Induksi mutasi Stevia rebaudiana dengan perendaman kolkisin secara in vitro (Induced mutation of Stevia rebaudiana through colchicine soaking in vitro)

Stevia rebaudiana Bert. is a plant producing steviol glycosides that have 200-300 times sweeter than sucrose. These steviol glycosides are produced in the leaves and then spread to all parts of the plant including stems. The use of superior stevia planting material is important for stevia sugar industry. One of the stevia breeding programme is to increase genetic diversity through colchicine soaking to produce polyploid plants. Polyploid plants usually have higher vigor than diploid plants. The purpose of this research was to induce genetic diversity of stevia through colchicine soaking in vitro. Single nodes of sterile stevia clone BS were soaked in colchicine at the concentration of 0.01; 0.02; 0.04; 0.08 and 0.1% for 48 and 72 hours, and in sterile aquadest as a control. Plantlet subcultures were done until MV4 (mutant vegetative 4). Putative mutants were observed by plantlet vigor and stomata analyses on MV5. Vigor of plantlets was observed by counting the number of leaves, nodes, roots, fresh weight and dry weight of the plantlet. Stomata analysis was performed by calculating stomata density, stomata size and chloroplast number in stomata guard cells. Results showed that colchicine soaking treatment increased significantly fresh weight and dry weight of putative mutants. Colchicine soaking treatment increased chloroplast number on stomata guard cell and stomata size, but decreased stomata density. Stevia soaked in colchicine for 48 hours at concentration 0.01-0.04% produce putative mutants with high chromosome numbers. [Key words: poliploidy, stomata, chloroplast, mutant]AbstrakStevia rebaudiana Bert. merupakan tanaman penghasil glikosida steviol yang memiliki tingkat kemanisan 200-300 kali lebih tinggi dibandingkan sukrosa. Glikosida steviol ini diproduksi di daun yang kemudian disalurkan ke bagian tanaman lainnya termasuk batang. Penggunaan klon terbaik stevia merupakan salah satu kunci penting keberhasilan industri gula stevia. Salah satu program pemuliaan tanaman stevia adalah meningkatkan keragaman tanaman melalui mutasi dengan kolkisin sehingga menghasilkan tanaman poliploid. Tanaman poliploid umumnya memiliki vigor lebih baik dibandingkan tanaman diploid. Tujuan dari penelitian ini adalah untuk meningkatkan keragaman stevia melalui peren-daman kolkisin in vitro. Buku tunggal steril stevia klon BS direndam dalam kolkisin dengan konsentrasi 0,01; 0,02; 0,04; 0,08 dan 0,1% selama 48 dan 72 jam dengan perendaman dalam air steril sebagai kontrol. Sub kultur dilakukan hingga MV4 (mutan vegetatif 4). Pengamatan mutan putatif dilakukan meliputi analisis morfologi dan stomata pada MV5. Analisis morfologi dilakukan dengan mengamati jumlah daun, buku, akar, bobot basah serta bobot kering planlet. Analisis stomata dilakukan dengan menghitung kerapatan stomata, ukuran stomata serta jumlah kloroplas pada sel penjaga stomata. Hasil menunjukkan bahwa perendaman stevia pada kolkisin meningkatkan bobot basah serta bobot kering stevia in vitro. Perlakuan perendaman kolkisin meningkatkan jumlah kloroplas pada sel penjaga stomata serta ukuran stomata namun menurunkan kerapatan stomata. Perendaman stevia selama 48 jam pada konsentrasi kolkisin 0,01-0,04% menghasilkan mutan putatif dengan jumlah kromosom tertinggi.[Kata kunci: poliploidi, stomata, kloroplas, mutan]

Mutasi Induksi Dendrobium sylvanum var. flava Menggunakan Kolkisin secara In Vitro

ABSTRACTIn Vitro mutation using colchicine on 2 month of self-pollinated protocorm like bodies of Dendrobium sylvanum var. flava was conducted to determine the effects of concentration and immersion duration in colchicine on proliferation of PLBs, and to identify of ploidy variants based on stomatal variable. Research was arranged using factorial completely randomized design with three factors in three replications. The first factor was concentration of colchicine, consisted of five concentrations (0.02; 0.04, 0.06; 0.08; dan 0.1%). The second factor was duration of immersion in the colchicine, consisted of four durations (1; 24; 48; 72 hours). The third factor was proliferation medium consisted of two concentrations of BAP (1; 0.5 mg L-1). Analysis of variance showed the significant effect of colchicine treatment on percentage of survived explants. LD50 in media 1 mg L-1 BAP was obtained at a colchicine concentration of 0.069% with duration immersion of 58.19 hours. On Media 0.5 mg L-1 BAP, LD50 was obtained at colchicine concentration of 0.054% with duration immersion of 47.63 hours. Percentage of solid polyploid mutant of Dendrobium sylvanum var. flava can not be determined on MV2 generation because the stomata leaf showed chimeras based on the chloroplast number in cell guard and stomata size.Keywords: colchicines, Dendrobium sylvanum, mutation, number of chloroplast stomatal density.ABSTRAKMutasi dengan kolkisin pada PLBs hasil selfing Dendrobium sylvanum var. flava umur 2 bulan dilakukan secara In Vitro dengan tujuan mempelajari pengaruh konsentrasi kolkisin, durasi perendaman dalam kolkisin, media proliferasi terhadap pertumbuhan PLBs Dendrobium sylvanum var. flava serta mengidentifikasi variasi ploidi berdasarkan variabel stomata. Penelitian disusun dalam Rancangan Acak Lengkap Faktorial 3 Faktor dengan 3 ulangan. Faktor pertama ialah konsentrasi kolkisin yang terdiri atas 5 taraf (0.02; 0.04, 0.06; 0.08; dan 0.1%). Faktor kedua ialah durasi perendaman yang terdiri atas 4 taraf (1; 24; 48; 72 jam). Faktor ketiga ialah media proliferasi media V&W yang ditambah BAP terdiri atas 2 taraf (1; 0.5 mg L-1). Hasil analisis ragam menunjukkan pengaruh kolkisin yang nyata terhadap variabel persentase hidup. LD50 pada media 1 mg L-1 BAP diperoleh pada konsentrasi 0.069 % dengan durasi perendaman 58.19 jam. Pada media 0.5 mg L-1 BAP, LD50 diperoleh pada konsentrasi 0.054 % dengan durasi perendaman 47.63 jam. Persentase mutan poliploid pada MV2 Dendrobium sylvanum var. flava ini belum dapat ditentukan karena stomata daunnya masih kimera berdasarkan karakter jumlah kloroplas sel penjaga dan ukuran stomata.Kata kunci: Dendrobium sylvanum, jumlah kloroplas, kerapatan stomata, kolkisin, mutasi.

Nuclear DNA endoreplication and plastid index in mesophyll of some dicotyledonous species

Cytophotometric studies of nuclear DNA content after Feulgen procedure indicate that in mesophyll of all the seven studied species the highest nuclear DNA endoreplication level occurs in II or III leaf and it varies for particular species. No differences were found in nuclear DNA endoreplication dynamics between the basal and apical parts of the leaf blade. Chloroplast number per cell generally decreases in the successive leaves, and the plastid index is the smallest in the first (oldest) leaves, being similar in both zones. In four species chloroplast number and plastid index show relatively low negative correlation with nuclear DNA contents (expressed as endoreplication index), in two species this correlation is positive, and one species displays very low r value.

Measure of the Photosynthetic Efficiency of the Cabbage Leaves by Using Photo-Acoustic Tomography Spectroscopy Technology

By using a new type of photo-acoustic tomography spectroscopy with non-damage and weak signals detection, the normalized photo-acoustic tomography spectroscopy (PAS-CT) and optical absorption characteristic of the green and yellow leaves of the cabbage are measured. The results show that: the leaves of the cabbage could get different levels of photo-acoustic spectroscopy from different chopping frequency. The chloroplast number in the yellow leaves was less than that in the green leaves, so the photosynthesis in the yellow leaves was significantly weakened compared with the green leaves. The more the chloroplast number in the cabbage leaves were, the stronger the photosynthesis was and the higher the photosynthetic efficiency was. The chopping frequency of 24Hz could activate more chloroplasts than 34Hz and improve the photosynthetic efficiency of the cabbage leaves. What’s more, it could improve the yield of cabbage. Photo-acoustic tomography spectroscopy is a new way of studying photosynthesis. It has a bright and far-reaching future.