TITTLE: EffECTS OF DIESEL FUEL CONTAMINATION ON SEED GERMINATION OF SIX CROP PLANTS DEGREE PROGRAM:













MOLECURAL BIOLOGY AND BIOTECHNOLOGY (MBB) COURSE:   BN 300 (ENVIRONMENTAL BIOTECHNOLOGY

ABSTRACT
The aim of this practical was to find out which of the given crop plant seeds are most tolerant to the diesel fuel contaminant, which can be using for decontamination of diesel contaminated soil in Tanzania in future. Plant  toxicity  bioassays  through  fast  germinating  agricultural  crops  can  indicate  the  phytoremediation potential,  effects  on  growth  and  survival  and  also  assess  extent  of  pollution.  In this study, the phytotoxic effect of diesel fuel contamination was studies on six agricultural crops namely maize (Zea mays), sorghum (sorghum bicolor), groundnuts/ peanut (Arachis hypogaea), peas (vigna unguiculata), pigeon pea (cajanus cajan), dark-green pea/ bean mung (phaseolus aureus). At ten levels of Diesel concentration of ratio (0, 0.8, 1.62, 2.43, 3.24,) were prepared by addition of 10ml distilled water, then both seeds were planted in each concentration for further observation.
 All the test plant species tolerated diesel fuel contamination at small percent levels and the total percent seed germination was intermediate. Diesel fuel contamination also caused a reduction in the length of the radicle of the six crop plants studied. At 3.2 and 4.8% level of contamination, the longest radicle (1.92 cm) was recorded in peas. There was a reduction of radicle growth of all the species in subsequent treatment levels.  Almost  same  trend  was  observed  in  plumule  growth  of  all  six  species. Phytotoxicity bioassays results revealed that Maize, Groundnuts, Pigeon pea and Dark-green pea species exhibited better growth and germination even at high concentration of diesel as compared to Sorghum and Peas. Hence, it was concluded that these two species have higher potential for phytoremediation of diesel contaminated soils.











INTRODUCTION

The  increasing  use  of  diesel  in  diesel  engines  of  cars, industrial  trucks  and  generators  has  led  to  a  marked increase  in  the  demand  for  diesel  fuel  in the world.  Accidental  spills  caused  by  pipeline  leakages  and  ruptures and  accidents  during  transport  have  been  reported.  The environmental  consequence  of  soil  pollution  cause adverse  effect  on  the  soil  microflora,  and  reduces  soil fertility.  Contamination  of  soil results  in  damage  of  crop  growth,  depending  on  the degree  of  contamination,  the  soil  may  remain  unsuitable for  plant  growth  for  months  or  several  years.  Contamination  of  soil  with  petroleum  products  has  been  a  major cause  for  concern.  Damages due to soil contamination may be extensive and its effect may be long term. Diesel fuel is not a systemic killer; it kills plants cells on contact.  Contamination  by  diesel  fuel  can  kill  the  roots,  and  this prevents  the  plant  from  taking  up  water  and  other nutrients, (Torstenssen  et  al.,  1998). 
It  can  also  disrupt  plant  and  water  relationship in  soil, Petroleum  derived  diesel consist  of  75%  saturated  hydrocarbons  primarily  paraffin and  25%  aromatic  hydrocarbons.  Regardless of this complexity, diesel fuel can be degraded by a number of soil microorganisms. Diesel fuel is phytotoxic to plants at relatively low concentrations.  The development of plants grown in diesel fuel contaminated soil differs greatly from plants grown in normal soil conditions (Adam and Duncan, 1999).
Contamination  of  soil  by  oil  spills  is  a  wide  spread environmental  problem  that  often  requires cleaning up of the contaminated sites (Bundy et al., 2002).  These petroleum hydrocarbons adversely affect the germination and growth of plants in soils (Samina and Adams 2002).  Oil  spills  affect  plants by  creating  conditions  which  make  essential nutrients  like  nitrogen  and  oxygen  needed  for plant  growth  unavailable  to  them  (Adam  and Duncan, 2002). Phytoremediation is an alternative to  more  expensive  remediation  technologies because it is a feasible, effective and non-intrusive technology  that  utilizes  natural  plant  processes  to enhance  degradation  and  removal  of  oil contaminants  from  the  environment  (Marmiroli and McCutcheon, 2003)
 Phytotoxicity  tests  have  been  suggested  as  useful tools  in  assessing  the  risk  of  contaminated  soil  or to  evaluate  the  efficacy  of  a  remediation  process. Germination and root elongation are two critical stages in plant development  that  are  sensitive  to  environmental contaminants, Plant height and shoot biomass are also good indicators of plant health and the sustenance of plant growth by  the  treated  soil  is  an  indication  of  enhanced bioremediation (Banks et al., 2003). Many authors have  reported  a  lower  rate  of  germination  in petroleum  or  its  derivatives  contaminated  soil (Adam  et al 2002).
 Petroleum hydrocarbons  may  form  a  film  on  the  seed, preventing  the  entry  of  oxygen  and  water  and  toxic  hydrocarbon molecules  could  inhibit  the  activities  of  amylase and  starch  phosphorylase  and  thereby  affecting the  assimilation  of  starch. Also reported  that  petroleum hydrocarbons  consisting  of  small  molecules  and those  that  are  water  soluble  are  more  phytotoxic for the germination. The  most  common  and  important  symptoms observed  in  the  plants  contaminated  with  oil  and its  by  products  include  the  degradation  of chlorophyll  (Malallah  et  al.,1998),  alterations  in the  stomatal  mechanism  and  reduction  in photosynthesis  and  respiration  (Baker,  1970)


METHODOLOGY
MATERIALS
·         Petri dishes
·         Six crop seeds, maize seeds (Zea mays), sorghum (Sorghum bicolor), groundnuts/peanuts (Arachis hypogaea), peas (Vigna unguiculata), pigeon pea (Cajanus cajan) and dark-green pea/bean mung/balck gram (Phaseolus aureus).
·         Diesel oil
·         Filter papers
·         Marker pen
·         Distilled water
·         Measuring cylinder
·         Beakers
·         Test tubes
·         Thread and ruler

PROCEDURES
·         Each clean Petri dish was divided in six portions by using marker pen
·         Labeling was done to each portion of the Petri dish with the seed name and level of contamination.
·         Different levels of contamination were prepared by mixing the right volume of water to 0, 0.8, 1.6, 2.4, 3.2, 4.0, 4.8, 5.6, 6.4, and 7.2 ml of diesel oil to make 10ml of mixtures respectively in the test tubes
·         Filter paper was laid in each Petri dish followed by pouring of the contamination volume mixture respectively
·         Ten seeds of each crop were sown into the Petri dish at each portion that already contained the contaminated water, and then Petri dishes were closed and incubated at 250c for about seven days.
METHODS
Length measurement- the lengths of plumule and radicle were measured using ruler and thread.
ANOVA and Duncan’s multiple range tests- these were used to analyze the differences between control treatment (p<0.05).


RESURTS
                            
Diesel conc
               Germinating seeds picture
0
Description: E:\mengineyo\Received files\IMG_20131126_100257.jpg
0.8
Description: E:\mengineyo\Received files\IMG_20131126_100324.jpg
1.6
Description: E:\mengineyo\Received files\IMG_20131126_100340.jpg
2.4
Description: E:\mengineyo\Received files\IMG_20131126_100353.jpg
3.2
Description: E:\mengineyo\Received files\IMG_20131126_100408.jpg
4.0
Description: E:\mengineyo\Received files\IMG_20131126_100429.jpg
4.8
Description: E:\mengineyo\Received files\IMG_20131126_100441.jpg
5.6
Description: E:\mengineyo\Received files\IMG_20131126_100515.jpg
6.4
Description: E:\mengineyo\Received files\IMG_20131126_100504.jpg
7.2
Description: E:\mengineyo\Received files\IMG_20131126_100515.jpg










                                          Percentage of seeds germination (%)
Diesel conc
Maize
Groundnut
Peas
Dark-green pea
Pigeon pea
Sorghum
O
100
100
100
100
100
100
0.8
0
0
20
20
0
70
1.6
0
20
60
60
0
80
2.4
0
0
40
80
0
40
3.2
0
0
40
80
0
20
4.0
0
0
80
20
0
30
4.8
0
0
20
0
0
10
5.6
0
0
60
0
0
20
6.4
0
0
0
0
0
0
7.2
0
0
40
0
0
0
                                    


                      Average length of germinated seeds (radical / cm)
Diesel conc
Maize
Groundnut
Peas
Dark-green pea
Pigeon pea
Sorghum
O
14
11.3
2.5
2.5
5.9
4
0.8
0
0
0
2
0
0.3
1.6
0
0.2
0.5
0.5
0
0.2
2.4
0
0
0.3
1.1
0
0.1
3.2
0
0
0.2
1.96
0
0.1
4.0
0
0
0.4
0
0
0
4.8
0
0
1.96
0.2
0
0.2
5.6
0
0
0.5
0
0
0.1
6.4
0
0
0
0
0
0
7.2
0
0
0.1
0
0
0


                 Average length of germinated seed ( plumule in cm)
Diesel conc
Maize
Groundnut
Peas
Dark-green pea
Pigeon pea
Sorghum
O
4.1
0
5
1.2
0
9.6
0.8
0
0
0
0
0
0.2
1.6
0
0
0
0
0
0.1
2.4
0
0
0
0
0
0.1
3.2
0
0
1.1
1.2
0
0.1
4.0
0
0
0
0
0
0
4.8
0
0
0.5
0
0
0.1
5.6
0
0
0
0
0
0
6.4
0
0
0
0
0
0
7.2
0
0
0
0
0
0


STATISTICAL DATA ANALYSIS





DISCUSSION,




CONCLUSION
The study reached the conclusion that higher level contamination by diesel fuel has negative effect on the all test agricultural crops under study. But, Peas  and Dark-green pea species  exhibited  better growth  and  germination  even  at  high concentration  of  diesel,  so,  these  can  be  used  for phytoremediation of diesel contaminated soils. On the  other  hand,  bioassays  using  sensitive  plants like Sorghum vulgareb can evaluate  soil  pollution  and  remediation  because  a plant’s  reactions  can  reflect  the  level  of  pollution in  its  environment.  The  results  indicate  a  wider possibility  for  utilizing  tolerant  agricultural  species in  remediation  on  contaminants  and  sensitive species to monitor the level of polluted soil. 

REFFERENCES
1.      Adam, G. and Duncan,  H.  J. (2002):  Influence of Diesel Fuel on Seed Germination.   Environ. Pollut. 120:363-370.
2.      Baker, J.M.  (1970):  The effects of oils on plants. Environ. Pollut., 1:27-44.
3.      Banks, M. K., Kulakow, P., Schwab, A.P., Chen, Z., Rathbone, K.  (2003):  Degradation of crude oil in the rhizosphere of Sorghum bicolor. International Journal of Phytoremediation, 5(3):225-234
4.      Bundy, J.  G., Paton, G.  I., Campbell, C.  D. (2002): Microbial communities in different soil types do not converge after diesel contamination.  Journal of Applied Microbiology, 92:276–288
5.      Malallah, G., Afzal, M., Kurian, M., Gulshan, S. and Dhami, M.S.I.  (1998):  Impact of oil pollution on some desert plants. Environ. Int., 24:919-924.
6.      Marmiroli, N and McCutcheon S.  C. (2003): Making phytoremediation a successful technology. Phytoremediation.Transformation and Control of Contaminants. John Wiley, Hoboken. 

7.      Torstenssen L, Mikaelpell O, Bostenberg C (1998). Need of a Strategy for Evaluation of Arable Soil Quality. Environ. Pollut.  27: 4-7.
Tags:

Powered by Blogger.