KERAGAMAN GENETIK SIFAT KAYU Acacia mangium UNTUK PRODUKSI PULP DAN KERTAS

MUDJI SUSANTO, Prof. Dr. Ir. Mohammad Na’iem, M. Agr. Sc.

2014 | Disertasi | S3 Ilmu Kehutanan

Penelitian keragaman sifat-sifat kayu Acacia mangium dilakukan untuk mendukung pelaksanaan pemuliaan kualitas kayu untuk produksi pulp dan kertas. Penelitian tersebut dilaksanakan di 4 uji keturunan A. mangium Pelaihari, Kalimantan Selatan; di Wonogiri, Jawa Tengah; dan di Subanjeriji, Sumatera Selatan. Sifat-sifat yang diukur meliputi diameter batang dan sifat-sifat kayu (penetrasi pilodin, berat jenis kayu, panjang serat, diameter lumen, tebal dinding serat, kadar ekstraktif kayu, kadar lignin, kadar holo-selulosa, dan kadar alfa-selulosa). Analisis data yang dikerjakan meliputi analisis keragaman genetik, analisa parameter genetik dan prediksi nilai pemuliaan sifat-sifat kayu. Hasil penelitian menunjukkan bahwa berat jenis kayu mempunyai nilai besar di posisi dekat dekat hati dan menurun ke arah kulit, panjang serat mempunyai nilai rendah di posisi dekat hati dan naik ke arah kulit . Penetrasi pilodin, berat jenis kayu, panjang serat, kadar holo-selulosa dan kadar alfa-selulosa mempunyai keragaman antar famili di uji keturunan A. mangium. Penetrasi pilodin dengan berat jenis kayu mempunyai korelasi genetik negatif yang kuat di 4 uji keturunan tersebut (rg=-0,67 sd -0,91). Heritabilitas individu untuk sifat-sifat kayu tergolong beragam yaitu h 2 i=0,35 sd 0,57 untuk berat jenis kayu; h 2 i=0,30 sd 0,62 untuk penetrasi pilodin; h 2 i=0,10 sd 0,39 untuk panjang serat; h 2 i=0,27 untuk kadar holoselulosa; dan h 2 i=0,37 untuk kadar-alfa selulosa. Berat jenis kayu mempunyai perolehan genetik yang stabil (∆G =9,72% di Subanjeriji; ∆G=13,18% di Wonogiri; dan ∆G=13,70 di Pelaihari). Materi genetik dan korelasi genetik antar sifat kayu mempengaruhi hasil prediksi nilai pemuliaan sifat kayu.

Research of wood properties variation of Acacia mangium was done to support wood quality improvement for pulp and paper production. The research were conducted in 4 progeny test A. mangium in Pelaihari, South Kalimantan; in Solo, Central Java, and in Subanjeriji, South Sumatra. Assessment in the progeny tests were done in stem diameter, wood properties (pillodyn penetration, wood density, fiber length, lumen diameter, fiber wall thickness, wood extractive content, lignin content, holocellulose content, and alphacellulose content). Data of wood properties were analysed in analysis of variance, genetic parameter analysis and prediction of breeding values of wood properties The results of investigations showed that specific gravity was high near the pith and decreased toward the bark, fiber length was low near the pith and increased toward the bark. The pillodyn penetration, wood density, fiber length, holo-cellulose content and alpha-cellulose content were significant difference among families in progeny test of A. mangium. Pillodyn penetration and wood density was a strong negative genetic correlation in the progeny test (rg = -0.67 to -0.91). Individual heritability for wood properties is quite varied (h 2 i= 0.35 to 0.57 for specific gravity; h 2 i= 0.30 to 0.62 for pillodyn penetration; h 2 i=0.10 to 0.39 for fiber lenght; h 2 i=0.27 for holocellulose content, and h 2 i=0.37 for alpha cellulose content). The gentic gain (∆G) of specific gravity was stable (∆G =9.72% in Subanjeriji; ∆G=13.18% in Wonogiri; and ∆G=13.70 in Pelaihari). The genetic correlations between the wood properties affect the results of breeding values prediction of wood properties.

Kata Kunci : sifat kayu, korelasi genetik, nilai pemuliaan, A. mangium, arah radial