Diversity of Sorghum (Sorghum bieolor (L.) Moench) in North Shewa and South Welo Region of Ethiopia: Focus on Farmers' Varieties with _ Emphasis on Frequency of Occurrence and Use Values in Relation to Morphological and Biochemical Characters
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Date
2000
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Abstract
Thirty four sorghum (S.bieolor (l).Moench) landraces consisting of 1020 indi vidual plants
(30 plants of each land race) collected from five agroecosites in North Shewa and South
Wela regions of Ethiopia (Bati 8, Fontenina 5, Hayike 2. Layignaw alaye 17, and Merewa
Adere 2) were lIsed in this study. The materials were classified on the basis of
administrational zones (4 cl ass ifying variables; Woredas, ecosite of origin and altitudes,
Morphological variation for the fourteen quali tative characters that showed two or more
phenotypic classes were estimated using the Shanon•Weaver diversity index (H').
Phenotypic variation was found between and within each classifying variable. The value of
H' for ailiandraces varied from 0.32 to 0.98 with an overall mean of 0.77 ± 0.04. One way
analysis of variance (ANOVA) showed significant differences between characters within
all classifying variab les and this contributed to the largest portion of the total variance.
Cluster analysis based on ordinal variables grouped the landraces in 5 clusters. A higher
proportion of landraces sharing similar altitude groups and similar agroecological sites
were grouped together. Panicle compactness and shape as well as stalk juiciness were the
predominant characters in grouping the land races into th ei r respective cl uster. Panicle
compactness and shape also contributed relatively more to altitudinal and ecological
di ffe rentiation. This differential distribution of different panic le types with respect to
compactness and shape revealed the adap tive significance o f panicle compactness and
shape that re nected the patterns of di stribution of different races in north Shewa and south
Welo regions. X2 test was carried out to detect the deviation of the observed rrequencyof
all the characters from the expected ones. Significant dirferences were not observed for
most or the characters between the observed and expected rrequenc ies.
Isozyme analysis was perfomled usmg two-enzyme systems esterase (EST) and acid
phosphatase (ACP) to see the allelic variation among the 34 sorghum landraces. However,
phenotypic polymorphism was not observed for any of the enzymes used in the analysis.
For the analysis of frequency of existence (diversity) of sorghum landraces under the
environmental variability (altitudes and field size), transect method over 100 plots (fields)
was used. As altitude levels increased or decreased beyond the range of 1500- 1650 m.a.s.l,
the diversity of tile sorghum land races also decreased. A relatively lower field size located
nearer to the home range was found to contain higher diversity. The use values of the 34
sorghum landraces were also analyzed by interviewing 30 informants in nonh Shewa and
south Welo regions. Thirty informants were contacted and the uses of the identified
sorghum landraces were recorded on 30 pl ots. Of atl the landraces zen gada and ahiyo
comprised the maximum number of uses (15 and 13, respectively). However, almost alt-30
landraces were known to have been selec ted for their nutritional value as injera making
and for their sui tability for beverage. Ethnobotanical survey was conducted and the
important data on fann er perceptions about the agromorphologica! traits distinguishing
land races. cultural val ucs and prefcrred traits of sorghum landraces were coll ected.
The knowledge of farmers, which is documented in this study. is an important input to the
build ing up of the scient ific basis of ill-sil/l conservation of agrobiodiversi ty in sorghum
crops. The information retained from the famlers' knowledge can also be applied in future
breeding activities and designingin-situ conservation program.