Variability of Alternaria Leaf Spot Resistance in Jerusalem Artichoke (Helianthus Tuberosus L.) Accessions Grown in a Humid Tropical Region

Abstract

Alternaria leaf spot is an emerging disease of Jerusalem artichoke (Helianthus tuberosus L.) in tropical regions. The lack of known resistant germplasm sources is an important constraint to development of Jerusalem artichoke varieties with resistance to Alternaria leaf spot. The objectives of this study were to identify variability of Jerusalem artichoke genotypes for resistance to Alternaria leaf spot under field conditions and to investigate the relationships among resistance characters, yield, and yield components for selection of resistant varieties. Ninety six accessions of Jerusalem artichoke were evaluated in replicated trials under field conditions in early rainy and late rainy seasons in Khon Kaen, Thailand during 2014. Parameters evaluated included disease incidence, disease score, disease severity index, area under disease progress curve of disease incidence, area under disease progress curve of disease severity index, number of tubers/plants, tuber size, and fresh tuber yield. The genotypes HEL 335, HEL 256, HEL 317, HEL 308, and JA 86 were identified as sources of leaf spot resistance in both seasons. These genotypes can be used as sources of leaf spot resistance for Jerusalem artichoke breeding programs. HEL 293 and HEL 246 showed susceptibility to leaf spot disease in both seasons and should be used as standard susceptible checks.

Jerusalem Artichoke (Helianthus tuberosus L.): A Versatile and Sustainable Crop for Renewable Energy Production in Europe

“…Leaf spot caused by Alternaria helianthi is an emerging disease of JA in tropical regions. The disease appears as small yellow spots on leaves and then causes severe leaf damage and defoliation of both mature and young leaves [44]. Similar symptoms were found for brown spot caused by Bipolaris zeae in China [45].…”

“…There is a general lack of resistant germplasm for all of important JA diseases [2]. Only a few genotyping surveys are reported so far, two for the Southern stem rot caused by Sclerotium rolfsii [75,76] and one for each ring spot viruses, powdery mildew caused by Oidium neolycopersici [41] and leaf spot caused by Alternaria species [44].…”

Effective Plant Ages for Screening for Field Resistance to Alternaria Leaf Spot (Caused by Alternaria spp.) under Natural Infection in Jerusalem artichoke (Helianthus tuberosus L.)

“…JA is currently classified as a functional food crop in tropical regions [5]. However, the production of JA in the tropic's can be subject to severe the yield loss due to drought [6], stem rot [7] and Alternaria leaf spot [8]. Alternaria leaf spot is an emerging disease of JA in these regions.…”

“…The spots then to continue to expand and coalesce. Defoliation of infected leaves begins on mature leaves and spreads upward to younger leaves [8]. The initial inoculum is from plant debris and weedy host [10].…”

Transcriptome changes induced by drought stress in Jerusalem artichoke (Helianthus tuberosus L.) and weighted gene co-expression network analysis (WGCNA)

“…Therefore, during the process of the restoration of vegetation and construction of grassland ecological sandy land, it is necessary to select ecologically economical plants that can restore the environmental ecology and increase income of farmers and ranchers [8][9][10]. Jerusalem artichoke (Helianthus tuberosus L.) is a type of plant that is highly adaptable to infertile lands, drought, cold and salt and is suitable for growing in dry, cold, sunny climates and soil with a high concentration of sediment [11]. Jerusalem artichoke tubers are rich in inulin, which comprises 70-90% of their dry matter.…”