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(Upload on November 18 2021) [ 日本語 | English ]

Individual (個体)






Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

Individual

Oxford English Dictionary, Internet version

  1. Inseparable things.
  2. A single member of a species; a single specimen of an animal or plant.
Genet (ジェネット): a genetic individual that develops from a zygote (seed) and is therefore a product of sexual reproduction
Ramet (ラメット): an individual that develops from a genet or another ramet and is a product of asexual reproduction

clone
Fig. Genet (clone)

索引

Efficiency (効率)

the ratio of useful output to total input

r = P/C × 100 (%),
where P is the amount of useful output (product) produced per the amount C (cost) of resources consumed

Ex. the percentage of the solar energy reaching the plant that is used in photosynthesis or else ‘fixed’ as organic materials

Solar energy

x% of energy absorbed for photosynthesis x% = efficiency

Ex. Plant productivity and use of solar energy Plant productivity (in a year)
(1500-6000 kg carbon/ha/yr) × (8000 kcal/kg carbon)

= 12 × 106 to 48 × 106 kcal/ha/yr

Solar radiation arriving ground level

= 11.6 × 109 kcal/ha/yr

(Higher) Efficiency

(48 × 106)/(11.6 × 109) × 100 = 0.4%

Quiz. How is the lowest efficiency?
Water use efficiency 水利用効率

[ sex ]

Reproduction (生殖, 繁殖)


I. asexual reproduction (vegetative reproduction)
II. sexual reproduction
iteroparous (多回繁殖性): multiple reproductive cycles over the course of its lifetime
semelparous (一回繁殖性): a single reproductive episode before death

I. Asexual reproduction (無性生殖)


= agamic reproduction, or apomixis (clone)
Reproduction, not concerned with gametes

One or more individuals develop from a part (e.g., cells and spores) of the parent
→ the combinations of genes are identical between parent and the child(ren)

At cell level

Asexual gametic reproduction (無性配偶子生殖)

= gamogony
= somatic reproduction, all-inclusive term
Division (分裂)
Cell division of monocellular organisms

Binary division (二分裂, 二分法)

Transverse division (横分裂): bacteria, paramecium
Longitudinal division (縦分裂): Euglenophyceae, vorticellae

Multiple division (複分裂, 多分法)

trypanosome

Budding (出芽)

yeasts (division, s.l.)

Sporogenesis (胞子生殖)
New individuals are produced by spores (spore cells)

Ex. bacteria, mosses, ferns, algae, (seed plants)

Diplospory (generative apospory, 複相胞子生殖): the megagametophyte arises from a cell of the archesporium. Ex. Taraxacum officinale
Apospory (somatic apospory, 無胞子生殖): the megagametophyte arises from some other nucellus cell

planospore (遊走子): a spore motile by flagellum(a) = a zoospore
aplanospore (不動胞子): a nonmotile spore
ascospore (子嚢胞子): a spore contained in an ascus or that was produced inside an ascus, specific to ascomycetes
basidiospore (担子胞子): a spore produced by Basidiomycete fungi
tetraspore (四分胞子): one of the four haploid asexual spores developed meiotically in the red algae
monospore (neutral spore, 単胞子): a simple nonmotile asexual spore
conidiospore (分生子): an asexually produced fungal spore formed on a conidiophore

At tissue level

Division (分裂)

sea anemone

Budding (出芽)

hydra, sea sponge

Propagule (栄養体生殖, 栄養体繁殖)
Stolones and runners (匍匐枝, ストロン), developed on the ground surface

saxifrage, strawberry

Rhizomes and tubers (地下茎), developed in the ground

potato, Colocasia, lotus, iris, Chrysanthemum

Storage and tuberous root (貯蔵根, 塊根)

sweet potato, dahlia

Adventitious buds (むかご, 珠芽, 肉芽), on cut stems or fallen leaves

Japanese yam, lily

False vivipary (偽胎生): vegetative progagules within a flower
Artificial vegetative reproduction

cuttage, layerage, grafted tree, division
→ used for the persistence of cultivars, etc.

II. Sexual reproduction (有性生殖)


= reproduction (s.s.), = amphimixis
reproduction induced by gametes

→ the combinations of genes are changed from parents to the child(ren)

Agamospermy (無融合種子形成)
Gametophytic apomixis: more in tropical regions

Adventitious embryony: northern elements
apomixis
antipod → antipodal embryo


synerig → [agamospermy] → synerigid embryo

synerigid embryo Ex. Taraxacum, Alnus, Poa
antipodal embryo Ex. Elatostema, Allium → false vivipary

Agamic complex (無融合性複合体)

agamosperms, related sexual species
A. Normal sexual cycle
Sporophyte 2nSpore nGametophyte n → [Fertilization]

Zygote 2nSeed with embryo 2n

B. Cagetophytic apmixis
___[Diplospory]_________________[Diploid parthenogenesis]
___Embyro-sac mother cell 2n__Egg cell 2n____
Sprophyte 2n____Gametophyte 2n____Seed with embryo 2n
___Sotamtic cell of ovule 2n____Sotamtic cell 2n
___[Apospory]___________________[Apogamety]
C. Adventitious embryony
Sprophyte 2nSotamtic cell of ovule 2nSeed with embryo 2n
Fig. 31.1. Modes of agamospermous reproduction. A normal sexual life cicle is shown for comparison.

zygote (接合子): the cellular product of gametic union

Apomixis (無配偶生殖)
Reproduction is achieved without fertilisation, the sexual process being wholly or partly lost (the term and its definition are according to Winkler 1908). Two types of system are found: vegetative apomixis and agamospermy.
1) Vegetative apomixis
While for a time plants are usually rooted to the precise spot where germination and establishment has occurred, radial growth by means of rhizomes, stolons, runners, etc., is characteristic of many perennial species. Bulbils (small, readily detachable propagules, often borne on aerial structures, (Figure) are found in some species. Plants arising from such propagules will, of course, have the same genotype as the parent plant. Certain crop-plant varieties, e.g. potatoes, and such familiar garden plants as Pelargonium (the gardener's 'Geranium') are regularly propagated by vegetative means.
2) Agamospermy
In certain plants normal seed is set but no sexual fusion has occurred in its production. Offspring have the genetic constitution of the plant which produces them. A plant reproducing by seed apomixis or agamosperrny has all the advantages of the seed habit (dispersal of propagules and a potential means of survival through unfavourable seasons) without the risks which may be associated with pollination. As there is no essential genetic difference between simple agamospermy and asexual reproduction, Winkler grouped these two types of reproduction under the common term of apomixis.
apomixis Fig. 7.6. Bulbils. (a) Saxifraga cernua: 1. (× 1); 2. a cluster of bulbils; 3, bulbils in various stages of development (From Kerner 1895) (b) Poa alpina:1. P. olpina with bulbils replacing its flowers (× 1); 2. a portion of the inflorescence; 3. a miniature grass-plant developed between the glumes of a spikelet of P. alpina.

Apospory (無胞子生殖)

apomixis
Figure 31.2. Apospory in Crepis occidentalis. (A) Embryo-sac (胚嚢) mother cell dividing (ESMC) and below it an enlarging somatic cell (SC). (B) Linear tetrad above and somatic cell below developing into aposporic embryo-sac (AES). (C) Embryo-sac mother cell degenerating in first division and below it a one-celled aposporic embryo-sac (AES). (Stebbins & Jenkins 1939). (D-G) Diplospory in Antennaria porsildil. Embryo-sac mother cell developing into unreduced embryo-sac. (Urbanska 1974)
Pollination (授粉)
apomixis
Self-pollination (自家授粉, s.l.) = autogamy + geitonogamy: a form of pollination in which pollen from the same plant arrives at the stigma of a flower

• autogamy (自家生殖/自家受精/自家受粉, s.s.) ≈ self-fertilization: pollen is transferred to the stigma of the same flower
• geitonogamy (隣花受粉): pollen is transferred from the anther of one flower to the stigma of another flower on the same flowering plant

Cross-pollination (他花授粉) ≈ allogamy, xenogamy: pollen is delivered from the stamen of one flower to the stigma of a flower on another plant of the same species
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