Class 11 · Plant Growth and Development

Ethylene: Plant Growth Regulator — NEET Biology

✅ Asked in NEET 2023
📖 NCERT Source

Ethylene is used to initiate flowering and for synchronising fruit-set in pineapples. It also induces flowering in mango. Since ethylene regulates so many physiological processes, it is one of the most widely used PGR in agriculture. The most widely used compound as source of ethylene is ethephon. Ethephon in an aqueous solution is readily absorbed and transported within the plant and releases ethylene slowly. Ethephon hastens fruit ripening in tomatoes and apples and accelerates abscission in flowers and fruits thinning of cotton, cherry, walnut. It promotes female flowers in cucumbers thereby increasing the yield.

NCERT Biology · Class 11 · Chapter 13 · Paragraph 45
How NTA Uses This Concept

NTA tests ethylene's role in initiating flowering (pineapples, mangos) and fruit ripening using ethephon as the commercial source. Students mistake ethylene for auxin or gibberellin, or confuse which hormone controls which process. The key trap: ethylene promotes abscission (leaf/fruit drop) AND ripens fruits simultaneously—opposite effects on different organs. To get it right, remember ethephon = ethylene source, and ethylene's dual roles: flowering initiation in some crops, fruit ripening, and senescence/abscission in others. This distinguishes ethylene from other PGRs and is highly testable for agricultural applications.

Solve This NEET Question

This paragraph was tested 2 times in NEET.

Q1 of 2NEET 2023

Match List-I with List-II: (NEET 2023) List-I: A. Auxin B. Gibberellin C. Cytokinin D. Ethylene List-II: I. Promotes flowering in pineapple II. Overcoming apical dominance III. Increase in the length of grape stalks IV. Promotes female flower formation in cucumber Choose the correct answer from the options given below:

Q2 of 2NEET 2022

Production of cucumber has increased manifold in recent years. Application of which of the following phytohormones has resulted in this increased yield as the hormone is known to produce female flowers in the plants? (NEET 2022 Phase 1)

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