Tuesday, June 30, 2009

Basic about Flower - Floral formula



A floral formula is a way to represent the structure of a flower using specific letters, numbers, and symbols. Typically, a general formula will be used to represent the flower structure of a plant family rather than a particular species. The following representations are used:


Ca = calyx (sepal whorl; e.g. Ca5 = 5 sepals)
Co = corolla (petal whorl; e.g., Co3(x) = petals some multiple of three )
Z = add if zygomorphic (e.g., CoZ6 = zygomorphic with 6 petals)
A = androecium (whorl of stamens; e.g., A = many stamens)
G = gynoecium (carpel or carpels; e.g., G1 = monocarpous)


x: to represent a "variable number"
∞: to represent "many"


A floral formula would appear something like this:


Ca5Co5A10 - ∞G1





















Basic about Flower - Ovary Position

A fruit is the ripened ovary or ovaries. The fruits of a plant are responsible for dispersing the seeds that contain the embryo and protecting the seeds as well. In many occasions, the fruit incorporates some surrounding tissues, or is dispersed with some non-fruit tissues.

Type of fruit also determined by the position of ovary within a flower.

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I. A superior ovary is an ovary attached to the receptacle above the attachment of other floral parts. A flower with this arrangement called hypogynous.

Examples are drupes and true berries.

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II. A half-inferior ovary is called perigynous, is surrounded by receptacle, has nearly equal portions of ovary above and below the insertion point.

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III. An inferior ovary lies below the attachment of other floral parts. It is also called epigynous.

Examples are orchids, Fuchsia, Asteraceae, Cucurbitaceae, banana, some pomes type fruits


Basic about Flower - Pollination

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Pollination is the process by which pollen is transferred in plants, thereby enabling fertilization and sexual reproduction.

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Pollen may b transferred between plants via a number of vectors.

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Anemophily is a form of pollination whereby pollen is distributed by wind. Eg. Grasses, conifers, sweet chestnuts, members of Juglandaceae family.

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Hydrophily is a fairly uncommon form of pollination whereby pollen is distributed by the flower of waters. Eg. Posidonia australis, ribbonweed.

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Entomophily is a form of pollination whereby pollen is distributed by insects, particularly bees, Lepidoptera, flies and beetles. Eg. Sunflower, orchid, cycad.

Melittophily refers to pollination by bees.

Cantharophily specifically refers to beetle pollination.

Myophily refers to pollination by flies feeds on nectar and pollen

Sapromyophily refers to pollination by flies attracted by plants emitting odoriferous scent.

Psycophily refers to pollination by butterflies.

Phaelaenophily refers to pollination by moths

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Zoophily refers to pollination by vertebrates.

Ornithophily is the pollination of flowering plants by birds. Eg. Babiana ringens, Heliconiaceae, Costaceae, Zingiberaceae, Amaryllidaceae, Rubiaceae, Apocynaceae, Bromeliaceae, Gesneriaceae, Lobeliaceae, etc.

Chiropterophily specifically refers to bat pollination. Eg. Durios

Pollination can be accomplished by cross-pollination or by self-pollination :

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Allogamy is a cross-pollination, occurs when pollen is delivered to a flower from a different plant. Allogamious plants normally have taller stamens than carpels.

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Autogamy is self-pollination, when pollen from same flower is delivered.

Geitonogamy is self-pollination, when pollen from flower of same individual transferred to another flower.

These plants normally have similar stamen and carpel lengths.

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Cleistogamy is self-pollination that occurs before flower opens. Eg. Peanut, peas, beans, grasses, Viola.

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Chasmogamy refers to flowers that opens and exposes the stamens and styles to the environment. Thus encourage cross-pollination


Basic about Flower - Symmetry

Floral symmetry refers to whether, and how, a flower can be divided into 2 or more identical or mirror-image parts.






Most flowers are actinomorphic, meaning they can be divided into symmetrical halves by more than one longitudinal plane passing through the axis. Examples are flowers of Liliaceae, Ranunculaceae.

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However, some familiar and seemingly actinomorphic flowers, such as those from Asteraceae, are actually clusters of tiny zygomorphic flowers arranged into a radially symmetric inflorescence.


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Zygomorphic flowers can be divided by only a single plane into 2 mirror-image halves. Examples are flowers of Zingiberales, Lamiales ( Scorphulariaceae, Gesneriaceae )

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Actinomorphic flowers are basal angiosperm character ; zygomorphic flowers are a derived character that has evolved many times.






Basic about Flower - Morphology



Peduncle = terminal offshoot of the stem or twig ; it first connects the flower, then the fruit, to the plant

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Receptacle = enlarged portion of the peduncle containing and supporting the other parts of the flower.

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Sepal = usually green part of the flower that protects the flower’s internal structures ; it may fall after flowering occurs or remain until the fruit has ripened.

Calyx = part of the flower composed of all its sepals.

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Petal = usually colourful and scented part of the flower that surrounds the male and female reproductive organs ; it often helps attract pollinators.

Corolla = part of the flower composed of all its petals

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Pistil = each of the female floral organs at the flower’s center, consisting of an ovary, a stylus and a stigma.

Stigma = upper part of the female floral organ ( pistil ) that receives and holds pollen.

Style = cylindrical axis connecting the stigma to the ovary.

Ovary = hollow structure containing one or more ovules ; the fruit usually develops from it after fertilization.

Ovule = small rounded structure produced by the ovary and containing the female cell ; after fertilization, the seed develops from it.

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Stamen = each of the male floral organs, consisting of a filament and an anther.

Anther = upper part of the male floral organ ( stamen ) that produces pollen grains ; at maturity, it splits to release them.

Filament = cylindrical axis connecting the anther to the rest of the flower

Plant Taxonomy - Kingdoms and Domains


1. Carl Linnaeus in his book Systema Naturae published in 1735, classified 4,400 species of animals and 7,700 species of plants.
Linnaeus's prime contribution to taxonomy was to establish conventions for the naming of living organisms that became universally accepted in the scientific world—the work of Linnaeus represents the starting point of binomial nomenclature.

2. The formal taxonomic category Protoctista was first proposed in the early 1860's John Hogg, who argued that the protists should include what he saw as primitive unicellular forms of both plants and animals. He defined the Protoctista as a "fourth kingdom of nature", in addition to the then-traditional kingdoms of plants, animals and minerals.
The kingdom of minerals was later removed from taxonomy by Ernst Haeckel, leaving plants, animals, and the protists as a “kingdom of primitive forms.

3. Edouard Chatton (1883 — 1947), was a French biologist who first distinguished between the eukaryotic and prokaryotic systems of cellular organisation, and coined the terms themselves in his 1925 paper, Pansporella perplex: Reflections on the Biology and Phylogeny of the Protozoa.

4. Herbert Faulkner Copeland (1902-1968) , an American biologist who contributed to the theory of biological kingdoms.  He was responsible for the fourth kingdom, Monera.

5. In 1968, R. H. Whittaker proposed an additional kingdom for the Fungi.

6. Carl Richard Woese, an American microbiologist who defined the Archaea (a new domain or kingdom of life) in 1977 by phylogenetic taxonomy of 16S ribosomal RNA, a technique pioneered by Woese and which is now standard practice.

7. Carl Richard Woese, in 1990,  redrew the taxonomic tree, divided life into 23 main divisions, all incorporated within three domains: Bacteria, Archaea, and Eucarya.

1
2
3
4
5
6
7
Linnaeus
Haeckel
Chatton
Copeland
Whittaker
Woese et al.
Woese et al.
1735
1866
1937
1956
1969
1977
1990
2 kingdoms
3 kingdoms
2 empires
4 kingdoms
5 kingdoms
6 kingdoms
3 domains
(not treated)
Protista
Prokaryota
Monera
Monera
Eubacteria
Bacteria
Archaebacteria
Archaea
Eukaryota
Protista
Protista
Protista
Eukarya
Vegetabilia
Plantae
Fungi
Fungi
Plantae
Plantae
Plantae
Animalia
Animalia
Animalia
Animalia
Animalia


Plant Taxonomy - Ranks








Domain/
Superkingdom
Superphylum/
Superdivision


Phylum/Division
Genus
Infrakingdom/
Branch










source : Wikipedia

3 subfamilies of Fabaceae

Fabaceae ( or known as Leguminosae ) is a large and economically important family of flowering plants. It is commonly known as the legume family, pea family, bean family or pulse famiy.

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The name ‘Fabaceae’ comes from the defunct genus Faba, now included into Vicia. However, Leguminosae is still considered a valid name.

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Fabaceae is the 3rd largest family of flowering plants, with some 730 genera and over 19,400 species. The largest genus is Astragalus, with more than 2,000 species. Acacia have more than 900 species, Indigofera have some 700 species, Crotalaria have 600 species, and Mimosa have 500 species.

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The Fabaceae are placed in the order Fabales, according to most taxonomic system.

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The Fabaceae comprise 3 subfamilies : Mimosoideae, Caesalpinioideae, and Faboideae/Papilionoideae.





Mimosoideae have some 80 genera and 3,200 species.

Classified in 4 tribes : Acacieae, Ingeae, Mimoseae, Mimozygantheae.

Distributed mostly tropic and warm temperate Asia and America.

Flowers with small petals and numerous prominent stamens. Inflorescences actinomorphic, capitate clusters, spikes or racemes.

Fruit dry when mature, dehiscent along both groove.

Leaves bicompound.

Nodulation is common.

Monophyletic.

Important species : Acacia acuminate, Adenanthere pavonina (saga), Mimosa pudica, Parkia speciosa (petai).





Caesalpinioideae have some 170 genera and 2,000 species.

Classified in 4 tribes : Caesalpinieae, Cassieae, Cerdieae & Detarieae.

Distributed cosmopolitan.

Caesalpinioideae are mainly trees, distributed in the moist tropics.

Flowers with non-papilionaceous corolla, petals not equals, stamen 10 or fewer. Inflorecence spikes, racemes or heads.

Fruit varies.

Leave compound.

Nodulation is rare.

Paraphyletic.

Important species : Caesalpinia pulcherrima, Delonix regia, Senna alexandrina, bauhinia blakeana.




Faboideae, also know as Papilioinoideae, have some 470 genera and 14,000 species.

Classified in 32 tribes : Abreae, Adesmieae, Aeschynomeneae, Amorpheae, Bossiaeeae, Brongniartieae, Carmichaelieae, Cicereae, Crotalarieae, Dalbergieae, Desmodieae, Dipterygeae, Euchreasteae, Galegeae, Genisteae, Hedysareae, Indigofereae, Liparieae, Loteae, Millettieae, Mirbelieae, Phaseoleae, Podalyrieae, Psoraleeae, Robinieae, Sesbanieae, Sophoreae, Swartzieae, Termospsideae, Trifolieae, Vicieae.

Faboideae may be trees, shrubs or herbs, distributed cosmopolitan.

Flowers with papilionaceous corolla, petals not equal. Stamen 10, often united into a tube, uppermost filament free. Infrorecence strongly zygomorphic, spikes or racemes.

Fruit dry when mature, dehiscent along both sutures or breaking into loments.

Leaves compound, palmate or pinnate.

Nodulation is common.

Monophyletic sensu stricto

Important species : Archis hypogea (peanut), Cicer arietum (chickpea), Glycine max (soybean), Lens culinaris (lentil), Medicago sativa (alfafa), Phaseolus vulgaris (French bean), Pisum sativum ( common pea), Vigna sesquipedalis (long bean).

Tuesday, June 2, 2009

Organic Farming - Controversies

Organic Fertilizers

In organic farming, compost made from manure is somehow questionable. The manure used in preparing compost may originate from non-organic animals. Some compost may contain sewage sludge, and discarded animal parts from slaughter house.

Organic fertilizers made of guano, blood meal, bone meals, fish meals, etc, are more complex than chemical fertilizers. The mineral contain are difficult to identify and quantify. Lack of crucial information on the mineral contain may easily lead to over fertilized, nutrient leaching, heavy metal toxicity and many other issues.

Composting is a very complex process, which involved micro-organisms and subject to specific ideal conditions : temperature, moisture content, O2 content, C:N ratio and type of ingredient. Anaerobic composting releases CO2, hydrogen sulfide and methane ; while aerobic system releases co2 and heat. High temperature destroys insects, larvae, weed seeds, but no compost will be totally sterilized by high temperatures alone, thus open a window for contamination of pathogens and disease vectors to the farm and the consumers.

Organic fertilizers are bulky, making it less manageable. The use of agricultural machinery powered by diesel-engine during preparation of compost, storing, transporting and application contribute equally to depletion of non-renewal energy sources.



Productivity

Issue of productivity is more than a summary of yield per arable land. However, the hidden costs of conventional farming’s side-effects, like environmental damage, health risk, consumption of energy, usage of water, of which eventually will reach to the consumer.

However, basic economy sees only production per arable land. There are still no conclusive data supporting the claim that farming is able to meet the demand for affordable food. Norman Borlaug, father of the ‘Green Revolution’, a Nobel Peace Prize laureates, asserts that organic farming can at most feed 4 billion people, after expanding cropland dramatically and destroying ecosystems in the process.

However, some believe that organic farms require more land to produce same amount of foods as conventional farms. If this argument is true, organic farming could potentially destroy the rainforests and wipe out many ecosystems. ( Bob Goldberg. 2000. The Hypocrisy of Organic Farmers. )


Pesticide Residue

Organic farming standards do not allow the use of synthetic pesticides, but they do allow the use of specific pesticides derived from plants. The most common organic pesticides, accepted for restricted use by most organic standards, include Bt, pyrethrum and rotenone. Rotenone is a rotenoid plant extract obtained from barbasco, cub, haiari, nekoe and timbo. it is EPA toxicity class I or III – highly toxic or slightly toxic, depending on formulation.

A study published in 2002 showed that organically grown foods consistently had about one-third as many residues as conventionally grown foods. ( Baker, et al. 2007. Pesticide Residues in Conventional, IPM-Grown and Organic Foods : Insights From Three U.S. Data Sets. ) (Goldberg. 2005. Consumers Union Research Team Shows : Organic Foods Really do Have Less Pesticides )


High Retail Price

One of the objectives of organic movement is to produce food for local community. However, due to the low yield/acre, the organic farmers had no choice but to sell their produce at higher retail price. Without proper certification and control, anyone can claim their produce as ‘organic’ and sell at premium price. Thus organic becomes the food for the ‘fooled’ wealthy-few.


Healthier & Safer Food

There is no conclusive proof to support the claim that organically grown produce are healthier and nutritious. Organically grown produce are equally susceptible to contamination without proper use of organic fertilizers and pesticides, poor handling and storage.

Some unethical shop owners simply market their poor-quality produce as ‘naturally grown’ or ‘no chemical fertilizers used’, insect-damaged as ‘insecticide-free’, etc.


Soil Conservation

Some organic farming practices are claimed to do more damage than conventional practices, for instance, soil preparation by ploughing is claimed to increase soil damage compared to using Roundup.


Sustainability

Although it is generally held that organic farming is sustainable agriculture, the two are not synonymous. Sustainable is a concept with the idea of approaching as closely as possible a balance between what is taken out of the soil, and what is returned to it, without outside inputs.

Application of organic fertilizer, in the contrary, is act of imports of nutrient, which violates the concept of sustainability.

Thus, an organic farm, even operated in small scale, shall be able to self-sustain as a complete ecosystem. While the nutrients are taken out ( harvested produce ) from the soil, equal amount of the nutrients are to return to the soil ( in-situ manure ).


Environmental Friendly

Organically grown produce are normally sale in specialty store or special refrigerated shelves in hypermarkets, packed in individual plastic bags. Instead of side-tracked to centralized food system, organic produce should market directly to the local community to avoid unnecessary transportation cost, packaging, storage as a more energy-saving, and less-waste-production approach.