Researchers develop a new way to describe plantain diversity in DRC

Researchers studying the morphological (structure and form) diversity of plantain in the Democratic Republic of Congo (DRC) have developed an innovative way to describe plantain diversity using descriptors based on performance, grouping them into main, secondary, and rare descriptors.

The morphological identification of plantain cultivars is important since molecular tools appear to have little value in supporting research in plantain taxonomy to differentiate plantain cultivars.

Three new descriptors

In the new system, three sets of descriptors are used: the first are the main descriptors such as bunch size and orientation, plant size and height, which allow a quick and easy separation of plantain cultivars.

Bunch type was a major striking difference and quickly separated plantain cultivars into three main types. Other striking differences were the size of the pseudostem or trunk (giant, medium-sized, and small-sized) and the bunch orientation (which was generally pendulous or subhorizontal, and rarely horizontal and erect).

The secondary descriptors allow the differentiation of one cultivar from another within the same main group of bunch type, pseudostem size, or bunch orientation. Multiple secondary descriptors include pseudostem color, immature fruit peel color, fruit shape, fruit apex, fruit position, number of hands, fruit size, number of fingers per hand, and flower relicts at the fruit apex.

The third set are the rare descriptors, which allow the differentiation of one cultivar from all the others in the subgroup.

According to the researchers, this approach proved useful in differentiating the nearly 100 plantain accessions in the collection of the University of Kisangani (UNIKIS) in DRC. This approach makes cultivar description logical and faster because it moves from general to particular characteristics.

The study, titled The morphological diversity of plantain in the Democratic Republic of Congo by J.G. Adheka, D.B. Dhed’a, D. Karamura, G. Blomme, R. Swennen, and E. De Langhe, focused on the morphological characterization of plantain cultivars collected in the period 2005–2014 in 280 villages across nine provinces of DRC. These cultivars were established in two field collections at UNIKIS.

Picture of A False Horn plantain variety called Tala Lola from Central DR Congo
A False Horn plantain variety called ‘Tala Lola’ from Central DR Congo

Most of the collected cultivars were French plantains (64 out of 98), followed by False Horn (23) and Horn (10) plantains.

Banana cultivars are usually described using Descriptors for bananas (Musa spp.) developed by IPGRI-INIBAP/CIRAD in 1996. The researchers had adapted these existing descriptors to better differentiate the variation and improve future research on plantains. This new work, published in Scientia Horticulturae, however, showed that this descriptor list is not appropriate for describing variation within the plantain subgroup, with 77 out of a total of 117 descriptors not considered useful.

The researchers believe that this existing descriptor list for banana will also not be appropriate in describing variation within other subgroups of banana, like the East African Highland banana, Pacific plantain, etc.

The observed variation was reproduced in the collection during succeeding cycles and confirmed the stability of the cultivars, as well as the value of the new descriptors. The classification of the plantain cultivars at the UNIKIS collection can be used as a standard for investigating plantain diversity for the entire African continent.

Large plantain diversity in DRC

The study results showed that the humid zone of DRC contains an exceptionally large diversity of plantains among the edible Musa subgroups. This means that DRC also has the largest diversity of plantains in Africa. The 100 different cultivars covered in the study represent just a part of the entire plantain variability zone in DRC. More cultivars are expected to be found in regions of the country that still need to be explored. The researchers believe that the diversity of plantain in DRC could be substantially larger than 120 cultivars.

Picture of A Horn plantain variety called Ikpolo Noir found in DR Congo
A Horn plantain variety called ‘Ikpolo Noir’ found in DR Congo

Plantain characterization data from DRC offer a platform for reflections on the pan-African scale of plantain diversity. Assessing and characterizing the complete plantain diversity in Africa is possible by compiling characterization results of all Central and West African countries whereby UNIKIS in DRC will play a key role given its expertise and access to the largest plantain variability.

Since the planting of all accessions in one location is not feasible due to financial constraints, the researchers encouraged plantain curators to continue intensive contact, with regular exchange visits and discussions, to progressively reach an agreement on classification, synonymy, and uniqueness of all plantain cultivars.

In sub-Saharan Africa, an estimated 30 million people depend on banana as the principal source of dietary carbohydrate, with small-scale farmers making up the vast majority of banana and plantain producers. They grow the crop mainly for home consumption or for local markets. In West and Central Africa, about two-thirds of the banana cultivated and produced are plantain, which need to be processed and/or cooked for consumption.

The other third consists of dessert and other cooking bananas. In Africa, the major producing countries are Cameroon, Ghana, Nigeria, and Côte d’Ivoire. According to the FAO, production of plantain in these countries ranks high (12.3 million tons in 2014) among the starchy staples.

The study was conducted as part of a collaboration of researchers from University of Kisangani (UNIKIS), IITA, Bioversity International, and the Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, Katholieke Universiteit, Belgium.

Media contact: Katherine Lopez, k.lopez@cgiar.org

IITA and partners conduct first proteomic investigation in plantain and banana

Scientists from IITA and partner institutions have carried out the first known proteomic investigation into plantain. The results of the study are featured in a paper, titled “The plantain proteome, a focus on allele specific proteins obtained from plantain fruits” by N.A. Campos, R. Swennen, and S.C. Carpentier. Proteomics entails the study of the expression of proteins in a cell or organism. This is important because proteins are responsible for both the structure and the functions of all living things.

Picture of Plantain fruit. Nádia Campos, KU Leuven.
Plantain fruit. Nádia Campos, KU Leuven.

IITA banana breeder Rony Swennen said the identification and public release of the plantain fruit proteome is an important step for plantain varietal selection and breeding. He said the research is important because little attention has been given to postharvest research in plantain, a staple especially in Central and West Africa and Latin America, which grows most of the world’s plantains.

Fruit development and maturation in plantain is hardly studied unlike in the more popular dessert banana. As a result, he said plantain suffers from many pests and diseases, although it is currently bred for higher yield. The acceptance of new plantain hybrids by farmers needs to be accelerated, hence the importance of better understanding the fruit physiology of plantain to develop hybrids that are more acceptable to consumers and have a better shelf life.

The proteomic research into plantain used an easy and reproducible procedure for protein extraction and identification, resulting in the first proteome (set of proteins) of plantain fruits. The results were compared with the proteome from the dessert banana Cavendish.

The scientists found that both the plantain and Cavendish cultivars were relatively close genetically but showed contrasting phenotypic or physical differences such as size, texture, color of fruit, and flavor. These characteristics, the scientists said, comes from a different physiology and maturation process.

The plantain fruit preserves more starch for longer periods than sweet banana. The type of starch also differs. According to the scientists, there are two types of starch in banana: resistant starch (RS) and non-resistant starch. This classification is linked to the capacity to be digested by the human body. Plantain degrades RS faster, but at maturation, is richer in resistant starch.

The paper concluded that an improved understanding of the fruit maturation process may yield benefits for public health, farming, and agricultural business.

The study was conducted as part of a collaboration of researchers from IITA, the Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, Katholieke Universiteit, Belgium, and SYBIOMA: Facility for SYstems BIOlogy based MAss spectrometry, KU Leuven.

Media contact: Katherine Lopez, k.lopez@cgiar.org

First banana hybrids bred in Arusha go for field trials

Three years after starting its activities, the IITA banana breeding team based in Arusha-Tanzania has planted its first banana hybrids for field evaluation. While this is a major milestone for the program, it also underscores the complexity and slow pace of banana breeding.

Dr Brigitte Uwimana, planting the hybrid banana in the trial field in Arusha.
Dr Brigitte Uwimana, planting the hybrid banana in the trial field in Arusha.

The program started its activities in Arusha in early 2011 after many years of successful banana breeding in Nigeria (for plantain) and Uganda (for matooke or highland cooking bananas) in collaboration with the National Agricultural Research Organization (NARO).

In Tanzania, the breeding is focusing on Mchare, an important group of cooking banana varieties in the Arusha-Kilimanjaro region and in other East African countries. This breeding program aims to develop Mchare banana varieties that are high yielding with resistance to Fusarium wilt, a soil-borne fungal disease that is attacking the crop in Tanzania. “This breeding program follows two main streams. One stream targets crosses to gather information to accelerate banana breeding. The other target crosses that aim at producing improved Mchare,” said Dr Brigitte Uwimana, the postdoc banana breeder based in Arusha.

“Banana breeding is a tedious undertaking, mainly because banana are sterile and don’t generally produce seeds (parthenocarpy). This makes the generation of new hybrids a challenge. These hybrids will be evaluated in the field and the best will be selected for further breeding Mchare banana,” Brigitte explained.

The successful breeding of the new hybrids involves the selection of fertile parents, seed extraction, seed germination in the laboratory, and nursery management.

Improving agriculture, changing lives: IITA’s 20 years of agriculture research in Tanzania

In 2014, IITA marked its 20th anniversary in Tanzania. This video highlights some of the activities researchers have been involved in and the successes achieved so far from some of the beneficiaries. These include research on tackling the major pests and diseases of important food crops in the country, adding value through processing and better postharvest handling and building the capacity of researchers in the country and region.

Video highlights

Tackling poverty and hunger in Tanzania through working with small-holder farmers: IITA has been working with small-holder farmers in Tanzania who are not only a majority of the population but are also a majority of the poor living in rural areas. Therefore, according to Dr Victor Manyong, IITA director for eastern Africa, improving their income and livelihoods can have a significant impact in efforts to reduce hunger and poverty and develop the country.

Wilting bananas: Banana is an important crop not only in Tanzania but also in the whole of the Great Lakes region where it’s grown by over 70 million people. However, their livelihoods and food security are currently threatened by a deadly bacterial disease, the Banana Xanthomonus Wilt (BXW) which is spreading through the region.  Former IITA Plant pathologist Dr Fen Beed explains ongoing efforts on tackling and controlling this disease.

Double scourge for cassava farmers:  Cassava, another important crop for small-holder farmers in Tanzania is currently under attack from two viral diseases: Cassava Brown Streak Disease (CBSD) and Cassava Mosaic Disease (CMD). IITA’s plant virologist Dr James Legg has been hot on the trail of the vector transmitting the diseases, trying to understand them, how they spread the diseases, and how to control them.

Improving farmers’ varieties: One way to increase the production of smallholder farmers is by giving them improved high-yielding varieties. Working together with their counterparts at the Ministry of Agriculture, Food Security and Cooperatives, IITA researchers have worked hard to develop improved varieties of important crops to smallholder farmers. This is one area in which IITA has had considerable success in the country notes Dr Fidelis Myaka, the Director for Research and Development.

The farmers are also involved in the improvement of their varieties through a process known as Participatory Variety Selection (PVS) to ensure the new crops are not only high yielding but that they also meet their preferences  in terms of taste, texture, mealiness and other traits as explained by Dr Edward Kanju, IITA’s cassava breeder.

The improved high-yielding varieties developed by IITA and their partners are motivating farmers to grow cassava as attested by James Mele, a farmer in the coast region of Tanzania who had nearly abandoned growing cassava altogether due  to diseases.

Reducing unsafe use of pesticides by vegetable farmers: Vegetables are high-value crops in urban areas. They are therefore attractive to surrounding farmers who often cultivate them intensively using a lot of pesticides and many times incorrectly. This poses a health risk to themselves and their consumers as well as to the environment. IITA’s Dr Danny Coyne, a soil health specialist, is working with vegetable farmers to show them safe and more sustainable ways to control pests and diseases in vegetables.

Adding value to farmers’ produce:   Supporting farmers to increase production is not enough to tackle food insecurity and poverty if it’s not accompanied by efforts to protect yields and ensure farmers have access to markets. IITA’s value chain specialist, Dr Adebayo Abass has been working with farmers to process their produce into high value products with longer shelf lives and which fetch more money in the market.

Capacity building:  IITA has also put in a lot of effort to train researchers – its own staff and those from partner institutions. These include conducting short courses, supporting Msc and PHD studies and through internship. Dr Fidelis Myaka, Director for Research and Development sees this as another important contribution by IITA to the country’s effort to develop its agriculture sector.

New science facility: To ensure IITA is well equipped to deal with current and emerging agricultural issues in Tanzania and the whole of Eastern Africa, the Institute has constructed a state-of-the art science facility with five well-equipped laboratories. The facility was inaugurated by the president of Tanzania, His Excellency, Dr Jakaka Mrisho Kikwete in May 2013.

African organizations unite to address the threat of a dangerous form of Fusarium wilt of banana

An  African  consortium of international researchers and growers, backed by policymakers in regional blocs of eastern and southern Africa has declared “war” against Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), a highly pathogenic form of the banana Fusarium wilt, previously confined to Asia, but recently introduced to a farm in northern Mozambique.

FoC TR4 (also known as Panama disease) is caused by a fungal strain that can survive for decades in the soil, and once introduced to a country has never been previously eradicated. Production of Cavendish types of banana which dominate export markets, and some other local forms of banana, has been devastated across Asia, no thanks to Foc TR4.

Its introduction to Africa, probably by infected planting material by people, has already had a massive impact on the commercial plantation in Mozambique, and efforts are in place to contain the disease on this farm, to avert further spread and to prepare other African countries against similar incursions, says Dr Fen Beed, Plant Pathologist with the International Institute of Tropical Agriculture (IITA).

To manage the disease outbreak and to prepare African countries reliant on banana for food security and income generation, a stakeholder workshop of the African Consortium for Foc TR4 (AC4TR4) was held in Stellenbosch, South Africa, 23-24 April 2014, on the theme: Development of a Strategy to address the threat of Foc TR4 in Africa. Representatives from the following organization took part: Southern African Development Community (SADC), The Common Market for Eastern and Southern Africa (COMESA), the East African Community (EAC), Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA), Food and Agriculture Organization (FAO), National Plant Protection Organizations (NPPO), IITA, Bioversity International, Stellenbosch University, national research organizations, and commercial growers.

Recommendations from the workshop have now been harmonized. A major output has been “The Stellenbosch Declaration on addressing the threat of Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) to banana production in Africa,” convened by SADC and COMESA, signed by member states and endorsing institutions.

This unique Declaration aims to combine forces to curtail the introduction and spread of Foc TR4 in Africa and in particular to achieve the following:

  • Fully develop and implement a continental strategy under the direction of an African Foc TR4 task force to contain the incursion of Foc TR4 in the Nampula   province of Mozambique and prevent similar incursions elsewhere.
  • Provide and enhance technical capacity on the continent, and to implement and monitor phytosanitary systems, including wider use of International Standards for Phytosanitary Measures (ISPMs) and other matters concerning plant health to address the threat of Foc TR4 in Africa.
  • Report and map electronically by means of a web portal any new outbreaks of Foc TR4 in African member states and communicate information on new outbreaks, successful containment, and prevention initiatives.
  • Establish recognition that Foc TR4 is a continental issue that requires coordination and collaboration between NPPOs, RECs, ICPs, research institutions, universities, governments, and other relevant stakeholders throughout Africa by means of regular meetings and consultations.
  • Develop and apply appropriate diagnostic services, provide training, raise awareness, monitor disease spread, and screen banana germplasm for Foc TR4 resistance for deployment by vulnerable banana growers.
  • Call upon African and international organizations to recognize and support the activities of AC4TR4 by investing in research, awareness programs, human capacity, and infrastructure development on the continent.
  • Develop a regional Pest Risk Analysis document and a set of phytosanitary measures to be enforced by member states to prevent the introduction and spread of Foc TR4 and other quarantine pests of banana.
  • Encourage governments in Africa to formulate the necessary legislation and to implement the required activities to protect the crops of vulnerable farm owners against destructive exotic pests.Dr Fen Beed of IITA and Dennis Ochola of Bioversity at the Foc TR4 afflicted farm in northern Mozambique

Giant strides in IITA plantain breeding for West Africa

 

Amah during her contract review seminar
Amah during her contract review seminar

IITA has made significant progress in its plantain research in West Africa with the generation of seedlings from crosses with in vitro induced tetraploids from diploids―a first for the Institute.

The IITA Regional Banana Breeding Manager, Delphine Amah, who supervised execution of the crosses in IITA-Ibadan, said the crosses were vital for plantain improvement in West Africa in the years ahead.

Delivering her contract review seminar titled: Support to Banana and Plantain Breeding―Updates on West Africa, Amah said the Banana Unit had recorded giant strides in the recent years.

For instance, as part of a revised pre-breeding strategy to produce improved parents while shortening the breeding cycle for plantain, the unit was now producing tetraploids which have four sets of chromosomes from diploids (which have two) using optimized in vitro doubling techniques.

In addition, tissue culture techniques have been employed to generate seedlings from crosses through embryo culture and mass propagation of plants for clonal evaluation.

The unit is also promoting the use of macropropagation and field propagation techniques for the production of clean planting material and good agronomy practices.

So far, Amah and her team have produced and distributed thousands of Agbagba plantain plantlets to the IITA farm unit and Youth Agripreneur project for propagation and distribution.

Furthermore, they have established pollination blocks with female fertile plantain landraces and Black Sigatoka resistant tetraploid plantain hybrids for accelerated breeding.

The team has established recently imported Musa acuminata ssp. banksii accessions for evaluation and use as parents in crosses to breed for plantains with high provitamin A content.

They have also established a propagation scheme for the production of plantlets for pollination blocks and planned trials to enable registration of new IITA hybrids.

All these activities are aimed at rejuvenating plantain breeding in IITA for efficient delivery of improved varieties to farmers, she said.