Saturday, March 28, 2015
The Impact of Elevated Carbon Dioxide in Martian Atmosphere in the Process of Germination of Seeds
Global climate changes tend to increase the concentration of CO2 in our atmosphere. The structure and composition of atmosphere is entirely different in different planets, not similar as that of earth.The cultivation of plant food in earth with drastic climate changes or in other planets either in solar or non-solar systems under entirely new atmospheric and soil conditions needs a detailed study to understand the effect of increased CO2 levels in the process of germination and growth of planets. Besides the abundance of CO2 in atmosphere, many other factors such as quality of seeds, ambient temperature, soil pH, percentage of moisture ,concentration of nitrogen and oxygen in the atmosphere also determine the successful agricultural production .Infact all these factors play vital role in the process of germination too.
An artificial Martian atmosphere is created inside a large enclosure made of glass,whose open face is kept immersed in a pool of water, so that the space enclosed is isolated from the surrounding. The abundance of nitrogen is reduced by displacing the air with fumes and smokes produced by burning camphor in the space before erecting the enclosure. The abundance of oxygen in the space is reduced by burning a candle inside. The concentration of carbon dioxide is increased by producing the gas chemically. A beaker with baking powder and vinegar kept inside liberates copious carbon dioxide gas. Taking calcium carbonate in a black coated flat plate placed inside and heating with solar radiation also increases carbon dioxide level inside regularly.. Calcium carbonate taken in a test tube fitted tightly with a cork and an outlet tube is heated externally to conduct carbon-dioxide into the enclosure through a long rubber tube whose outlet is well immersed in the pool. The pressure inside is maintained at one atmospheric pressure.The temperature inside is measured with two mercury thermometers.Due to green house effect there is a temperature gradient of 0.6 o C / cm height. The temperature at the lower layer is in the range of 28-35 o C and it is 38-53o C at the upper layer depending upon the solar flux.
Two pair of cups with different soil are taken and in each pair same number of fenu greek seeds (15) are sowed for germination. One set of pair is placed inside and other set is placed outside the enclosure to compare the probability and the length of germination of the seeds After a couple of weeks ,as an average 10 out 15 seeds are sprouted in the cups ouside while nothing is grown in the cups inside. It showed that the germination of the spice is inhibited in elevated carbon dioxide with reduced nitrogen and oxygen
The increased CO2 level increases the soil pH.If soil’s pH becomes too acetic (or too alkaline) various key nutrients become insoluble and unavailable to the plants and by this way it affects the growth of the plants.Due to green house effect the temperature of the surrounding is increased which alters the optimal soil temperature ,less favouring for maximum number of seeds for germination.However the seed germination in response to elevated CO2 has been reported to decrease 1-3,show no change4 , to increase5 .It is shown that the responses vary among species6-7.
Germination is the growth of seeds into seedlings – a kind of biological process converting the seed from its passive to active phase.Biological materials are rich in carbon and occur in aqueous environments and hence the presence of water play an important role in determining the structure and specific activities of biopolymers. The required biopolymers are always synthesized by the active plant itsef. But in the case of passive seed, the biopolymers required for germination are initially inducted by nature with congenial environment. During germination, the seed synthesizes biopolymers with storage compounds in the seed, water in the soil and oxygen and nitrogen in the atmosphere This primary biopolymers activate further a chain of biological process that determines its further growth It decides all the future of the plant- the development of various part of the plant with specific activities,reproduction of similar seeds for its existence etc ., The biopolymers are the root cause of making the dormant seed to turn into self active seedling.Any change in the environment thus affects this chain process of germination and growth.
In the atmosphere with depleted oxygen, less nitrogen and elevated CO2 the process of germination of fenugreek is very much hindered.Activating the seed to continue its state of living requires the generation of specific biopolymers which can be synthesized with water molecules through hydrogen bonding .The presence of oxygen is necessary to provide energy by oxidation required for the formation of biological molecules through hydrogen bonding8. Thus the cultivation in Mars is possible only if an optimum amount of oxygen is available in the environment to provide energy for the formation of complex biopolymers through hydrogen bonding to awaken the dormant seed. It is well established that any damage in achieving the physiological maturity will have a substantial reduction in germination.This is true in the process of generation because of their deterorated ability to sysnthesize biopolymers.