PENAMPILAN MORFOLOGI, VARIABILITAS FENOTIPIK PRODUKSI DAN UKURAN GELONDONG TANAMAN JAMBU METE HASIL PERSILANGAN

ABSTRAK Penelitian telah dilakukan di KP Muktiharjo, Pati, Jawa Tengahdengan tujuan untuk mengetahui pewarisan sifat morfologi dan keragamanfenotipik produksi dan ukuran gelondong nomor-nomor persilangan CF,CM, CA, CS, FM, FA, FS, MA, MS, AS. Tanaman hasil persilanganditanam tahun 1997 dengan jarak tanam 6 m x 6 m. Pengamatan karaktermorfologi tanaman (habitus, warna daun pucuk, warna buah semu) danukuran gelondong dilakukan pada umur tanaman 5 tahun, sedangkantingkat produksi tanaman per pohon diamati selama 4 tahun produksi(2000 - 2003). Karakter tanaman yang diamati dikelompokkan ke dalam 3group yaitu (1) karakter tanaman dan daun, (2) karakter buah, dan (3)karakter gelondong. Terhadap data kualitatif dilakukan penggolongan yangmengacu pada descriptor list tanaman jambu mete (IPBGR). Analisisdeskriptif dan proporsi tanaman (%) dihitung sesuai pembagian karakteryang diamati. Terhadap data kuantitatif (produksi dan ukuran gelondong)dilakukan analisis variabilitas fenotipik. Hasil pengamatan menunjukkantanaman hasil persilangan mempunyai karakter tanaman dan daun beragam,sebagian mirip tetua betina, sebagian mirip tetua jantan, sebagian lagimerupakan karakter antara kedua tetuanya, dengan proporsi setiapkombinasi persilangan berbeda. Penurunan sifat bentuk buah padatanaman jambu mete beragam, tetua dengan bentuk buah yang sama(kerucut) dapat menghasilkan keturunan dengan bentuk buah bervariasi(kerucut, silinder, membulat). Demikian pula dengan karakter warna buahsemu. Persilangan antar tetua dengan warna buah merah menghasilkanketurunan dengan warna buah merah, orange, dan kuning. Kultivar Ssebagai tetua jantan dapat meningkatkan ukuran gelondong keturunannya,tetapi tidak pada semua keturunan dan tidak sebesar ukuran gelondongtetua jantan S tersebut. Variabilitas fenotipik produksi dan ukurangelondong tanaman hasil persilangan tergolong luas, sehingga dengantetua yang sama keturunannya tidak memiliki tingkat produksi dan ukurangelondong yang relatif seragam. Oleh karena itu tanaman hasil persilanganyang terseleksi sebaiknya diperbanyak dengan penyambungan agardiperoleh tanaman dengan karakter yang lebih seragam. Kata kunci : Anacardium  occidentale,  jambu  mete,  persilangan,variabilitas fenotipik ABSTRACT Morphology performance, yield and nut size phenotypicvariability of cashew progeny Progenies from five parents crossing combination of promisingcashew were planted at Muktiharjo experimental station, Pati, Central Javain 1997 to observe its variability. The progenies were the crossingcombinations of CF, CM, CA, CS, FM, FA, FS, MA, MS, and AS.Seedlings were planted in 6 m x 6 m space-row. Observation formorphological characters, such as habitus, shoot colour, apple colour, andnut size, were done at 5 years plant age. Moreover, for nut yield, theobservations were conducted for 4 times harvest period (2000-2003). Allof characters observed were divided into 3 groups : (1) habitus and leafcharacters, (2) fruit characters, and (3) nut characters. The qualitative datawere grouped based on cashew descriptor list (IPBGR). Qualitative datawere analyzed and the proportion of progeny performance in eachcharacter observed were counted. Yield and nut size phenotypicvariabilities were analized. Result indicated that the progeny showedvariation in plant habitus, trunk shape, and leaf. Some of progenyperformances alike a male parent, some likes female parents and someothers in between of their parents and differ in proportion of each crossingcombination. Fruit characters progeny are also showed variation. Parentwith the same apple shape (pyramid), having progeny with pyramid,silinder and rounded apple shape type. Crossing parent which has the samered apple colour, the progeny has red, orange and yellow apple colour. Fornut size characters, S as a male parent could increasing nut size of progenybut the nut size are not as big as the size of the male parent. Both parentand their progeny have the great variation of nut shape and colour.Phenotypic variability of yield and nut size of progeny are very broad, itimplies that progeny of the same parent has un-uniform yield and nut size.For further plant development, selected progeny of hybridization can bedeveloped by grafting to get more uniform plant. Key words : Anacardium occidentale, cashew, hybridization, phenotypicvariability