Seedling

Seedling bụ obere sporophyte na-eto eto site na ẹmbrayo osisi sitere na mkpụrụ. Mmepe nke seedling na-amalite site na germination nke mkpụrụ. Seedling na-eto eto nwere akụkụ atọ: radicle (mgbọrọgwụ embrayo), hypocotyl (ịgba embrayo), na cotyledons (akwụkwọ mkpụrụ). A na-amata klas abụọ nke osisi okooko osisi (angiosperms) site na ọnụ ọgụgụ nke akwụkwọ osisi ha: monocotyledons (monocots) nwere otu cotyledon dị ka agụba, ebe dicotyledons (dicots) nwere cotyledons abụọ. Gymnosperms dị iche iche. Dịka ọmụmaatụ, mkpụrụ osisi pine nwere ihe ruru cotyledons asatọ. Osisi nke ụfọdụ ifuru osisi enweghị cotyledons ma ọlị. A na-ekwu na ndị a bụ acotyledons.
plumule bụ akụkụ nke ẹmbrayo mkpụrụ nke na-etolite n'ime oge ịse nke nwere akwụkwọ mbụ nke osisi. N'ọtụtụ mkpụrụ, dịka ọmụmaatụ sunflower, plumule bụ obere ihe owuwu conical na-enweghị usoro akwukwo ọ bụla. Uto nke plumule anaghị eme ruo mgbe cotyledons tolitere n'elu ala. Nke a bụ epigeal germination. Otú ọ dị, na mkpụrụ ndị dị ka agwa sara mbara, a na-ahụ nhazi akwụkwọ na plumule na mkpụrụ ahụ. Mkpụrụ ndị a na-etolite site na plumule na-etolite site na ala na cotyledons fọdụrụ n'okpuru elu. A maara nke a dị ka hypogeal germination.
Osisi Dicot toro n'ọkụ na-etolite hypocotyls dị mkpụmkpụ ma mepee cotyledons na-ekpughe epicotyl. A na-akpọkwa nke a dị ka photomorphogenesis. N'ụzọ dị iche, osisi ndị toro n'ọchịchịrị na-etolite ogologo hypocotyls na cotyledons ha na-emechi n'akụkụ epicotyl na nko apical. A na-akpọ nke a dị ka skotomorphogenesis ma ọ bụ etiolation. Osisi Etiolated na-acha odo odo dị ka njikọ chlorophyll na mmepe chloroplast na-adabere na ìhè. Ha ga-emeghe cotyledons ha ma tụgharịa akwụkwọ ndụ akwụkwọ ndụ mgbe ejiri ọkụ gwọọ ya.
In a natural situation, seedling development starts with skotomorphogenesis while the seedling is growing through the soil and attempting to reach the light as fast as possible. During this phase, the cotyledons are tightly closed and form the apical hook to protect the shoot apical meristem from damage while pushing through the soil. In many plants, the seed coat still covers the cotyledons for extra protection.
Mgbe ọ gbajiri elu ma rute n'ìhè, a na-agbanwe usoro mmepe nke mkpụrụ osisi ahụ ka ọ bụrụ photomorphogenesis. Cotyledons na-emeghe mgbe ha zutere ìhè (na-ekewa mkpuchi mkpụrụ ahụ, ma ọ bụrụ na ọ ka dị) ma ghọọ akwụkwọ ndụ akwụkwọ ndụ, na-emepụta akụkụ photosynthetic mbụ nke osisi ahụ. Ruo n'oge a, mkpụrụ osisi ahụ na-ebi site na ike echekwara na mkpụrụ ahụ. Oghere nke cotyledons na-ekpughe osisi apical meristem na plumule nke nwere ezigbo akwụkwọ mbụ nke osisi ahụ.
Mkpụrụ osisi na-anụ ìhè site na ndị na-anabata ìhè phytochrome (ìhè uhie na nke na-acha uhie uhie) na cryptochrome (Ìhè na-acha anụnụ anụnụ). Mgbanwe na ndị na-anabata foto ndị a na ihe ndị na-eme ka ha nwee mgbaàmà na-eduga na mmepe nke na-ekwekọghị na ọnọdụ ìhè, dịka ọmụmaatụ, mkpụrụ osisi ndị na-egosi photomorphogenesis mgbe ha toro n'ọchịchịrị.
Ozugbo mkpụrụ osisi ahụ malitere photosynthesis, ọ naghịzi adabere na ike nke mkpụrụ ahụ. Meristems apical na-amalite itolite ma na-ebute mgbọrọgwụ na osisi. Akwụkwọ mbụ "ezi" na-agbasa ma nwee ike ịmata ọdịiche dị na cotyledons gburugburu site na ụdị dị iche iche dabere na ụdị ha. Ka osisi ahụ na-etolite ma na-eto eto akwụkwọ ndị ọzọ, cotyledons na-emesị bụrụ ndị agadi ma daa. Uto mkpụrụ na-emetụtakwa site na mkpali, dị ka ifufe ma ọ bụ ụdị mmetụ anụ ahụ ndị ọzọ, site na usoro a na-akpọ trigmomorphogenesis.
Temperature and light intensity interact as they affect seedling growth; at low light levels about 40 lumens/m a day/night temperature regime of 28 °C/13 °C is effective (Brix 1972). A photoperiod shorter than 14 hours causes growth to stop, whereas a photoperiod extended with low light intensities to 16 h or more brings about continuous (free) growth. Little is gained by using more than 16 h of low light intensity once seedlings are in the free growth mode. Long photoperiods using high light intensities from 10,000 to 20,000 lumens/m increase dry matter production, and increasing the photoperiod from 15 to 24 hours may double dry matter growth (Pollard and Logan 1976, Carlson 1979).
Mmetụta nke carbon dioxide enrichment na nitrogen supply na uto nke white spruce na trembling aspen ka Brown na Higginbotham nyochara (1986). A na-akụ mkpụrụ n'ebe a na-achịkwa na gburugburu ma ọ bụ ikuku CO2 (350 ma ọ bụ 750 f/L, n'otu n'otu) yana ihe ngwọta na-edozi ahụ nke nwere nnukwu, nke dị n'etiti, na nke dị ala (15.5, 1.55, na 0.16 mM). A na-ewepụta mkpụrụ, tụọ ya, ma tụọ ya n'ihe na-erughị ụbọchị 100. N na-emetụta n'ụzọ siri ike nchịkọta biomass, ịdị elu, na mpaghara akwụkwọ nke ụdị abụọ ahụ. Naanị na spruce na-acha ọcha, oke ibu mgbọrọgwụ (RWR) mụbara nke ukwuu na ọchịchị nitrogen dị ala. Mmụba CO2 maka ụbọchị 100 mere ka akwụkwọ na ngụkọta nke mkpụrụ osisi spruce na-acha ọcha n'ọchịchị N dị elu, RWR nke mkpụrụ osisi na ọchịchị N dị n'etiti, na mkpụrụ osisi mgbọrọgwụ nke mkpụrụ osisi n'ọkwa N dị ala.
Mkpụrụ osisi nke afọ mbụ na-enwekarị ọnụ ọgụgụ dị elu nke ọnwụ, ụkọ mmiri ozuzo bụ isi ihe kpatara ya, ebe mgbọrọgwụ enweghị ike ịzụlite nke ọma iji nọgide na-emetụta ala nke na-ekpo ọkụ iji gbochie mmepe nke nrụgide mmiri na-egbu egbu. Otú ọ dị, n'ụzọ na-emegide onwe ya, Eis (1967a) chọpụtara na ma na mineral na ahịhịa, ọnwụ mkpụrụ osisi dị ukwuu na ebe obibi mmiri (alluvium na Aralia-Dryopteris) karịa na ebe obibi kpọrọ nkụ (Cornus-Moss). O kwuru na n'ebe ndị kpọrọ nkụ mgbe oge mbụ nke uto gasịrị, mkpụrụ osisi ndị dị ndụ yiri ka ha nwere ohere ka mma nke ịnọgide na-adị ndụ karịa ndị nọ na mmiri ma ọ bụ mmiri, ebe oyi na-arị elu na asọmpi sitere na obere ahịhịa ghọrọ isi ihe n'afọ ndị sochirinụ. Ọnwụ kwa afọ nke Eis dere (1967a) na-akụzi ihe.
Ụmụ ọhụrụ na-enwekarị ohere maka mwakpo nke ụmụ ahụhụ na ọrịa ma nwee ike ịnwe ọnụ ọgụgụ dị elu nke ọnwụ. Ọrịa ndị na-emebi mkpụrụ osisi karịsịa gụnyere damping off. Nje ndị na-egbu egbu nke na-emebi mkpụrụ osisi gụnyere cutworms, pillbugs, slugs na snails.
A na-etinyekarị mkpụrụ osisi, mgbe akwụkwọ abụọ mbụ pụtara. A na-akpọkarị nke a pricking out na UK. Enwere ike inye ndò ma ọ bụrụ na ebe ahụ kpọrọ nkụ ma ọ bụ na-ekpo ọkụ. Enwere ike iji vitamin hormone dị n'ahịa zere mgbagwoju anya nke nwere ike ịnwe thiamine hydrochloride, 1-Naphthaleneacetic acid na indole butyric acid.