Bananas (Musa. spp) are a vital fruit and food crop for millions of people worldwide, primarily cultivated in the tropical and subtropical regions. In China, bananas are mainly cultivated in the southern regions, including Guangxi, Guangdong, Hainan, Yunnan, Fujian and Taiwan province. Among these, Guangxi is one of the major banana-producing regions, contributing 31% of the country's total annual yield. However, Fusarium wilt of banana (FWB), a devastating soilborne fungal disease in banana, has severely impacted Guangxi's banana plantations since it was first detected in 2006. Within a decade, the disease has spread to 80% of the region's plantations, leading to substantial banana yield losses. To mitigate the impact of Fusarium wilt, the Guangxi Academy of Agricultural Sciences initiated a project focused on disease diagnosis, integrated disease management, resistance evaluation, and resistance breeding. Pathogenic isolates collected from Cavendish bananas across different plantations in Guangxi were all identified as Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4) with VCG 0123/16, confirming Foc TR4 as the causal agent of FWB in the region. As part of the disease management strategy, a new breeding variety, 'Guijiao 9′, a mutant of Musa AAA Cavendish, demonstrated strong resistance to Foc TR4 in both glasshouse and field trials. This high-yielding variety is characterized by superior quality and a short growth cycle. Comparative transcriptome response of 'Guijiao 9′ and Williams bananas were performed to understand the molecular basis that contribute to the enhanced Foc TR4 resistance of 'Guijiao 9'. The results revealed that genes involved in the synthesis of defense-related metabolites were significantly up-regulated in 'Guijiao 9′ in response to Foc TR4 infection. 'Guijiao 9′ has been authorized as the leading banana variety by the Ministry of Agriculture and Rural Affairs of China, and it has since become the primary cultivar in Guangxi, covering 60,000 hectares of cultivation area. The incidence of Foc TR4 in 'Guijiao 9′ plantations is 40%~50% lower than in other Williams varieties. To further understand the evolution of Foc TR4, long-read genome sequencing was performed on representative TR4 strains to identify genetic variations at both structural and gene levels. Secreted small effector proteins from Foc TR4 that interfere with the defense responses of the host plant will be examined. While Foc TR4 has been effectively controlled to some extent in Guangxi, continued collaborative research and management efforts are essential to maintaining long-term control of this significant disease.
References：
Jiaman Sun*, Jinzhong Zhang, Hui Fang, Liyun Peng, Shaolong Wei, Chaosheng Li, Sijun Zheng, Jiang Lu. Comparative transcriptome analysis reveals resistance-related genes and pathways in Musa acuminata banana 'Guijiao 9' in response to Fusarium wilt. Plant Physiology and Biochemistry，2019, 141, 83-94.
Huang S.，Zhou W.，Wei L.P.，Wei D.，Li C.S，Qin L.Y.，Tian D.D，He Z.F，Long S.F., Wei S.L. A New Banana Cultivar ‘Guijiao 9’with Resistance to Fusarium Wilt. Acta Horticulturae Sinica, 2023，50 (S2):45–46.