Kiwifruit is very popular among consumers due to its high nutritional value. The increasing expansion in kiwifruit cultivation has led to the spread of rot diseases. To identify the pathogens causing kiwifruit ripe rots in China, 24 isolates were isolated from the diseased fruit and wart in trees. Botryosphaeria dothidea was recognized as the pathogen causing kiwifruit ripe rot and wart in the tree through internal transcribed spacer (ITS) sequencing, pathogenicity testing, morphological and microscopic characteristics. The rapid and accurate detection of this pathogen will lead to better disease monitoring and control efforts. A loop-mediated isothermal amplification (LAMP) method was then developed to rapidly and specifically identify B. dothidea. These results offer value to further research into kiwifruit ripe rot, such as disease prediction, pathogen rapid detection, and effective disease control.

Botryosphaeria dothidea causes white rot, which is among the most devastating diseases affecting apple crops globally. In this paper, we assessed B. dothidea resistance to carbendazim by collecting samples from warts on the infected branches of apple trees or from fruits exhibiting evidence of white rot. All samples were collected from different orchards of nine provinces of China in 2018 and 2019. In total 440 B. dothidea isolates were evaluated, of which 19 isolates from three provinces were found to exhibit carbendazim-resistance. We additionally explored the fitness and resistance stability of these isolates, revealing that they were no less fit than carbendazim-sensitive isolates in terms of pathogenicity, sporulation, and mycelial growth and that the observed carbendazim resistance was stable. Sequencing of the β-tubulin gene in carbendazim-resistant isolates showed the presence of a substitution at codon 198 (GAG to GCG) that result in an alanine substitution in place of glutamic acid (E198A) in all 19 resistant isolates. A LAMP method was then developed to rapidly and specifically identify this E198A mutation. This LAMP method offers value as a tool for rapidly detecting carbendazim-resistant isolates bearing this E198A mutation, and can thus be used for the widespread monitoring of apple crops to detect and control the development of such resistance