166
cb ca m
l m ci
l' m
ca m
ci m
Figure 68: A. sessilis ‘Red’. Two, three and four-celled proembryos.
A: Two-celled proembryo.
B: Four-celled proembryo. Remnants of degenerated synergid persist (indicated by arrow).
C: Three-celled proembryo.
C1: Prominent cell ca. C2:
Cell cb divides before ca giving rise to cells ci and m. Remnants of degenerated synergids persist (indicated by arrow).
k m
A B
C1
C2 ca
m
m ci
170
Figure 69: A. sessilis ‘Red’. Linear, quadrant and octant proembryos.
A: Seven-celled linear proembryo.
B: Quadrant proembryo with accumulation of endosperm nuclei around it.
C and D: Octant proembryo.
n'
l' l m
d f
h m
k m
p o m m
l l' m
l' m l'
m l
l
d
d d
f
f f
h m
h m
h m k
m
k m
k m n'
n'
A B
C D
167
170 d
su f m
su m
A B
C D
E
Figure 70: A. sessilis ‘Red’. Octant proembryo and globular embryo.
A: Octant proembryo with dermatogen initiated (indicated by arrows).
B: Young globular embryo with multiseriate suspensor.
C: The lens-shaped hypophysis cells are detached from the upper cell of the suspensor (indicated by arrows).
D: Late globular embryo. Dermatogen is formed.
E: Late globular embryo. The suspensor is uniseriate except at the basal end where it is multiseriate (indicated by arrow).
142:
168
171
Figure 71: A. sessilis ‘Red’.
Late globular and hearth- shaped embryo, mature embryo.
A: Late globular embryo with cotyledon initiated.
B: Heart-shaped embryo.
B1: Cotyledons growing.
B2: Procambial cells in the hypocotyl of the embryo axis (indicated by circle).
C: The mature embryo is dicotyledonous, curved and annular.
A B1
B2 co
ep
C co
p
sa
169
172
Figure 72: A. sessilis ‘Green’. Two, three and four-celled proembryos.
A: Two-celled proembryo.
B: Three-celled proembryo. Cell cb divides before ca.
C: Four-celled proembryo. Remnants of synergids persist.
ca m cb m fe
ca m
m
ci
m ci
l' m l
sy
A B
C
170
174 l
l' m d f h km m n'
l l' d m
f h k
o p
l
l' m d m h k m m
f m
n'
l l' m
d m
f m h m
k m o m p m
A B
C D
Figure 73: A. sessilis ‘Green’. Linear, quadrant and octant proembryos.
A: Seven-celled linear proembryo.
B: Eight-celled linear proembryo.
C: Vertical division in l and l’ results in a quadrant.
D: The quadrant continues to divide vertically or obliquely and gives rise to an octant.
171
175 d
m d
m su
m
su m
A1 A2
Figure 74: A. sessilis ‘Green’. Octant and globular embryos.
A1 & A2: Octant proembryo with dermatogen initiated (indicated by arrows).
B & C: Late globular embryo. Dermatogen has been differentiated (indicated by arrow).
B C
172
176
Figure 75: A. sessilis ‘Green’.
Torpedo and mature embryo.
A: Torpedo-shaped embryo with distinct procambial cells.
B: The mature embryo is dicotyledonous, curved and annular.
A
B
173
177
A B1
fe m d
m
ci m f
l m
d m l' m
su
co p
D su
C B2
Figure 76: A. paronychioides. Embryo development.
A: Five-celled linear proembryo.
B1: Young globular embryo with dermatogen initiated (indicated by arrows).
B2: Elongated nucellar cells with dense cytoplasm and nucleus (indicated by circle).
C: Heart-shaped embryo with cotyledon initiated (indicated by arrows).
D: The mature embryo is dicotyledonous, curved and annular.
174
168
A B
C
D
Figure 77: A. paronychioides.
Abnormal embryo development.
A: Young globular embryo.
B: Remnant synergids persist.
C: Laterally situated antipodals degenerating.
D: Conspicuous primary endosperm nucleus situated below globular embryo.
Figure 77: A. paronychioides.
Abnormal embryo development.
A: Young globular embryo.
B: Remnant synergids persist.
C:Laterally situated antipodals degenerating.
D: Conspicuous primary endosperm nucleus situated below globular embryo.
175
176 p
co
sa
Figure 78: A. ficoidea.
Mature embryo.
A: The mature embryo is dicotyledonous, curved and annular.
8B: Root apical meristem (indicated by circle) and procambial cells (indicated by arrow).
C: Procambial cells growing in the cotyledons (indicated by arrows).
A
B
C
177
A B1
B1 Figure 79: A. brasiliana. Nucellar embryo initial cells.
A & B: Nucellar embryo initial cells with dense cytoplasm and conspicuous nuclei (indicated by arrows).
178
A1 A2
B1 B2
B3 B4
Figure 80: A. brasiliana. Degenerating egg apparatus, nucellar embryo initial cells and nuclear endosperm.
A1: Degenerating synergids.
A2: Nucellar embryo initial cells (indicated by arrow).
B1 & B2: Degenerating synergids.
B3: Degenerating egg cell.
B4: Free endosperm nucleus (indicated by arrows).
sy
sy sy
eg
179
A1 A2
B1 B2
B3 fe
fe fe
ne
Figure 81: A. brasiliana. Zygote and proembryo.
A1 & A2: Nucellar embryo growing into the embryo sac (indicated by arrows).
B1−B3: Two zygotes and a two- celled proembryo growing into the embryo sac (indicated by arrow).
micropylar region
Chalazal region
Chalazal region
zy
zy
180 Figure 82: A. brasiliana. Globular and torpedo embryos.
A1: Globular embryos without suspensor and located further away from the micropyle.
A2: Globular embryo without histogenic differentiation.
B: Two globular embryos in a single embryo sac.
C1 & C2: Torpedo embryo without suspensor and located further away from the micropyle.
A1 A2
B
C2 C1
co
181 A
b
co m
em 1 em 2
Figure 83: A. brasiliana. Mature embryo.
A: Two embryos in a seed.
B: The smaller embryo.