Diagnosis Penyakit Mosaik (Soybean Mosaic Virus) Terbawa Benih Kedelai

Abstract

Soybean mosaic disease is wide spread throughout soybean-growing countries. Incidence of this disease in East Java is caused by Soybean mosaic virus (SMV) and cowpea mild mottle virus (CMMV). This aim of study was to find the etiology of disease at 14-28 days after planting (dap) on soybean. Research was done by observing visual symptoms. Visual symptoms confirmed by infectivity test, serology assay,electron microscopy (EM) and molecular detection. Results from experiment indicated that soybean plants (14-28 dap) with symptom could be detected in infectivity test. Mechanical inoculation with symptomatic leaf extracts produced local lessions on Chenopodium amaranticolor. Positive results were obtained for Madiun, Ngawi, and Magetan samples when tested against antiserum of SMV in serological assay, however Ponorogo samples were not detected by serological assay. Electron microscopy was also done for the selected sample to confirm the result of positive results. In EM observations, characteristic filamentous particles with modal length close to 900 nm were observed in samples infected with SMV. We detected an array of amplification products of expected size 1385 bp fragment of cylindrical inclusion gene from Madiun, Ngawi, and Magetan isolates in former fields, but not detected in Ponorogo isolate. This result showed the existence of SMV of soybean seed transmission at 14-28 dap in Madiun, Magetan and Ngawi.

Ketahanan Beberapa Genotipe Kedelai terhadap Penyakit Karat Daun (Phakopsora pachyrizi)

“…Rendahnya produktivitas kedelai karena serangan hama dan penyakit, untuk serangan penyakti salah satunya disebabkan oleh serangan cendawan Phakopsora pachyrizi (penyebab penyakit karat daun) terutama saat musim kemarau (Sumartini, 2016). Hal ini sejalan dengan pernyataan dari (Adisarwanto, 2008), yang menyatakan bahwa karat daun dapat menurunkan jumlah polong yang dihasilkan dengan kisaran 30% sampai dengan 60%. Hal tersebut disebabkan karena daun kedelai yang terserang cendawan Phakopsora pachyrizi mengalami penguningan, sehingga daun tersebut mudah gugur sebelum terjadi pengisian polong.…”

Seed-transmission of Cowpea mild mottle virus on several varieties of soybean in Indonesia

“…Virus infection on soybeans have the potential to cause yield loss and reduce the quality of seeds. Soybean mosaic virus (SMV) (Andayanie 2012), Cucumber mosaic virus strain soybean (CMV-S) and Pepper yellow leaf curl virus (PYLCV) (Rahim et al 2015) were reported recently infecting soybean plants in Java. Cowpea mild mottle virus (CPMMV) was first reported to cause systemic mottling, chlorotic blotches and leaf malformations in cowpea (Vigna unguiculata L.) in 1973 and to be widespread in the Eastern Region of Ghana, West Africa.…”