AMFIDIPLOIDLAR (Yunoncha amr\u04bb\u0456yonida, atrofida, diploos \u2014 juft va eidos \u2014 ko’rinish, tur), allotetraploidlar \u2014 turlararo chatishtirish asosida paydo bo’lgan duragaylar xromosomalarining ikkita diploid to’plamiga ega bo’lgan organizmlar. Amfidiploidlar organism har bir turdan bittadan diploid xromosomalar to’plamini oladi. Turkumlararo allotetraploidlar \u2014 birinchi marta 20-yil boshida G. D. Karpechenko tomonidan turp bilan karamni chatishtirish orqali olingan. Keyinchalik Amfidiploidlar javdar bilan bug’doy tritikale, bug’doy bilan bug’doyiq \u2014 bug’doy-bug’doyiq duragaylari olingan. Amfidiploidlar dastlabki turlarning belgilarini mujassamlashtirgan bo’ladi. Masalan, turp bilan karam duragayi rafanobrassika mevasi qo’zog’ining bir qismi turp, ikkinchi qismi esa karam qo’zog’iga o’xshash bo’ladi. B. L. Astaurov ipak qurtlarining ikkita turi (Bombyx mori va V. mandarina) ni chatishtirish orqali Amfidiploidlarni olish mumkinligini isbotlaydi. Amfidiploidlarning har bir xromosomasi o’zining gomologiga ega bo’lishi, meyozda jinsiy hujayralarning vujudga kelishi normal kechishi tufayli Amfidiploidlar organizmlar serpusht bo’ladi. Amfidiploidlar tabiiy va sun’iy yo’llar: urug’langan tuxumhujayradagi yoki birinchi avlod (F,) duragaylarining yosh murtagi xromosomalari sonini ikki hissa orttirish; ikkinchi avlodda (F2) amfidiploidlikka olib keluvchi reduktsiyalanmagan gametalarni duragaylar birinchi avlodida (G’,) hosil qilish; autotetraploid formalarni chatishtirish va diploid gametalarni qo’shish; G’, duragayning arxesporiy to’qimasida xromosomalar sonini ikki hissa ko’paytirish va boshqalar natijasida olinadi. Tabiiy sharoitda Amfidiploidlar bo’linayotgan hujayra xromosomalarining qutblarga ajralish mexanizmiga turli omillar (haddan tashqari yuqori yoki past harorat, to’qimaning mexanik yoki kimyoviy shikastlanishi) ta’sirida vujudga keladi. Hujayra bo’linishidagi buzilishlar bo’linish urchig’i funktsiyasining to’xtashiga sabab bo’ladi va natijada xromosomalarning qutblarga ajralishi, ya’ni navbatdagi tsitokinez sodir bo’lmaydi. Selektsiyada Amfidiploidlardan turlararo duragaylar pushtsizligini bartaraf etishda foydalaniladi. Amfidiploidlar tur hosil bo’lish jarayonida muhim ahamiyatga ega, ulardan qadimgi turlarni tiklash (resintez) maqsadida foydalanish mumkin. Masalan, yovvoyi olcha (Prunus divarica va R. spinosa) ni chatishtirish orqali ekiladigan olxo’ri (P. domestica) ning olinishi olxo’rini turlararo duragaylash natijasida kelib chiqqanligini ko’rsatadi. Sayfillo To’ychiyev.<\/p>\n","protected":false},"excerpt":{"rendered":"
AMFIDIPLOIDLAR (Yunoncha amr\u04bb\u0456yonida, atrofida, diploos \u2014 juft va eidos \u2014 ko’rinish, tur), allotetraploidlar \u2014 turlararo chatishtirish asosida paydo bo’lgan duragaylar xromosomalarining ikkita diploid to’plamiga ega bo’lgan organizmlar. Amfidiploidlar organism har … Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":8256,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[107],"tags":[],"class_list":["post-8335","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-a-harfi","entry"],"translation":{"provider":"WPGlobus","version":"3.0.2","language":"kr","enabled_languages":["uz","kr","ru"],"languages":{"uz":{"title":true,"content":true,"excerpt":false},"kr":{"title":false,"content":false,"excerpt":false},"ru":{"title":false,"content":false,"excerpt":false}}},"_links":{"self":[{"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/posts\/8335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/comments?post=8335"}],"version-history":[{"count":1,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/posts\/8335\/revisions"}],"predecessor-version":[{"id":8338,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/posts\/8335\/revisions\/8338"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/media\/8256"}],"wp:attachment":[{"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/media?parent=8335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/categories?post=8335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/milliycha.uz\/kr\/wp-json\/wp\/v2\/tags?post=8335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}