Y., Lu, C.Y. and Wong, Y.S., (2005). Effects of salinity on germination, seedling growth and physiology of three salt-secreting mangrove species.Aquat. Bot. 83:193–205.


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