In the mid 1990s, plant biotechnology burst onto the scene in world agriculture, beginning a second ‘green revolution’ and precipitating one of the great public debates of this era.
Primitive forms of cereal grains were among the first pants domesticated by early humans more than 10000 years ago during the Neolithic age when agriculture gradually replaced hunting and gathering.
The evolution of the different types of wheat was mainly by chance by occurred with a little help from human ancestors who choose to cultivate seed from the best plants they could find in nature.
By the best what they were looking for was the variety that would give them the highest yields in their climate and on their land.
The search for the best variety is still going, but most of the wheat varieties grown today exist as the direct results of man’s intervention.
They are the results of thousands focused breeding trial in which the superior varieties are selected out of the existing genetic pool (much as our ancestors did), but these varieties are then deliberately developed into thousands of modern hybrids by using just three species (T. aestivum, T. sphaeroccum, and T. compactum).
To ensure that the correct genetic combination is achieved, the breeder first removes the unripe anthers (pollen-containing organs) from one parent plant.
Next the plants “contained” to prevent pollination from any undesirable source.
As soon as the stigmas are ready to be pollinated, the breeder introduces pollen from the desired second “parent” plant.
The seed derived from this first generation hybrid are all identical, but subsequent generations will exhibit a range of characteristics from which seed the desired characteristics can be selected.
Once selected, they can be “amplified” through successive plantings into a pure genetic line.
A major factor that limits the world’s cereal production is abiotic caused by drought, high salinity or low temperature.
Plants respond to these environmental changes through a number of homeostatic mechanism that maintain the water balance and the integrity of tissues. This includes several regulatory mechanism that activate the expression of tolerance effector genes.
Genetic Biotechnology of Cereal
