BIO3: Plant Reproduction

PLANT REPRODUCTION

A. Asexual Reproduction

a) Natural – Vegetative propagation using vegetative propagules such as metamorphosed organs.

Ex.

b) Artificial – cuttings -- layering (marcotting) -- grafting -- tissue culture

Ex.

Cuttings

Air-layering (Marcotting)

Grafting

Tissue culture

B. Sexual Reproduction

- plants have diplo-haplontic life cycles, which means, there is an alternating diploid (sporophyte) and haploid (gamerophyte) generations. These generations are heteromorphic (different structures).

1. FLOWERPARTS: a) essential/ fertile parts

-CARPEL or PISTIL (megasporophyll)- stigma, style, ovary and ovule: GYNOECIUM-STAMEN (microsporophyll)- anther and filament: ANDROECIUM

b) non-essential/ sterile parts-PETALS – corolla-SEPALS – calyx -perianth- collective term for corolla and calyx.

*all floral parts are attached to the receptacle and held by the peduncle.

2. VARIATIONS IN FLORAL STRUCTURE

a) presence or absence of floral parts COMPLETE FLOWER- when the stamen, pistil, petals and sepals are present within the flowerINCOMPLETE FLOWER- when any of the four floral parts is missing

Complete Incomplete

What’s missing in the incomplete flower?_________________

b) presence or absence of reproductive structuresPERFECT FLOWER- 1 flower: present both stamen and pistil (bisexual)IMPERFECT FLOWER- either stamen or pistil is missing in a flower (unisexual): STAMINATE (with stamen only) or PISTILLATE (with pistil only)

MONOECIOUS- both male and female flowers in one plant (“live-in”)

DIOECIOUS- the male and female flowers are housed in different plants (“separated”)

Monoecious incomplete flower

Dioecious incomplete flower

c) similarity in shape and distance of floral partsREGULAR FLOWER- all parts are similar in shape and distance from the receptacleIRREGULAR FLOWER- parts are different in shape and distance

Regular Irregular

d) symmetryACTINOMORPHIC – radially symmetricalZYGOMORPHIC – bilaterally symmetrical

Zygomorphic Actinomorphic

e) attachment of petalsAPOPETALOUS – each petal is attached at its base to the

receptacleGAMOPETALOUS – petals are fused at their bases, forming a

corolla tube

Apopetalous Gamopetalous

f) arrangement of floral partsWHORLED FLOWER- all floral parts in whorls or circles the axis

(receptacle)SPIRAL FLOWER- all floral parts in spiral or helical arrangement

spiral flower

g) position of floral parts with respect to the ovaryHYPOGYNOUS- floral parts below the ovaryEPIGYNOUS- floral parts above the ovaryPEIGYNOUS- half- superior, half-inferior

h) position of ovary with respect to other floral partsSUPERIOR OVARY- hypogynous flowerINFERIOR OVARY- epigynous flower

3) ANTHER

a-epidermis; b-tapetum; c-spore mother cell; d-pollen

4) OVARY

Types of placentation:

Lilium ovary

5) OVULE

A- ChalazaB- NucellusC- IntegumentsD- AntipodalsE- Polar nucleiF- EggG- SynergidsH- FuniculusI- micropyle

6) TYPES OF INFLORESCENCE

Spike – sessile florets (no pedicel)Catkin – inverted spikeSpadix – spike and spatheRaceme – pedicellatePanicle – branched floretsCyme – odd nos., terminal flowers bloom firstCorymb- flat top, matginal flowers bloom firstUmbel – pedicels, equal in length; one point of originHead or capitulum- 2 types of florets: ray and tube flowers