Seed Germination:

Germination of seed is natural process it also depends upon on some physical and chemical properties of soil.

Germination occurs when a spore or seed starts to grow. It is a term used in botany. When a spore or seed germinates, it produces a shoot or seedling, or (in the case of fungi) a hypha. The biology of spores is different from seeds.

A spore germinates if and when conditions are right. It has a very limited lifespan. The method of spore-bearers, which are lower plants such as mosses, ferns and also fungi, is to produce vast numbers of spores, of which only a small percentage germinate.

Seeds contain an embryo, a store of food (the endosperm), and a protective coat. Seed plants include Gymnosperms (such as conifers) and Angiosperms (such as flowering plants). Seeds can survive much longer than spores, sometimes for hundreds of years. The strategy of seed-bearing plants is to invest energy and material in the substance of seeds, and they have evolved more sophisticated methods of dispersal than just wind.

Seeds do not germinate until their requirements are met, and these needs differ from species to species.

1.      The dormancy period must be over. Dormancy is governed by changes inside the seed. Each species has its own dormancy period, and will not germinate until that period is over.

2.      Their hibernation must be over. The hibernation is ended when events in the environment trigger germination. Sometimes this is just temperature and water, sometimes fire, sometimes the seed must go through a long cold spell.

The requirements for fruits is the same as for seeds. A fruit is just a seed with one or more extra layers derived from parts of the flower.

Zinnia

Zinnia is a genus of 20 species of annual and perennial plants of the family Asteraceae. They are native to scrub and dry grassland in an area stretching from the Southwestern United States to South America, with a centre of diversity in Mexico.^[3] Members of the genus are notable for their solitary long-stemmed flowers that come in a variety of bright colors. The genus name honours German botanist Johann Gottfried Zinn  Sun exposure: Full Sun Soil type: Any, Sandy, Loamy Flower color: Red, Pink, Orange, Yellow, Purple, White,Multicolor Bloom time: Summer Get a zing from zinnias! Zinnias are one of the easiest annuals to grow, grow quickly, and bloom heavily. They make a massive burst of color in your garden. Zinnias have bright, solitary, daisy-like flowerheads on a single, erect stem. The most common zinnia is "dahlia-flowered" and grows up to three feet. Other types are "cactus-flowered." Use in an annual or mixed border. Smaller zinnias are suitable for edging, windowboxes or other containers. The narrow-leaf zinnia also works well in hanging baskets. Zinnias are very popular for cut flowers. Planting Zinnias are grown from seed; they grow very quickly in the right conditions. Zinnias do not like to be transplanted. Full sun is essential wiht a minimum daylight temperature of 60 degrees F. Zinnias are adaptable but prefer fertile, humus-rich, well drained soil at pH preference 5.5 - 7.5. If soil is amended with compost, the flowers will grow more quickly. Sow seeds 1/4-inch deep. Space plants 4 to 24 inches apart depending on variety. (Many common varieties are 6 inches within the row and 2 feet in between rows.) See back of seed package. Germination occurs at 74 to 80 degrees F in 5 to 76 days. Sow in succession for a longer flowering display. Care Deadhead to prolong flowering. Maintain moderate soil moisture and fertilize lightly. Zinnias will die with the first frost. Pests Bacterial and fungal spots, powdery mildew, bacterial wilt. Minimize wetting of foliage to avoid disease. Caterpillars, mealybugs, and spider mites also cause problems. Avoid spraying and tolerate some leaf damage unless the situation is uncontrolled. Harvest/Storage Zinnias generally take 60 to 70 days from seed to flower (though it depends on conditions). Recommended Varieties Get a full-size flower on a compact plant with cultivars of the 'Dreamland Series.' Dwarf and compact, these zinnias have fully double flowerheads, to 4 inches across in a wide color range; stems are 8–12 inches tall. The 'Thumbelinia Series' cultivars and dwarf and spreading, with single or semi-double, weather-resistant flowerheads in many colors. Their petals are 1-1/4 inch across and stems grow up to 6 inches long. The 'State Fair Series' are the biggest and tallest of them all with large, double flowerheads that are 3 inches across. Stems grow to 30 inches tall. Special Features Attracts Butterflies Wit & Wisdom The small narrow-leaf zinnias make nice dried flowers, too.

Uses

A number of species of zinnia are popular flowering plants. Their varied habits allow for uses in several parts of a garden, and their tendency to attract butterflies and hummingbirds is seen as desirable.

Flower Structure

Structure of the Flower The floral meristem differentiates into four concentric groups of cells that form the four parts of the flower. The cells in whorl 1 develop into a whorl of sepals. These form at the lowest level. Collectively they make up the calyx. Whorl 2 forms above the calyx, forming the petals. Collectively these make up the corolla of the flower (the part that most ornamentals are grown for). Whorl 3 develops into the stamens, the male reproductive organs. The innermost whorl, 4, forms carpels, the female reproductive organs. Carpels often fuse to form a single structure, which some botanists call the pistil. What triggers the various parts of the floral meristem to enter one or another of these four developmental pathways?

Almonds flowers introduction

Almonds have been found in the ancient Greek tombs dating back to 8000 BC. In a society where philosophy was so important, the almond fruit came to symbolise knowledge, the ‘secret’ meaning hidden within, that has to be ‘cracked’ from its shell. The known and unknown world present in the almond’s form. Hence the term ‘kernel’s of wisdom’. The Romans showered newlyweds with almonds as a fertility charm. Almond trees are self-infertile and require cross fertilisation, for this reason the honeybees are essential to almond trees often colonising the trees themselves. Due to its early flowering the almond tree came to herald the arrival of spring, symbolising birth and resurrection.

Almond Blossoms is a group of several paintings made in 1888 and 1890 by Vincent van Gogh in Arles and Saint-Rémy, southern France of blossoming almond trees. Flowering trees were special to Van Gogh. They represented awakening and hope. He enjoyed them aesthetically and found joy in painting flowering trees. The works reflect Impressionist, Divisionist and Japanese woodcut influences. Almond Blossoms was made to celebrate the birth of his nephew and namesake, son of his brother Theo and sister-in-law Jo.

More information about "Almond Blossom"

Composition

Already in Arles, Van Gogh had been fascinated by the orchards, filled with apricot, peach and plum trees and in full bloom at the time of his arrival in March 1888. The composition of Almond Blossom is, however, both unusual and unique in Vincent’s oeuvre. The branches seem to float against the blue sky, and it is unclear if they are still part of the tree or set in a vase, as in one of his earlier works. With an unusual regularity, the entire pictorial surface has been filled with branches, which are further accented by the use of dark contours. Both this sharp outlining and the placement of the tree were certainly inspired by Japanese prints, which Van Gogh had seen for the first time in Paris. This influence can also be seen in a number of other paintings.

Biochemistry

Biochemistry, sometimes called biological chemistry, is the study of chemical processes within and relating to, living organisms

defination of statistics

The practice or science of collecting and analysing numerical data in large quantities, especially for the purpose of inferring proportions in a whole from those in a representative sample.

Temperature and flowers

Temperature Many annual plants (e.g., winter wheat) and biennial plants have their time of flowering delayed unless they have undergone a preceding period of wintertime cold. The change brought about by this prolonged exposure to the cold is called vernalization. In the "model" plant Arabidopsis thaliana, vernalization works like this. A gene designated Flowering Locus C (FLC) encodes a transcription factor that blocks the expression of the genes needed for flowering. The level of FLC mRNA is high in the fall. But with the onset of cold temperatures, production of an antisense transcript of FLC (called COOLAIR) increases as does, later, a sense transcript of part of the FLC gene. Both of these RNAs are non-coding; that is, they are not translated into protein. But they cooperate in suppressing the production of FLC mRNA and its translation into FLC protein. With the arrival of spring, there is no FLC protein remaining to suppress flowering so flowering can begin. The buds of many species of woody angiosperms found in temperate climates, such as apples and lilacs, also need a preceding period of cold weather before they can develop into flowers. So these plants cannot be grown successfully at lower latitudes because the winters never get cold enough (a few days at 0–10°C). This bud dormancy is localized. Prior chilling of one bud on a lilac stem enables it to flower while the other, nonchilled, buds on the stem remain dormant.

process of flower formation

plant metamorphosis - environment controls how the plant changes phase change - internal development >> competence, ability to reproduce reproductive structures added on to existing structures distinct juvenile, adult phases easier to revert adult into juvenile than to induce phase change flower production pathways - 3 regulated pathways to flowering light-dependent (photoperiodic) pathway - length of day (amount of daily sunlight) affects flowering daylight shorter than critical length (12 hours) >> flowering in short-day plants (blooms in late summer/fall) daylight longer than critical length >> flowering in long-day plants (crop plants, blooms in spring/summer) day-neutral plants - flower when mature, regardless of day length 2 critical photoperiods >> will not flower if day too long/short facultative-long-or-short-day-plants - flower speed depends on day length cryptochrome/phytochrome detect photoperiods repress gene that represses flowering >> flowering takes place temperature-dependent pathway - cold temperatures >> faster flowering vernalization - shoots/seeds chill >> reproduce gibberellin hormones controls flowering, expression of certain genes.zzz

parts of the flower - no direct contact between pollen, ovule

• pollinators - animals that transfer pollen between plants
• complete flower - has all 4 whorls (calyx, corolla, androecium, gynoecium)
• perfect flower - has stamen/carpel (androecium/gynoecium)
• calyx - outermost whorl
  • contains the sepals (protects the flower in the bud)
• corolla - collective name for the petals
  • used to attract pollinators
• androecium - stamens in a flower
  • microsporangia on anthers
  • held up by filaments
• gynoecium - female flower parts
  • contains single/fused carpel
  • ovules - produced in the ovary, become seeds
  • stigma - receives pollen at top of carpel
  • style - connects stigma to ovary
  • floral specialization - floral parts either fused or reduced/lost
    • more advanced angiosperm >> less parts in each whorl
    • modifications sometimes due to pollination techniques (wind replaces animals)
    • artificial selection >> flowers less able to adapt
      • corn (maize) wouldn’t be able to survive as easily w/o human aid
    • floral symmetry - different between primitive/advanced flowers
      • primitive >> radial symmetry
      • advanced >> bilateral symmetry
    formation of angiosperm gametes - gametophytes completely enclosed by sporophyte
    • male gametophytes = microgametophytes, pollen grains
      • forms in 2 pllen sacs in anther
      • microspore mother cells - found in specialized chambers of sac
      • microspore mother undergoes meiosis >> haploid microspores >> 4 pollen grains after mitosis

 female gametophytes = megagametophytes, embryo sac forms in ovules megaspore mother cells - found in each ovule megaspore mother cell undergoes meiosis >> haploid megaspores, only 1 survive >> 8 haploid nuclei after mitosis 1 nucleus >> egg, rest arranged in precise locations (2 polar nuclei in middle of sac, 2 in synergids flanking egg, 3 in antipodal cells)

flowering stages of sunflowers

Stage 1) Cut at this stage in the field to decrease petal damage. This is the first stage of the Sunflower, which we call "Tight." - When received at this cut stage the most important action is to re-cut the Sunflower and put the flower in a vase/bucket that has at least 5 inches of fresh water. - Takes approx. 2-3 days to go from Stage 1 to Stage 2. Stage 2) This is the second stage of the Sunflower cut which we refer to as the "Opening Stage." Be prepared to have stems within the bunch open inconsistently. - When received at this cut stage the most important action is to make sure the vase/bucket has fresh water (must be changed every 2 days) and is maintained at a consistent temperature (between 55º - 70º F). Stage 3) Ideal Stage for Sunflowers as they should have a more uniform cup-stage appearance. This third stage is known as the "Blooming Stage." - Make sure water has been replaced from initial uptake (Stage 2) and re-cut to accelerate opening stage. - Takes approx. 5-7 days to go from Stage 3 to Stage 4. Stage 4) This is the fourth and final stage of the Sunflower and is subsequently named the "Open Stage." Once it reaches the full blown state, petals will begin to fall off. - When Sunflowers reach this stage, they should be kept in low to moderate temperature (55º - 70º F), so they last longer and age less quickly. - Takes approx. 2-3 days before petals start falling off.

Pollination without insects

It's not always insects that pollinate the flowers; plants may use the wind, birds or even bats as pollinators! With wind-pollinated plants - such as grasses, cereals and some trees - the flowers are very simple, with no bright colours or nice smells as they don't need to attract the insects. These plants have both male and female reproductive parts and they make a lot of pollen. This is why a pollen allergy is called 'hay fever'.