Biotic and abiotic resistance are two forms of defense mechanisms in crops against various stressors. Here's a full explanation of each:
1. Biotic Resistance: Biotic resistance refers to a plant's ability to defend itself against pests, diseases, and other living organisms that can harm or damage crops. It involves the plant's physiological and biochemical responses to these biotic stressors. Some examples of biotic resistance mechanisms include:
a. Physical Barriers: Plants may have physical barriers such as tough outer layers, thorns, or trichomes (small hairs) that deter pests and make it difficult for them to feed or lay eggs.
b. Chemical Defenses: Plants can produce chemical compounds that act as repellents, toxins, or deterrents to hinder the growth or attack of pests and diseases. Examples include insect-repellent compounds or antimicrobial substances.
c. Induced Responses: When plants sense the presence of pests or diseases, they can initiate an induced response. This response triggers the release of chemicals or hormonal signals to activate defense mechanisms, such as producing toxic compounds or strengthening cell walls.
d. Genetic Resistance: Genetic resistance involves the plant's innate ability to resist pests and diseases due to specific genetic traits. Plant breeders select and develop crop varieties with genetic resistance to specific pests or diseases through breeding programs or genetic engineering.
2. Abiotic Resistance: Abiotic resistance refers to a plant's ability to withstand and adapt to non-living environmental stresses. These stresses can include extreme temperatures, drought, salinity, floods, nutrient deficiencies, or soil contaminants. Abiotic resistance mechanisms help plants function and survive under adverse conditions. Examples of abiotic resistance mechanisms include:
a. Drought Avoidance: Some plants have adaptations that allow them to conserve water or reduce water loss through mechanisms like deep root systems, thick cuticles on leaves, or the ability to close stomata during dry periods.
b. Temperature Tolerance: Plants can develop physiological mechanisms to tolerate extreme temperatures, such as producing heat-shock proteins or altering metabolic processes.
c. Osmotic Regulation: Osmotic regulation helps plants cope with high salinity or changes in soil water availability. They may have mechanisms to adjust osmotic potential, regulate ion uptake, or excrete excess salt through specialized structures.
d. Nutrient Efficiency: Plants can develop strategies to optimize nutrient uptake and utilization efficiency, such as enhanced nutrient absorption, root adaptations, or physiological adjustments to nutrient deficiencies or toxicities.
Overall, both biotic and abiotic resistance mechanisms contribute to crop productivity and are important considerations in crop breeding and management practices. By enhancing these resistance mechanisms, farmers and researchers can develop more resilient crop varieties that can better withstand pests, diseases, and adverse environmental conditions, ultimately leading to higher yields.
Answers & Comments
Crops production can go down due to biotic and abiotic stresses under different situations.
Varieties resistant to these stresses can improve crop production.
Answer:
Biotic and abiotic resistance are two forms of defense mechanisms in crops against various stressors. Here's a full explanation of each:
1. Biotic Resistance: Biotic resistance refers to a plant's ability to defend itself against pests, diseases, and other living organisms that can harm or damage crops. It involves the plant's physiological and biochemical responses to these biotic stressors. Some examples of biotic resistance mechanisms include:
a. Physical Barriers: Plants may have physical barriers such as tough outer layers, thorns, or trichomes (small hairs) that deter pests and make it difficult for them to feed or lay eggs.
b. Chemical Defenses: Plants can produce chemical compounds that act as repellents, toxins, or deterrents to hinder the growth or attack of pests and diseases. Examples include insect-repellent compounds or antimicrobial substances.
c. Induced Responses: When plants sense the presence of pests or diseases, they can initiate an induced response. This response triggers the release of chemicals or hormonal signals to activate defense mechanisms, such as producing toxic compounds or strengthening cell walls.
d. Genetic Resistance: Genetic resistance involves the plant's innate ability to resist pests and diseases due to specific genetic traits. Plant breeders select and develop crop varieties with genetic resistance to specific pests or diseases through breeding programs or genetic engineering.
2. Abiotic Resistance: Abiotic resistance refers to a plant's ability to withstand and adapt to non-living environmental stresses. These stresses can include extreme temperatures, drought, salinity, floods, nutrient deficiencies, or soil contaminants. Abiotic resistance mechanisms help plants function and survive under adverse conditions. Examples of abiotic resistance mechanisms include:
a. Drought Avoidance: Some plants have adaptations that allow them to conserve water or reduce water loss through mechanisms like deep root systems, thick cuticles on leaves, or the ability to close stomata during dry periods.
b. Temperature Tolerance: Plants can develop physiological mechanisms to tolerate extreme temperatures, such as producing heat-shock proteins or altering metabolic processes.
c. Osmotic Regulation: Osmotic regulation helps plants cope with high salinity or changes in soil water availability. They may have mechanisms to adjust osmotic potential, regulate ion uptake, or excrete excess salt through specialized structures.
d. Nutrient Efficiency: Plants can develop strategies to optimize nutrient uptake and utilization efficiency, such as enhanced nutrient absorption, root adaptations, or physiological adjustments to nutrient deficiencies or toxicities.
Overall, both biotic and abiotic resistance mechanisms contribute to crop productivity and are important considerations in crop breeding and management practices. By enhancing these resistance mechanisms, farmers and researchers can develop more resilient crop varieties that can better withstand pests, diseases, and adverse environmental conditions, ultimately leading to higher yields.
Hope that helps!