Physiology of Flowering

Abstract

About 90% of the ≈ 350,000 known plant species are the flowering plants. Flowering is the most enigmatic phase in the life of a plant. It provides a mechanism to plants for genetic outcrossing which provides a means of securing a greater variety of genetic recombination. Flowers are specialized structures which differ extensively from the vegetative plant body in form and cell types. Numerous physiological and biochemical changes take place within the shoot apex when it prepares itself for transition into floral bud. The precise time of flowering is important for reproductive success of the plant. Plants need to sense when to produce flowers so that fruit and seed development can be attained which will ensure its survival in the next season. Synchronous flowering is significant in outcrossing plants. Since long, people have wondered how plants are able to flower in a particular season. Plants possess the ability to anticipate and sense change of seasons. It has always been a fundamental question as to how environmental signals influence flowering and how these signals are perceived.

Multiple-Choice Questions

• 1. Induction of flowering by low temperature treatment is termed as:

  • (a) Vernalization

  • (b) Photoperiodism

  • (c) Cryopreservation

  • (d) Defoliation

• 2. A gene that represses flowering in Arabidopsis:

  • (a) LFY (Leafy)

  • (b) FLC (Flowering locus C)

  • (c) CO (Constans)

  • (d) CRY2

• 3. The phenomenon of photoperiodism in plants was discovered by:

  • (a) Chailakhyan

  • (b) Borthwick and Hendricks

  • (c) Skoog and Miller

  • (d) Garner and Allard

• 4. Which of the following pigment plays a role in induction of flowering as identified by Chailakhyan:

  • (a) Cytochrome

  • (b) Vernalin

  • (c) Florigen

  • (d) Xanthophyll

• 5. According to ABC model in Arabidopsis, B and C genes are required for:

  • (a) Petals

  • (b) Stamens

  • (c) Sepals

  • (d) Carpels

Answers

1. a

2. b

3. d

4. c

5. b