Production of banana bunchy top virus (BBTV)-free plantain plants by in vitro culture

Open Access ArticleBanana Bunchy Top Disease (BBTD) caused by the Banana Bunchy Top Virus (BBTV) is one of the most important banana diseases in the Democratic Republic of Congo. This study focused on the production of BBTV-free plantain seedlings from infected banana plants. A total of 10 suckers from the French plantain Litete (Musa AAB) and the False Horn plantain Libanga Likale (Musa AAB) with advanced BBTD symptoms were collected. Meristematic apices excised from those suckers were cultured in vitro and subcultured five times. The presence of BBTV was evaluated by the Triple-Antibody Sandwich Enzyme-linked Immunosorbent Assay (TAS-ELISA). The BBTV was confirmed in all suckers prior to in vitro culture but 73.3% of Litete plantlets and 66.6% of Libanga Likale plantlets regenerated from meristematic tissues were virus-free. This indicates that in vitro culture is a simple tool to generate BBTV-free plantains

Congolese rhizospheric soils as a rich source of new plant growth-promoting endophytic Piriformospora isolates

In the last decade, there has been an increasing focus on the implementation of plant growth-promoting (PGP) organisms as a sustainable option to compensate for poor soil fertility conditions in developing countries. Trap systems were used in an effort to isolate PGP fungi from rhizospheric soil samples collected in the region around Kisangani in the Democratic Republic of Congo. With sudangrass as a host, a highly conducive environment was created for sebacinalean chlamydospore formation inside the plant roots resulting in a collection of 51 axenically cultured isolates of the elusive genus Piriformospora (recently transferred to the genus Serendipita). Based on morphological data, ISSR fingerprinting profiles and marker gene sequences, we propose that these isolates together with Piriformospora williamsii constitute a species complex designated Piriformospora (= Serendipita) 'williamsii.' A selection of isolates strongly promoted plant growth of in vitro inoculated Arabidopsis seedlings, which was evidenced by an increase in shoot fresh weight and a strong stimulation of lateral root formation. This isolate collection provides unprecedented opportunities for fundamental as well as translational research on the Serendipitaceae, a family of fungal endophytes in full expansion

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

Eastern Democratic Republic of Congo constitutes an area where the East African Highland bananas (Musa-AAA-EA) and plantains (Musa-AAB) meet. However, Musa diversity in this region has never been characterized nor represented in national or international collections, yet increasing human activities and build-up of pests and diseases, especially Xanthomonas wilt of banana and banana bunchy top disease, could negatively affect this diversity. This study assessed, collected and morphologically characterized on-farm Musa diversity in the North Kivu and Ituri provinces. Musa accessions collected were added to the UCG-Butembo in situ field collection. A total of 90 and 150 farms were assessed, respectively, in the North Kivu and Ituri provinces. High Musa variability was observed in both provinces. Forty-one cultivars (six presumed new) were identified in Ituri Province compared to 38 cultivars (13 presumed new) in North Kivu Province. Nineteen cultivars occurred in both provinces. Beni and Lubero territories in North Kivu and Mambasa territory in Ituri Province had greater Musa diversity, varying between 27 and 38 cultivars, approximately double of the number of cultivars observed in the other territories. Twenty-three of the 34 Musa descriptors contributed more to the discrimination of the cultivars identified across the provinces and were therefore used for grouping the cultivars using principal component analysis (PCA). The Morisita index of similarity between Ituri Province and North Kivu Province territories was less than 0.5, suggesting dissimilarity in diversity between these sites. Six cultivars: ‘Kirisirya’, ‘Pakuma’, ‘Nziravahima’, ‘Vuhindi’, ‘Tundu’ and ‘Kisubi musa’ were reportedly at risk of genetic erosion

Expression of a rice chitinase gene in transgenic banana ('Gros Michel', AAA genome group) confers resistance to black leaf streak disease

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The morphological diversity of plantain in the Democratic Republic of Congo

This work focused on the morphological characterization of plantain cultivars collected in the period 2005–2014 in 280 villages across 9 provinces of the Democratic Republic of Congo. These cultivars were established in two field collections at the University of Kisangani.Existing descriptors were adapted to better differentiate their variation to address better the taxonomic handicap and the synonymy handicap to improve future research on plantains.Most of the collected cultivars were French plantains (64 out of 98), followed by False Horn (23) and Horn (10) plantains. The bunch type was the main striking difference which allows the quick separation of plantain cultivars into three main types. Other striking differences within plantain were the size of the pseudostem (giant, medium-sized and small-sized) and the bunch orientation (which was generally pendulous or subhorizontal, and rarely horizontal and erect). These three descriptors were considered as main descriptors. Other descriptors (pseudostem colour, immature fruit peel colour, fruit shape, fruit apex, fruit position, number of hands, fruit size, number of fingers per hand and flower relicts at the fruit apex) allowed the differentiation of one cultivar from another within the same main group of bunch type, pseudostem size or bunch orientation. These descriptors are considered as secondary descriptors. Rare descriptors allowed to differentiate one cultivar from all the others in the subgroup. This approach makes the cultivar description logical and faster because it moves from general to particular characteristics, and it offers a platform for reflections on the Pan-African scale of plantain diversit

Banana diversity in the Oriental provinces, northeastern Democratic Republic of Congo

Studies on banana diversity and distribution have been carried out in the Democratic Republic of Congo (DR Congo) since the 1950s. However, there are still insufficient data on the distribution of diversity in large areas of the Congo basin. The present study was conducted in the surrounding region of Kisangani (Lubuya Bera sector) and in 24 territories of the Oriental province. Three villages were randomly selected in the Lubuya Bera sector and in each territory, totalling 75 villages. In each village, a group discussion was conducted to assess farmers' knowledge of banana diversity. Ten farmers per village (750 in total), each having at least 20 banana mats, were randomly selected for a diagnostic survey focusing on banana germplasm diversity, criteria that influence the selection of planting material and cultivar preference. Morphological descriptors were recorded and photos taken of each cultivar. In total, 92 cultivars were characterized consisting of 70 Plantains (AAB genome), 11 dessert bananas (AAA, AAB, and AABB genome), 10 cooking bananas (AAA-EA and ABB genome) and 1 ABB cultivar ('Kayinja') used for brewing. Fruit pulp quality, availability of planting material, marketing potential and bunch size were the main criteria used by farmers for selection. The five most appreciated Plantains were 'Libanga Likale', 'Litete', 'Amakake', 'Yumba' and 'Chwachwa', while 'Gros Michel', 'Kamaramasenge', 'Grande Naine', 'Petite Naine' and LSQUOYangambi Km 5' were the most appreciated dessert bananas. Future efforts should also be focused on agronomic, post-harvest and molecular aspects for enhanced knowledge, use and conservation of banana diversity across DR Congo