Botryosphaeriaceae Fungi as Causal Agents of Dieback and Corky Bark in Rambutan and Longan

Abstract

Fungi in the Botryosphaeriaceae family cause dieback, fruit rots, and stem cankers in many tropical fruit trees. To identify which species of Botryosphaeriaceae were present in tropical fruit in Puerto Rico and the symptoms they cause in rambutan and longan, a disease survey was conducted throughout the island from 2008 to 2016. Diseased organs of rambutan, longan, mango, and tangerine were collected and 39 isolates belonging to the Botryosphaeriaceae family were isolated and identified. Phylogenetic analysis of three nuclear genes identified nine species: six Lasiodiplodia spp. and three Neofusicoccum spp. All 39 isolates were inoculated on healthy 1-year-old rambutan and longan seedlings to confirm their pathogenicity. Dieback on both rambutan and longan was observed at 14 days after inoculation (DAI). Fourteen isolates from seven Botryosphaeriaceae species (Lasiodiplodia brasiliensis, L. hormozganensis, L. iraniensis, L. pseudotheobromae, L. theobromae, Neofusicoccum batangarum, and N. parvum) caused dieback in rambutan. Five of these pathogenic isolates were collected from rambutan, four from longan, two from mango, and three from tangerine. Ten isolates of four Lasiodiplodia spp. caused dieback in longan: L. hormozganensis, L. iraniensis, L. pseudotheobromae and L. theobromae,. Of these, three were collected from rambutan, three from longan, one from mango, and three from tangerine. Abundant development of pycnidia on branches, called corky bark, were observed on both rambutan and longan 60 DAI. Cross-inoculations showed that pathogenicity is wide in spectrum, indicating that different planting alternatives should be considered for better crop management.

The Negative Impact of Excessive Moisture Contributes to the Seasonal Dynamics of Photosynthesis in Amazon Moist Forests

“…Thus, excessive atmospheric moisture may also affect the photosynthetic intensity of plants by affecting the transpiration process. In addition, excessive water in the environment may promote the growth of harmful molds for trees in the ecosystem; by increasing the risk of diseases, it also affects the photosynthetic productivity of the moist forest ecosystem at the colony scale (Serrato‐Diaz et al., 2020; Speight & Woodward, 2015). Ignoring the water absorption by deep roots and the potential existence of excessive moisture stress, current models experience problems with the expression of water stress in Amazon rainforests (Green et al., 2020).…”

Fungal pathogens of mango (Mangifera indica L.) inflorescences

“…Neofusicoccum parvum has been reported as causing mango tip blight in Australia (Slippers et al, 2005), Brazil (de Oliviera Costa et al, 2010, Italy (Ismail et al, 2013), Perú (Javier-Alva et al, 2009, South Africa (Jacobs et al, 2002) and New Zealand (Slippers et al, 2005). More recently, Lasiodiplodia iraniensis and Neofusicoccum batangarum isolated from mango tip blight were shown to be pathogenic, causing dieback to rambutan seedlings in Puerto Rico (Serrato-Díaz et al, 2020).…”

Neofusicoccum batangarum Causing Dieback of Mango (Mangifera indica) in Florida

“…For example, Neofusicoccum batangarum was described as a species in 2010, after being isolated from Terminalia catappa in Cameroon [17]. Since then, it has been reported causing disease on grapevine in Brazil [25], cashew in Brazil and Guinea-Bissau [26,27], rambutan and longan in Puerto Rico [28], and prickly pear in Sicily [29]. This fungus has a wide potential host range that includes many commercially valuable crops.…”