PRACTICAL 4: PROPAGATION OF SEAWEED IN ENRICHMENT MEDIA

INTRODUCTION

Micropropagation is a method for sustainable utilization and conservation of populations of Rhodophyta. Thus, micropropagation or name as in vitro clonal propagation, allows the production of a large number of individuals within a short period. Hence, micropropagated clones could be used as seedlings for seaweed cultivation by Nair S. Yokoya et al (2011).

Gracilaria changii, is one of the more abundant agarophytic seaweeds found in Malaysia based on Malaysia and Thailand record. Agar content and gel strength in wild population of Gracilaria changii as well as spore production mangroves was monitored for seasonal variation. Agar yield and gel strength ranged from 12 to 25% dry weight and 294 to 563 g cm⁻², respectively, over a 15-month period. Rainfall is correlated with gel strength but not yield was positively. Thus, cystocarps, sporetraps showed that spore release peaked around July–August and January–February after the two monsoon periods by Phang et al (1996). 

METHODOLOGY

1.      Placed the seaweed in a glass jar filled with sterile seawater.

2.      Rinsed seaweed by submerging and shaking with sterile seawater vigorously several times.

3.      Then, cut the seaweed into small fragment cu of 1 cm. Recorded the weight of seaweed.

4.      Next, placed the fragment into sterile 12 well plates contain 3 different media which is VSE, PES, sterilze seawater.

5.      Thu, incubated seaweed for a photoperiod of 12 hour light and 12 hour dark in “Makmal Pengajaran 1.”

6.      Changed the samples media in well plates once a week without disturbing the fragments.

7.      Then, compared the growth by determining the gain/loss of the seaweed wet weight/length/any procedures.

8.      Recorded any changes that can be observed ( new bud).

 Figure 1: Seaweed sample

 Figure 2: Cutting seaweed

 Figure 3: Culture plate

 Figure 4: Adding media

RESULTS

Figure 5: Initial length of seaweed

Figure 6: Propagation of seaweed after one week.

Figure 7: Propagation of seaweed after four weeks (from upper to bottom layer; seawater; VSE; PES)

Figure 8: Propagation of seaweed after five weeks (from upper to bottom layer: seawater; VSE; PES)

Figure 9: Propagation of seaweed in seawater medium after five weeks

Figure 10: Propagation of seaweed in VSE medium after five weeks

Table 1: Growth rate of Gracilaria changii within 5 weeks

Species name: Gracilaria changii
Week/Media/ Measurement	Sterile seawater			VSE			PES
	Length (cm)	Protuberance count	Weight (g)	Length (cm)	Protuberance count	Weight (g)	Length (cm)	Weight (g)
4	Initial = 1	-	1.      0.055 2.      0.057 3.      0.041 Mean = 0.0051	Initial = 1	-	1.      0.052 2.      0.033 3.      0.037 Mean = 0.041	Initial = 1	1.      0.028 2.      0.029 3.      0.031 Mean = 0.030
5	1)1.0 2) 1.0 3) 1.0 Mean = 1.0	1) - 2) 2 3) – Mean = 2	1) 0.060 2) 0.065 3) 0.043 Mean = 0.056	1)1.0 2)1.0 3)1.0 Mean = 1.0	1) - 2) - 3) 1 Mean = 1	1)0.078 2)0.049 3)0.064 Mean = 0.064	*	*
6	1)1.0 2) 1.1 3) 1.0 Mean = 1.0	1) 1 2) 3 3) 1 Mean = 2	1) 0.074 2) 0.071 3) 0.052 Mean = 0.066	1)1.1 2)1.2 3)1.2 Mean = 1.2	1) 2 2) 1 3) 3 Mean = 2	1)0.099 2)0.051 3)0.085 Mean = 0.078	*	*
7	1)1.1 2) 1.2 3) 1.2 Mean = 1.2	1) 3 2) 4 3) 3 Mean = 3	1) 0.079 2) 0.063 3) 0.055 Mean = 0.066	1)1.2 2)1.2 3)1.4 Mean = 1.3	1) 4 2) 4 3) 5 Mean = 4	1)0.125 2)0.080 3)0.117 Mean = 0.107	*	*
8	1)1.2 2) 1.3 3) 1.4 Mean = 1.3	1) 4 2) 5 3) 7 Mean = 5	1) 0.098 2) 0.074 3) 0.061 Mean = 0.078	1)1.6 2)1.5 3)1.7 Mean = 1.6	1) 5 2) 5 3) 7 Mean = 6	1)0.139 2)0.087 3)0.126 Mean = 0.117	*	*
9	1)1.3 2) 1.4 3) 1.4 Mean = 1.4	1) 5 2) 6 3) 8 Mean = 6	1) 0.101 2) 0.088 3) 0.074 Mean = 0.088	1)1.8 2)1.7 3)1.7 Mean = 1.7	1) 6 2) 7 3) 8 Mean = 7	1)0.143 2)0.096 3)0.133 Mean = 0.124	*	*

This sign (*) indicate that the seaweed was bleached right after one week.

DISCUSSION

Based on table 1, the average length of Gracilaria changii in sterile water is 1.15cm which lower than sample in VSE medium which is 1.3cm. Furthermore, Gracilaria changii average weight on VSE media is higher than sample in sterile water medium. This shows that, our experiment  Gracilaria changii thalli is growth better in VSE medium. Thus, PES medium culture sample is 1 cm for average length because it bleach. However, this contrast with Gran'laria edulis registered higher growth rate in PES medium (50.42 f 3.82 mg/d) than in Walne's and Gamborg media R. Girees and P. Kaladharan (2003). 

CONCLUSION

Based on our experiment, Gracilaria changii thalli growth better in VSE medium in between sterilze water and PES media.

REFERENCES

Nair S. Yokoya, Yocie Yoneshigue-Valentin, Micropropagation as a tool for sustainable utilization and conservation of populations of Rhodophyta. Brazilian Journal of Pharmacognosy 21(2): 334-339, Mar./Apr. 2011. http://dx.doi.org/10.1590/S0102-695X2011005000077.

Phang, SM., Shaharuddin, S., Noraishah, H. et al. Hydrobiologia (1996) 326: 347. doi:10.1007/BF00047829

P. Kaladharan, R. Girees. Laboratory culture of Gracilaria spp. and Ulva lactuca in seawater enriched media. Semi~eed Res. Utiln., 25 (1 6 2 ) : 139 - 142, 2003.