UNIVERSITI TEKNOLOGI MARAINTERNATIONAL EDUCATION CENTRE(INTEC)

BIOLOGY LABORATORY REPORTA LEVEL PROGRAMME2014

10 MARCH 2014

NAME: MAISARAH BINTI ZAINUDDINIC NUMBER: 950201-14-5724GROUP: 11SC6SID NUMBER: 1311171707TITLE: INVESTIGATING PLANT MINERAL DEFICIENCIES

1.0TITLE Investigating Plant Minerals Deficiencies2.0OBJECTIVES To investigate the effects of different plant minerals deficiencies3.0INTRODUCTION Lemna sp.[endnoteRef:2] [2: Germplasm Resources Information Network. United States Department of Agriculture. 2006-11-03. Retrieved 2013-04-13.]

Lemna sp. or commonly known as duckweed among society. Duckweed is the common name for a family of small aquatic herbs known as Lemnaceae. It is an aquatic plant that floats freely on or just beneath the water surface. They have the unique distinction of being the smallest flowering plants on earth which mostly do not exceeding 5mm in length. This species grow abundantly forming colonization in ponds and lakes in large number mainly by vegetative reproduction, specifically through budding. Lemna sp. is flowering plant and most of them produce sexually. Duckweed meal also high in protein, fats and fibres and its a good cattle feed.

Image 1: Budding of Lemna sp.These plants are also unique in that they do not have any stem structures. The plant is simply a fleshy ovoid or flattened structure that may or may not bear simple roots. These highly successful plants represent the ultimate in reduction for a vascular plant. Duckweed is ubiquitous to most temperate and tropical regions of the world, making it readily available to most farmers. They are typically found floating in thick mats of homogeneous populations in quiet streams or ponds containing high levels of organic matter. Another amazing feature of these plants is that they can double their mass in less than two days under ideal conditions of nutrient availability, sunlight and temperature.Since Lemna sp. grow rapidly in short time, it is used as a model system for studies in community ecology, basic plant biology, in ecotoxicology, in production of biopharmaceuticals, and as a source of animal feeds for agriculture and aquaculture so that no ethical issues will rise. Micronutrients and Macronutrients[endnoteRef:3] [3: Flour Fortification Initiative, GAIN, Micronutrient Initiative, USAID, The World Bank, UNICEF, Investing in the future: a united call to action on vitamin and mineral deficiencies, p. 19.]

Sixteen elements altogether are known to be important to a plant's growth and survival. They are carbon, hydrogen, oxygen, nitrogen, phosphorous, sulphur, potassium, calcium, magnesium, copper, zinc, molybdenum, boron, iron, chloride and manganese.

Image 2: Physical Changes in Plant due to Mineral Deficiencies[endnoteRef:4] [4: http://hydrophytesblog.com/?paged=4. Accessed on 3th March 2012]

Each of these nutrients has a critical function in plants and is required in varying amounts in plant tissue. Plants show symptoms being unhealthy when they experience insufficient nutrients. Too little or too much of any one nutrient can cause problems. Plant nutrients fall into two categories: macronutrients and micronutrients. As the name suggest, macronutrients are those elements that are needed in relatively large amounts while micronutrients are those elements that plants needed in small amount. Both macronutrients and micronutrients are naturally obtained by the roots from the soil. Macronutrients are further divided into two groups: primary and secondary nutrients. The primary nutrients are nitrogen (N), phosphorus (P), and potassium (K). These major nutrients usually are lacking from the soil because plants use large amounts for their growth and survival. The secondary nutrients are calcium (Ca), magnesium (Mg), and sulphur (S).Micronutrients are nutrients required by humans and other organisms throughout life in small quantities to orchestrate a range of physiological functions. For people, they include dietary trace minerals in amounts generally less than 100 milligrams/day - as opposed to macronutrients which are required in larger quantities. The micronutrients or trace elements include at least iron, cobalt, chromium, copper, iodine, manganese, selenium, zinc and molybdenum. Micronutrients also include vitamins, which are organic compounds required as nutrients in tiny amounts by an organism.4.0PROBLEM STATEMENT How does absence of one or more of any macronutrients and micronutrients can lead to mineral deficiencies in plants?5.0HYPOTHESIS All plants need optimum amount of both macronutrients and micronutrients in order for them to achieve optimal growth and development. Absence of any of these macronutrients or micronutrients in plants will eventually lead to mineral deficiencies. This can be proven by observing several symptoms that are showed up in the plant.6.0VARIABLESManipulated Variable:Type of culture solution usedUse different types of culture solution of same volume measured by using small beakers.

Responding Variable:Growth condition of the Lemna sp. plantlets Observe and record the following symptoms and conditions of the plantlets:a. Number of leavesb. Any physical changes such as changes in colours

Constant Variable:Type of Lemna sp. usedUse the same Lemna sp. plantlets which were taken from the same pond area and were kept in the same solution before they are being used for the experiment.

7.0 APPARATUS 8 petri dishes with lids, small beakers, forceps and labelling stickers8.0 MATERIALS Lemna sp. plantlets from pond water, distilled water, cellophane tape, 15 cm3 of different culture solutions containing:a. All nutrientsb. Lack of potassiumc. Lack of calciumd. Lack of phosphoruse. Lack of ironf. Lack of nitrateg. Lack of magnesiumh. Lack of all nutrients (distilled water)9.0 TECHNIQUES Observe and record the growth of the Lemna sp. plantlets over 10 days period which have been placed in different culture medium10.0 PROCEDURES1. Eight petri dishes were rinsed with distilled water and labelled by using labelling stickers to indicate nutrient absent in each of their culture medium, as following:AComplete nutrients

BLack of potassium

CLack of calcium

DLack of phosphorus

ELack of iron

FLack of nitrate

GLack of magnesium

HLack of all nutrients (distilled water)

Table 1: Labelling on each Petri Dishes2. By using a small beaker, 15cm3 of the culture solution containing complete nutrients is measured and poured in petri dish labelled A.3. Five pairs of Lemna sp. plantlets each containing two buds and roots were picked up by using a pair of forceps and gently transferred into the petri dish labelled A.4. Steps 2 and 3 were repeated for petri dishes labelled B, C, D, E, F, G and H.

5. All of the petri dishes were then covered with cellophane tape to prevent the solution from spilling out of the petri dish.6. The experiment was allowed to proceed for ten days and the growth of the Lemna sp. plantlets were observed and examined over the 10 days period.

11.0RESULTSPETRI DISH CONTENTFEATURESDAYS

0246810

Complete nutrientsNumber of LeavesAll of the plantlets had one leave onlyOne plantlet already had two leaves while the rest still having one leave onlyThree of the plantlets had two leaves while the other two had one leave onlyTwo of them had three leaves, the other two had two leaves and the remaining plantlet still had one leaf onlyOne had four leaves, one had three leaves, two had two leaves and the remaining one only had one leafTwo had four leaves, two had three leaves and the remaining one only had one leaf

Change in Physical AppearanceAll plantlets were green in colourFour of them were green in colour while the other one was yellowishThree of them were green in colour while the rest looked yellowishThose who had four and three leaves were green in colour while the remaining were yellowish

Lack of potassiumNumber of LeavesAll of the plantlets had one leave onlyOnly one plantlet had two leaves while the rest still had one leave onlyTwo of them had two leaves, another two plantlets had one leaf only and one plantlet deadAnother plantlet was dead, two surviving plantlets had two leaves while the other one only had one leafThe remaining three plantlets were all had two leaves

Change in Physical AppearanceAll plantlets were green in colourOne of the plantlets was transparent while the rest are yellowish greenFour plantlets looked yellowish green while one was deadAll of the surviving platelets looked yellowish and had holes on their surfaceTwo of them were green in colour while the other one looked pale and all of them had holes

Lack of calciumNumber of LeavesAll of the plantlets had one leaf onlyTwo of the plantlets started to have two leaves while the others remain oneTwo of the plantlets dead, one of them had two leaves while the other two had one leaf onlyOne of them had two leaves, two plantlets had one leaf only and the other two were already dead

Change in Physical AppearanceAll plantlets were green in colourThree plantlets were green in colour while the other two were yellow in colourThree plantlets were yellow in colour while the other two were in pale green.All of the surviving plantlets were in pale green and had holes on the surface of the leaves

Lack of phosphorusNumber of LeavesAll of the plantlets had one leaf onlyAll of the plantlets had one leaf onlyThree plantlets had one leaf while the rest had two leaves.Four of them had two leaves while the other one only had one leaveTwo of them had three leaves, two had two leaves while the other one had one leafThree of them had three leaves, one had two leaves while another one had one leaf

Change in Physical AppearanceAll plantlets were green in colourAll plantlets were green in colourThree were green in colour while the other two were yellow in colourTwo were green in colour while the remaining three were in pale greenThree plantlets were in pale green, one was green in colour while another one was yellowish

Lack of ironNumber of LeavesAll of the plantlets had one leaf onlyThree plantlets had three leaves, one plantlet had two leaves while the other one was deadFour plantlets had three leaves while the other one was already dead

Change in Physical AppearanceAll plantlets were green in colourOne plantlet was transparent, two were in pale green and the remaining two were yellow in colourThree of them were in pale green while the other one looked more paleAll of the surviving plantlets were in pale green

Lack of nitrateNumber of LeavesAll of the plantlets had one leaf onlyTwo plantlets had two leaves, the other two plantlets had one leaf only while the other one was dead

Change in Physical AppearanceAll plantlets were green in colourFour of them were in yellowish green while the remaining one was transparentTwo were yellow in colour with holes, the other two were in pale green with holes and the other one was dead

Lack of magnesiumNumber of LeavesAll of the plantlets had one leaf onlyOnly one plantlet had two leaves while the rest still had one leaf onlyThree plantlets had two leaves, the other two were dead

Change in Physical AppearanceAll plantlets were green in colourThree of the plantlets were green in colour, one was yellow in colour while the other one was transparentThree plantlets were green in colour while the other two were transparentThe surviving plantlets were all in very pale green

Lack of all nutrientsNumber of LeavesAll of the plantlets had one leaf onlyOnly one plantlet had two leaves while the rest still had one leaf onlyOnly one plantlet had three leaves while the remaining four were all dead

Change in Physical AppearanceAll plantlets were green in colourTwo of the plantlets were green in colour while the other started to change to yellowThree of them were transparent, one was pale green while the other one was greenThe one surviving plantlet was green in colourThe remaining plantlets looked really paleThe remaining plantlet was decreasing in size and looked really pale

Table 1: Observations on Lemna sp. plantlets over 10 days

DAYNO OF LEAVES PRESENTNO OF PLANTLETS HAVING PARTICULAR NO OF LEAVES IN EACH PETRI DISH

ABCDEFGH

00 (dead)--------

155555555

2--------

3--------

4--------

Total55555555

20 (dead)--------

145355555

21-2-----

3--------

4--------

Total65755555

40 (dead)--2-----

124235544

23112--11

3--------

4--------

Total86475566

60 (dead)-12-1124

11221-2--

22214123-

32---3--1

4--------

Total1164911663

80 (dead)-22-1124

11221-2--

22112123-

31--23--1

41-------

Total12441111663

100 (dead)-221124

11-21-2--

2-311-23-

32--34--1

42-------

Total15641212663

Table 2: No of Leaves of Plantlets in each Petri Dish

12.0 DISCUSSIONThis experiment was conducted to study the effect of various mineral deficiencies on the Lemna sp. plantlet or also known as duckweed. Lemna sp. plantlets were used in this experiment because they are found abundantly in pond environment, easily obtained and have less ethical issues but most importantly, the effects of any deficiency of mineral can be seen quite clearly in short amount of time as this plant only possesses short life span. Amount of sunlight (by placing all petri dishes containing medium nearby window), air and temperature for the Lemna sp. plantlets were kept in control for all the cultures. This is to ensure that the only factor that will affect the growth of the Lemna sp. plantlets were the different culture solution used. As discussed in procedure, by manipulating the absence of the minerals in culture solution, the effect of mineral deficiencies that were shown physically (number of leaves and changes in colour of the leaves) by the Lemna sp. plantlets which are responding variables in this experiment, were noted.A culture medium containing all necessary nutrients were used as a control in this experiment to show the actual growth and development that should be achieved theoretically by Lemna sp. plantlets. This controlled culture medium sample was then used as comparison with other mineral deficient cultures to point out the effect resulted by specific mineral deficiency.Looking at the result , it can be concluded that presence of all the macronutrients namely nitrogen, phosphorus, potassium, magnesium, calcium and sulphur and micronutrient iron results in increase in both number of plantlets and number of green leaves. Increase in number of plantlets is due to their vegetative reproduction (budding) since there is enough availability of source and nutrients needed for their development. Average of the root length also seems to be constant and this indicates good root development despite the increase in number of the plantlets. Other that this, it also noted that only one of the green leaves turn to yellow and then white and this may due to the competition in obtaining nutrients among the plants.On the other hand, the plantlets that was grown in the solution that lack the mineral potassium had shown different growth characteristics. Out of the 5 plantlets only 3 survived over the 10 day period and only grew two leaves. Of the remaining plantlets, they all had a yellowish green colour to them and they all had holes in them. The roles of potassium in plants are for the opening and closing of the stomata, photosynthesis and it alsorequires potassiumions(K+) forprotein synthesis. Thus when the plantlets lacked potassium in its nutrient solution, it prevented the proper function of the opening and closing of the stomata which then prevented the entry of important gases needed for photosynthesis. Therefore this caused some of the plantlets to die off while the remaining plantlets to have slightly yellowish colours on their leaves.The plantlets that were grown in the solution that lack the mineral calcium too showed different characteristics in terms of its growth. Some of the roles of calcium in plants are that in controls the permeability of membranes and also it combines with pectin to form calcium pectate. Without calcium present in the nutrient solution, it caused the yellowing of leaves and holes which indicated death at the growing regions. The blossom-end rotting could not be seen through this experiment as this plant species that was used has no fruits.On the other hand, the plantlets that was grown in the solution that lack the mineral phosphorus had shown different growth characteristics. Phosphorus plays a major role in the growth and development of a plant. Phosphate ions are needed for the phosphate groups in adenosine diphosphate (ADP) and adenosine triphosphate (ATP), which are involved in energy transfers in cells. When phosphorus is not present in the nutrient solution or in the soil, the energy generation of a plant will be disrupted and thus, basic processes such as photosynthesis and nutrient movement cannot occur normally. Usually when a plant is deficient of the mineral phosphorus, its leaves experience dark green colouration with the purpling of veins of the older leaves as well as stunted growth. However, in this experiment the results that were obtained were quite different in which the plantlets continued to grow leaves and the colour of the leaves turned yellow instead. The plantlets that was grown in the solution that lack the mineral iron and magnesium had shown different growth characteristics as well. Both iron and magnesium are needed in the formation of chlorophyll. The condition in which leaves produce insufficient chlorophyll is known as chlorosis. As chlorophyll is responsible for the green colour of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacturecarbohydrates due to the lack of chlorophyll in its leavesthrough photosynthesisand may die unless the cause of its chlorophyll insufficiency is treated. This is shown to be true in this experiment in which the leaves of the Lemna sp. plant turned pale yellow over the time period.The plantlets that was grown in the solution that lack the mineral nitrogen had shown different growth characteristics as well. Nitrate ions are required to make amino acids, enzymes, and DNA which are all essential for the growth of a plant. The results obtained in this experiment had shown that the leaves of the plantlets had turned pale yellow and even had holes in them. One of the plantlet even died during the 10 day period while some experience slower growth than the other plantlets. These all coincides with the usual symptoms of nitrogen deficiency in plants.Without any essential nutrients, the number of plantlets and number of leaves goes down the slope and eventually none of the plantlet survives till the final day except for one only. This is because all the metabolic activities are restricted thus the plants cant produce any food to survive thus resulting in zero survival chance.13.0 FURTHER STUDIESAnother experiment can be carried out by replacing Lemna sp. plantlets with barley seedlings using water culture technique. The seedlings are grown in culture solution (same with the above procedure) but in a test tube. The test tube should be covered by foil to exclude light, preventing algae growth. The seeds have to be moist so that it can germinate a week before use. Plants should inspect regularly for general growth, shape of leaves, length of leaf growth, colour of upper leaves, length of root growth, colour of lower leaves and mass of the seedling (before and after the experiment).[endnoteRef:5] [5: http://www.nuffieldfoundation.org/practical-biology/investigating-effect-mineralsplant-growth. Accessed on 3th March 2012]

Image: Set up of Apparatus14.0 SAFETY PRECAUTIONIn order to avoid any kinds of accidents or injuries during the experiment, there is a list of precautionary steps should be taken and applied. First and foremost, wearing lab coat and a pair of closed shoes are compulsory while conducting the experiment at all times in order to protect the skin and clothing from spillage of any chemicals or substances.Besides, it is also compulsory to wash hands thoroughly with soap and water before and after conducting the experiment. This is important to avoid contamination. Furthermore, all of the glassware especially small beakers should be handled with full care since they are small and very fragile. Other apparatus such as forceps also must be sterilised before being used during conducting the experiment to prevent infection of microorganisms and must be used with full care to avoid any injury.Other than that, all of the Lemna sp. plantlets should be choose carefully as they are very fragile little creature. The petri dishes also must be rinsed with distilled water before culture medium together with the Lemna sp. plantlets being placed in them. This is to remove any impurities and microorganisms that may cause disruption to the plants growth and development.After using all of the samples and apparatus, they should be discarded properly and returned back to their original places at the end of the experiment. This is to avoid any injury and unnecessary accidents that may result fatal results.15.0 CONCLUSION All plants need both macronutrients (potassium, calcium, phosphorus, nitrates and magnesium) ad micronutrients (iron) in order to achieve optimal growth and development. Deficiency or absence of any of the nutrients can be spotted through the symptoms than can be seen on its physical appearance such as changes in colours and number of roots. This proves that different types of mineral deficiency results in different effects on the growth of the Lemna sp. plantlets. Thus, the hypothesis is accepted.

16.0 REFERENCES