The Reproductive Body: Fruits and Seeds PBIO 006 Summer 2015 Chapter 6

Outline I. Fruit Types II. Fruit Dispersal III. Seed Structure and Germination

Ovary to fruit

Kinds of Fruits

Kinds of Fruits Simple fruits develop from a single ovary (simple or compound) of a single flower Fleshy (e.g., tomatoes, lemons, cucumbers, cherry, apple) Dry, dehiscent (e.g., legumes, like peanuts) Dry, indehiscent (e.g., sunflower “seeds”) Aggregate fruits develop from many separate simple pistils in a single flower (e.g., raspberries, strawberries) Multiple fruits develop from the fusion of ovaries from many separate flowers on an inflorescence (e.g., pineapples)

Berry: a simple, fleshy fruit with a soft pericarp Grapes Tomato www.ecigexpress.com Blueberry Kiwifruit

Drupe: A simple, fleshy fruit where the pericarp is divided into three layers Peach, Prunus persica

Dry fruits have a woody or papery pericarp Some dry fruits are dehiscent Amaryllis capsule http://dragonplants.blogspot.com Dry, dehiscent fruits Milkweed (Asclepias syriaca) follicle

Dry, indehiscent fruits Red maple fruit is a samara Sunflower fruit is an achene Fruit of the grass family is a grain www.wholesystemsdesign.com

Aggregate fruit A raspberry is an aggregate fruit: each little “drupelet” is the product of a separate ovary. Each drupelet contains a single seed.

Accessory fruit strawberry achene The strawberry is an accessory fruit: the sweet, juicy part is receptacle, not ovary wall! The true fruit part is the achene.

Multiple fruits The pineapple is an example of a multiple fruit: the fruit is derived from the fusion of an entire inflorescence.

What kind of fruit is an olive? A berry A capsule A drupe A pome It’s not a fruit, it’s a vegetable

A fruit develops from a single pistil A fruit develops from a single pistil. It has a tough, woody pericarp and splits open at maturity to reveal dozens of small seeds. Which of the following terms would be appropriate in describing this fruit? simple dry dehiscent A and B A, B and C

wind animal (active) animal (passive)

Fleshy fruits are dispersed by birds and other frugivorous animals.

Coconuts are dispersed by water.

Outline I. Fruit Types II. Fruit Dispersal III. Seed Structure and Germination

So what is a seed again? A brief review…

(in central cell) cell

S E D T R U C

S cotyledons E D hypocotyl G R M I N A epicotyl T (not visible) O radicle lev70065_06_02.jpg Dicot embryo

Germinating peanut seedling Seed structure Germinating peanut seedling epicotyl

Seed germination in the common garden bean, a eudicot Foliage leaves Cotyledon Cotyledon Cotyledon Figure 38.9 Two common types of seed germination. Radicle Seed coat Seed germination in the common garden bean, a eudicot

Chapter 6 Review Questions Describe the relationship between the ovary and the fruit; between the ovule and the seed. What is a simple fruit? Describe several different kinds, distinguishing between them. How do aggregate and multiple fruits differ from simple fruits? What functions do fruits serve in the life of the plant? Diagram a seed. What are its principal parts and what functions do they serve?