Genetic Diversity of Fusarium oxysporum f.sp. cubense Isolates (Foc) of India by Inter Simple Sequence Repeats (ISSR) Analysis

Abstract

To find out the genetic diversity of Indian Foc isolates of banana, a total of 107 isolates of Fusarium which includes 98 Foc isolates obtained from different banana growing regions of India and seven Foc isolates belong to all known VCGs obtained from Australia and two non-pathogenic Fusarium oxysporum (npFo) isolates were subjected to ISSR analysis. In the initial screening of ISSR primers, out of 34, 10 primers which generated more polymorphic bands were selected for further analysis. The Phylogenetic analysis carried out based on the fingerprints obtained through ISSR analysis indicated the presence of wide genetic diversity among the Foc isolates of India and also its polyphyletic nature. Totally, seven different clusters were obtained and these clusters differentiated the Foc isolates of India based on the races/VCGs. Besides, the cluster analysis clearly distinguished the freshly emerged Foc strain obtained from cv. Grand Naine (Cavendish-AAA) and Poovan (Mysore-AAB) from the other Foc isolates. The non-pathogenic F. oxysporum isolates which have been included for comparison purpose also clustered separately. All these above said findings indicates for the first time the discriminatory power of ISSR to clearly distinguish and separate the Foc isolates according to its race/VCGs and also its virulence. This study would be useful not only to design and develop effective management strategies but also useful for quarantine purposes.

The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia

“…An unusual association between VCG 0124 and Cavendish bananas, however, was reported by Thangavelu et al . (2012) [68] following a survey conducted in the Tamil Nadu region. Cavendish bananas are considered immune to Foc race 1 and was employed to control the Fusarium wilt epidemic on Gros Michel bananas in Central America during the 1960s.…”

Analysis of genetic and aflatoxin diversity among Aspergillus flavus isolates collected from sorghum seeds

“…flavus populations have been studied extensively with regard to diversity in aflatoxigenic ability . To date, RFLP , RAPD , AFLP , inter‐simple sequence repeat (ISSR) , and multi locus gene sequencing methods are used most extensively to study the diversity among the species of Aspergillus and other fungi.…”

Isolation and Identification of Shoot-Tip Associated Endophytic Bacteria from Banana cv. Grand Naine and Testing for Antagonistic Activity against <i>Fusarium oxysporum</i> f. sp. <i>cubense</i>

“…The pathogen is broadly categorised into four races, of which races 1, 2 and 4 are pathogenic to banana, with race 1 infecting most banana cultivars excluding "Cavendish group" [13] [14] [17]. In India, the disease is prevalent in all banana growing areas with race 1 forming the most common one followed by race 2 [16] [18], while race 4 has been reported in certain pockets [19].…”