Pewarisan gen opaque 2 (0-2) pada persilangan jagung lokal Madura (Zea mays L. cv. Guluk-guluk) dengan jagung unggul (Z. mays L. cv. Srikandi kuning)

ROFIAH, Dr. Budi Setiadi Daryono, M.Agr.Sc

2008 | Tesis | S2 Biologi

Jagung merupakan salah satu makanan pokok kedua setelah padi. Pada umumnya, jagung mempunyai kandungan asam amino lisin dan triptofan rendah. Produksi jagung di Indonesia terus meningkat, namun belum mencukupi kebutuhan, meskipun upaya peningkatan produksi melalui pemuliaan telah banyak dilakukan. Persilangan antara jagung lokal Madura kultivar Guluk-guluk dengan jagung mutu protein tinggi kultivar Srikandi kuning belum dilakukan. Pada jagung, gen opaque 2 (gen o-2) merupakan gen resesif, meregulasi sejumlah enzim pada glikolisis dan siklus asam trikarboksilat, meregulasi dan mereduksi ekspresi sekelompok gen zein serta mempengaruhi gen ask1 dan gen ask2 sebagai gen pengkode sintesis asam amino lisin dan treonin, sehingga gen ini mampu meningkatkan sintesis asam amino terutama lisin dan triptofan pada jagung. Tujuan penelitian ini adalah untuk mengetahui pewarisan gen o-2 pada persilangan jagung lokal Madura kultivar Guluk-guluk dengan jagung kultivar Srikandi kuning. Penelitian ini diawali dengan persilangan antara jagung Gulukguluk dengan jagung Srikandi kuning untuk mendapatkan benih F1, F2 dan back cross. Selanjutnya dilakukan uji protein total pada biji jagung induk Guluk-guluk, Srikandi kuning, F1, F2 dan back cross menggunakan metode Kjeldahl. Hasil uji protein pada F2 dan back cross dianalisis menggunakan chi-kuadrat untuk mengetahui pola pewarisan gen o-2. Untuk mengetahui keberadaan gen o-2 pada jagung, dilakukan isolasi DNA dan uji kualitas DNA dengan elektroforesis gel agarose 2%. Keberadaan gen o-2 dideteksi menggunakan Polymerase Chain Reaction (PCR). Berdasarkan hasil uji chi-kuadrat kadar protein total jagung dan jumlah DNA penyandi gen o-2 menunjukkan bahwa pola pewarisan gen o-2 pada F2 dan back cross mengikuti hukum Mendel dan dikontrol oleh gen resesif tunggal.

Maize (Zea mays L.) is one of the main food instead of rice in Indonesia.Generally, aminic acid of lysin and tryptophan content in maize is low. Maize production in Indonesia has been increasing but its production is still low. Many efforts has been applied to enhance the maize production through breeding. However, breeding of a Madura’s local maize (Guluk-guluk) with a Quality Protein Maize (Srikandi kuning) has not been conducted. In maize, opaque 2 gene (o-2 gene) is a ressecive gene and could be regulating a number of enzymes of glycolysis and tricarboxylic acid pathway, regulates and reduced of zein gene expression, influencing of ask1 and ask2 gene wich encode of lysin and threonin synthesis. Hence, the gene has been increasing of aminic acid of lysin and triptophan particularly. The research was carried out to study the inheritance of o- 2 gene in crossing between Guluk-guluk and Srikandi kuning. The research was started with crossing between Guluk-guluk and Srikandi kuning to obtain of F1, F2 and back cross population. The total proteins of Guluk-guluk, Srikandi kuning, F1, F2 and back cross individuals were determined using Kjeldahl method. The results of F2 and back cross total protein were analyzed using chi square. The DNA maize was isolated and its DNA quality was determined by electrophoresis on 2% agarose gel. Polymerase Chain Reaction (PCR) was applied to detect o-2 gene in maize. Based on the results of chi square test on total potein and detection of o-2 gene, it could be revealed that the inheritance of o-2 gene in maize follows the Mendel law and controlled by a single ressecive gene.

Kata Kunci : Gen O2,Jagung Guluk,guluk,Jagung Srikandi kuning,Gen resesif, o-2 gene, ressecive gene, Guluk-guluk, Srikandi kuning.