Introductory Crop Physiology (1+1)

Effect and Types of Stress

Effect of stress

• Plants usually yield to any stress conditions and its reaction may be elastic or plastic. The stress may be immediately made out in the plant or plants may become resistant when exposed to stress conditions. This state is called hardening. Sometime the effect produced is carried over in the subsequent generations. Thus pea or bean plants subjected to low temperature tend to become dwarf and this effect is passed on for several generations.
• However, recent years are witnessing studies on genetic basis of resistant strains. Breeders are also making efforts to evolve the genetic lines which are gradually adapted to diverse climatic conditions. The reactions of plants to the stress conditions are highly complex and are manifested in the form of several physiological responses.

Types of stress

The most common stresses to which the plants are expressed to are drought, heat, cold and frost. In addition to these several other stresses also exist eg. Shade, salt, high altitude etc. In recent time occurrence of excessive pollutants, effluents, etc also gives toxic environments to the plants.


Stress response

Acclimation : Adjustment to environmental change by an individual. The physiological adjustment or increased tolerance shown by an individual organism to environmental change.
Acclimatization: The physiological adaptation of plant to changes in climate or environment often multiple stress such as light, temperature, altitude, etc
Adaptation: An alteration or adjustment in structure or habits, often hereditary, by which a species or individual improves its condition in relationship to its environment.

or an inherited or acquired modification in organisms that makes them better suited to survive and reproduce in a particular environment