<p>ABSTRAK</p><p>Busuk pangkal batang (BPB) lada yang disebabkan oleh cendawanPhytophthora capsici merupakan masalah utama pada budidaya lada diIndonesia. Penyakit ini telah ditemukan di semua areal produksi lada diIndonesia. Sampai saat ini, saran pengendalian yang dianjurkan adalahpengendalian secara terpadu untuk mengurangi kerugian ekonomi akibatpenyakit ini. Akhir-akhir ini usaha untuk mendapatkan jenis lada yangtahan dilakukan melalui persilangan. Tujuan penelitian ini adalahmengevaluasi ketahanan F1 yang diperoleh dari persilangan beberapatetua. Penelitian dilakukan di laboratorium dan rumah kaca, BalaiPenelitian Tanaman Rempah dan Obat, Bogor, dari Januari sampaiDesember 2005. Dari 400 aksesi hasil persilangan yang ada, dipilih 15aksesi yang menunjukkan hasil yang menjanjikan pada uji pendahuluan.Tiga isolat Phytophthora yang menunjukkan virulensi yang berbedadigunakan sebagai isolat uji. Di laboratorium, helaian daun ke-3 dan 4diambil dari tiap aksesi dan diletakkan dalam kotak yang telah diberi tissuebasah untuk menjaga kelembapannya. Inokulasi secara buatan dilakukandengan meletakkan potongan koloni masing-masing isolat Phytophthorapada permukaan bawah daun. Luas nekrosa yang terbentuk pada masing-masing aksesi diukur dengan leaf area meter setelah diinkubasi selama 72jam. Percobaan di rumah kaca dilakukan dengan cara menyiramkansuspensi zoospora sebanyak 50 ml pada bibit lada dari masing-masingaksesi yang telah berumur 4 bulan. Jumlah tanaman yang mati dihitungsetelah diinkubasi selama 1 bulan. Data hasil pengukuran luas serangandianalisis dengan rancangan faktorial dengan dua faktor untuk duakegiatan di atas. Hasil penelitian menunjukkan bahwa tidak ada interaksiyang nyata antara aksesi dengan isolat Phytophthora yang digunakan, baikpengujian in vitro maupun rumah kaca. Sembilan aksesi menunjukkankerusakan kurang dari 20% saat di laboratorium maupun di rumah kaca,dan aksesi 27-1, 36-31, dan 4-5L menunjukkan kerusakan kurang dari10%. Persilangan lebih lanjut perlu dilakukan pada aksesi-aksesi tersebutuntuk mendapatkan keturunan yang mempunyai ketahanan lebih baik danstabil.</p><p>Kata kunci : Piper nigrum L., Phytophthora, ketahanan, persilangan</p><p>ABSTRACT</p><p>Resistance of Black Pepper Accessions to Phytophthora capsiciFoot rot disease of black pepper caused by Phytophthora capsici ismain constraint in black pepper cultivation in Indonesia. The diseasespread widely over all pepper producing areas in Indonesia. Integratedpest managements are suggested to reduce the economic loss due to thedisease. Recently, breeding program has been developed in Indonesiathrough hybridization to find out promising accessions resistant to foot rotdisease. The objective of the present study was to evaluate the resistanceof F1 progenies obtained from polination of various parents to foot rotdisease. Among 400 accessions of black pepper obtained from breedingprogram, 15 accessions were selected based on previous evaluation. ThreePhytophthora isolates were used as tester in the study. The research wascarried out in laboratory and glass house of Indonesian Spice andMedicinal Crops Research Institute, from January to December 2005. Invitro screening was carried out by inoculating detached third and fourthleaves of each accession. The leaves were set in boxes abaxial surfacefacing up, while wet tissue papers were used to retain air humidity in thebox. The lower leaf surface of each pepper accession was inoculated witha piece of Phytophthora colony then incubated in room temperature. Thewidth of necrotic areas was measured with leaf area meter after the leaveswere incubated for 72 hours. Each treatment was replicated 5 times. Ingreen house experiment, 4 month seedlings of each accession wereinoculated with 50 ml of zoospore suspension (10 5 zoospore/ml), replicated3 times, and each replication consisted of 5 seedlings. The number ofinoculated seedlings was counted after one month of incubation. Bothexperiments were arranged using factorial design with two factors: pepperaccession and Phytophthora isolate. There was no significant interactionbetween black pepper accession and the Phytophthora isolates, neither invitro nor green house. Nine accessions showed disease severity less than20%, and accession number 27-1, 36-31, and 4-5L showed disease severitybelow 10% in both experiments. To obtain better progeny resistant to stemrot disease and more stable, it is suggested to continue this pollinationprogram by using those promising accessions.</p><p>Key words: Piper nigrum L., Phytophthora, resistance, pollination</p>
The growth of three varieties of black pepper (Piper nigrum) under different light intensities related to indigenous hormones role