advanced anatomy of plants vascularization

this video have the important content regarding advanced anatomy of plants including vascularization

1. Advanced anatomy of plants vascularization

2. Advance anatomy of plant BS Botany 8 th EA submitted to mam sadia submitted by Farwa tariq Government college women university Faisalabad

3. Vascularization definition The gradual sequence of development and arrangement of xylem phloem and cambium in plant is called vascularization. Evolution of  vascular tissues  in plants was one of the essential adaptations to terrestrial habitats. Vascular tissues are the specialized conducting tissues,  xylem  and  phloem . Plants with vascular tissues are grouped as the  Tracheophyta  and include  Pteridophyta ,  Gymnosperms  and  Angiosperms .

4. Xylem:   It is a specialized tissue for  conduction  of  water  and  minerals  from roots to all other parts of the plant. Xylem is a complex and heterogeneous tissue composed of four types of elements namely (a)  tracheids  ,(b)  vessels  ,(c)  fibers  ,and   (d)  xylem parenchyma  . The first three elements are  dead  and  lignified . Hence, xylem is described as a dead tissue.

5. Phloem It is a living, complex and heterogenous food-conducting tissue. It is composed of (a)  sieve tubes ,  (b)companion cells ,  (c) phloem fibers  and  (d) parenchyma  . In plants, vascular tissues are organized into strands called  vascular bundles . These are spread over all parts of the plant and form the vascular tissue system. In gymnosperms and dicotyledons,  cambium  is also present in the vascular bundles.

6. Steles:   The vascular tissues are organized into  steles . The vascular bundles, with or without other non- vascular tissues, when surrounded by the pericycle and the endodermis are referred to as steles. Main types of steles and their evolution Protostele   This is the simplest and most primitive type of stele in which xylem forms the central cylinder and is surrounded by phloem cells. Pith is totally absent. Common in pteridophytes like  Psilotum, Lycopodium , etc.

7. vascularization Vascularization refers to the process of the formation of the vascular tissues of the xylem and the phloem. The meristem that gives rise to the vascular tissues is called the cambium. During the primary growth of the plants, the procambium develops first which then forms the xylem followed by the phloem. During the secondary growth, this task is performed by the vascular or secondary cambium. Hence, the correct answer is 'Differentiation of procambium followed by the development of xylem and phloem .'

8. What happen during vascularization: Development of vascular bundles from procambium is called as vascularization. Thin walled elongated procambium strands are produced during the early growth and differentiation, which in turn immediately differentiate into primary xylem and primary phloem simultaneously. Development of procambium is followed by formation of primary vascular tissues. Secondary xylem is developed from vascular cambium during secondary growth, not from procambium.

9. It is widely held that the vascular systems in flowers are conservative, that is, they may remain relatively unchanged even when the general shape of the flower has altered by evolution. This may lead to the formation of odd-looking loops or curves in some of the vascular strands to accommodate changes in the relative positions of the floral parts. . Vascularization gives the origin of flowering plants

10. In some flowers, small branches of the vascular system end blindly. This could be taken to mean that in one or more of the ancestors of the plant similar strands served some organs or appendages that are lacking in the present-day representative. For example, a modern, unisexual female flower might have remnants of a vascular system that would have served stamens in a bisexual ancestor.

11. Fusion in vascularization Stamen fused with a petal It often follows that the vascular supplies of the two become fused into one strand. Bundle fusions can make it more difficult to interpret the vascular systems of flowers in comparative studies. .

12. Traces in floral description The number of traces to each floral organ can vary. Often petals have only one trace, but petals in certain families regularly have three petal traces. The number of traces to each sepal is often the same as that to the foliage leaves of the same plant. Stamens may have one or three traces, but one is by far the most common number. Carpels may possess one, three, five or more traces. Dorsal and marginal or ventral traces are distinguished in descriptions, when three or more are present.

13. Theories of vascularized angiosperm Several theories concerning the origin of the angiosperm flower have their basis in comparative studies of floral and vegetative vascular pat-terns of both living and fossil plants. Despite the amount of work done by numerous people, there is no common consensus. Doubtless, new theories will be proposed. Some think that we have all the evidence we need, if only we will interpret it properly. Others consider that there are such large gaps in the fossil record that no one will ever be able to prove their theories! Modern molecular studies have led to the development of much less subjective phylogenies, and it has become profitable to study flower morphology in the light of the new information these contain

14. First condition In one of them the vasculature to floral parts on the same radius arises from a common bundle in the ovary wall as in Gaylussacia frondosa and all bundles as seen in cross-section have the xylem internal to the phloem. Thus, they are found, for example, in the Rosaceae and Ericaceae as well as in other families Second condition In the other organization, the bundles that supply the carpel arise from a recurved bundle in the ovary wall as in Nestroniaumbellulata , where the recurved bundles in the fruit wall are in-verted, so that the phloem is interior to the xylem. they are found, for example, in the Cactaceae and Santalaceae as well as in other families Basic pattern of vasculature to floral part:

15. Basic pattern of vasculature to floral part:

16. SUMMARY- VASCULARIZATION Conducting tissues  in sporophyte plant body of vascular plants were evolved in response to terrestrial habitat. Xylem conducts water and minerals, while phloem conducts organic solutes. The strands of xylem and phloem form vascular bundles, which may or may not have  cambium . The vascular bundles are organized into various types of stele. The simplest type is the protostele, while the eustele of dicots and the atactostele of monocots are supposed to be the most evolutionary advanced type.

17. https://www.youtube.com/watch?v=do3rG1RoW-8

18. References: http://www.brainkart.com/article/Vascularization---Plant Anatomy_19100/ https://www.toppr.com/ask/question/vascularisation-in-plants-occur-through/ https://pubmed.ncbi.nlm.nih.gov/11141169/ http://pinkmonkey.com/studyguides/subjects/biology-edited/chap15/b1515501.asp