Musa germplasm diversity status across a wide range of agro-ecological zones in Rwanda, Burundi and Eastern Democratic republic of Congo.

Abstract

Objectives: This study assessed the on-farm Musa germplasm diversity across different agro-ecologies of Rwanda and the socio-economic utilization options and selection practices that create/maintain this diversity on-farm. Methodology and results: A Musa germplasm diagnostic survey was carried out in 2007 in five Rwandan districts on a transect from Lake Kivu (West) to Kirehe district (East) bordering Tanzania. Across all sites, 118 farms, each having at least 50 mats were sampled for determining Musa diversity. Forty three Musa cultivars were recorded across the five districts. Higher diversity was observed in the east declining westwards to the Lake Kivu region as reflected by the number of cultivars and their relative abundance. Nearly half of the recorded cultivars had a low diversity index (Gini-Simpson 1-D < 0.2) and therefore prone to genetic erosion. Cooking cultivars only dominate in the district of Kirehe, while beer cultivars dominate the banana production landscape in the other districts. Taste/flavor, bunch size and market demand were the most important criteria for banana cultivar selection and thus greatly influenced cultivar conservation and distribution on-farm. Diseases such as Fusarium wilt and Xanthomonas wilt greatly contributed to genetic erosion. Conclusion and application of results: Musa cultivar diversity in Rwanda is under threat. Ex-situ conservation of the menaced cultivars is of crucial importance. Beer cultivars dominated the landscape. Cultivar diversity on-farm was influenced by the prevailing altitude; taste/flavor, bunch size, and market demand of the cultivars; and their susceptibility to diseases especially Fusarium and Xanthomonas wilt. Banana breeding or adaptation strategies therefore should take into account the farmer preferred traits. In addition, strategies for managing these diseases are critical for preventing the genetic erosion of the affected cultivars.

Diversity and morphological characterization of Musa spp. in North Kivu and Ituri provinces, Eastern Democratic Republic of Congo

“…Nsabimana and van Staden (2005) reported similar population migrations in Rwanda to result in the disappearance or retaining of some Musa cultivars (with resultant confusion in the nomenclature). Musa production and diversity is currently also under high pressure due to plant nutritional problems and various pests and diseases (especially the Xanthomonas wilt of banana (XW) disease and banana bunchy top disease) (Okech et al, 2002(Okech et al, , 2005Ocimati et al, 2013aOcimati et al, , 2014. For example, XW has devastated many plantations in the region, with farmers abandoning the crop for alternatives such as cassava, taro, legumes and sweet potato (Ocimati et al, 2016a, b).…”

“…This exceptionally high Musa diversity is attributed to the presence of three agro-ecological zones characterised by high, medium and low altitude sites (Ndungo, 2002;Ocimati et al, 2013b). However, Musa diversity has been reported to be eroding in the centres of origin (including DR Congo) because of human development activities, land pressure, pests and diseases, market demands and civil unrest (Okech et al, 2002(Okech et al, , 2005Nsabimana and van Staden, 2005;Doré and Varoquaux, 2006;Ndungo et al, 2008;Ocimati et al, 2013aOcimati et al, , b, 2014. For example, the region also experienced armed conflicts for over three decades, resulting in population migrations and abandonment of banana fields.…”

Multi-locational evaluation of cooking banana cultivars NARITA 4 hybrid and Mpologoma in Rwanda

“…Therefore, both exotic cooking cultivars produced acceptable bunches. As bunch size and market demand are important criteria in the selection of cooking cultivars for cultivation in Rwanda by farmers (Ocimati et al, 2014), 'Mpologoma' and even 'NARITA4' have a high chance to be adopted by farming communities.…”

“…(Karamura et al, 1998). Nevertheless, Rwanda has experienced declines in banana diversity and production in the past decades due to several factors including social unrest/insecurity, land/population pressure, pests and diseases (such as Fusarium wilt and Xanthomonas wilt of banana), and declining soil fertility (Okech et al, 2002;Nsabimana and van Staden, 2005;Ocimati et al, 2014). Increasing the diversity of banana germplasm through the introduction of high-yielding conventionally bred hybrids and other commercial cultivars/landraces forms an integral part of technology packages for improving banana diversity and production in the central African region.…”

“…Like the entire African Great lakes region, the most common and economically important cultivars in Rwanda belong to the East African highland banana group (Musa AAA-East Africa [-EA] genome) and are mainly used for cooking and beer/wine production (Karamura et al, 1998;Ocimati et al, 2013Ocimati et al, , 2016. East African highland banana plants grow and perform well at altitudes ranging from 1000 to 2000 m above sea level (m a.s.l.)…”