Thangavelu Raman, Amaresh Hadimani, Gopi Muthukathan, Loganathan Murugan, Nithya Boopathy, Ganga Devi Perumal, Anuradha Chelliah, Thirugnanavel Anbazhagan, Patil Kalyansing Baburao, Blomme Guy, Selvarajan Ramasamy
ICAR-National Research Center for Banana, Plant Pathology Division, Tiruchirappalli 620102, Tamil Nadu, India.
ICAR-Central Citrus Research Institute, Nagpur 440033, Maharashtra, India.
J Fungi (Basel). 2024 Dec 21;10(12):887. doi: 10.3390/jof10120887.
wilt of banana is a major production constraint in India, prompting banana growers to replace bananas with less remunerative crops. Effective disease management practices thus need to be developed and implemented to prevent further spread and damage caused by f. sp. (), the cause of wilt. Currently, knowledge of disease incidence, affected varieties, and the geographical spread of races in India are only scantily available. An extensive field survey was conducted in 53 districts of 16 major banana-growing states of and one union territory of India that covered both tropical and subtropical regions. Disease incidence ranged from 0 to 95% on farms, with Cavendish bananas (AAA) most affected. No wilt symptoms due to R1 were observed in Nendran (AAB) or Red Banana (AAA) in South India. During the survey, 293 isolates were collected from Cavendish, Pisang Awak (ABB), Silk (AAB), Monthan (ABB), Neypoovan (AB), and Mysore (AAB) bananas. Isolate diversity was assessed through Vegetative Compatibility Group (VCG) analyses, sequencing of EF1α gene sequences, phylogenetic analyses, and characterisation by gene composition. Thirteen VCGs were identified, of which VCGs 0124, 0125, 01220, and 01213/16 were dominant and infected Cavendish bananas. Phylogenetic analysis divided the Indian isolates into race 1 (R1), subtropical race 4 (STR4), and tropical race 4 (TR4). ( gene analyses indicated that the effector genes 4 and 6 were present in the VCGs 0124, 0124/5, 0125, and 01220 of race 1, 7 was present only in STR4, and 8 was found only in R4 (TR4 and STR4) isolates. Insights into the geographical distribution of races, and their interactions with banana varieties, can guide integrated disease management intervention strategies across India.
香蕉枯萎病是印度香蕉生产的主要制约因素，促使香蕉种植者改种收益较低的作物。因此，需要制定并实施有效的病害管理措施，以防止尖孢镰刀菌古巴专化型（Fusarium oxysporum f. sp. cubense）（香蕉枯萎病的病原菌）进一步传播和造成损害。目前，关于印度病害发生率、受影响品种以及生理小种地理分布的信息非常有限。在印度16个主要香蕉种植邦的53个区以及1个联邦属地开展了一次广泛的实地调查，调查范围覆盖热带和亚热带地区。农场的病害发生率在0%至95%之间，其中卡文迪什香蕉（AAA）受影响最大。在印度南部的Nendran（AAB）或红香蕉（AAA）中未观察到由生理小种1（R1）引起的枯萎病症状。在调查过程中，从卡文迪什、阿哇蕉（ABB）、粉蕉（AAB）、蒙丹蕉（ABB）、奈坡文蕉（AB）和迈索尔蕉（AAB）中收集了293个分离株。通过营养体亲和群（VCG）分析、EF1α基因序列测序、系统发育分析以及基于基因组成的特征鉴定来评估分离株的多样性。共鉴定出13个营养体亲和群，其中营养体亲和群0124、0125、01220和01213/16占主导地位，并感染卡文迪什香蕉。系统发育分析将印度分离株分为生理小种1（R1）、亚热带生理小种4（STR4）和热带生理小种4（TR4）。基于Avr基因的分析表明，效应子基因4和6存在于生理小种1的营养体亲和群0124、0124/5、0125和01220中，效应子基因7仅存在于亚热带生理小种4中，效应子基因8仅在生理小种4（热带生理小种4和亚热带生理小种4）的分离株中发现。了解生理小种的地理分布及其与香蕉品种的相互作用，可为印度各地的综合病害管理干预策略提供指导。
