Early Identification of Morpo-Physiological Traits Divergence Among Four Arabica Coffee Cultivars

Abstract
Description
Arabica coffee is a perennial crop hence it has a long selection cycle.  Therefore, efforts to shorten the selection process is necessary, such as at seedling stage.  This study aims to identify morpho-physiological characters variability among Arabica coffee cultivars at seedling stage. The experiment was conducted at Pakuwon Experimental Garden of Indonesian Industrial and Beverage Crops Research Institute, Sukabumi, from January to October 2017. Seeds collected from open pollinated trees of four arabica coffee cultivars (Ateng Super, P88, Gayo 1, and Gayo 2) were then sown on seedbed and newly-emerged cotyledonous seedlings were transferred immediately into polyethylene bag (polybag). Seedlings were arranged in randomized complete block with 5 replications, each consisted of 10 seedlings of each cultivar. Morpho-physiological characters observed and analyzed were shoot (plant height, lateral shoot formation, number of internodes, internode length, stem diameter, shoot’s dry weight); leaves (number of leaves, leaf length, leaf width, L/W ratio, leaf area, stomata density , chlorophyll content); and root (root length, number of primary roots, root volume, root’s dry weight, root/shoot ratio). The result showed value of genetic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), and broad sense heritability (h2bs) of plant height characters are classified as high, each of which is 21.66%; 23.66%; and 0.84, respectively. The characters of the stem length and leaf width showed high h2bs value (0.97 and 0.67 respectively), while the KKG and KKF values were classified as moderate (19.60% and 19.88%, respectively and 10.71% and 13.10%, respectively). Those three characters could be utilized as distincitive markers of the four Arabica coffee cultivars.
Kopi Arabika (Coffea arabica L.) termasuk tanaman tahunan sehingga siklus seleksinya cukup panjang. Oleh karena itu diperlukan upaya untuk mempercepat proses seleksi, salah satunya melalui seleksi awal di pembibitan. Tujuan penelitian adalah mengidentifikasi secara dini keragaman karakter morfofisiologi antar empat kultivar kopi Arabika pada tahap pembibitan. Penelitian dilaksanakan di Kebun Percobaan Pakuwon, Balai Penelitian Tanaman Industri dan Penyegar (Balittri), Sukabumi, mulai bulan Januari sampai Oktober 2017. Benih dikumpulkan dari tanaman yang bersari bebas dari empat kultivar kopi Arabika (Ateng Super, P88, Gayo 1, dan Gayo 2), ditaburkan di persemaian dan bibit dengan kotiledon yang baru muncul segera dipindahkan ke kantong polyethylene (polybag). Bibit disusun dalam rancangan acak kelompok dengan 5 ulangan, masing-masing terdiri dari 10 bibit tiap kultivar. Karakter morfofisiologi yang diamati dan dianalisis adalah tunas (tinggi tanaman, pembentukan tunas lateral, jumlah ruas, panjang ruas, diameter batang, berat kering tunas); daun (jumlah daun, panjang daun, lebar daun, rasio L/W, luas daun, kerapatan stomata, kandungan klorofil); dan akar (panjang akar, jumlah akar primer, volume akar, berat kering akar, rasio akar/tajuk). Hasil penelitian menunjukkan nilai koefisien keragaman genetik (KKG), koefisien keragaman fenotipik (KKF), dan heritabilitas arti luas (h2bs) karakter tinggi tanaman tergolong tinggi, yaitu masing-masing 21,66%; 23,66%; dan 0,84. Karakter panjang ruas pada batang dan lebar daun menunjukkan nilai h2bs yang tinggi (masing-masing 0,97 dan 0,67), sedangkan nilai KKG dan KKF-nya tergolong sedang (masing-masing 19,60% dan 19,88% serta 10,71% dan 13,10%). Ketiga karakter tersebut dapat dijadikan sebagai penciri yang membedakan empat varietas kopi Arabika untuk seleksi pada tahap pembibitan.
Keywords
Arabica coffee; cultivar; genetic variability; seedling stage, , Kopi Arabika; kultivar; tahap pembibitan; variabilitas genetik,
Citation