International Seminar sustainable utilization of coastal resources in tropical zone, 19-20 October,2016, Bengkulu, Indonesia

Effect of Salinity on Biduri (Calotropis gigantea) under Several Light Intensities Maimunah*a, Enggar Aprianto*, Putranto B.A.N* *Department of Forestry Bengkulu University Jln. WR Supratman Kandang Limun Bengkulu 38371 a Email : [email protected]

ABSTRACT

Biduri grows widely along sea-shore. It is an important pioneer vegetation for sea dune ecosystem. However, only few information can be found about it. Biduri can be found in areas with high salinity and exposed to high light intensity but also found under trees with low light intensity and salinity. This research aims to find out effects of salinities on growth of Biduri under several ligh intensities. The experimental design was set up as Randomized Block Design with four different levels of saline water for watering were used as treatments; 0% sea water (100% fresh water), 50% sea water , 75% sea water, and 100% sea water, under three light intensities as blocks; 0% shading, 40% shading and 70% shading, and nine seedlings per treatment at each block. The results showed that salinity has negatif effects on survival rate of Biduri and Biduri grows better under lower light intensity (shading) condition. Key words : Calotropis gigantea, salinity, shading

INTRODUCTION Bengkulu province has 525 km-length of sea-shore facing Indonesian ocean (Anonimous, 2013).

but in some areas are in critical condition caused by lack of vegetation

and erosion. To rehabilitate these areas,

Anwar et al. (1984) recomended using pioneer

trees or shrubs that grows faster and more adaptable to harsh condition.

Pioneer shrubs or

trees are able to colonize an area in an extrim condition with low availability nurient (Wiryono, 2009). One of pioneer shrub that can be found on sea-shore is Biduri (Calotropis gigantea) Biduri spread out in tropical and sub tropical areas (Kumalasari, 2010). The species is adaptif to dry and high temperature conditions. Mostly, Biduri are growing along sea-shore with high salinity condition and exposed to light, but they can also be found under trees on no-saline land. The ability to grow on long range of light intensity and salinity might became potential for Biduri for coastal rehabilitation. However, very few research has been done on it. This experiment aims to evaluate effects of salinity on growth of Biduri under several light intensities.

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International Seminar sustainable utilization of coastal resources in tropical zone, 19-20 October,2016, Bengkulu, Indonesia

MATERIALS AND METHOD The experiment was conducted from January to April 2016 at Field Laboratory Faculty of Agriculture, Bengkulu University, Medan Baru, Bengkulu. Sea water was used as source of salt. Four different levels of saline water for watering were used as treatments;

0% sea water (100% fresh water), 50% sea water

(≈531,1 mg /l), 75% sea water (≈720,3 mg/l), and 100%

sea water(≈901,2 mg/l). The

experimental design was set up as Randomized Block Design with three light intensities as blocks; 0% shading, 40% shading and 70% shading, and

nine seedlings per treatment

within each block. 108 polybags filled with 500mg of sand were prepared. Cleaned, washed and sterilized sand was used as media. Two months-old good and healthy seedlings of Biduri were prepared

from seeds

collected from Nature Conservation Area, TWA Pantai Panjang Bengkulu, and germinated in sand box. Seedlings were mantained for 1 week after transfered to polybag, without treatment, for adaptation. Watering was conducted every two days as much as 100 ml according to the treatments. Every 4 days, the media were washed by pouring 300ml pure water per polybag. The excess water was collected and measured, for estimating residual salt in the media and salinity of the media Survivale rate, height, and diameter, were measured biweekly. Number of leaf, leaf size, chlorophyll and stomatal density were measured at the end of experiment. Analysis of varians were used to compare between salinities treatments. In addition, a simple t-test were conducted to compare data between block (shading/light intensities).

RESULTS AND DISCUSSION Survival Rate Figure 1. shows relationship between survival rate of Biduri and salinities of the media. The best survival rate were shown by no-saline water treatments following by 50% saline-water treatment, while the 75% and 100% treatments could not survive till the end of expriment.

This indicated that salinity have an impact on survival rate of Biduri. Salinity

may increase toxid-ion concentration

in the plant, or reducing osmotic potential of soil

water such that disturbing water transport, and affecting growth and development (Sopandie, 2013) The mortality of Biduri started from 42 days after treated and increased to as high as 50% of mortality for 50% salinity and totally death for 75% and 100% salinities, at 56 days. High salinity reduce survival rate of Biduri. It is different from the result shown for 437

International Seminar sustainable utilization of coastal resources in tropical zone, 19-20 October,2016, Bengkulu, Indonesia

Nyamplung (Calophyllum inophillum). Hani (2011) reported that Nyamplung survive and grow better on saline media. It grow better

at 75 % and 100% sea-water.

Figure 1. also shows that during the experiment, the salinity of the media increased by time. The high mortality of Biduri might be an effect of high salinity in the media caused by the accumulation of salt

250mg/l of salinity. 350

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International Seminar sustainable utilization of coastal resources in tropical zone, 19-20 October,2016, Bengkulu, Indonesia

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Figure 1.

survival rate (M0) salinity (Mo)

survival rate (M0) Salinity (M1)

Survivale rate (%) of Biduri and salinity of media (mg/l) by days after treated, at 0% shading (a), 40% shading (b) and 70% shading (c)

Height Average height growth of Biduri during the experiment are shown at Figure 2. Analysis of varians shown non-significant different among salinity treatments. However, t-test among shading condition showed that seedlings under 70% shading growth better than the lower ones. Light is an important factor for growing or development of plant, as it has main role in photosynthetic processes (Sopandie, 2013). In general, growth pattern of Biduri under 40% shading and 70% shading increased faster, while under 0% shading slower. Under 40% and 70% shading, plant growth earlier after treated, but under 0% shading (full sun) started growing after 42 day of treatment. It indicated that under high light intensity, Biduri need longer time to adapt for start growing. Plant under shading grow higher because the cell in the stem cell will grow longer (Salisbury

Height growth (cm)

( a)

Days (after treated)

Height growth (cm)

dan Ros, 1995)

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International Seminar sustainable utilization of coastal resources in tropical zone, 19-20 October,2016, Bengkulu, Indonesia

Height growthi (cm)

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Figure 2. Means of height growth (cm) of Biduri at 0% (a) shading, and 70% shading (c) Diameter

40% shading (b)

Means of diameter growth during the experiment are shown at Figure 3. Analysis of variance showed no-significant different of growth among salinity treatments. But t-test among seedling under different shadhing showed significant different. Diameter increased from the begining of the experiment in all of shadings, but diameter growth of Biduri favour to lower light intensity. Diameter growth of Biduri is higher under shading. Rina et al

(2010) showed a similar result on Suren (Toona surensis). Diameter

growth of Suren is better under shading. It is in contrast with what reported by Sastrawinata

(a)

Diameter growth (mm)

Diameter growth (mm)

(1984), that low light intensity could not produce maksimal photosyntate.

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Days (after treted))

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M1 M3

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Figure 3. Means of diameter growth of Biduri (mm) under 0% shading a (a), 40% shading (b) and 70% shading (c) Number of leaf, Leaf size, Chlorophyl and Stomata Means number of leaf, leaf size, number of chloropyll, and

number of stomata per

plant of Biduri under different treatments are shown at Table 1. 440

Analysis of variance

International Seminar sustainable utilization of coastal resources in tropical zone, 19-20 October,2016, Bengkulu, Indonesia

showed significant effect of salinities on number of leaf of Biduri. Biduri under no-saline media have more leaf than those under saline media. Biduri with higher saline media has less number of leaf

A similar result on Ceriop tagal was shown by Ramayani et al. (2012).

Increasing salinities reduced number of leaf of Ceriop. However, different effect were shown on Sorgum and Nyamplung. Unaiyatin et al. (2010) reported that there was no significant effect of salinity on

number of leaf of Sorgum, and

Hani

(2011) reported that

Nyamplung is in favor to higher salinity. Higher salinity increase number of leaf of Nyamplung. Tabel 1.

Means of number of leaf, leaf size, chlorophyll, and stomata under different salinities and shading treatments Chlorophyll Stomata Leaf size (mm2) Number (per plant) (per plant) Treat of Leaf per ment Per plant Per leaf plant M0 4,8 98,0 471,6 14771 8222 M1 1,7 100,1 166,8 4707 1862 N0 2,0 57,6 115,2 3228 2504 N1 3,6 80,9 287,6 8678 4261 Total number of chlorophyll and stomata per plant are affected by number of leaf and

leaf size. Biduri on non saline media has more but smaller leaf than those under 50% salinity and vice versa. Plant adapt to higher salinity by reducing leaf size but increasing number of leaf in order to reduce respiration. Biduri in and leaf area that might

give better

non saline media has more chlorophyll, stomata

effects on photosinthetic and respiration processes.

Biduri under higher shading (70%) has more number of leaf, larger leaf size and more chlorophyll. In order to catch light, plant under high shading adapted itself by increasing number of leaf and leaf area. Under low light intensity plant also increase number of chlorophyll.

From the results, it can be conclude that (1) Salinity has negatif effects on

survival rate of Biduri and (2) Biduri grows better under shading (lower light intensity).

REFFERENCES Anwar, J., S.J. Damanik., N.Hisyam., dan A.J. Whitten. 1984. Ekologi Non saline Sumatra. Gadjah Mada University Press, Yogyakarta. Anonymus 2013. Profil Kehutanan 33 Provinsi. Balai Penelitian dan Pengembangan Teknologi Konservasi Sumber Daya Alam (BALITEK KSDA).

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http://balitek-ksda.or.id/2014/02/profil-kehutanan-33-provinsi/. 17 Agustus 2016. Hani, A. 2011. Pengaruh penyiraman air laut terhadap bibit nyamplung (Calopyllum inophylum). Tekno Hutan Tanaman 4(2): 79 – 84. Kumalasari. 2010. Uji efektifitas ekstrak daun biduri (Calotropis gigantea) sebagai antifertilitas pada keong emas (Pomacea canaliculata). http://yeye.blog.uns.ac.id/files/2010/04/biduri-keong 1.pdf. 27 Nov 2015. Ramayani, A., M. Basyuni, dan L. Agustina. 2012. Pengaruh salinitas terhadap pertumbuhan dan biomassa semai dan kandungan lipida pohon non-sekresi Ceriops tagal. Skripsi. Universitas Sumatra Utara, Medan. Rina, K.B., Budiman, dan M. Suartana. 2010. Pengaruh media dan naungan terhadap mutu bibit suren (Toona sureni ). Jurnal Penelitian Hutan Tanaman 7 (2): 77 – 83. Rizka, A.M., T. Nurhidayati, dan K.I. Purwani. 2012. Persaingan tanaman jagung (Zea mays) dan rumput teki (Cyperus rotundus) pada pengaruh cekaman garam (NaCl). Jurnal Sains dan Seni Its 1(1): 54 – 57. Salisbury, M. B., dan C.W. Ross. 1995. Fisiologi Tumbuhan. Cetakan ketiga. ITB, Bandung. Sastrawinata, H.A. 1984. Pengaruh intensitas cahaya matahari terhadap pertumbuhan bibit Shorea laevis di komplek Wanariset Kalimantan Timur. Puslitbang Hutan 461: 27-54. Sopandie, D. 2013. Fisiologi Adaptasi Tanaman Terhadap Cekaman Abiotik pada Agroekosistem Tropika. IPB Press, Bogor. Unaiyatin, H., Taryono, dan P. Yuono. 2010. Pengaruh salinitas terhadap komponen hasil empat belas kultivar sorgum (Sorghum bicolor (L) moench). Skripsi. Fakultas Pertanian UGM, Yogyakarta. Wiryono. 2009. Ekologi hutan. Cetakan kedua. UNIB Press, Bengkulu

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