Germination percentage (%) was determined by dividing the number of germinated pollen grains per field of view by the total number of pollen per field of view.
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How do you calculate pollen?

It’s actually pretty simple: pollen counts are generally taken with a system called a “rotorod.” The sampling device uses silicone grease-coated clear rods that test the air on a schedule, usually over the course of 24 hours. The rods are then examined for the number of pollen grains covering the rod or portions of it.

How is pollen tube growth measured?

The most common procedure is to measure and compare the lengths of individual pollen tubes. inhibition patterns. to the line of pollen, and their lengths can thus be easily measured. 24 C for about 20 hr and were then observed for tube growth.

What is pollen germination?

Definition: The physiological and developmental changes that occur in a heterosporous plant pollen grain, beginning with hydration and terminating with the emergence of the pollen tube through the aperture.

How many pollen tube emerges from a pollen grain?

Only a single pollen tube emerges from a pollen grain that contains pollen nuclei. Pollen tube helps the nuclei to reach the ovule. there fertilization takes place.

What does a pollen count of 11 mean?

1 to 9 is a low pollen count. 10 to 49 is a moderate pollen count. 50 to 499 is a high pollen count. 500 or higher is a very high pollen count.

How is pollen viability measured?

Pollen viability counts were made after two hours; then pollen was placed on a TTC solution. Pollen grains stained that orange or bright red color were counted as viable. In the second staining method, 1 g potassium iodide and 0.5 g iodine were dissolved in 100 mL distilled water for the IKI solution.

How do you prepare a pollen germination slide?

This is done by dissolving 10g of sucrose as well as 10mg of boric acid in 100ml of water. Pour a few drops of this solution onto the cavity slide. Then, use a brush or fingers to gently dust a few pollen grains from the stamen of mature flowers. Let the slide set for 5 mins.

What do you know about double fertilization?

Double fertilization is a complex fertilization mechanism of flowering plants (angiosperms). This process involves the joining of a female gametophyte (megagametophyte, also called the embryo sac) with two male gametes (sperm). … The pollen tube proceeds to release the two sperm in the megagametophyte.

How many male gametes are carried in the pollen tube for fertilization?

Two male gametes. Two male gametes are produced from a single pollen grain in flowering plants.

What is percentage germination?

Introduction: Germination percentage is an estimate of the viability of a population of seeds. The equation to calculate germination percentage is: GP = seeds germinated/total seeds x 100 . The germination rate provides an measure of the time course of seed germination.

What are the 5 steps of germination?

The process of seed germination includes the following five changes or steps: imbibition, respiration, effect of light on seed germination, mobilization of reserves during seed germination, and role of growth regulators and development of the embryo axis into a seedling.

What is the difference between pollen germination and seed germination?

Answer: Pollens are very different from seeds because they are fine and powdery. They contain the microgametophytes or the gametes (comparable to the sperm cells) of seed plants. Like ordinary seeds, pollens can also have a hard coating for the pollen grain to provide protection during movement (pollination).

How many male gametes does a pollen grain has?

Complete answer: In flowering plants, a single pollen grain produces two male gametes. At the two-celled stage, pollen grains are released from pollen-sacs, where the generative cell divides further to form two male gametes.

Why do pollen grains fail to germinate?

1)Some pollen grains fail to germinate as they don’t get all the essential conditions for the germination of pollen. … The stigma of flower receives different kinds of pollen, but pollen belonging to same species grows and survive and rest of the pollens fail to grow.

Is sperm a pollen cell?

Pollen is a powdery substance consisting of pollen grains which are microsporophytes of seed plants, which produce male gametes (sperm cells).

What does a high pollen count mean?

Pollen counts will typically include measurements of mold spores and the pollen from grasses, weeds, and trees. A “high” pollen count means that most everyone with a pollen sensitivity may be affected, while a “low” pollen count means that only people with severe seasonal allergies should be affected.

What does a very high pollen count mean?

These levels of pollen represent a person’s risk of experiencing allergy symptoms. Generally, when the pollen count is high, the greater the chance that people suffering from hay fever will experience symptoms when outdoors or exposed to outdoor air.

Does moderate pollen cause allergies?

3 It is likely that some allergic people will have symptoms with exposure to “low” pollen levels, more allergic people will have symptoms to “medium” pollen levels, and most allergic people will have symptoms with “high” pollen levels.

What is pollen grain viability?

Pollen viability is the ability of pollen to effect fertilization and consequent development of fruit and seed; therefore fruit set and seed set form the most authentic test for pollen viability.

Which plant can lose viability in 30 min?

Some cereals such as rice and wheat pollen grains lose viability within 30 minutes of their release. So, their pollen viability is for 30 minutes.

How long do you think the pollen grain retain viability?

Pollen grains of cereals such as wheat, rice, etc. show viability only for 30 minutes, whereas some maintain viability for months, e.g. some plants belonging to the family Rosaceae, Fabaceae and Solanaceae.

What are the 3 stages of germination?

In general, germination process can be distinguished into three phases: phase I, rapid water imbibition by seed; phase II, reactivation of metabolism; and phase III, radicle protrusion [6].

How do you observe pollen grains under a microscope?

  1. Take a slide and put a few drops of water on it.
  2. Take any flower like hibiscus, tridax, marigold, etc., tap it over the drop of water.
  3. We will see small dot like structures in water. …
  4. Observe the pollen grains under hand lens then under a compound microscope.
Which flower is used for pollen germination?

In the biology videos for Classes 11 & 12 I noticed that Vinca rosea (Periwinkle) is commonly used to show pollen germination.

When a tetraploid female plant is crossed with a tetraploid male?

When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the resulting seed is. Explanation: Primary endosperm nucleus is formed by the fusion of a male gamete with the two polar nuclei. The endosperm is generally triploid as the male gamete is haploid.

What happens to a flower after fertilization?

After fertilization occurs, each ovule develops into a seed. Each seed contains a tiny, undeveloped plant called an embryo. The ovary surrounding the ovules develops into a fruit that contains one or more seeds.

Why stigma at the top of the pistil is often sticky?

The top part of the pistil is called the stigma and is sticky so it will trap and hold pollen. … The style is the tube-like structure that supports the stigma. The style leads down to the ovary which contains the ovules. During the process of pollination, pollen moves from the male parts to the female parts.

Are ovules female gametes?

Male gametes are found inside tiny pollen grains on the anthers of flowers. Female gametes are found in the ovules of a flower.

How many male gametes can 4 pollen mother cells produce?

Thus, a pollen mother cell generates four gametes. Hence, the correct answer is option (A).

How many female gametes are formed by a pollen grain?

In flowering plants, two male gametes from a single pollen grain fuse with two female gametes, the egg and central cells, to form the embryo and endosperm, respectively.

How do you calculate seed rate?

Sowing rate (kg/ha) = target plant population (p/m2) x TGW (g) x 100. % germination x % emergence.

What is the formula for calculating seed rate?

  1. WTS = Weight of thousand seedlings in gram.
  2. DPP = Desired plant population.
  3. PSA = Pure Percentage of safety allowance.
  4. PP = Percentage of purity.
  5. PG = Percentage of germination.
How do you calculate germination index?

GI = ∑ (Gt/Dt), where Gt is the number of the germinated seed on day t and Dt is time corresponding to Gt in days.

What is germination of pollen on stigma?

The germination of pollen grain in stigma occurs in ‘in-vivo’ conditions. It is called as fertilization. Pollen grains are the male gametes and stigma is the female floral part where the ovule is present.

What are the 4 steps of germination?

  • Step 1: Imbibition: water fills the seed.
  • Step 2: The water activates enzymes that begin the plant’s growth.
  • Step 3: The seed grows a root to access water underground.
  • Step 4: The seed grows shoots that grow towards the sun.
  • Step 5: The shoots grow leaves and begin photmorphogenesis.
What are the 6 stages of germination?

The stages that plants go through are from seed to sprout, then through vegetative, budding, flowering, and ripening stages. Similarly, the nutritional needs of people and plants change as they grow.

How many phases and which are that for germination of pollen grain?

Hence, the question of how progamic phase duration evolves is intertwined with the question of how male gametophyte developmental rates evolve. The progamic phase comprises two semi-independent phases of male gametophyte development: pollen germination and pollen tube growth from stigma to egg.

Do all pollen tubes reach the ovules?

When more than one pollen grain lands on a stigma whose ovary contains only one ovule, usually only one pollen tube can successfully enter the ovule while the other pollen tubes stop growing.

How many Megaspore mother cells are required to produce 100 seeds?

25 Microspore mother cells and 100 mega spore mother cells are required to produce 100 seeds in angiogsperm because 25 Microspore mother cells undergo meiosis to form 100 pollen grains and 100 mega spore mother cells undergo meiosis and produce 100 embryo sacs(ovules) {because 1 megaspore mother cell undergo meiosis …

What is the fate of two male gametes?

Summary. In flowering plants, two male gametes from a single pollen grain fuse with two female gametes, the egg and central cells, to form the embryo and endosperm, respectively. The question then arises whether the two male gametes fuse randomly with the egg and central cells.