Kaviri muchangosangana

Mukume zviyo kuti uuraye rusarura kwenzira imwe kana mumwe, kutanga imere. Grain unozvimba, mukume chubhu achiumbwa kubva vegetative masero. Saka, kumera inotanga. The goko Anoparadza panguva thinnest panzvimbo mukume chubhu. Kubva muromo chubhu dzinounzwa chaiwo zvinhu. Ivo kupfavisa machira mbiru uye rusarura.

Musimboti rokubereka uye vegetative masero kuyambukira mukume chubhu. Sero rokubereka runoparadzanisa nokuumba dzisingaoneki maviri. Kuburikidza micropyle (buri goko) ovule mukume chubhu iri rakapinda mumba embryo zai. Inside musaga chubhu wakaputsika uye zvirimo akadurura.

Zvadaro Fusion kunoitika pamwe dzisingaoneki kubva zai. Saka, zygote, vakabva kupa kutanga mbeu mudumbu. Pamwe chete ichi chechipiri Kubatanidza pamwechete nechepakati musimboti urume. Izvi zvinotungamirira paumbwe triploid neerekitironi tikaisa gare gare triploid endosperm, inova yechipiri.

pamusoro zvose muitiro wacho anonzi "mbiri pakusangana mu maruva miti."

Antipodes uye synergids (polar nuclei mu embryo zai) pashure pokupedza kwacho vari ichiputswa, uye integuments (zvifukidziro) vanoumba mbeu jasi.

Double pakusangana mune miti yakawanikwa ne musayendisiti wokuRussia S. Navashin.

Panguva iyi, musimboti mu embryonic zai iri kazhinji yakakura zvikuru kupfuura urume musimboti, izvo zviri kukonzerwa kuwana interphase yokutanga (zvenguva kutotanga). In ichi uye Maumbirwe nuclei embryo zai dzingasiyana. Somuenzaniso, vamwe Asteraceae vangave elongated, dzimwe nguva chakakombama, asiri nucleoli. Kazhinji, dzisingaoneki dzinoturwa muchimiro woita interphase nuclei pamwe nucleoli, mune zvimwe zviitiko, asina Kusiyana nemamiriro munhukadzi nuclei.

Double muchangosangana rinogona mhando mbiri, zvichienderana hunhu pamwe vechirume nuclei.

Saka, kana muitiro kunoitika premitotic kunyudza dzisingaoneki nuclei ari munhukadzi chinoumba, apo despiralization (unwinding) okutodza. In ichi pamwe nemhando vose okutodza mune interphase nuclei akaita.

Postmitotic kaviri muchangosangana ane panopindwa vechirume nuclei, ukaramba goko mu prophase, iyo inoguma kuwadzana kwavo. Education interphase nuclei, ane mashoko okutodza rinovira, anouya pashure vachava naHama wokutanga mitotic nokupesana zygote.

Kana kaviri muchangosangana rikaitika zai Fusion zviviri haploid (ine hafu nhamba okutodza) cores, zvisinei diploid zygote neerekitironi (ane yakazara vanochengeta okutodza).

Zvichienderana nokuwanda polar nuclei zviri nechepakati muchitokisi aumbwa chromosome nokuwanda endosperm nuclei.

Double muchangosangana kunoita vanoratidza unhu richikunda ari endosperm mbeu (chemasanganiswa) chirimwa endosperm kubva baba. Nengano kupinda embryo zai shoma mukume sepombi, muitiro kunosanganisira dzisingaoneki kubva pakutanga chubhu, mune dzimwe sepombi dzisingaoneki vakaderera. Double aberekeswe maviri spermatozoa iri apo neapo.

Panguva kuferefeta embryological vanoverengeka achishandisa vamiririri angiosperms siyana (Compositae, Ranunculaceae, Liliaceae) Navashin chishongedzo endosperm kwakaratidzei sezvo embryo kuti kurara kwacho maruva miti. Fani iyi ndiwo maitiro chete vamiririri angiosperms kasvisto.

Zvinofanira kucherechedzwa kuti basa Navashin akabvumira kujekesa nyaya Nezvekwakabva endosperm. Zvinorehwa zvakawanwa musayendisiti kunge yakatanga mberi.