Induksi Embriogenik Mikrospora Paprika dengan cekaman Suhu dan Starvasi

WALIDAH, Nasikhatul, Dr.Ir. Aziz Purwantoro, M.Sc

2004 | Tesis | S2 Agronomi

Sel gametofit jantan (mikrospora) dibawah kondisi tertentu dapat dibelokkan perkembangan normalnya secara in vitro menjadi sporofitik melalui jalur embriogenesis untuk membentuk embrio haploid. Proses perkembangan ini dipengaruhi oleh berbagai macam cekaman yaitu cekaman suhu panas (heat shock), cekaman suhu dingin (cold shock) dan cekaman starvasi. Penelitian ini bertujuan untuk menginduksi perkembangan normal mikrospora paprika menjadi embriogenik dengan perlakuan cekaman starvasi karbohidrat dan suhu. Kemudian setelah lepas dari cekaman, mikrospora embriogenik dikulturkan dalam medium embriogenesis A2 sampai terbentuk proembrio. Penelitian ini dilakukan di Laboratorium Kultur Jaringan, Fakultas Biologi Universitas Gadjah Mada dari bulan September 2003 sampai bulan Januari 2004. Mikrospora yang diisolasi pada stadium uninukleat akhir dikulturkan pada medium tanpa sumber gula dan diinkubasi pada suhu 4°C, 25°C dan 34°C selama 2, 4 dan 7 hari. Mikrospora embriogenik yang dihasilkan ditumbuhkan dalam medium embriogenesis sampai terbentuk proembrio. Pengamatan yang dilakukan meliputi penetapan stadium perkembangan mikrospora, jumlah mikrospora viabel, persentase mikrospora embriogenik, persentase proembrio. Pengambilan data berdasarkan persentase yang dianalisis menggunakan Rancangan Acak Lengkap Faktorial yang dilanjutkan dengan Uji Pembanding Berganda DMRT (Duncan’s Multiple Range Test) taraf nyata 5 %. Hasil penetapan stadium perkembangan mikrospora paprika menunjukkan bahwa stadium uninukleat akhir terdapat pada kuncup bunga berukuran 4 mm, dengan stadium uninukleat akhir paling banyak 65,28%. Induksi cekaman suhu dan starvasi berpengaruh nyata terhadap persentase mikrospora viabel sebanyak 43,57% pada perlakuan suhu 25 °C selama 4 hari, dan persentasenya menurun setelah 7 hari. Persentase mikrospora embriogenik setelah diinduksi dengan cekaman suhu dan starvasi berpengaruh nyata terhadap persentase tipe-tipe mikrospora embriogenik. Persentase mikrospora embriogenik tipe I tertinggi pada perlakuan cekaman suhu 4 °C selama 2 hari yaitu 20,33%, tipe II tertinggi pada perlakuan cekaman suhu 34°C selama 4 hari yaitu 16,17%. Sedangkan persentase mikrospora embriogenik tipe III tertinggi 14,47 % pada perlakuan cekaman suhu 34°C selama 7 hari. Mikrospora embriogenik tipe III inilah yang relatif lebih cepat membentuk proembrio uniseluler 14,56% (praperlakuan 4°C), jumlah 2 sel yang terdiri dari tipe pembelahan asimetri 9,86% dan tipe pembelahan simetri 8,46%. Tipe pembelahan simetri akan berkembang menjadi 4 sel yaitu 4,39%.

The male gametophyte (microspore) of flowering plants can be switched in vitro from their normal development towards the sporophytic pathway under appropriate conditions via embryogenesis and form haploid embryo. This process is triggered by various stresses including cold shock, heat shock and starvation. This research have purposed to induce embryogenic microspores by stress carbohydrat starvation and temperatur. The embryogenic microspores was cultured in embryogenesis (A2) medium to form proembryo. This research was conducted in Tissue Culture laboratory, Faculty of Biology, Gadjah Mada University from September, 2003 to January, 2004. Embryogenic microspores which isolated from late uninucleate were isolated and cultured in a medium without sugar and incubated at 4°C, 25°C and 34°C for 2, 4 and 7 days to form proembryo in embryogenesis (A2) medium. The measurements were stages of microspores development, amount of viable microspores, embryogenic microspores percentage’s, type of embryogenic microspores and proembryo percentage’s. The data were obtained based on the average and analyzed with Factorial’s Complete Randomized Design and compared between treatments with Duncan’s Multiple Range Test (a=5%) Based on result analysis, it can be concluded that stage of bell pepper microspores development which showed a good respons to induce microspores embryogenesis in 4mm bud length which have higher frequency of late uninucleat microspores up to 65,28%. Induction of thermal and starvation streses after 4 days at 25°C were significantly different with viability of microspores percentage’s up to 43,57%, and decreased after 7 days. Temperatur and starvation streses pretreatment were significantly different to percentage embryogenic microspores based on its types. Percentage of embryogenic microspores in type I were higher up to 20,3% after 2 days starvation at 4°C stress treatment, type II up to 16,17% (34°C for 4 days). Percentage of microspores embriogenic type III were higher up to 14,47% in medium starvation at 34°C for 7 days. Type III of embryogenic microspores (4°C pretreatment) were more faster form proembryo 14,56% unicelluler, 2 cells of assymetric division 9,86% and symetric division 8,46%. Embriogenic microspore which had symetric division developed to form 4 cell up to 4,49%.

Kata Kunci : Tanaman Paprika,Embriogenesis Mikrospora, Heat shock, cold shock, starvation, embryogenic microspore, Bell Pepper