Virulensi Phytophthora capsici Asal Lada terhadap Piper spp.

Abstract

Black Pepper (Piper nigrum) is Widely Cultivated inIndonesia by Smallholder. Foot rot disease caused by Phytophthora capsici is the main constraint in pepper cultivation in Indonesia. Developing a resistant variety is considered the most effective means to reduce the foot rot disease impact. However, the genetic variability of cultivated pepper in Indonesia is narrow. Therefore, attempt to find new gene source from other Piper spp. is an alternative method to get resistant genes against foot rot disease. Six Piper spp. i.e. Piper betle, P. colubrinum, P. cubeba, P. hispidum, and P. retrofractum were tested, while P. nigrum used as control. To find the resistance of those Piper spp. against P. capsici, artificial inoculation experiment was conducted in laboratory. Third and fourth leaves of Piper spp. were inoculated by placing a piece mycelial colony of tested Phytophthora isolates, 5 mm in diameter on abaxial leaf surface. Fifty isolates of P. capsici obtained from various pepper areas in Indonesia were used in the experiment. Width of necrotic area on each inoculated leaves were measured after incubated for 72 hours. Results of statistical analyses showed that P. betle, P. cubeba, P. retrofractum existed in the same group with P. nigrum; while P. colubrinum and P. hispidum presented in another group. Those 50 isolates P. capsici were grouped into 3 groups, the first was a big dominant group that infected all Piper spp., second group consisted of isolates infected P. betle, P. cubeba, P. retrofractum and P. nigrum; and the last one was isolates that infected P. colubrinum and P. hispidum. Hence, virulence of P. capsici was wide and not all Piper spp. were resistant against P. capsici.Keywords: Piper spp., Phytophthora capsici, virulence. ABSTRAKLada telah dibudidayakan secara luas di Indonesia dan sebagian besar diusahakan oleh petani bermodal kecil. Salah satu kendala dalam budi daya lada di Indonesia ialah penyakit busuk pangkal batang lada yang disebabkan oleh Phytophthora capsici. Salah satu usaha pengendalian yang dianggap efektif ialah menggunakan varietas tahan, tetapi keragaman genetik lada budi daya sempit. Hal ini merupakan kendala dalam program perbaikan varietas. Untuk itu perlu dicari sumber gen ketahanan dari spesies lainnya, yaitu Piper betle, P. colubrinum, P. cubeba, P. hispidum, dan P. retrofractum; sedang P. nigrum digunakan sebagai pembanding. Inokulasi dilakukan dengan cara meletakkan potongan hifa P. capsici pada permukaan bawah daun ketiga dan keempat dari masing-masing Piper spp. Sebanyak 50 isolat P. capsici asal lada yang diperoleh dari berbagai lokasi digunakan dalam penelitian. Daun yang telah diinokulasi diinkubasi pada kotak yang dijaga kelembabannya pada suhu kamar. Luas nekrosa yang terbentuk diukur 72 jam setelah inokulasi. Data luas nekrosa dianalisis secara statitistik untuk melihat ketahanan masing-masing Piper spp. terhadap isolat P. capsici yang digunakan. Hasil analisis menunjukkan bahwa P. betle, P. cubeba, dan P. retrofractum terdapat dalam kelompok yang sama de...

PENGARUH DOSIS PUPUK NPK TERHADAP PERTUMBUHAN DAN PRODUKSI STEK POHON INDUK LADA SAMBUNG (Piper nigrum/Piper colubrinum)

“…Selain itu, teknik sambung juga memegang peranan penting dalam pembibitaan lada, karena pada teknik sambung bibit yang dihasilkan lebih efektif, efisien dan praktis serta bibit yang dihasilkan mempunyai sifat yang sama dengan pohon induknya. Penggunaan P. colubrinum untuk batang bawah dalam penyambungan dengan batang atas lada kemungkinan besar akan terhindar dari penyebab penyakit busuk pangkal batang (Alconero et al, 1972, Wahyuno et al, 2010.…”

PRETREATMENT EFFECT OF BLACK PEPPER SEEDLINGS WITH Pseudomonas, Trichoderma AND MYCORRHIZA ON FOOT ROT DISEASE INCIDENCE

“…Contaminated planting materials or infected black pepper vine seedlings are important means in disease distribution (Manohara et al, 2005, Anandaraj, 2005. The disease has been found in several important pepper producing areas of Indonesia (Wahyuno et al, 2010). Two mating types (A1 and A2) of P. capsici population were also found in Lampung, Kalimantan and others cultivation area of black pepper (Manohara and Sato, 1992); those are vary in their virulence against Piper spp.…”

“…Two mating types (A1 and A2) of P. capsici population were also found in Lampung, Kalimantan and others cultivation area of black pepper (Manohara and Sato, 1992); those are vary in their virulence against Piper spp. (Wahyuno et al, 2010). The disease caused yield lost of about 19.6 billion rupiah annually (Ditlintanbun, 2007).…”