Yam: a neglected and underutilized crop in Brazil

Abstract

In Brazil current studies and investments on yams are incipient. Similarly, the literature in recent decades lacks adequate information on this group of plants. The existing literature, on its turn, requires more than ever to be revised and organized. Yams have joined the so-called "neglected" group of crops for several reasons, but particularly because they are associated with poor and traditional communities. Many vegetables introduced in Brazil during the colonization period have adapted to different cropping systems, yams being an excellent example. This diversity resulted very widespread, yet poorly recognized in the country. In turn, the gardens using traditional farming systems continue to maintain and enhance yam local varieties. Studies from other countries, with an emphasis on characterization and genetic breeding, brought to light an urgent need for Brazil to invest in yams as a food rich in carbohydrates, even to the point of alterations in food public policy. Reversal of the yam's current stigma is both a challenge to the scientific community and to the population as a whole. This paper aims to raise pertinent questions about Dioscorea species, an important key group for many communities in tropical countries, yet still unrecognized as so in Brazil.

DNA fingerprinting of water yam (Dioscorea alata) cultivars in Brazil based on microsatellite markers

“…Nine microsatellite loci based on Tostain et al (2006) and Siqueira et al (2011) were used ( Table 2). The polymerase chain reactions (PCR) were conducted in a final volume of 16 μL, consisting of 1 U of Taq DNA polymerase (LGC, Brazil); 1X Amplification Buffer (Mg + free); 1.5 mM of MgCl 2 ; 0.3 µM of each primer; 0.2 mM of each dNTPs and 20 ng of DNA template.…”

“…Despite a growing interest in water yam, published data on molecular characterization and genetic diversity of this crop are scanty (Siqueira, 2011). Few studies on genetic diversity of water yam have been reported using isozymes (Lebot et al, 1998;Bressan et al, 2011), RAPDs (Random amplified polymorphic DNA) (Asemota et al, 1996;Mignouna et al, 2002;Zannou et al, 2009), AFLPs (Amplified fragments length polymorphism) (Malapa et al, 2005;Egesi et al, 2006;Tamiru et al, 2007) and Expressed Sequence Tags (Narina et al, 2011), with each method differing in terms of principle, application, type and amount of polymorphism detected and time requirements (Agarwal et al, 2008).…”

“…Microsatellites or SSR (Simple sequence repeats) markers are, in general, more abundant in most genomes, possessing highly informative content. Microsatellite primers have been developed for a few Dioscorea species (Mizuki et al, 2005;Hochu et al, 2006), including D. alata (Tostain et al, 2006;Siqueira et al, 2011), and have been used on segregation studies, and genetic characterization of Dioscorea species (Mignouna et al, 2003;Scarcelli et al, 2005;Bousalem et al, 2006;Tostain et al, 2007;Arnau et al, 2009;Obidiegwu et al, 2009b,c).…”

Produção do inhame em solo adubado com fontes e doses de matéria orgânica

“…A rate of 20.9 t ha -1 of goat manure provided the maximum commercial productivity of tubers of 14 t ha -1 , while mean productivity of 10.1 t ha -1 was obtaines with the use of bovine manure. The goat manure is better than bovine manure and the rate around of 20 t ha (Siqueira, 2011;Silva et al, 2012).…”

Distribution, management and diversity of yam local varieties in Brazil: a study on Dioscorea alataL.

“…These factors, coupled with the wide distribution of D. alata in Brazil, justify the inclusion of this species in the group of crops that deserves better attention as they are referred to as neglected or underutilised species (Siqueira and Veasey, 2009;Siqueira, 2011). This study aimed to obtain an overview of the yam (D. alata) cultivation, diversity and distribution in various regions in Brazil, as well as the reality of the agriculturists that grow this crop within the rural systems where they are inserted.…”