Horticulture Exam 1

Scarification

The process of physically breaking or softening the seed coat to enhance germination by allowing water and gases to penetrate.

Ethylene

A plant hormone that promotes growth, a gaseous hormone involved in regulating fruit ripening and flower wilting. Can counteract the effects of abscisic acid.

Scarification

The process of physically breaking or softening the seed coat to enhance germination by allowing water and gases to penetrate.

Ethylene

A plant hormone that promotes growth, a gaseous hormone involved in regulating fruit ripening and flower wilting. Can counteract the effects of abscisic acid.

Abscisic Acid

A plant hormone that inhibits growth, promotes seed dormancy, regulates germination and helps plants respond to stress conditions such as drought.

Auxin

A plant hormone that regulates growth, particularly in elongation, apical dominance, and root development. Regulation of cell division and expansion, Stem elongation, Branching of the stem, and Regulates tropism plays a key role in the response of plants to light and gravity. Transport; moves from top to bottom - The only plant hormone know to do this

Cytokinin

A plant hormone that promotes cell division and lateral bud development. Most concentrated in the roots and become less concentrated towards the shoots. Modify optical dominace and promotes lateral growth.

Cytokinin > auxin

shoot development

Auxin > cytokinin

root development

Equal parts of auxin and cytokinin

callus development

Apical dominance

the phenomenon where the main central stem of a plant grows more strongly than the other side stems, often regulated by auxin. (The Christmas tree effect)

The Christmas Tree Effect

Suppresses lateral bud growth

Blending inheritance

a genetic concept where the traits of offspring are a mixture of the traits from both parents, rather than a strict dominance of one trait over another.

Perennial

A plant that lives for more than two years, Repeat vegetative and reproductive growth annually. Typically survives a cold winter in a dormant state, or by means of roots or stem modifications

Annual

A plant that completes its life cycle in one year. Monocarpic - die after reproducing

Biennial

A plant that completes its life cycle in two years, or two growing seasons.

First season: vegetative growth,

Second season : reproductive growth

The Ovual / ovary

The swollen base of the gynoecium, which includes. A chamber called a locule. Inside the locule, one or more ovules. Inside the ovules, an embryo sac which when fertilized by pollen the ovule becomes a seed.

Gibberellins

Regulatory plant hormone. Produced in seeds, Stimulate germination by breaking seed dormancy. Activate a number of enzymes.Control cell division and overall plant growth. Produced in very young expanding leaves, immature seeds and roots.

Vivipary

Germination of a seed while it is still attached to the mother plant. Viviparous or precious germination

A Propagule

Any plant material used for propagation.

Totipotency

The concept that each living plant cell has the potential to reproduce an entire organism since it possess all necessary genetic information in its genes.

Determinism

Describes the degree to which cells are committed toward a specific direction at a given time. The development of competency by a tissue before it is expressed requires a certain amount of time.

Endosperm

The tissue within a seed of a flower plant that nourishes the developing embryo. Essentially acting as a food source for the growing seedling during germination

Deficiency in gibberellin

Dwarfism

Seed

the reproductive unit in plants that leads to sexual propagation.

Stigma, Style, Ovary

Structures in the carpel or pistil of a flower.

Apomixis

Unsuals type of seen development results in a genetic clone of the mother plant.

Dominant Trait

A genetic factor that blocks another genetic factor. Deen when offspring have either one or two dominant factors.

Inter-generic Hybrid

The cross between two plants of different genera. 

2 categories of cell division 

Meiosis and Mitosis

Meiosis

specialized cell division process that occurs in plants during sexual reproduction. Produces reproductive cells like pollen and ovules.

Mitosis

The process where a plant cell divides into two identical daughter cells for vegetative growth and development of plant tissues.

What is stratification

The horticulture practice of providing moist, aerated cooling for seeds to germinate.

Protandry

Pollen shed before the stigma is receptive. Male reproductive parts mature before female reproductive parts.

Protogyny

Stigma is receptive before pollen shed. Female reproductive parts mature before the male reproductive parts.

Polyembryony

Development of multiple embryo sacs within a single ovule (seed). Happens with citrus.

Cleistogamy

Common in self-pollinating crops. Flower remains closed, preventing external pollen from reaching the stigma.

Competence

A term used to describe the potential of a cell or tissue to develop in a particular direction. Successfully perform tasks related to cultivation.

4 phases in the life cycle of a seed development 

Embryonic, Juvenile, Transitional, Adult

Pollination

When pollen lands on the pistil of a flower. Sperm cells from the pollen then fertilize egg cells in the pistil.

Fertilization

The process where the male gamete (pollen) from a flower fuses with the female gamete (ovule) to form a zygote. Must occur for seed development.

Imbibition

Is a physical process in which the seed rapidly takes up water and hydrates the inner tissues.