Identification and pathogenicity of Fusarium species associated with pokkah boeng of sugarcane in Brazil

Abstract

Brazil is the world’s biggest producer of sugarcane (Saccharum spp. hybrids). Pokkah boeng is an important fungal disease in this crop caused by members of the Fusarium fujikuroi species complex (FFSC) and characterized by deformation of the aerial part of the plant and stem rot. While the occurrence of symptoms has been reported in plantations in Brazil, no official reports of the disease exist. In this study, species of the FFSC were identified that are associated with sugarcane plants with symptoms of pokkah boeng in Brazil. This was achieved using two‐loci molecular phylogeny, sexual compatibility and analysis of morphological markers. The ability of strains to cause disease in plants of sugarcane, maize, sorghum and millet was also evaluated. The 39 isolates studied were identified as F. sacchari, F. proliferatum and another, still unknown, phylogenetic lineage that is sister to F. andiyazi. Crossing field isolates of F. sacchari and F. proliferatum with their respective tester strains produced fertile perithecia and viable ascospores. All three species induced symptoms of pokkah boeng on inoculated sugarcane plants and caused stem rot in maize, sorghum and millet. Symptoms on sugarcane are chlorosis and necrosis of leaves, punctured lesions, twisted leaves, reduction of the total leaf area, death of the top of the plant and stalk rot. The findings confirmed the aetiology of the disease in Brazil, generated basic knowledge for the development of strategies for diagnosis and monitoring of the disease and support breeding programmes for selecting resistant germplasm.

Colletotrichum falcatum and Fusarium species induce symptoms of red rot in sugarcane in Brazil

“…Morphological characteristics of the three Fusarium species were consistent with that described in the literature (Costa et al, 2019;Ezekiel et al, 2020;Leslie & Summerell, 2006;Leslie et al, 2005).…”

“…madaense represented 73% of the isolates obtained from plants with red rot symptoms. These species cause pokkah boeng disease in sugarcane in Brazil, and in other countries such as China and South Africa (Costa et al, 2019; Govender et al, 2010; Lin et al, 2014). F .…”

“…Plants sprayed with water and agar plugs without inoculum served as negative controls. Disease symptoms were evaluated daily after inoculation, and compared with the descriptions of red rot and pokkah boeng diseases (Abbott, 1938; Costa et al, 2019; Siti Nordahliawate et al, 2008; Viswanathan, 2021). After 9 days, stalks were cut longitudinally to observe internal symptoms.…”

Identification and First Report of Fusarium andiyazi Causing Sheath Rot of Zizania latifolia in China

“…Fusarium andiyazi was first reported in sorghum ( Sorghum bicolor L.) in Africa and the United States [ 19 ] and was considered one of the most virulent species causing rot and stalk rot on sorghum seedlings [ 20 , 21 , 22 ]. Up to date, F. andiyazi has been reported to cause disease on many plants worldwide, such as pokkah boeng on sugarcane [ 23 , 24 , 25 ], ear and root rot in maize [ 26 , 27 ], vascular wilts in oriental melons [ 28 ], wilting disease in tomatoes [ 29 ], Bakanae on rice [ 16 , 18 , 30 , 31 ] and seedling wilt and root rot on sugar beets [ 32 ]. However, there are no reports of F. andiyazi causing disease in Z. latifolia .…”

Panicum maximum as a reservoir of a potential maize pathogen

“…One seed was sown at a depth of 1 cm in sterilized soil contained in 15 L pots and cultivated in the greenhouse under natural photoperiodic conditions at 30 °C until the seedlings reached the phonological stage V7. The stalks were inoculated at approximately 10 cm above the soil level by inserting a sterile toothpick tip overgrown with mycelia of the Fusarium strains CMM 3363, CMM 3557, CMM 3558, and one positive control -F. verticillioides strain CMM 3131 (Scauflaire et al 2012;Costa et al 2019). Sterile toothpicks without a fungal inoculum were included as a negative control.…”