Morphological and Isozyme Characterization of Matoa (Pometia pinnata Forst.).

Abstract

Variability of wild and cultivated matoa has long been the subject of controversy because of its morphological variation. It was also recognized also as several species names of matoa, although it has been revised under one type name and some synonyms at forma category that are seldom used. It is difficult to differentiate between morphological characters of matoa variants, therefore it needs to use other approaches. Nineteen accessions originated from six areas, Papua Forest, Mekarsari Fruit Garden, Germplasm of LIPI Cibinong, Bogor Botanical Garden, Arboretum of Bogor Agricultural University, and Bogor Research and Development Agency of Forestry and Conservation were characterized and examined their diversity of morphological and isozyme characters. Three isozyme analysis systems, esterase (EST), malate dehydrogenase (MDH), and peroxidase (PER) were used. Morphological characters were transformed into binary and multistate character data and then were analyzed to build a phenogram based on UPGMA approach using NTSYs pc. 2.2i software. Matoa has variation on 16 morphological characters: root pattern; stem texture and color; rachis size and colour of leaves; hair of rachis, the number of pinna; pinnae position; auricle shape; pinnae size, the base, apex, margin shapes of pinna, pinnae colour; and young pinna colour. Matoa also varied on the three enzyme systems, but only PER showed clear isozyme banding patterns of matoa at 0.29 to 0.34 migration length (Rf). Phenetic analysis based on 16 morphological characters grouped 19 matoa accessions into three major groups, and the bigest group consisted of two sub-group included four identic accessions of cultivated matoa. All accession studied were identified as one species, Pometia pinnata, with two varieties, var. pinnata and javanica, and one cultivated variety, cv. Kelapa. Pinnata variety consist of three forma which were f. pinnata, f. tomentosa, f. repanda, while var. javanica has one forma, f. glabra.

Variabilitas matoa di hutan alam maupun yang dibudidaya telah direvisi di bawah nama jenis tunggal Pometia pinnata Forst., dan subdivisinya diberi sinonim di bawah kategori forma, tetapi jarang digunakan karena terdapat beragam interpretasi terhadap variasi morfologinya yang cukup tinggi pada karakter, pola, bentuk dan ukuran serta warna pada bagian akar, batang dan daun. Varian matoa juga sukar dibedakan, maka dilakukan analisis isozim sistem enzim esterase, malatdehidrogenase dan peroksidse terhadap 19 aksesi matoa yang dipilih secara purposif dari Hutan Wisata Alam Gunung Meja Manokwari-Papua Barat, Kebun Raya Bogor, Taman Buah Mekarsari, Kebun Plasma Nutfah LIPI Cibinong, Arboretum IPB serta Balitbang. Kehutanan dan Konservasi Alam Bogor. Karakter morfologi dan isozim dicirikan dan diidentifikasi berdasarkan spesimen koleksi di Herbarium Manokwariense dan Herbarium Bogoriense. Enambelas karakter morfologi telah dianalisis menggunakan program NTSYSpc 2.02i, SAHN-Clustering untuk mendapatkan fenogram UPGMA