Analisis Kariotip dan hubungan kekerabatan beberapa kultivar Dieffenbachia spp

YULIASTRI, Yovita Endah, Dr.Ir. Aziz Purwantoro, M.Sc

2005 | Tesis | S2 Pemuliaan Tanaman

Dieffenbachia merupakan tanaman hias daun dan sering dimanfaatkan sebagai tanaman hias dalam ruangan. Genus ini berasal dari Amerika tropis, dan merupakan anggota dari famili Araceae. Penelitian ini bertujuan untuk mengidentifikasi jumlah dan morfologi kromosom serta hubungan kekerabatan beberapa kultivar Dieffenbachia berdasarkan analisis kariotip. Pengamatan kromosom somatik metafase dilakukan pada sel-sel somatik ujung akar tanaman yang sedang tumbuh. Pembuatan sediaan kromosom berdasarkan metode squash aceto-orcein (Armstrong, 1995). Data-data kariotip yang diukur dan dianalisis meliputi jumlah, panjang lengan pendek dan panjang, panjang absolut, rasio lengan kromosom, indeks intra maupun interkromosomal (A1, A2), rasio pasangan kromosom terpanjang terhadap yang terpendek ( R ), dan proporsi kromosom (PK) yang memiliki rasio lengan lebih besar dari 2,00. Hubungan kekerabatan antara beberapa jenis Dieffenbachia ditentukan berdasarkan nilai-nilai komponen kariotip, yaitu A1, A2, R, dan PK dengan analisis gerombol (cluster analyses). Hasil penelitian menunjukkan bahwa tiga kultivar Dieffenbachia, yaitu Dieffenbachia compacta, Dieffenbachia maculata and Dieffenbachia Rudolph Roerhs mempunyai jumlah kromosom yang sama 2n = 4x +2 = 34, Dieffenbachia bausei 2n = 4x + 4 = 36, Dieffenbachia spp. Kultivar A 2n = 4x + 3 = 35, and Dieffenbachia Paradise dan Dieffenbachia spp. Kultivar B had 2n = 10x = 80. Kultivar-kultivar yang memiliki jumlah kromosom yang sama belum tentu memiliki rumus kariotip yang sama. Dari nilai-nilai simetri kariotip seperti A1, A2, R dan PK, dapat disimpulkan bahwa Dieffenbachia spp Kultivar B merupakan kultivar yang lebih maju dalam evolusi jika dibandingkan dengan kultivar Dieffenbachia yang lain.

Dieffenbachias are ornamental plants grown and bred for their attractive foliage, and popular as indoor plants. The plants belong to the genus of Dieffenbachia and the Araceae family. This cytological study of several Dieffenbachia plants was to identify the numbers and morphologies of their chromosomes, and to obtain karyologically relationship. Root tips of the young growing plants were collected for obtaining somatic chromosomes at metaphase. Slides prepared according to aceto arcein squash method (Armstrong, 1995). The slides were observed under microscope and the cells had well spreading chromosomes were photographed at 1000x magnification. Karyotype data were collected and included chromosome number, length of the short and long arms, absolute length, and arm ratios, intra and interchromosomal asymetry indexes, ratio of the longest to the shortest pair of chromosomes, and the proportion of chromosomes having arm ratio up to 2.00. Phenetic relationship among several Dieffenbachia plants had analysed based on the karyotype data using cluster analysis. The results showed that Dieffenbachia compacta, Dieffenbachia maculata and Dieffenbachia Rudolph Roerhs had the same chromosome number, 2n = 4x +2 = 34. Dieffenbachia bausei had 2n = 4x + 4 = 36, and Dieffenbachia spp. Kultivar A had 2n = 4x + 3 = 35. Dieffenbachia Paradise and Dieffenbachia spp. Kultivar B had 2n = 10x = 80. There were differences in karyotype formulas among cultivars of Dieffenbachia. Therefore, Dieffenbachia spp. Kultivar B was considered to be the most advanced karyologically among Dieffenbachia plants.

Kata Kunci : kariotip, hubungan kekerabatan, Dieffenbachia, karyotype, phenetic interrelationship, Dieffenbachia