Pemuliaan Tanaman Secara In Vitro Melalui Metode Embryo Rescue dan Hibridisasi Somatik
Menyerbuk silang
Konvensional
Menyerbuk sendiri
vegetatif
Pemuliaan Tanaman
Perbaikan SIfat Tanaman Embryo Culture – Embryo Rescue
Inkonvensional – In Vitro
Hibridisasi Somatik
Tanaman Haploid / Diploid
PROSES PEMULIAAN TANAMAN SECARA IN VITRO • Penentuan tujuan pemuliaan tanaman • Ketersediaan materi pemuliaan atau plasma nutfah : • Penentuan metode yang sesuai / tepat • Seleksi melalui penilaian genotip atau populasi untuk memenuhi varietas harapan • Pengujian genotip atau varietas harapan • Pelepasan varietas harapan menjadi varietas baru
TUJUAN PEMULIAAN • Jangka panjang : mengantisipasi perubahan iklim (global warming) – varietas toleran • Jangka pendek: a) memenuhi keinginan konsumen: - perbaikan kualitas produk: ukuran, warna, kandungan bahan, ketahanan simpan, keindahan, dll. b) memenuhi kebutuhan petani/produsen: - peningkatan hasil panen (kuantitas) - umur genjah, tahan hama penyakit dll. c) memenuhi kebutuhan industri: - meningkatkan kandungan bahan - pembuangan sifat-sifat yang tidak disukai
Ketersediaan Materi Pemuliaan / Plasma Nutfah Jenis liar
mutan
Jenis lokal
Hasil persilangan
Galur harapan Varietas yang sudah ada
Sumbangan Pemuliaan Tanaman terhadap Kemajuan Pertanian • Menghasilkan sifat baru dengan kualitas unggul hasil tinggi - tahan hama/penyakit - rasa enak - umur pendek - estetika tinggi - kandungan nutrisi tertentu - dll. • Pelestarian plasma nutfah sebagai koleksi
Mature Embryo Culture Embryo culture Immature Embryo Culture (Embryo Rescue)
Obtaining Viable Plants
Embryo rescue – embryo culture: • The number of in vitro technique to promote the development of a weak, immature of hybrid embryos into a viable plants • Embryo abortion due to endosperm fails to develop properly • In interspesific or intergeneric crosses, crosses between diploid and tetraploid the endosperm often develops poorly or not at all
Plant A
Plant B
Wild hybridization
Advantage: possible to initiate embryo development from different species
Genetic barriers Abnormal development of zygote or seed Hybrid endosperm fails to develop or produce toxin
Abortion of hybrid embryo
RESCUE: Isolating and culturing immature hybrid embryos Disadvantage: pre-mature embryo could initiate fully developed plants, but sterile
Culture medium factors: • Mineral salts: K, Ca, N most important • Carbohydrate and osmotic pressure : 2% for mature embryo, 8-12% for immature embryo, transfer to progressively low levels as embryo grows, altern. to high sucrose – auxin and cytokinin • amino acids: reduce N, many amino acids can be added to replace N salts • natural plant extracts: coconut milk (liquid endosperm of coconut) undefined hormonal factors, and/or organic compounds others : extract of dates, bananas, tomato juice, etc.
Culture medium factors: • PGRs globular embryos : low concen. of auxin and cytokinin heart stage and later : none required germination : GA (promotes) and ABA (suppreses)
SOMATIC HYBRIDIZATION • Development of hybrid plants • Through the fusion of somatic protoplasts of two different plant species/varieties • Subsequent development of the product (heterokaryon) produce a hybrid plant
SOMATIC HYBRIDIZATION TECHNIQUE Isolation of protoplasts Fusion of the protoplasts of desired species/varieties Identification and selection of somatic hybrid cells
Culture of the hybrids cells
Regeneration of hybrid cells
SOMATIC HYBRIDIZATION TECHNIQUE
IDENTIFICATION AND SELECTION
IDENTIFICATION AND SELECTION OF SOMATIC HYBRID CELLS Culturing them on selective medium
Complimentary selection of somatic hybrids on specific culture medium
Mechanical isolation – visual means
Morphology of the plant after regeneration
