Abstract
The underutilized crop "yam" plays multifaceted roles on food and nutritional security
among the poor and marginal people of Bangladesh. In view of availability of frugal
information, the current research entitled "Morpho-molecular characterization of yam
(Dioscorea spp.) in Bangladesh" was conducted with the aim of generating scientific
evidences on morphological, nutritional and molecular characteristics of native yam
germplasm available in Bangladesh. For this purpose, thirty-five indigenous yam
germplasm were collected from different parts of the country. Those collected germplasm
were subjected to plantation at experimental plot BAU-GPC after following the standard
protocol and guidelines and thirty-one germplasm were survived, fully grown and assessed
during the period of April 2017 to June 2020. The yam germplasm were analyzed using 115
morphological descriptors (qualitative 94 and quantitative 21), where descriptors, relating to
young and mature stem, young and mature leaves, aerial and underground tubers including
quality characteristics (organoleptic) of tubers, were assessed both qualitatively and
quantitatively by following the IPGRI descriptors. From nutritional point of view, the
highest concentration of N, Ca and P was observed in the underground tuber of accession
number DS 016. Considering both underground and aerial tubers, it clearly indicated that
several accessions (DS 016, DS 001, DS 010, DS 033, DS 020, DS 028) were substantially
higher in nitrogen contents and other essential trace and macro elements. Genetic diversity
of yam germplasm was estimated in two ways; univariate technique and multivariate
technique, using the data (qualitative and quantitative) obtained from morphological
experiment. Differences between both the maximum and minimum genotypic and
phenotypic variances (GCV and PCV) for the collected genotypes were quite large. The
genotypic and phenotypic variance varied from 0.193 to 1322.88 and 0.224 to 1404.68,
respectively. Genetic diversity from the multivariate analysis with 15 quantitative
morphological characters and 11 qualitative morphological characters was grouped into
seven clusters both. It was observed that accessions collected from the same location had
been grouped into different clusters or different location grouped into same cluster due to
the variation of morphological features into seven different cluster. Results obtained using
the descriptors showed wide variability of the characteristics that would facilitate its use in
preparing the specification for geographical indication of the indigenous yam products.
However, RAPD analysis of experimental yam accessions led to formation of six unique
clusters applying four primers OPA-02, OPG-13, OPW-08 and OPW-16. On the basis of
organoleptic evaluation (taste, attractiveness, cooked tuber color, tongue feeling), yield
performance, geographical distribution and nutritional quality, DS 002, DS 010, DS 033, DS
001, DS 007, DS 016, DS 028, DS 030, DS 031 considered very good and nutritious quality for
cultivation. Albeit, DS 002 and DS 010 were very tasty, but DS 002 and DS 028 are popular
among the people. The local name is "Mou alu" and "Mete alu", respectively. The future
research area of yam could be carried out in the field of varietal release, post-harvest
processing for value added yam-based products, functional foods and alternative medicinal
values.