Afzoishi rastanihoi luchtukhm

Darakhti archa ba monandi digar rastanihoi suzanbarg asosan tavassuti tukhmash afzoish mekunad. Tukhmi archa dar pulakchahoi chalguzaash ba tavri kushod (yane luch) joygir ast. Az in ru, archa va digar rastanihoi suzanbargro rastanihoi luchtukhm nom mebarand.

Archa rastanii dukhonagi, bazan yakkhonagi meboshad. Pulakchahoi khurd (mikrosporofill) dar chalguzai (mardonai) khurdi tukhmshakl joygir shudaast. CHalguzakho dar bagalaki bargi navdahoi soli gu- zashta yo dar okhiri navdachahoi pahlui inkishof meyoband. Az hosilshavii mikdori ziyodi chalguzahoi mardona (mikrostrobil) darakhti archa ba khud jiloi zardcharo megirad.

Har yak chalguza az tiri markazy va pulakchahoi khurdi dar on choygirifta iborat buda, dar har yak pulakchai khurd 2 yo 6-togy khaltachahoi gardi (mikrosporangiya) mavjudand. Dar khamin holat chalguzai khurd (mardona) zimistonro az sar meguzaronad. Bo faro rasidani fasli bahor tiri chalguza sabzida, daroz meshavad. Va hamin tavr, dar bayni pulakchaho kovoki paydo meshavad. Tavassuti in kovoki gardhoi ba kamol (pukhta) rasida az khaltachahoi gardhosilkunanda ba berun partofta shuda, tufayli shamol ba joyhoi dur burda meshavand.

CHalguzahoi zanona (megastrobil) dar fasli tiramoh dar bagalaki navdai kutoh paydo mesha- vand. Saravval in chalguzaho khele khurd buda, az mugchai nashvi kam farq mekunand. Har yak chalgu zai zanona az tiri markazi va pulakchahoi kaloni (megasporofilli) dar on joygirifta iborat ast. Dar bahori peshbiyo chalguzai zanona ba zudi inkishof meyobad va dar tiri markazii on ba shakli davri setogi pulakchahoi kalon hosil meshavand. Dar har pulakcha 1-3-togi tukhmmugjai kuzachamonand inkishof meyobad. Dar tukhmmugja surokhii khurdi garddaro mavjud ast. Dar davrai gardoludshavi az in surokhi qatrai moddai moei chaspak khorij meshavad. In moddai moe na tanho gardro dar tukhmmugja nigoh medorad, balki boz onro namnok karda, boisi sabzishi mutadili naychai gard meshavad.

Gardhoi pukhtarasida (dar chalguzai mardona) ba tufayli shamol to tukhmmugjaho ovarda meshavand. Faqat hamon gard boisi gardo- ludi meshavad, ki agar vay ba surokhii khurdi garddaroi tukhmmugja aftida boshad. Pas az gardoludii tukhmmugja pulakchahoi chalguza sergusht gardida, bo ham jafs meshavand va bo moddai zift mechaspand.

Boyad qayd kard, ki dar garddon gametai narina, dar tukhmmugja boshad, gametai zanona tashakkul meyobapd. Bordori dar tukhm- mugjahoi dar chalguza pinhonshuda amali megardad. Az hujayratukhmhoi bordor (zigotaho) janin va az tukhmmugjaho tukhm inkishof meyobad. Dar in vaqt pulakchakhoi kalon (megasporofillho) bo tezi sabzida, sergushtu gafs meshavand, sipas bo ham doimi chaspida, chalguzai sershiraro paydo mekunand. Archa az digar daraHtoni suzanbarg bo hosil namudani chunin chalguzai sergushtu sershira farq mekunad.

CHalguzahoi archa saqqoshakl yo tukhmmonand buda, hangomi pukhtanashon shakli tarmevaro megirand. CHashuzahoi archa, odatan, dar soli duyum yo seyumi badi gardoludshavi pukhta merasand.

Odatan dar okhiri soli avval chalguzaho shakli asosii (haqkonii) khudro girifta, lekin sabz boqi mondan megirand. Dar okhiri soli duyum boshad, onho muloim gardida, rangashon kabudu siyohcha yo si- yohchatobu surkhcha meshavad va bo qabati mumii kabudchatob ruykash megardand.

Vobasta ba namudi archa dar chalguzaho az 1 to 12 adad tukhm hosil meshavad. Pukhtarasii tukhm dar tiramohi soli duyum ba anjom me- rasad. Tukhmhoi bavoyarasidai archa surkhchatobi sakht buda, bo osoni az chalguzai muloimi bo mum pushidashuda judo meshavand.

Aftida posh khurdani chalguzahoi pukhtarasida az okhirhoi tobis- ton shuru shuda, to miyonahoi fasli tiramoh davom mekunad. To on lahzae, ki tukhm az chalguza naaftad, sabzishi on ba amal name- oyad va tukhm qobiliyati sabzishro muddati tuloni nigokh medorad.

Omili asosii pahnkunandai tukhmi archa hayvonhoi gunogun me- boshand. Hususan, parrandagon va digar hayvonhoi dar muhiti archazor zindagikunanda ba chalguzai shiranoku shirin va sergizoi archa tavajjuhi ziyod dorand. In chalguzaho khuroki doimi va
dustdoshtai parrandaho dar mavsimi zimiston meboshand. Tukhmi archa bo jildi gafsi sakht (ustuvor) ihota shudaast. Az in ru, tukhme, ki parrandaho va yo digar hayvonho bo chalguza furu burdaand, be yagon khel osebbini ba berun khorij meshavad va qobiliyati sabzishashro gum namekunad.

Afzoishi sanavbar ba archa monand buda, faqat farqiyat dar on ast, ki dar darakhti sanavbar pulakchahoi pushish va meva bo ham doimi nachaspidaand va chalguzai onho shakli tarmevaro namegirand .

1. Tukhmmugjai archa dar kujo joygir shudaast?
2. Dar darakhti archa khaltai garddon dar kujo va chi tavr tashakkul meyobad?
3. Rastanihoi suzanbargro charo luchtukhm meguyand?
4. Tukhmi archa chi tavr ba vujud meoyad va kay pukhta merasad?
5. Tukhmi archa chi tavr pahn meshavad?
6. CHaro chalguzai archaro chalguzameva meguyand?