Characterization of 56 Soybean Accessions on Yield Components and Maturity-related Traits - I Made Tasma; Puji Lestari; Reflinur Reflinur (Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian, 2015)
Peningkatan produktivitas kedelai nasional dapat dilakukan dengan penggunaan varietas produktivitas tinggi dan manipulasi indeks panen menggunakan varietas genjah. Pembentukan varietas di atas memerlukan plasma nutfah dengan potensi hasil tinggi dan berumur genjah. Tujuan dari penelitian ini adalah untuk mengidentifikasi aksesi kedelai yang mempunyai potensi hasil tinggi dan aksesi kedelai berumur genjah. Sebanyak 56 aksesi kedelai terdiri atas varietas elit dan introduksi, aksesi lokal dan galur-galur persilangan ditanam di Kebun Percobaan Cikeumeuh (250 m dpl) dan Pacet (1.200 m dpl) menggunakan Rancangan Acak Kelompok dengan tiga ulangan. Pengamatan dilakukan terhadap karakter morfologi, komponen hasil dan karakter reproduktif yang meliputi umur berbunga (fase R1, R3, R7, dan R8). Hasil penelitian menunjukkan 28 aksesi (50%) diuji di Cikeumeuh dan 43 aksesi (76,79%) diuji di Pacet menunjukkan jumlah polong/tanaman lebih dari 50. Sekitar 35,71% aksesi di Cikeumeuh dan 41,07% aksesi di Pacet menghasilkan biji/tanaman lebih dari 10 g/tanaman. Aksesi kedelai yang menunjukkan komponen hasil tinggi hanya di KP Cikeumeuh adalah B2981, B3517, dan B3628. Aksesi kedelai yang menunjukkan komponen hasil tinggi hanya di KP Pacet adalah B4441, B3628, B382, B4334, dan B3414. Aksesi yang menunjukkan komponen hasil tinggi di kedua lokasi (Cikeumeuh dan Pacet) adalah B3417. Aksesi B3417 diklasifikasikan sebagai aksesi dengan adaptasi luas karena berkeragaan komponen hasil tinggi di dataran rendah dan di dataran tinggi. Aksesi dengan umur panen genjah ditunjukkan oleh B2973 (74 hari setelah tanam, hst) yang tidak berbeda nyata dengan aksesi B1430 (75 hst), B3611 (76 hst), B4433 (77 hst), dan B4439 (80 hst) berdasarkan uji DMRT (p<0,05). Berdasarkan karakter morfologi, sebagian besar plasma nutfah kedelai terbagi dalam tiga kelompok termasuk landraces tanpa mempertimbangkan asal daerahnya. Analisis klaster berdasarkan karakter agronomi mendukung analisis DMRT bahwa aksesi kedelai dengan hasil biji tinggi dan umur genjah dapat dibedakan. Aksesi kedelai dengan jumlah polong banyak, hasil biji tinggi, umur genjah potensial digunakan dalam program pemuliaan kedelai produktivitas tinggi dengan umur genjah. AbstrakOne effort to improve soybean production in Indonesia is by using high yielding and manipulating harvest index by using early maturing varieties. Such variety development requires the availability of soybean germplasm with high yield potential and early maturity. The objective of this study was to identify soybean genotypes showing high yield potential and early maturity. A total of 56 soybean accessions consisting of elite and introducing varieties, landraces, and breeding lines were characterized in the field with different altitudes i.e. Cikeumeuh (250 m above sea level) and Pacet (1.200 m asl). The experiments were arranged in a randomized block design using three replications. Characters observed were morphological chracters, yield components and maturity-related traits (days to R1, R3, R7, and R8). Results showed that 28 accessions (50%) tested at Cikeumeuh and 43 accessions (76.79%) tested at Pacet demonstrated pod number/plant more than 50. About 35.71% at Cikeumeuh and 41.07% at Pacet showed seed yield more than 10 g/plant. Soybean accessions demonstrating high yield components only at Cikeumeuh were B2981, B3517, and B3628. Soybean accessions demonstrating high yield components only at Pacet were B4441, B3628, B382, B4334, and B3414. The accession demonstrating high yield component performance at both locations (Cikeumeuh and Pacet) was shown by B3417. Accession B3417 is then classified as a broad adaptating soybean genotype. The early pod maturing accession was demonstrated by B2973 (74 dap) that was not significantly different from accessions B1430 (75 dap), B3611 (76 dap), B4433 (77 dap), and B4439 (80 dap) based on DMRT at p = 0.05. Three distinct clades were generated based on morpho-agronomical variables on both locations (Cikeumeuh dan Pacet). Cluster analysis of agronomical characters was able to distinguish accessions with high yield components in either one or both locations (B3417, B3628, and B2981), and accessions with early maturiy and least pod number (B4439 and B4433). Cluster analysis results were in well-agreement with the results based on DMRT. Soybean accessions having high pod number, high seed yield and early in maturity are potentially used for developing high yielding soybean varieties with early in maturity.