Diversity and Utilization of Dioscorea Spp. Tuber as Alternative Food Source in Nganjuk Regency, East Java

Dioscorea spp. is local tuberous food crop that has potential as alternative food source to support food security program in Indonesia. Exploration study and collecting mission subjected to Dioscorea spp. have been conducted in Nganjuk Regency. The study was aimed to 1) determine the distribution of Dioscorea spp. in Nganjuk, 2) to characterize tuber's morphological characteristic, and 3) to know how tuber's utilization by local peoples. The results showed that there were 4 species of Dioscorea found in Nganjuk. They are Dioscorea alata L, Dioscorea esculenta (Lour.) Burkill, Dioscorea hispida Dennst and Dioscorea bulbifera L. Dioscorea alata (uwi) is the most cultivated by farmers in Nganjuk. It has the largest cultivar numbers which consists of 11 cultivars. Dioscorea esculenta (gembili) consists of 3 cultivars and Dioscorea hispida (gadung) consists of 4 cultivars, whereas Dioscorea bulbifera (uwi gantung) consists only 1 cultivar in one location. Farmers and local peoples play important role in conservation of Dioscorea in Nganjuk region by cultivating and utilizing it as alternative food source for home consumption

Explorations Diversity of Dioscorea Spp. Varieties From Pasuruan, East Java: Inventory and Characterization

Dioscorea spp. is the edible tubers from Dioscoreaceae family. Dioscorea is also an important crop which serves as a staple food and medicine. Discoreaceae exploration collecting mission had been conducted in 10 Districts of Pasuruan, East Java. Forty-four accessions were obtained during the exploration. It comprised of 5 species and 29 varieties i.e. 17 varieties of Dioscorea alata L., 8 varieties of Dioscorea his-pida Dennst., 2 varieties of Dioscorea esculenta (Lour.) Burkill., 1 variety of Dioscorea pentaphylla L. and 1 variety of Dioscorea bulbifera L. The results showed that morphological characteristic features of Dioscorea spp. tubers were broadly varied among species and even within varieties at the same species. Dioscorea spp. varieties ori-ginated from Pasuruan were mostly character-ized by its tuber shape, tuber flesh colour, outer and inner skin colour and tubers skin texture. Based on the interviews to local farmers, D. alata and D. hispida varieties were still widely grown because of its high tuber yields and its most acceptable taste than other Dioscorea species

Development of micropropagation system for yam (Dioscorea spp.) using somatic embryogenesis

Inadequate availability of disease-free planting materials remains a major constraint to yam production. The tissue culture technique has been used to regenerate disease-free plantlets from pre-formed, heattreated meristems followed by micropropagation. This procedure, however, has a low multiplication ratio with an average of 1: 4 every eight weeks. Embryo production from somatic cells (somatic embryogenesis, SE) is a system in which each somatic cell can regenerate a complete plantlet. However, previous reports show low SE induction frequencies and significant variations in success rates among different genotypes while hardly any report exist for improved varieties that farmers desire, especially in Nigeria. Studies were carried out to evaluate the effects of different plant growth regulators (PGRs) on induction of somatic embryogenesis of the following genotypes: one improved Dioscorea alata (TDa 291) and three improved (TDr 95/19177, TDr 89/2665, TDr 95/18544) and one landrace (Obioturugo) of Dioscorea rotundata. Leaf, stem, and axillary bud explants were cultured in MS basal medium containing fifteen treatment combinations of 2,4-Dichlorophenoxyacetic acid (2,4-D), Naphthaleneacetic acid (NAA), Benzylaminopurine (BAP), Picloram, and Uniconazole-P (UP). The genotype TDr 95/19177 was tested for SE in Temorary Immersion Bioreactor System (TIBS). The incidence of induction of callus formation and plantlet regeneration from the three explants were recorded. Embryogenic callus induction was highest (87%) from axillary buds cultured on modified MS + 2 mg/l of 2,4-D + 1 mg/l of NAA while 1 mg/l of BAP + 9. 9 mg/l of UP had the highest percentage plantlet regeneration of 50% in TDr 95/18544 and an average of 37% across genotypes at a mean of 5 plantlets per explant. The genotype TDr 95/19177 was successfully regenerated via indirect somatic embryogenesis in the SETIS Type Temporary Immersion Bioreactor System

Shoot and plantlet regeneration from meristems of Dioscorea rotundata Poir and Dioscorea alata L.

In vitro culture media capable of regenerating moderate to high shoots and/or plantlets from meristems of two yam species - Dioscorea rotundata and Dioscorea alata within comparable duration of 10 weeks as commonly obtained in other monocots and root and tuber crops were investigated. The study comprised 125 phytohormone combinations investigated in three factorial experiments each consisting of an auxin (NAA) and a cytokinin (BAP or kinetin), or two cytokinins only. The frequency of direct plantlet regeneration, though significantly (P < 0.05) higher for D. alata than for D. rotundata, was low and ranged from 0 to 10% at 3 weeks after culture (WAC) and 0 to 35% at 8 WAC. At 8 WAC, shoot regeneration of 42-75% was obtained in D. rotundata in MS medium supplemented with 0.1 M NAA + 0.20 M BAP, and shoot + plantlet regeneration of 60-82% obtained in media containing 0.05 M + 0.20 M BAP or 0.46 M BAP + 0.50 M kinetin in D. alata. Both shoot induction and plantlet regeneration were species-dependent. Induced shoots were successfully rooted in MS medium within 3 to 4 weeks, bringing time taken for plantlet regeneration to 11 to 12 weeks. Regenerants were morphologically similar to the mother plants. Results of the present study will facilitate regeneration of plantlets via meristem in D. rotundata and D. alata

KARAKTERISTIK TEPUNG PREBIOTIK UMBI UWI (Dioscorea spp)

Umbi uwi (Dioscorea spp.) merupakan salah satu jenis umbi yang banyak tumbuh di Indonesia memiliki kandungan karbohidrat yang tinggi. Keanekaragaman uwi sangat banyak baik dilihat dari bentuk, ukuran, warna, maupun rasa umbinya. Terdapat lebih dari 600 spesies dari genus Dioscorea spp. tersebar di berbagai negara, termasuk Indonesia, antara lain Dioscorea hispida (gadung), Dioscorea esculenta (gembili), Discorea bulbifera (gembolo), Dioscorea alata (uwi ungu/purple yam), Dioscorea opposita (uwi putih), Dioscorea villosa (uwi kuning), Dioscorea altassima, Dioscorea. Penelitian terdahulu menunjukkan bahwa 10 jenis umbi Dioscorea spp. memiliki kadar inulin bervariasi antara 2,88-14,77%. Umbi Dioscorea spp. biasanya digunakan sebagai sumber karbohidrat alternatif di pedesaan, namun belum banyak dimanfaatkan sebagai bahan baku aneka olahan produk pangan, khususnya pangan fungsional. Tujuan penelitian adalah mengevaluasi karakteristik fisiko-kimia tepung umbi uwi dan dodol prebiotik yang berbahan baku umbi uwi (Dioscorea spp). Karakteristik fisiko-kimia yang dievaluasi meliputi kadar air, pati, amilosa, amilopektin, inulin (pada tepung umbi uwi) dan tekstur, kadar gula reduksi dan uji organoleptik (pada dodol). Data yang diperoleh dianalisis menggunakan ANOVA dan uji lanjut menggunakan analisis Tukey HSD. Hasil penelitian menunjukkan bahwa 6 jenis umbi uwi memiliki kadar pati yang bervariasi. Kata kunci : dioscorea spp, inulin, prebiotik, tepung umbi uw