Diversity, trait preferences, management and utilization of yams landraces (Dioscorea species): an orphan crop in DR Congo

Abstract

Yam (Dioscorea spp.) is cultivated in many villages of DR Congo as a means to sustain food security and alleviate poverty. However, the extent of the existing diversity has not been studied in details thus, considered as an orphan. A survey covering 540 farmers in 54 villages was conducted in six major yam growing territories covering three provinces in DR Congo to investigate the diversity, management and utilization of yam landraces using pre-elaborate questionnaires. Subject to synonymy, a total of 67 landraces from five different species were recorded. Farmers’ challenges limiting yam production were poor tuber qualities (69%), harvest pest attack (7%), difficulty in harvesting (6%), poor soil status (6%). The overall diversity was moderate among the recorded yam germplasm maintained at the household level (1.32) and variability exist in diversity amongst the territories and provinces. Farmers’ in territories of Tshopo and Mongala provinces maintained higher level of germplasm diversity (2.79 and 2.77) compared to the farmers in territories of Bas-Uélé (1.67). Some yam landraces had limited abundance and distribution due to loss of production interest in many villages attributable to poisons contained hence, resulting in possible extinction. Farmers’ most preferred seed source for cultivation were backyard (43%) and exchange with neighboring farmers (31%) with the objective of meeting food security and generating income. In villages where yam production is expanding, farmers are relying on landraces with good tuber qualities and high yield even though they are late maturing. This study revealed the knowledge of yam landrace diversity, constraints to production and farmers’ preferences criteria as a guide for collection and conservation of yam germplasm for yam improvement intervention.

Assessment of the Yam Landraces (Dioscorea spp.) of DR Congo for Reactions to Pathological Diseases, Yield Potential, and Tuber Quality Characteristics

“…In DR Congo, yam is a major staple of the rural community, whose major occupation is farming, and is a scarce food commodity in the major city markets due to insufficient production capacity. Of the economically significant species, seven have been previously reported to play a major role in subsistence livelihoods: white guinea yam (D. rotundata), yellow guinea yam (D. cayenensis), water yam (D. alata), bitter yam (D. dumetorum), bush yam (D. praehensilis), wild yam (D. burkilliana), and aerial yam (D. bulbifera) [10][11][12]. Many of these species are being cultivated under wide agro-ecological zones, though with higher preference for D. rotundata and D. alata [10,13].…”

Association mapping in multiple yam species (Dioscorea spp.) of quantitative trait loci for yield-related traits

“…Experimental site and planting materials A panel of 182 yam accessions distributed across six species of yam (Sup. Table S1) obtained from previous germplasm collection exercise [4] were used for this study. The yam accessions are cultivated and were collected from farmers with their consent sorted prior to collection.…”

“…It is a group of multi-species monocot, cultivated for the starchy underground tubers and aerial bulbils in the yam belts of west and central Africa [2]. In the Democratic Republic of Congo (DRC), yams plays an important role in ensuring the sustenance of food security, primarily for the rural populace [4]. DRC is home to a few species of yam which includes D. alata (water/greater yam), D. cayenensis (yellow guinea yam), D. dumetorum (bitter yam), and D. rotundata (white guinea yam), D. bulbifera (aerial yam), D. burkilliana (wild yam), and D. praehensilis (bush yam) [4]- [6].…”

“…In the Democratic Republic of Congo (DRC), yams plays an important role in ensuring the sustenance of food security, primarily for the rural populace [4]. DRC is home to a few species of yam which includes D. alata (water/greater yam), D. cayenensis (yellow guinea yam), D. dumetorum (bitter yam), and D. rotundata (white guinea yam), D. bulbifera (aerial yam), D. burkilliana (wild yam), and D. praehensilis (bush yam) [4]- [6]. Though, D. alata, D. cayenensis and D. rotundata are widely cultivated among the farmers compared to other species [4], [7].…”

“…Despite the contribution of yam to the rural sustenance in DRC, production is seasonally met with several constraints including but not limited to poor agronomic performance (yield and related traits) and major pathological issues namely yam mosaic disease (YMD) and yam anthracnose disease (YAD). These constraints have consistently affected the perfromance of many cultivated landraces and thus, aggravating the loss of interest in yam prodcution in many producing areas [4]. YMD is caused by yam mosaic viruses (YMV) while YAD is caused by Colletotrichum glo-eosporioides (Penz.).…”