GENETIC VARIABILITY AND GENOTYPIC CORRELATION OF SOME AGRONOMICAL CHARACTERISTICS OF M4 AND M5 GENERATIONS OF GAMMA IRRADIATED Sesamum indicum L.

Wijen (Sesamum indicum L.) merupakan tanaman semusim menyerbuk sendiri dan penghasil biji yang sering digunakan sebagai bahan indutsri karena mengandung minyak rendah asam lemak jenuh. Bahan penelitian terdiri 18 galur generasi M4 dan 39 galur generasi M5 dari galur mutan wijen. Terdapat dua penelitian yang dilakukan untuk mendapatkan informasi tentang keragaman genetik dan korelasi genotipik beberapa karakteristik agronomi dari generasi M4 dan M5 galur mutan wijen, setelah dilakukan seleksi berdasarkan tinggi tanaman dan jumlah kapsul per tanaman. Penelitian pertama dilakukan untuk mempelajari dan memilih generasi M4 sejak tahap vegetatif, berdasarkan tinggi tanaman dan jumlah kapsul per tanaman. Penelitian kedua dilakukan untuk membudidayakan generasi M5 yang merupakan hasil seleksi individu generasi M4 yang berasal dari setiap galur mutan wijen. Salah satu langkah pemuliaan adalah seleksi berdasarkan pertimbangan keragaman genetik dan korelasi genotipik beberapa karakteristik agronomi. Keragaman genetik dapat mempengaruhi keberhasilan proses seleksi dalam program pemuliaan. Sifat kualitatif terekspresi dalam berbagai kategori, karakteristik ini sangat berguna untuk identifikasi tanaman. Karakterisasi dan evaluasi generasi M4 dan M5 wijen menunjukkan keanekaragaman sifat kualitatif (sistem perakaran, susunan daun, tepi daun basal, sayatan cuping daun basal, bentuk kapsul bicarpellate, karakteristik biji, warna cangkang biji). Secara umum, karakteristik kualitatif dari generasi M4 akan diikuti oleh keturunan generasi M5 galur mutan wijen. Seleksi berdasarkan tinggi tanaman dan jumlah kapsul per tanaman secara signifikan dapat menurunkan keragaman genetik hasil biji dan komponen hasil generasi M4 dan M5 galur mutan wijen. Koefisien korelasi genotipik dan fenotipik meningkatkan secara signifikan tinggi tanaman, jumlah cabang primer, jumlah cabang sekunder, jumlah ruas per tanaman, jumlah kapsul per tanaman, dan berat 1000-biji setelah seleksi. Sesame (Sesamum indicum L) is an important commodity supporting various industries and produce oil lower in saturated fat meal. The experimental material consisted of 18 lines M4 generation and 39 lines M5 generation of sesame mutant lines. There were two experiments carried out to obtain information on genetic variability and genotypic correlation of some agronomical characteristics of M4 and M5 generations of sesame mutant lines after selection based on plant height and number of capsules per plant. The first experiment was performed to study and selected M4 generation begins at the vegetative stage, based on plant height and number of capsules per plant. The second experiment was done to cultivated M5 generation which is the result of individual selection in M4 generation derived from every sesame mutant lines. One of breeding steps is a selection based on the consideration of the genetic variability and genotypic correlation of some agronomical characteristics. The genetic variability can influence the success of a selection process in the breeding program. Qualitative traits are expressed into different categories, it kinds of characteristics can be very useful for the identification of plants. M4 and M5 generations of sesame characterization and evaluation studies indicate wide diversity in qualitative traits (root system, leaf arrangement, basal leaf margin, lobe incision of basal leaf, bicarpellate capsule shape, seed characteristics, seed coat color). In general, the qualitative characteristic of M4 generation will be followed by a descent in M5 generation of sesame mutant lines. Selection based on plant height and number of capsules per plant can significantly decrease the genetic variability of seed yield and yield components in M4 and M5 generations of sesame mutant lines. The genotypic and phenotypic correlation coefficients significantly increase in plant height, number of primary branches, number of secondary branches, number of nodes/plant, number of capsules/plant, and 1000-seed weight after selection.