Evaluation of banana germplasm and genetic analysis of an F1 population for resistance to Fusarium oxysporum f. sp. cubense race 1

Abstract

Fusarium wilt of bananas (Musa spp.), caused by Fusarium oxysporum f. sp. cubense (Foc) causes up to 100% yield loss in bananas. Foc race 1 in particular is very devastating to dessert bananas in Uganda. One of the effective control strategies for the disease is the development of resistant cultivars through breeding. The objectives of this study were to identify suitable banana germplasm for generating a segregating population for resistance to Foc race 1 and understand the mode of inheritance of resistance to Foc race 1. Twenty-two banana accessions sourced from the National Agricultural Research Organisation in Uganda were challenged with Foc race 1 in a screen house experiment. Monyet, resistant to Foc race 1 and Kokopo, susceptible, were selected and crossed to generate 142 F1 genotypes. These F1 genotypes were also challenged with Foc race 1 in a screen house experiment. Data were collected on rhizome discoloration index (RDI), leaf symptom index (LSI) and pseudo-stem splitting (PSS), and analysed for variability. The banana accessions evaluated showed varying degrees of resistance to Foc race 1. Segregation ratios for resistant versus susceptible progenies fitted 13:3 (χ2 = 0.12, P = 0.73) for RDI and 11:5 (χ2 = 3.04, P = 0.08) for PSS. Estimated broad sense heritability was 27.8% for RDI, 13.9% for LSI and 14.7% for PSS. The results suggest that resistance to Foc race 1 in banana is controlled by at least two dominant genes with epistatic interaction and that heritability of resistance to Foc race 1 is low in Musa spp.

Evaluation of Mchare and Matooke Bananas for Resistance to Fusarium oxysporum f. sp. cubense Race 1

“…This study, therefore, provides the first comprehensive evaluation of diploid EAHB cultivars and hybrids for resistance to Foc race 1. It expands on the works of Arinaitwe et al (2019) [ 33 ], which found seven Mchare cultivars were susceptible to Foc race 1 in screen house evaluations, and the report of Kung’U and Jeffries (2001) [ 34 ] which found a Muraru cultivar in Kenya to be affected by Fusarium wilt. Kung’U and Jeffries (2001) [ 34 ] also showed Muraru to be less susceptible to Foc race 1 (VCGs 0124 and 01220) than Bluggoe and Gros Michel bananas [ 34 ].…”

“…Until recently, a limited amount of information was available on the response of diploid EAHB bananas to Foc race 1, despite the seasonal appearance of Fusarium wilt on Mchare and Muraru bananas in Tanzania and Kenya, respectively [ 33 , 34 ]. This lack of information delayed the management of banana Fusarium wilt in areas where losses occur, including efforts to improve EAHB diploids genetically for Fusarium wilt resistance.…”

“…Results obtained from pot trials when using the millet seed technique reflected those from field evaluation. The millet seed technique has also been widely used for the mass screening of banana varieties for Fusarium wilt resistance [ 33 , 43 , 44 ]. Foc-infected millet seeds were also successfully used for the field screening of banana for Fusarium wilt resistance [ 45 ].…”

“…Matooke bananas are resistant to Foc races 1 and 2 [ 31 , 32 ], but diploid EAHBs have only been partially evaluated. Seven Mchare cultivars maintained at Kawanda in Uganda were found to be susceptible to Foc race 1 in a screen house evaluation [ 33 ], but there are no scientific reports of Fusarium wilt of Mchare bananas in the field in Uganda and Tanzania. The disease has, however, been reported on a close relative of Mchare bananas, the Muraru banana [ 34 ].…”

Selection of somaclonal variants of the cultivar ‘Prata-Anã’ for resistance to Fusarium oxysporum f. sp. cubense race 1

“…cubense (Foc) (PLOETZ, 2015;DITA et al, 2018). In addition to concerns about managing the pandemic caused by tropical race 4 (TR4) of the pathogen, some countries are searching for strategies to cope with race 1 which is endemic in the main banana producing regions of the world (ARINAITWE et al, 2019;GONÇALVEZ et al, 2019). In Brazil, there are no records of TR4; however, Foc race 1 has had a great impact, either by reducing the productivity of banana plantations or by making the soil unsuitable for planting susceptible cultivars, especially in fields under irrigation which constitute a large proportion of banana production areas (REBOUÇAS et al, 2018;GONÇALVEZ et al, 2019).…”