Final Answer:
Some plant growth regulators (PGRs) containing ethylene include ethephon and ethylene gas.
Explanation:
Plant growth regulators (PGRs) are substances that influence the growth and development of plants. Ethylene, a key plant hormone, plays a crucial role in regulating various physiological processes in plants. Some PGRs contain ethylene or its derivatives as active ingredients to manipulate plant growth.
One notable PGR is ethephon, which releases ethylene upon breakdown in plant tissues. It functions as a plant growth regulator by promoting fruit ripening, stimulating flower development, and aiding in abscission (the shedding of plant organs).
Ethylene gas itself is used as a PGR in agricultural practices. It regulates fruit ripening, promotes flowering, and influences plant responses to stress. Ethylene gas is often employed in controlled environments, such as greenhouses, to manipulate the growth and development of plants.
These PGRs containing ethylene or its derivatives are utilized in agriculture and horticulture to manage various aspects of plant growth, such as flowering, fruiting, and overall development, demonstrating the significance of ethylene-based regulators in agricultural practices.