SOURCES OF RESISTANCE TO Fusarium oxysporum f. sp.cubense IN BANANA GERMPLASM

Abstract

Fusarium wilt (syn= Panama disease), caused by Fusarium oxysporum f. sp. cubense (FOC), is one of the most destructive diseases of banana, being genetic resistance the main management strategy for this disease. Since the pathogen is constantly evolving to supplant the genetic resistance, new sources of resistance must be investigated by genetic improvement programs aiming to developing new varieties. The objective of the present study was to identify sources of resistance from the different accessions maintained in the banana active germplasm bank (BAGB) at Embrapa Mandioca e Fruticultura. Forty-one BAGB accessions were evaluated, including 17 diploids, 21 triploids, and two tetraploids. The area under the disease progress curve, disease index, and incubation period were also evaluated. In relation to FOC resistance, there is genetic variability available among the BAGB accessions. The genotype M53 is notable for the complete resistance it expressed, and the accessions Birmanie, PA Songkla, Pirua, Imperial, Poyo, Ambei, Walebo, and Kongo FRF 1286 expressed quantitative resistance.

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

“…Ten out of 18 (* 55.6%) of the diploids evaluated were classified as either highly resistant or resistant and the tetraploid (Monyet) was grouped as resistant. The results reported in this study are in agreement with those reported by Uma et al 2011and Ribeiro et al (2017) where the authors reported that diploid banana accessions they assessed were resistant to most of the pests and diseases tested. A study by Kumar et al (2009) also found a majority (4/7 synthetic diploids and 4/6 diploid parents) of the diploid banana cultivars to be resistant to Foc race 1.…”

“…The advanced yellowing of these genotypes may not be associated with Fusarium wilt infection since they had lower RDI values or no rhizome discoloration, but is possibly associated with mineral deficiency and/ or excessive water. Ribeiro et al (2017) reported that a plant can show external characteristics such as advanced yellowing (high LSI) due to nutritional deficiency and excess water, but internally may not exhibit rhizome discoloration (high RDI). According to Li et al (2015), Foc can cause internal corm discoloration without causing any external symptoms such as yellowing of leaves.…”

“…According to Li et al (2015), Foc can cause internal corm discoloration without causing any external symptoms such as yellowing of leaves. Ribeiro et al (2017) and Li et al (2015) suggested that dissecting the rhizome to verify the absence/presence of discoloration is the most precise evaluation of Fusarium wilt. Therefore, we grouped the germplasm into resistance groups and selected parents contrasting for Foc race 1 resistance, only based on the DSI for RDI.…”

Interaction between Fusarium oxysporum f. sp. cubense and Radopholus similis can lead to changes in the resistance of banana cultivars to Fusarium wilt

“…Consequently, the use of resistant cultivars is the most efficient way to control FW (Li et al 2013;Costa et al 2015;Haddad et al 2018). Banana genotypes have been evaluated via the banana breeding program of Embrapa in Brazil to detect genotypes resistant to the pathogens among diploid accessions with an appropriate level of genetic variability, such as M53, Jaran, Birmanie, Pipit, and Malaccensis and between the Figo type and Silver type genotypes with Foc race 1 resistance alleles (Silva et al 2011;Rebouças et al 2018;Ribeiro et al 2018).…”

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

“…For instance, NARITA 12 was partially resistant to Foc race 1, but its parents 1201 K-1 (Nakawere x Calcutta 4) and 9128-3 (Tjau Lagada x Pisang Lilin) are resistant [ 40 ]. Nakawere (Matooke), Calcutta 4, Tjau Lagada and Pisang Lilin are all bananas known to be resistant to Foc race 1 [ 31 , 47 , 48 ]. Although the Matooke cultivars are resistant to Foc race 1 and potentially to Foc tropical race 4 (TR4) [ 31 , 32 ], this study indicated that their hybrids can lose resistance following conventional breeding.…”