Rastanihoi pushidatukhm (guldor) — hamchun guruhi olitashkil

SHumo dar bobhoi avvali kitobi darsii sinfi 5-um ba sokht va khususiyathoi makhsusi uzvhoi nashvi va jinsii rastanihoi guldor shinos shuda buded. Rastanihoi pushidatukhm nazar ba on guruhi rastanihoe, ki to alhol shinos shudaed, sokhti murakkabtar doshta, dar onho bori avval gul paydo meshavad. Hamin tavr, paydo shuda- ni gul va bo meva pushida budani tukhm yake az alomathoi khos va farqkunandai rastanihoi pushidatukhm ba khisob rafta, onho bo in khosiyatashon az luchtukhmon farqi kulli dorand. Alomati digari farqnoki pushidatukhmon, dar onho mavjud budani tukhmdon mebo- shad, ki az gardgirak, sutuncha va gura iborat ast. Tukhmmugjai pushi- datukhmon dar dokhili gurai tukhmdon joygir ast.

Guli rastanihoi pushidatukhm andoza, shakl, rang va sokhti guno- gun dorad. Gardoludshavii onho bo yorii shamol, hasharot va dar yak guruhi kami onho tavassuti parrandaho amali megardad. Gar- doludshavi — aftodani gard az garddon ba gardgiraki tukhmdon me- boshad.

Gardi ba gardgirak aftoda inkishof yofta istoda, gardnaychai daroz va khele borikro ba vujud meovarad. Vazifai gardnaycha ba tukhmmugchaho burdani nutfaho meboshad. Hamin tavr, gardnaycha bo du nutfa to tukhmmugjaho sabzida, ba on dokhil megardad. CHunin tar- zi bordori faqat ba rastanihoi guldor khos ast. Dar natija yake az nutfaho bo tukhmhujayra omezish yofta, onro bordor mekunad. Dar barobari in nutfai duyum bo hujayrai kaloni markazii khal- tai janin omezish yofta, onro bordor mekunad.

Tukhmhujayra badi bordorshavi taqsim shuda, ba janini rasta- nii nav tabdil meyobad. Dar janini paydoshuda reshachai janini, poyachai janini, mugjai nugi va bargi avvalini janini yo tukhmpalla (dar rastanihoi dupalla 2-to, dar rastanihoi yakpalla 1-to) ta- shakkul meyoband. Badi bordorshavi hujayrai kaloni markazii khaltai janin niz taqsim shuda, hujayrahoi endospermro ba vuchud meovarad, ki dar on jo moddahoi gizoi zakhira meshavand. Endosperm janini inkishofyoftaistodaro hangomi sabzish bo moddahoi gizoi tamin mekunad. Hamin tariq, bad az gardolud va bordor- shavii guli rastanihoi pushidatukhm – tukhmmugjai on ba tukhm, jildi tukhmmugja ba pusti tukhm tabdil meyobad. Az gurai tukhmdon meva va az devori gura mevaparda inkishof meyobad. Mevai rasta- nikhoi guldor tukhmro az tasiri omilhoi nomusoidi muhiti zist emin nigoh medorad. Dar tashakkuli mevai baze rastanihoi gul- dor natanho gura, balki digar juzhoi gul niz ishtirok mekunand. Hamin tavr, tukhm dar dokhili meva pinhon (yo pushida) ast. Az in ru, rastanihoi guldorro bo iborai digar rastanihoi pushidatukhm niz menomand.

Davomnokii umri rastanihoi pushidatukhm gunogun meboshad. CHunonchi, umri rastanii lolakhasak, havoboronak, boychechak, guli siyohgush, guli navruzi va lola hamagi yak-du moh buda, baze namo- yandagoni on, az qabili darakhti chinor, bulut ziyoda az sadho sol umr mebinand.

Baze rastanihoi pushidatukhm nihoyat azimjussaand. Darakhti evkalipt ziyoda az 100 m qad meafrozad. Dar bayni onho rastanihoi nihoyat maydachussa niz hastand. Masalan, naskobi yo tukhlab.

1. Alomathoi farqkunandai pushidatukhmonro nombar kuned.
2. Janini tukhm va meva chi tavr ba vujud meoyad?
3. Dar rastanihoi pushidatukhm bordorii duchanda chi tavr amali megardad?
4. Endosperm chi khel tashakkul meyobad va on chi ahamiyat dorad?
5. CHaro rastanihoi guldorro bo iborai digar rastanihoi pushidatukhm menomand?