Pengembangan Teknik Deteksi Fusarium Patogen Pada Umbi Benih Bawang Merah (Allium ascalonicum) di Laboratorium

Abstract

Naskah diterima tanggal 7 Maret 2014 dan disetujui untuk diterbitkan tanggal 5 Juni 2014 ABSTRAK. Penyakit layu fusarium yang disebabkan oleh Fusarium oxysporum merupakan salah satu penyakit penting pada bawang merah (Allium ascalonicum). Sebagian besar petani menggunakan umbi sebagai benih dan diketahui bahwa beberapa patogen dapat terbawa oleh benih seperti Fusarium oxysporum. Oleh karena itu diperlukan pengujian kesehatan benih untuk mencegah penyebaran penyakit tersebut. Salah satu metode sederhana dan efektif untuk digunakan di laboratorium adalah blotter test. Namun beberapa strain F. oxysporum terbukti tidak bersifat patogenik, serta tidak dapat dibedakan secara morfologi dengan strain yang bersifat patogenik. Penelitian ini bertujuan menentukan parameter uji dan jumlah sampel minimal dalam deteksi Fusarium oxysporum pada umbi bawang merah dengan metode blotter test. Hasil pengujian menunjukkan bahwa parameter nekrosis pada basal plate umbi bawang merah mempunyai koefisien korelasi (r) sebesar 0,77 terhadap tingkat infeksi pada growing on test (GOT) dan lebih besar dari tingkat infeksi fusarium (0,34) pada blotter test. Dari 195 isolat Fusarium spp. yang diuji, diketahui bahwa sebagian besar isolat bersifat nonpatogenik. Penentuan jumlah minimal umbi dengan plot kurva rerata jumlah nekrosis pada basal plate dan standar deviasi, menunjukkan jumlah sampel umbi minimal untuk blotter test adalah 150 umbi. Perhitungan jumlah sampel dengan formal probability statement yang menunjukkan jumlah umbi minimal untuk blotter test adalah 138 umbi.Katakunci: Benih; Korelasi; Blotter test; Nekrosis; Sampel ABSTRACT. One of the most important diseases of shallot (Allium ascalonicum) in Indonesia is fusarium wilt caused by Fusarium oxysporum. Most farmer use shallot bulb for their plantation, and some pathogen can be transmitted by this bulb such as Fusarium oxysporum. Blotter test is a simple and effective method to apply in laboratory for seed health testing. Unfortunately, some strains of F. oxysporum are not patogenic and they cannot be distinguished morphologically from pathogenic strains. The research aimed to determine the parameter and the minimum sample number of seed should be applied for Fusarium oxysporum detection on shallot bulb by using blotter test. The result showed that necrosis on basal plate of shallot bulb had correlation coefficient (r) 0.77 to the disease infection in GOT and it was higher than Fusarium infection (0.34). Therefore, necrosis of basal plate can be applied as a parameter in blotter test for Fusarium wilt. The 195 isolats of Fusarium sp. were tested for pathogenicity and it showed many isolates were found in blotter test were not pathogenic to shallot. Curve plot of necrosis rate and its deviation standard were used to determine the minimum sample number of shallot bulb should be tested in the blotter. The result showed that the minimum sample for blotter test was 150 bulb, and the formal probability statement was also showed that minimum number of shallot was 138 bulbs.

Growth, Yield and Resistance Responses of Three Cultivars on True Seed Shallots to Twisted Disease with Salicylic Acid Application

“…is a soilborne pathogen where the initial attack of this pathogen infects the roots or leaves contact directly to the soil surface. Fadhilah et al (2014) reported that Fusarium-affected plants showed disturbed root growth. The LAI is the ratio of the overall leaf area to the land area.…”

In Vitro Induced Resistance of Fusarium Wilt Disease (Fusarium oxysporum f.sp. cepae) by Salicylic Acid in Shallot CV ‘Bima Brebes’

“…Fusarium wilt caused by Fusarium oxysporum f.sp. cepae (Wiyatiningsih, 2002;Fadhilah, 2014) is a soil borne fungus which can attrack almost at all stages of plant growth (Cramer, 2000). Control of this disease is usually done by pesticides, sanitation, and crop rotation.…”

Yields Losses Caused by Basal Plate Rot (Fusarium oxysporum f.sp. cepae) in Some Shallot Varieties

“…Nugroho et al (2011) specified that high intensity of basal plate rot disease can reduce the bulb weight. According to Fadhilah et al (2014), FOCe infection inhibits shallot growth and causes yield losses as the bulbs are rotting. In this study, there was no variety categorized as susceptible.…”