Anomalous secondary growth(Easy mind maps)

Any change can happen in cambium (abnormal activity)leads to secondary growth. For instance, Boerhavia, Bougainvillea, Raphanus and Beet root are dicot plant. Dracaena is a monocot plant.

1. ANOMALOUS
SECONDARY GROWTH
Saloni Rani Swain
Botany Student
President science college, Ahmedabad, Gujarat.

2. TOPIC
Introduction
Dracaena stem(Monocot)
Bougainvillea and Boerhavia stem(Dicot)
Raphanus and Beet (Root)
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3. Introduction
Anomalous or Abnormal secondary
growthdoesn’t follow normal secondary
growth in which vascular cambium produces
xylem on inside and phloem on outside.

4. ABNORMAL GROWTH
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STEM ROOT
Monocot Dicot
Dracaena
Boerhaavia
Bougainvillea
Raphanus Beet

5. DRACAENA
(MONOCOT)

6. PRIMARY
VASCULAR BUNDLE
❑It is a monocot plant but due to abnormal growth of
cambium it behave like a dicot.
❑Roughly circular
❑Epidermis is made up of single layered.
❑Ground tissue –Parenchyamatouscell.
❑Primary vascular bundle are collateral, conjoint, closed and
endarch.
❑They are scattered in parenchyma ground tissue. Each
primary bundle is enclosed with thick-walled
sclerenchymatoussheath.

7. SECONDARY
GROWTH
❑In old stem, epidermis replaced by formation of periderm
(cork cambium –phellogen).
❑Multilayered cortex.
❑Old stem cambium develop outside the primary vascular
bundle.
❑Cambium ring form and it divide into two side outer and
inner:
if talk about outer side of cambium then found little
parenchyma and conjunctive tissue is present inner side.
❑Special type of stele present in dracaena such as
Concentric Amphivasal vascular bundle( means secondary
phloem inner side and secondary phloem outside )

8. MICROSCOPIC VIEW
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9. BOERHAAVIA
(DICOT)

10. PRIMARY GROWTH
oBorder-Nearly circular
oEpidermis-Uniseriate, covered with cuticle, a few multicellular hair present.
oCortex-Outer 3-5 layer collenchyma(hypodermis) and inner layer is made up
chlorenchyma cell.
oEndodermis and Pericycle are not distinct.
oPrimary vascular bundle –Conjoint, collateral, Open, Endarch.
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11. 11
Three Vascular rings are form
Outside from
cambium there 15 to
20 small vascular
bundles are present
Middle ring –6 to 14 ,
oval in shape. It help
in secondary growth
Inner ring –2 to 3
larger vascular
bundle (medullary
ray)
The protoxylem of
these bundle face
each other (help in
secondary growth)

12. SECONDARY GROWTH
Cambium
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Secondary phloem –It present outer side ,thus it cut
parenchymatous ground tissue.
Secondary xylem-inner side and parenchymatous tissue
(lignified)
The activity of this cambium may stop and new cambium ring
formed

13. ❖SUCCESSIVE
CAMBIUM RING
ARISE.
PITH LARGER IN
SIZE AND MADE UP
OF PARENCHYMA
CELL

14. MICROSCOPIC
VIEW
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15. BOUGAINVILLEA
(DICOT)

16. PRIMARY GROWTH
•It is similar to Boerhavia ,but minor difference can be seen like, inside the stele
only two vascular bundles are form instead of three.
•Epidermis-single layered (cuticle, thick, made up of parenchyma).
•Hypodermis-Few layer thick (collenchyma).
•Endodermis-Not distinct yet present.
•Pericycle-Heterogenous arrangement of tissues (Parenchyma and sclerenchyma
cell alter to each other).
•Vascular bundle -Irregularly arrange.
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17. SECONDARY GROWTH
•Successive rings of Accessort cambia form.
•Secondary growth -Formation of first cambial ring which is extra stelar in origin.
•Cambium arise from pericycle.
•First cambium life is too short
•Secondary parenchyma-fusiform.
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when new
cambium form it
break from interally
and externally
Internally-
secondary xylem
alternate to
parenchyma
Externally-
secondary phloem
above secondary
xylem and
parenchyma

18. •Thus successive concentric rings of
vascular bundles are formed thick walled
conjuctive tissue.
•New cambium never make complete ring
surrounding the pericycle it attach to
above cambium
•In some species phloem can not be
distinguished.
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19. MICROSCOPIC VIEW
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20. RAPHANUS
(ROOT)
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21. RAPHANUS
•It is a dicotroot.
•Primary xylem and phloem tissue arranged alternative.
•Arrangement of protoxylemon outer side pr towards the cortex. It is called exarch.
•During secondary growth the cells of pericycle convert in cambium.
•The cells of upper portion of the xylem and cells of lower protion of phloem convert in cambium ring.
•The first ring of cambium behave normalit produce less amount of secondary phloem on outer side and
higher amount of secondary xylem inner side.
•The parenchymatous cells of the secondary phloem produced remaining all cambium ring it is known as a
accessory cambium.
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22. ➢The all accessory cambium behave
anomalous or abnormalfunction it
produce less amount of secondary
phloem on outer side and higher
amount of secondary in inner side.
➢Im secondary xylem the component of
xylem parenchyma is higher it a
anomalous of the root.
➢The function of secondary xylem
parenchyma is storage the foodit is
also a anomaly.
➢Due to higher amount of secondary
xylem parenchyma the Raphanus root
look thick and fleshy.
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23. RAPHANUS IN
MICROSCOPE
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24. BEET
(ROOT)
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25. BEET
•It is a dicot root, thus storage zone is present.
•Secondary growth in these storage root is anamalous.
•Primary structure-Cotyledon type root with radical diarch.
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Secondary
Abnormal activity
of cambium
Abnormal
position of
cambium

26. •Secondary growth is initiated by the formation of a cambial ring.
•Cambial ring formed pericycle outside protoxylem and parenchyma
between the xylem and phloem.
•Primary cambium---Abnormal
•Collateral, Conjoint.
•Cambium after sometime ceases its activity.
•Then second arise just outside the first parenchyma or outer ring of
pericycle.
•Second--Abnormally behave like first.
•Grow continiuosly parenchyma cell.
•Dark red colour just because of Anthocyanin.
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Inner side-sec. xylem and
parenchyma alternative.
Outer side-sec. xylem opposite to
sec. xylem and parenchyma.

27. BEET ROOT
MICROSCOPIC VIEW
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28. REFERENCE
•By S.N.PANDEY
• https://images.app.goo.gl/T8DqP8i4n1hhoMBEA
• https://images.app.goo.gl/ffE49jVmjeLj3uDLA
• https://images.app.goo.gl/vw4X7z8zjnB6X2Bh7
• https://images.app.goo.gl/YwTJzYb2qvon5BbQ9
• https://images.app.goo.gl/ys7QYm1YYNG91ut2A
• https://images.app.goo.gl/JKfyKaXRNUMLDMEv9
• https://images.app.goo.gl/sD1H3V4YQnLVVnK59
• https://images.app.goo.gl/XsiysexqJt4HLbbA6
• https://images.app.goo.gl/9GHC9EQNXMEKXMLW7
• https://images.app.goo.gl/3oeEwJr9QzCrz1ho6
• https://images.app.goo.gl/YWhKPxxd5K7jFZvn6
• https://images.app.goo.gl/BMfC5FmZXhh8bGvJA
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29. THANK
YOU
Saloni Rani Swain
[email protected]