A Rapid and Efficient Method for In Vitro Screening of Taro for Leaf Blight Disease Caused by Phytophthora colocasiae

Abstract

Taro leaf blight caused by Phytophthora colocasiae presents the single biggest constraint for taro cultivation globally. To accelerate breeding and selection for disease resistance to leaf blight, it is important to develop bioassays which could differentiate resistant and susceptible cultivars efficiently. In this study, thirty taro accessions and four released cultivars were evaluated for resistance to leaf blight using a modified floating leaf disc assay. A novel method for mass production of P. colocasiae zoospores was developed and used as inoculum for the assay. There were significant (P < 0.05) differences among accessions in their response to P. colocasiae infection in the detached leaf assay. The accessions could be efficiently classified into various resistance groups based on a 0-4 score. Also, the assay results were consistent with the field evaluation scores of taro accessions. Thus, this study reports the development of a rapid, simple and repeatable assay that can be used to screen large numbers of taro cultivars for resistance to P. colocasiae.

Fungicidal properties of ginger (Zingiber officinale) essential oils against Phytophthora colocasiae

“…Sporangium production was induced by inoculation of five culture slants (5 mm) with 10 ml sterilized distilled water in test tubes for 3 days under a bright fluorescent lamp. For the release of zoospores, sporangia were chilled at 4 °C for half an hour and then shifted to 25 °C for 15 min as described by Nath 52 . Zoospores separated from sporangia by sieving with thin filter paper.…”

Comparing the Susceptibility of Taro Leaves With Different Ages Against Phytophthora Leaf Blight Disease

“…Whole isolation activity was conducted with sterilized place and tools. Testing Satoimo cultivar using floating leaf disc assay method: Testing pathogenicity with floating leaf disc assay was previously demonstrated by Nath (2016). The procedure is to reach at Koch's postulate purpose.…”

“…Leaf is an essential tissue to produce phytohormone against the disease (Marta, et al, 2017). To cope with pathogen spread and yield loss due to leaf blight disease in developing taro industry in the future, seeking resistant cultivar is a very important component and one of them is by assay in vitro (Nath, 2016). Hence, this study was undertaken to examine resistance of different leaf ages of taro Satoimo cultivar against Phytophthora light blight disease that may contribute to profile resistant taro cultivar in the scale up stage.…”

Activity and Point Mutation G699V in PcoORP1 Confer Resistance to Oxathiapiprolin inPhytophthora colocasiaeField Isolates

“…The cultivation of resistant varieties and the application of fungicides play a vital role in taro blight management. 7,8 With few resistant taro cultivars available even now, the application of fungicides is the most practical and effective way to manage taro blight epidemics. 9 Metalaxyl has been introduced to control taro leaf blight since the 1980s.…”

“…The cultivation of resistant varieties and the application of fungicides play a vital role in taro blight management. , With few resistant taro cultivars available even now, the application of fungicides is the most practical and effective way to manage taro blight epidemics . Metalaxyl has been introduced to control taro leaf blight since the 1980s. , Also, dimethomorph and cymoxanil are additional fungicides used for controlling taro leaf blight disease. , However, due to fungicides resistance from several taro-growing areas, there has been unsatisfactory disease control efficacy. ,, Therefore, research into novel classes of fungicides with different modes of action became urgent.…”