Wednesday, November 13, 2019

Essay --

Sporadic surveys during the past 25 years (Mekete and Van den Berg, 2003) indicated that several plant- parasitic nematode genera and species were associated with various crops in different areas of Ethiopia. Ac- cording to Abebe and Geraert (1995), taxonomic stud- ies of plant-parasitic nematodes in Ethiopia are almost non-existent. These authors described four known and one new species. Recently, Mekete et al. (2008) reported the presence of various species of plant-parasitic nema- todes associated with coffee from Ethiopia and gave short descriptions and light microscope photos of Scutellonema paralabiatum Siddiqi et Sharma, 1994, and Rotylenchus unisexus Sher, 1965. During 2002, an ex- tensive survey was undertaken in Ethiopia. Eight species of various nematode genera were found of which short notes are given. Four species, Rotylenchulus borealis, S. brachyurus, S. clathricaudatum and S. mag- niphasmum are new records for Ethiopia. The survey was conducted during the June-Septem- ber 2002 cropping season. Two hundred samples were collected from different agro-ecological zones through- out the southern, western and southwestern regions of the country (Fig. 1). Samples were taken at a depth of 25-30 cm with a spade around the roots of the plants. Three to five soil cores were taken at each sampling site, bulked and a sample of approximately 1 kg was taken to the laboratory for extraction of the nematodes. Nema- todes were extracted from 200 g soil sub-samples by combining the Cobb’s sieving and decanting method with a modified Baermann’s funnel method (Hooper, 1985a). Nematode specimens were then killed... ... with all the previous descriptions of the species (Sher, 1964; Van den Berg and Heyns, 1973). Scutellonema clathricaudatum Whitehead, 1959. A few specimens of this species were found associated with Acacia sp. at Wendo Genet and maize at Shoboka (Jimma). This species was originally described from cot- ton in Tanzania (Whitehead, 1959) and subsequently re- ported from various other African countries viz. Cameroon, Ivory Coast, Kenya, Mali, Mozambique, Niger, Nigeria, Senegal, Sierra Leone, South Africa, Su- dan, Uganda and Zaà ¯re (Whitehead, 1959; Sher, 1964). It has also been identified from Ghana, Guinea-Bissau, Malawi and Zambia by the first author, but this is the first report for Ethiopia. Our specimens correspond well with the original as well as subsequent descriptions of the species (Whitehead, 1959; Sher, 1964). 212

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