Penentuan Karakter Pembeda Dua Populasi Kopi Arabika di Kebun Percobaan Pakuwon melalui Penggunaan Fungsi Diskriminan - Wardiana, Edi; Pranowo, Dibyo (Jurnal Tanaman Industri dan Penyegar, 2012)
Keragaman fenotipik dari beberapa genotipe tanaman karena pengaruh genetik dan lingkungan (GxE) dapat dianalisis melalui penggunaan fungsi diskriminan sehingga akan dapat diketahui informasi tentang karakter-karakter pembeda dari genotipe yang diuji. Penelitian dilakukan di Kebun Percobaan (KP) Pakuwon, Sukabumi, mulai bulan Desember 2010 sampai Mei 2012, dengan tujuan mengidentifikasi karakter-karakter yang dapat menjadi pembeda dua populasi kopi arabika (Kartika 1 dan 2) yang ditanam di KP. Pakuwon melalui pendekatan fungsi diskriminan. Contoh tanaman kopi varietas Kartika 1 dan 2 masing-masing sebanyak 20 tanaman dipilih secara sistematik, kemudian diamati pada umur 14-17 bulan setelah tanam terhadap 20 peubah morfologi tanaman. Data-data yang terkumpul dianalisis melalui penggunaan fungsi diskriminan. Hasil penelitian menunjukkan bahwa diperoleh 4 karakter pembeda dua varietas kopi arabika (Kartika 1 dan Kartika 2), yaitu jumlah cabang total/tanaman, jumlah ruas/cabang, jumlah tandan/cabang, dan bobot kering buah. Varietas Kartika 1 memiliki jumlah cabang total/tanaman, jumlah tandan/cabang, dan bobot kering buah lebih tinggi daripada Kartika 2, sedangkan jumlah ruas cabangnya lebih rendah. Keempat karakter tersebut secara nyata dapat membedakan kedua varietas kopi dengan tingkat validitasnya sebesar 82,5%. Hasil penelitian ini didasari oleh teori GxE dan dapat memberikan implikasi bagi kajian dan penelitian-penelitian berikutnya dalam upaya peningkatan produktivitas dan atau mutu hasil kopi, khususnya Kartika 1 dan 2 di KP. Pakuwon. .Determination of Characters to Distinguish Two Population of Coffea Arabica at Pakuwon Experimental Station by Discriminant Function Phenotypic variability of several plant genotypes is affected by genetic (G) and environment (E) factors, known as GxE. The GxE can be analyzed through discriminant functions being able to know information several characters as differentiator of genotypes. A study was conducted at Pakuwon Experimental Station (KP. Pakuwon), Sukabumi, from December 2010 to May 2012. To identify the characters being able to distinguish two populations of Coffea arabica (Kartika 1 and 2), the discriminant function was used.Â  Sistematic sampling of 20 sample plants of Kartika 1 and 2 each was used in this study. As many as 20 variables of plant morphology were observed for 14-17 months after planting. Data collected were analyzed by discriminant function. Results showed that there are four characters being able to distinguish two varieties of Coffea arabica ( Kartika 1 and 2) namely: total number of branch/plant, number of internode/branches, number of bunch/ branch, and dry weight of fruit. The total number of branch/plant, number of bunch/branch, and dry weight of bean of Kartika 1 were higher than those of Kartika 2, while the number of internode/branches was lower. These fourth characters were significantly able to distinguish the two varieties of coffee with 82.5% validity rates. This result was based on GxE theory and may have implications for improvement of productivity and quality of coffee, for future study.