Polysiphonia. Life cycle of Polysiphonia Dr. Purnima Saikia, Asst.Prof Dept of Botany2017

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1 Polysiphonia Life cycle of Polysiphonia Dr. Purnima Saikia, Asst.Prof Dept of Botany2017

2 Polysiphonia thallus

3 Development of female gametophyte

4 MALE SEX ORGANS

5 Cystocarp with carposporangium Mature Cystocarp Thallus with cystocarps

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8 Life cycle of Polysiphonia

9 Polysiphonia consists of 3 different phases- haploid gametophytic phase, diploid carposporophyte and diploid tetrasporophyte phases. Separate male and female gametophytic plants develop spermatia and carpogonia. Diploid carposporophyte- gonimoblast filaments, carposporangia and carpospores. Diploid tetrasporophyte-the diploid carpospores germinate to produce tetrasporophytic plants,on which develop diploid tetrasporangia. Reduction division produces haploid tetraspores, which gives rise to 2 male and 2 female plants. Life cycle is triphasic,haplodiplobiontic type.

10 Thank you

11 Plant Tissue Culture Dr.Purnima Saikia, Asst.Prof., Dept of Botany, MDKG College,Dibrugarh.

12 Definition: The term plant tissue culture is described as in vitro and aseptic cultivation of any plant part on nutrient medium.

13 Fundamental principles: There are three fundamental principles (1) The plant part must be isolated from the rest of plant body. (2) The plant part (explant; isolated cell that is not infected) must be in a controlled, preferably defined, nutrient medium. (3) Aseptic condition must be maintained.

14 Flow chart of tissue culture

15 CAREFUL CULTURE OF AN EXPLANT

16 Types of plant cultures: (1) Callus Culture. (2) Cell Suspension Culture. (3) Anther Culture. (4) Ovule Culture. (5) Embryo Culture. (6) Protoplast Culture. (7) Micro Propagation.

17 History: (1) HABERLANDT. (2) WHITE. (3) NOBECOURT. (4) VAN OVERBEEK. (5) SKOOG. (6) BRAUN. (7) STEWARD. (8) MURI.

18 (1) Callus Culture technique When an excised and isolated piece of tissue is cultured on a nutrient medium, an unorganized mass of cell appears, is called callus. This callus is transferred on to different media to regenerate plants. this technique is called tissue culture.

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20 Culturing in front of LAF

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22 Some in vitro developed plants

23 Culture racks

24 LAMINAR AIR FLOW CHAMBER

25 LAMINAR AIR FLOW

26 Laminar air flow

27 Culture racks

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29 (2) Cell Suspension Culture It is the culture of isolated cells or very small cell aggregates dispersed in liquid medium. The cell suspension is obtained by agitating pieces of callus in liquid medium on gyrating shaker.

30 (3) Anther Culture Anther culture is a mean to produce plants with a gametic number of chromosomes by aseptic culture of anther. The technique give rise to haploid plants either directly or through formation of a haploid callus.

31 (4) Ovule Culture Ovule culture techniques is an important technique in modern plant breeding. it is much easier to culture whole ovule than to isolate a single embryo, especially in small seeded plants. E.g., tobacco

32 (5) Embryo Culture The embryos are isolated from young seeds and placed on a solid medium containing nutrients and vitamins. Embryos are cultured at 25 c,first in dark until seedlings are about 2 cm long and root formation has started, and than in light until the seedlings can be planted in soil.

33 (6) Protoplast Culture It is one of the most significant and recent developments in the field of plant tissue culture. the protoplast are usually isolated from cultured cell or leaf mesophyll cell by treating them with enzyme solutions. the isolated protoplast may be used to regenerate the plants directly, or for the production of somatic hybrids through fusion.

34 (7) Micro Propagation It is in vitro asexual propagation of crop plants. This technique is advantages over the conventional practice of asexual propagation as only a small amount of plant is needed, species highly resistant to conventional bulk propagation can be propagated by this method and it is non season dependent. Micro propagation is used for rapid multiplication of stocks, elimination of diseases, germ plasm preservation, and induction of mutation.

35 Applications: Tissue culture technique has helped in studying various biochemical and physiological processes in pure cultures without complications of other factors. The effect of various hormones are differentiation and growth processes can be studied by using tissue culture technique. Organogenesis has been studied by inducing formation of roots, shoot tips etc from callus on nutrient medium.