Davrahoi hayoti rastaniho: janini, javoni, kamolot, pironsoli

Rastaniho dar muddati faoliyati hayotiashon vaznu andozai resha, poya va navdavu bargashon sol az sol muntazam afzuda, na tanho mesabzand, onho inchunin inkishof yofta, khususiyatu khosiyathoi nav ba nav paydo mekunand. Az in ru, dar rastanihoi guldor, yane pushidatukhmon chor davrai inkishof farq karda meshavad.

Saravval, ovoni janini — az davrai ba vujud omadani janin to hangomi ba sabzish shuru kardani on. CHi tavre ki malum ast, hayoti har yak rastanii guldor hangomi afzoishi tukhmi az bordorshavii tukhmhujayra va khosilshavii zigota ogoz meshavad. Zigo- ta borkho, takror ba takror taqsim shuda, ba janin tabdil meyobad.

Duyum, ovoni navrasi yo javoni, kiaz davrai ba sab- zish shuru kardani tukhm to lahzai gulshukufti nakhustini rastanii dar nashvu numubuda davom mekunad. Az hama pesh, on uzvhoe ba sab- zish shuru mekunand, ki onho allakay dar janini hosilshuda zaminai mutamad doshtand. CHunonchi, reshachai asosi yo janini, poyai janini va bargchahoi chanini yo tukhmpallagi. Onho to ba vujud oma- dani avvalin uzvhoi ruizamini asosan az hisobi moddahoi dar tukhm (endosperm) zakhirashuda gizo megirand. Sipas, reshaho sab- zida, shokha ronda, reshahoi ilovagi va pahlui hosil mekunand va sistemai (silsilamajmui) reshagi tashakkul meyobad.

Hamin tavr, navnihol ba tufayli reshavu barghoyash purra ba zindagonii mustaqilona meguzarad.

Hayotguzaronii oyandai rastanihoi javoni numuyobanda beshtar ba on vobasta ast, ki rastani ba kadom shaklhoi hayotii rastaniho taalluq dorad. Masalan, sabzishi rastanihoi yaksola dar davomi yak mavsimi nashunamo purra ba okhir merasad. Onho gul karda meva hosil mekuiand va nobud megardand (nakhud, bodiring, tarbuz, khar- buza va gayraho).

Baze alafhoi bisyorsola dar soli avvalini hayotashon khele boavj nashunamo karda, hatto gul mekunand (sebarga). Vale beshtari onho dar solhoi muayyani hayotashon gul mekunand. Hamin tavr dar rastanihoi gunogun davrai javoni metavonad solhoi gunogunro darbar girad.

Darakhtonu buttaho boshand dar davrai 5-10 soli hayotashon nisba- tan sust nashunamo mekunand. Sipas, nashunamoi onho avj girif- ta, reshaashon kalonhajmu boquvvat gardida, ba khok chuqur meravad. Qadkashni poyayu navdahoyashon niz avj girifta, har sol taqriban to 30-50 sm va bazan to 70-80 sm daroz meshavand.

Seyum, ovoni kamolot — az lahzai paydoshavii uzvhoi guli to hosilshavii tukhm yo mevabandi, ki dar bisyor namudhoi nabototi da- rakhtiyu buttagi solhoi ziyod (to davrai pironsoli) davom mekunad.

In davra dar hayoti rastanihoi yaksola va dusola nihoyat kutoh buda, badi yak bor mevabandi ba itmom merasad.

Dar rastanihoi bisyorsola boshad, in ovoni hayoti solhoi khele zi- yodero darbar megirad. Pas az har bori gulshukuft – gulshukufti duyum, seyum, chorum va hokazo, dar davomi bisyor solho idoma meyobad. Rastaniho dar in davra az jihati vaznu andoza va kalon gardidani poyavu navdahoyashon ba darajai balandi sabzishu inkishofashon merasand.

Davrai chorum ovoni pironsoli meboshad. Dar in davra rastani az gulshukuft va mevabandi boz monda, nobudshavii boavji uzvhoi on sar meshavad, ki in ba nobudshavii rastani ovarda merasonad. Zero alafhoi bisyorsola va rastanihoi darakhtiyu buttagi bo mururi zamon pir meshavand. Dar onho qobiliyati mevabandi nihoyat sust gardida, dar okhir qat megardad (masalan, sebhoi pi- ronsol tamoman meva namebandand). Dar rastanihoi pironsol qobi- liyati hosilshavii uzvhoi nav (resha, navda, barg) to darajai nihoi sust meshavad. Navdayu poyahoi qismhoi nugii rastaniho boshad ba khushkshavi sar mekunand. Dar tanai rastaniho kovokiho ba vujud omada, shokhahoi kamquvvatgardidayu khushkshuda shikasta meaftand.

Dar alafhoi bisyorsolai pir boshad, sabzish va az nav paydosha- vii uzvho nihoyat sust meshavad. Poyayu barghoi navrustai onho bisyor zaifu noqisand. Reshaashon ba kalonhajmii khud nigoh nakarda, da- runkovoku pusidaand. Hosilshavii reshahoi ilovagi va pahlui qarib ki ruy namedihad. Hosilshavii mugjahoi nav qat gardida, onho ba margi tabii duchor megardand.

Hamin tavr, donistani davrahoi inkishofi rastaniho imkon medihad, ki ba hayotu faoliyati uzvhoi onho bakhubi sarfahm ravem, parvarishu nashunamoi onhoro bo nazardoshti davrahoi hayotiashon maqsadnok idora kunem va az onho purmahsul istifoda barem.

1. Dar rastanihoi bisyorsola kadom davrahoi sinnusoli farq karda meshavand?
2. Davrai janini kay sar meshavad va to kay davom mekunad?
3. Hususiyathoi muhimi davrai javonii rastaniro nombar kuned yo sharh dihed.
4. Davrai javonii alafhoi bisyorsola va darakhtu buttaho chi tavr idoma meyobad?
5. Kadom alomathoi makhsusi davrai pironsolii rastaniro medoned?