Fruit Development and Seed Germination

These flashcards cover key concepts from the lecture on fruit growth, seed germination, seed dormancy, and the physiological processes related to these plant development topics.

What are the two main topics of Week 9's overview in plant development?

Fruit growth and seed germination.

What is the significance of climacteric fruit during ripening?

Climacteric fruit have a peak in respiration and ethylene production as they ripen.

What defines seed dormancy?

Seeds that do not germinate readily in 4–6 weeks under suitable conditions.

What is the difference between orthodox and recalcitrant seeds in terms of storage?

Orthodox seeds are stored at <10% water content and <10°C; recalcitrant seeds need high water content and warm temperatures.

What are the three types of seed dormancy?

Physical dormancy, physiological dormancy, and morphological dormancy.

What treatments can break seed dormancy?

Scarification, hot water treatment, concentrated acid treatment, and stratification.

What is gravitropism?

Growth response of plants to gravity, with roots showing positive gravitropism.

What does phototropism involve?

The growth of plant parts toward light, primarily regulated by auxin distribution.

What is the role of gibberellic acid in seed germination?

It can sometimes replace the need for dormancy-breaking techniques.

What are germination stimulants?

Substances that promote seed germination, such as gibberellic acid or smoke.

What is the role of light in seed germination?

Seeds detect red light via phytochrome, which regulates germination.

What are some examples of germination stimulants from fire-prone habitats?

Smoke and heat treatments that damage seed coats or leach inhibitors.

What are the phases in fruit growth?

Phase 1: Pericarp cell division; Phase 2: Enlargement of existing cells.

What defines non-endospermic seeds?

Seeds that do not utilize a storage endosperm; they have storage cotyledons.

What is the pericarp?

The part of the fruit formed from the ovary wall, which includes exocarp, mesocarp, and endocarp.

What defines seed longevity in relation to seed viability?

Viability may last for years in some species while in others, it could be just days or months.

What is xenia in plant reproduction?

The effect of the male parent on the phenotype of the seed or fruit.

How can controlled atmosphere storage extend the storage life of fruits?

By elevating CO2 and/or reducing O2 and absorbing ethylene.

What physiological changes occur during the ripening of fruits?

Increasing respiration, ethylene production, flesh softening, and color changes.

What strategies can be employed to extend the storage life of fruits?

Cool temperatures, heat treatments, maintaining humidity, and using ripening inhibitors.