Qhov Tseem Ceeb Qhov txawv - Apomixis vs Polyembryony
Paj paj tsim cov noob los txhawb nqa lawv tiam. Cov noob yog tsim los ntawm kev sib deev kev sib deev hauv feem ntau cov nroj tsuag. Txawm li cas los xij, hauv qee cov nroj tsuag, cov noob tau tsim yam tsis muaj fertilization ntawm qe hlwb. Cov txheej txheem no hu ua apomixis. Apomixis txhais tau hais tias yog kev tsim cov noob ntawm cov noob los ntawm cov qe qe tsis muaj menyuam, zam cov txheej txheem ntawm meiosis thiab fertilization. Polyembryony yog lwm qhov tshwm sim cuam tshuam nrog cov noob. Kev tsim ntawm ntau tshaj ib lub embryo los ntawm ib lub zygote nyob rau hauv ib lub noob yog hu ua polyembryony. Qhov sib txawv tseem ceeb ntawm apomixes thiab polyembryony yog tias apomixes tsim cov noob tsis muaj fertilization thaum polyembryony tsim ntau tshaj ib embryos hauv ib lub noob los ntawm fertilized qe cell (zygote).
Apomixis yog dab tsi?
Kev loj hlob ntawm noob yog txheej txheem nyuaj hauv kev sib deev ntawm cov noob nroj tsuag. Nws tshwm sim ntawm paj tsim, pollination, meiosis, mitosis thiab ob fertilization. Meiosis thiab fertilization yog cov kauj ruam tseem ceeb tshaj plaws hauv kev tsim cov noob thiab kev sib deev. Nyob rau hauv cov kauj ruam no, ib tug diploid niam cell (megaspore) undergoes meiosis los tsim ib tug haploid cell (megaspore) thiab ces tsim ib lub qe qe. Tom qab ntawd lub qe cell fuses nrog ib tug phev los tsim ib tug diploid zygote uas loj hlob mus rau hauv ib tug embryo (noob).
Txawm li cas los xij, qee cov nroj tsuag muaj peev xwm tsim cov noob yam tsis raug rau meiosis thiab fertilization. Cov nroj tsuag no hla ob peb kauj ruam tseem ceeb ntawm kev sib deev. Hauv lwm lo lus, kev sib deev muaj peev xwm ua rau luv luv hauv qee cov nroj tsuag los tsim cov noob. Cov txheej txheem no hu ua apomixis. Yog li apomixes tuaj yeem txhais tau tias yog txheej txheem tsim cov noob tsis muaj meiosis thiab fertilization (syngamy). Nws yog ib hom kev yug me nyuam asexual uas ua raws li kev sib deev. Nws tseem hu ua agamospermy. Feem ntau apomicts yog facultative thiab qhia ob qho tib si kev sib deev thiab asexual noob formations.
Apomixis tuaj yeem muab faib ua ob hom loj hu ua gametophytic apomixes thiab sporophytic apomixes raws li txoj kev embryo tsim. Gametophytic apomixes tshwm sim ntawm gametophyte thiab sporophytic apomixes tshwm sim ncaj qha ntawm diploid sporophyte. Kev sib deev li qub tsim cov noob uas muab cov xeeb ntxwv sib txawv. Vim tsis muaj fertilization nyob rau hauv apomixis, nws ua rau ib tug zoo xws li cov noob qoob loo ntawm leej niam.
Apomixis feem ntau tsis pom nyob hauv cov nroj tsuag feem ntau. Nws tsis muaj nyob hauv ntau cov qoob loo tseem ceeb thiab. Txawm li cas los xij, vim nws qhov txiaj ntsig zoo, cov kws cog qoob loo sim siv cov txheej txheem no los ua cov cuab yeej siv los tsim cov khoom noj muaj txiaj ntsig zoo rau cov neeg siv khoom.
Nws muaj qhov zoo thiab qhov tsis zoo hauv cov txheej txheem apomixis. Apomixis tsim cov noob qoob loo zoo ib yam li niam txiv. Yog li, apomixes tuaj yeem siv los tsim cov noob caj noob ces zoo ib yam thiab sai. Cov yam ntxwv ntawm niam cov nroj tsuag tuaj yeem khaws cia thiab siv los ntawm apomixis rau ntau tiam neeg. Hybrid vigor yog ib qho tseem ceeb yam ntxwv uas muab cov heterosis. Apomixis pab txuag hybrid vigor rau tiam neeg hauv ntau hom qoob loo. Txawm li cas los xij, apomixis yog ib qho tshwm sim nyuaj uas tsis muaj qhov tseeb ntawm caj ces. Kev saib xyuas ntawm cov noob qoob loo apomictic yog qhov nyuaj tshwj tsis yog txuas nrog lub cim morphological thaum lub sijhawm kev txhim kho.
Daim duab 01: Apomictic Taraxacum officinale
Polyembryony yog dab tsi?
Embryogeny yog txheej txheem uas tsim embryo los ntawm zygote (fertilized qe). Lub embryo yog ib feem ntawm cov noob uas dhau los ua cov xeeb ntxwv yav tom ntej. Kev tsim ntawm ntau tshaj ib lub embryo los ntawm ib lub qe fertilized nyob rau hauv ib lub noob yog hu ua polyembryony. Qhov tshwm sim no tau pom los ntawm Leeuwenhoek hauv xyoo 1719.
Muaj peb hom polyembryony: yooj yim, cleavage, thiab adventive polyembryony. Tsim cov embryos vim fertilization ntawm ntau tshaj ib lub qe qe yog hu ua yooj yim polyembryony. Tsim cov embryos los ntawm saprophytic budding yog hu ua adventive polyembryony. Tsim cov embryos vim cleavage ntawm loj hlob embryo yog hu ua cleavage polyembryony.
Polyembryony yog pom los ntawm qee hom nroj tsuag xws li dos, av, txiv qaub, txiv kab ntxwv, thiab lwm yam.
Daim duab 02: Polyembryony hauv citrus
Qhov txawv ntawm Apomixis thiab Polyembryony yog dab tsi?
Apomixis vs Polyembryony |
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| Apomixis yog ib hom kev yug me nyuam uas tsim cov noob tsis muaj fertilization (tsis muaj fusion ntawm gametes). | Poyembryony yog ib qho tshwm sim uas piav qhia txog kev tsim ntawm ntau tshaj ib lub embryo los ntawm zygote (ib lub qe fertilized). |
| Fertilization | |
| Apomixis tsis koom nrog kev yug menyuam. | Polyembryony yog tshwm sim ntawm fertilization. |
| Zygote Formation | |
| Zygote tsis tsim thaum lub sijhawm apomixis. | Zygote yog tsim ua ntej polyembryony. |
| Seedlings are genetic identical. | Vim tag nrho cov embryos tau tsim los ntawm ib lub zygote, cov noob tau zoo ib yam. |
| Zoo sib xws rau niam cog | |
| Lawv yog clones ntawm niam cog. | Lawv tsis yog caj ces zoo ib yam li niam cog. |
| Examples | |
| Qee hom Asteraceae thiab nyom yog piv txwv. | dos, av, txiv nkhaus taw, txiv qaub, thiab txiv kab ntxwv yog piv txwv. |
Summary – Apomixis vs Polyembryony
Apomixis thiab polyembryony yog ob nqe lus hais txog kev tsim cov noob nroj tsuag. Apomixis yog tsim ntawm cov noob tsis muaj fertilization. Nws tsim cov noob qoob loo zoo ib yam li niam txiv. Polyembryony yog muaj los yog tsim ntau tshaj ib lub embryo nyob rau hauv ib lub noob los ntawm ib tug fertilized qe cell (Zygote). Nws txhim kho cov nroj tsuag zoo ib yam li asexual reproduction. Qhov no yog qhov txawv ntawm apomixes thiab polyembryony.
