Pollen pistil interaction
Types of Incompatibility in plants
Methods to overcome Incompatibility
Prepared by
Dr. T. Annie Sheron
Assistant Professor of Botany
DEPARTMENT OF BOTANY
KAKATIYA GOVERNMENT COLLEGE, HANAMKONDA
Pollen pistil interaction
Types of Incompatibility in plants
Methods to overcome Incompatibility
Prepared by
Dr. T. Annie Sheron
Assistant Professor of Botany
DEPARTMENT OF BOTANY
KAKATIYA GOVERNMENT COLLEGE, HANAMKONDA
Vascular Cambium & Seasonal activity & its Role in Stem & RootFatima Ramay
Vascular Cambium & Seasonal activity & its Role in Stem & Root:
The vascular cambium (pl. cambia or cambiums) is a lateral meristem in the vascular tissue of plants.
The vascular cambium is a cylindrical layer of cambium that runs through the stem of a plant that undergoes secondary growth.
In Dicots:
The vascular cambium is in dicot stems and roots, located between the xylem and the phloem in the stem and root of a vascular plant, and is the source of both the secondary xylem growth (inwards, towards the pith) and the secondary phloem growth (outwards).
In Monocots:
Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots.
Cambium of some plants remains active for the entire period of their life, i.e., cambial cells divide and resulting cells mature to form xylem and phloem elements.
This type of seasonal activity usually found in the plants present in the tropical regions, and not all plants show cambial activity.
Percentage of ringless trees in the rain forests of; India : 75% Amazon : 43% Malaysia : 15%
In regions with definite seasonal climate; seasonal activity of cambium ceased with onset of unfavorable conditions; In Autumn, it enters the dormant state and lasts for the end of summer; In Spring, cambium again becomes active.
Duration of cambial activity is also affected by day-length, e.g., In Robinia pseudoacacia, cambium is dormant under short-day condition.
The cambium cells formed in circular in cross section from the beginning onwards.
The cambial ring is partially primary (fascicular cambium) and partially secondary (interfascicular cambium).
Periderm originates from the cortical cells (extra stelar in origin).
In Dicot stem, for mechanical support xylem is with comparatively smaller vessels, greater fibers and less parenchyma.
More amount of cork is produces for protection.
Lenticels on periderm are very prominent.
The cambial ring formed is wavy in the beginning and later becomes circular.
The cambium ring is completely secondary in origin.
Periderm originates from the pericycle (intra stelar in origin).
In Dicot root, xylem is with big thin walled vessels with few fibers and more parenchyma.
Less amount of cork is produced as root is underground.
Lenticels on periderm are not very prominent.
Double fertilization is the process found in angiosperms in which out of the two male gametes released inside the embryo sac, one fuses with the egg cell (syngamy) and another fuse with secondary nucleus (triple fusion).
Embyrology in relation to Taxonomy. It is one of the concepts in Modern Taxonomy.in which embryological data is used to strengthen existing classification system.
Vascular Cambium & Seasonal activity & its Role in Stem & RootFatima Ramay
Vascular Cambium & Seasonal activity & its Role in Stem & Root:
The vascular cambium (pl. cambia or cambiums) is a lateral meristem in the vascular tissue of plants.
The vascular cambium is a cylindrical layer of cambium that runs through the stem of a plant that undergoes secondary growth.
In Dicots:
The vascular cambium is in dicot stems and roots, located between the xylem and the phloem in the stem and root of a vascular plant, and is the source of both the secondary xylem growth (inwards, towards the pith) and the secondary phloem growth (outwards).
In Monocots:
Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots.
Cambium of some plants remains active for the entire period of their life, i.e., cambial cells divide and resulting cells mature to form xylem and phloem elements.
This type of seasonal activity usually found in the plants present in the tropical regions, and not all plants show cambial activity.
Percentage of ringless trees in the rain forests of; India : 75% Amazon : 43% Malaysia : 15%
In regions with definite seasonal climate; seasonal activity of cambium ceased with onset of unfavorable conditions; In Autumn, it enters the dormant state and lasts for the end of summer; In Spring, cambium again becomes active.
Duration of cambial activity is also affected by day-length, e.g., In Robinia pseudoacacia, cambium is dormant under short-day condition.
The cambium cells formed in circular in cross section from the beginning onwards.
The cambial ring is partially primary (fascicular cambium) and partially secondary (interfascicular cambium).
Periderm originates from the cortical cells (extra stelar in origin).
In Dicot stem, for mechanical support xylem is with comparatively smaller vessels, greater fibers and less parenchyma.
More amount of cork is produces for protection.
Lenticels on periderm are very prominent.
The cambial ring formed is wavy in the beginning and later becomes circular.
The cambium ring is completely secondary in origin.
Periderm originates from the pericycle (intra stelar in origin).
In Dicot root, xylem is with big thin walled vessels with few fibers and more parenchyma.
Less amount of cork is produced as root is underground.
Lenticels on periderm are not very prominent.
Double fertilization is the process found in angiosperms in which out of the two male gametes released inside the embryo sac, one fuses with the egg cell (syngamy) and another fuse with secondary nucleus (triple fusion).
Embyrology in relation to Taxonomy. It is one of the concepts in Modern Taxonomy.in which embryological data is used to strengthen existing classification system.
Fertilization is the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain. Fertilization in flowering plants was discovered by Strassburger in 1884.
Flowers are the reproductive structures of angiosperms. They vary greatly physically and are of great diversity in methods of reproduction. The process of fertilization in plants occurs when gametes in haploid conditions meet to create a zygote which is diploid.
The male gametes of the flower are transferred on to the female reproductive organs through pollinators. The final product of this process is the formation of embryo in a seed.
In this lesson you will learn about :
1) What is Fertilization?
2) The Pollen Grain (Male Gamete)
3) The Ovule (Containing Female Gamete)
4) Microsporogenesis and Megasporogenesis
5) Germination of Pollen Grain
6) Double Fertilization
7) Post Fertilization Events
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Genomics is a discipline in genetics that applies recombinant DNA, DNA sequencing methods, and bioinformatics to sequence, assemble and analyze the function and structure of genomes
Heredity or Hereditary is the process of passing the traits and characteristics from parents to offsprings.
The offspring cells get their features and characteristics aka genetic information from their mother and father.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
4. FLOWERING PLANT REPRODUCTION
•Flowers are modified leaves,
specialized for reproduction.
•Flower parts undergo meiosis
to produce haploid products.
•Pollen grain
•Ovule (contains egg cell)
Pollen
grains
Ovule
Flower
Meiosis
Mitosis
Mitosis
5. • The plant life cycle is characterized by the alternation of
generations between a haploid sporophyte and a diploid
gametophyte.
• The sporophyte functions to produce spores, which then
develop into gametophytes.
• The differentiated gametophytes in turn produce either
the male gametes (sperm) or female gametes (egg cells).
• In contrast to lower plant species, in which the
gametophyte is the dominant, free-living generation .
• Gametophytes of angiosperms are smaller and less
complex than the sporophyte and are formed within
specialized organs of the flower.
Pollen
grains
Ovule
Flower
Meiosis
Mitosis
Mitosis
14. MEGASPOROGENESIS
•Single cell in each ovule differentiate
into a megaspore mother cell.
•It undergoes meiosis to produce 4
haploid megaspores.
•3 – degenerated leaving one functional
megaspore per ovule.
16. MICROGAMETOGENESIS
•Production on male gamete of sperm.
•During maturation- microspore nucleus
divides mitotically to produce
•Generative
•Vegetative / tube nuclei
•Pollen generally released in binucleate stage.
17. •After pollination, the pollen germinates.
•Pollen tube enters the stigma and grows through the style.
•The generative nuclei now undergoes a mitotic division – two male gametes
•The pollen along with the pollen tube- micro gametophyte
•The pollen tube finally enters the ovule through a small pore- micropyle & discharge
2 sperm into embryo sac.
18. 1. Pollen grain deposited by vector on stigma.
2. Tube cell germinates through pollen wall.
4. Generative cell divides to make two sperm cells.
tube
nucleus
tube
nucleus
Synergids burst end of pollen tube. Sperm released into embryo
sac. Syngamy events follow.
3. Generative cell follows pathway of pollen tube.
tube
nucleus
generative
nucleus
pollen
tube
Golgi
and
vesicles
19. Microsporogenesis and Microgametogenesis
PMC
First
Meiotic
division
Dyad Tetrad
Second
Meitic
division
n n
n n
n n
n
Mitosis
n
n
Generative
nucleus
Microgametogenesis
Mitosis in
generative
nucleus
Microgametophyte
Binucleate
pollen
( Pollination )
Pollen grain
( Microspore)
Microsporogenesis
Anther
20.
21. MEGAGAMETOGENESIS
• Functional megaspore nucleus divides mitotically – 4 or more nuclei – depend
on the species
• 3 mitotic division – 8 nuclei
• Three nuclei move to one pole – Central egg cell & Two synergid cell either side
• Another 3 move to opposite pole – Antipodal cells
• 2 nuclei remaining in the center- Polar nuclei.
22. Fuse to form secondary nucleus.
•The megaspore develops into a mature mega gametophyte or embryo sac.
•The development of embryo sac from a megaspore – mega gametogenesis.
26. Megasporogenesis and Megagametogenesis
2 n
First meiotic division
n
n
second meiotic division n
n
n
n
3 degenerate
Megaspore
Megasporogenesis
Mitosis IMitosis II
Mitosis III
Polar nuclei ( 2 n)
Egg cell
Synergids
Antipodals
Megagametophyte or
Embryosac
Ovule
n
27.
28.
29. POLLINATION
Landing of active pollen on to a receptive stigma
Pollen grain germinate and pollen tubes enter the stigma
Pollen tube travels through style and reach ovule through Micropyle
Discharge the two sperm nuclei in to the embryo sac
30. Fertilization :
Fusion of one sperm with egg cell - Fertilization - Zygote
Fusion of another sperm with secondary nucleus - Double Fertilization -
Primary endosperm
31. Fertilization :
• In flowering plants pollen grains are deposited on the stigmal surface during
anthesis.
• If the pollen and stigma are compatible a pollen tube grows that enters the
intercellular space of the ovary .
• The pollen tube then grows through a specialised tissue of the ovary called the
transmitting tract and emerges at random points on the inner surface of the
carpel.
• It then grows towards the micropyle of the ovule where it delivers two sperm
cells and initiates the double fertilization event within the embryo sac.
32. Mature Pollen
Grain
POLLINATION AND
FERTILIZATION IN A FLOWER
Tube Cell Nucleus
Sperm Cells
1. pollen grains
land on stigma
Stigma
Style
Ovary
2. pollen tubes grow
down stigma to ovary
Sperm
Egg
3A: Fusion of
sperm + egg
3B: Fusion of 2nd
sperm + two
polar nuclei
3. double
fertilization
Polar nuclei
Ovule
