1,721,121 research outputs found
Changes in seed morphology, dormancy and germination from wild to cultivated hyacinth bean germplasm (Lablab purpureus : Papilionoideae)
No full textMorphological and physiological seed characteristics of the hyacinth bean (Lablab purpureus) were investigated in a set of 18 different germplasm accessions, from wild over semi-domesticated forms to landraces and current cultivars. The objective of this study was to improve the understanding of the domestication of this tropical legume crop. Wild accessions were easily distinguished by morphological characters, such as small, greyish-brown, mottled seeds. Cultivated or semi-domesticated forms showed a much wider variation in size, colour and shape. Seed mass of cultivated accessions reached up to almost 10 times that of wild accessions. Most wild accessions showed a greater spread of germination and larger proportions of hard seeds, up to about 70%, than most cultivated and so-called semi-domesticated accessions. Cluster analysis applied separately to morphological and germination data and a subsequent discriminant analysis did not help integrating the morphological variability observed. The presumed occurrence of semi-domesticated accessions within the germplasm tested as well as the crop's origin from Africa alone or both Africa and Asia are debated on the basis of seed germination and hard seed coat dormancy
Crop diversity and classification of homegardens in Central Sulawesi, Indonesia
No full textHomegardens are considered a sustainable production system in the tropics, which contributes to biodiversity conservation. The aim of this study was the description of crop diversity, structure and management of homegardens in Central Sulawesi and their classification. In 30 homegardens randomly selected from three villages adjacent to the Lore Lindu National Park, species diversity and abundance were assessed and the Shannon index was calculated. Overall 149 crop species were identified, mainly fruit, vegetable, spice, or medicinal plants. The number of vegetation layers differed depending on age and size of homegardens. Cluster analysis of crop species composition was used to classify different garden types. Not only the spectrum of species cultivated in the homegardens but also the occurrence of these garden types was different among the three villages. This finding was supported by Sorensen's coefficient. Homegardens from one village, mainly inhabited by transmigrants, contrasted strongly with those from the other two. A markedly lower number of crop species was cultivated there, and species composition was clearly different. The number of crop species and species composition found in homegardens may be attributed to socio-economic conditions of garden keepers as well as to soil quality. Both productivity and sustainability can be enhanced, e.g., by improved soil fertility management such as applying available farm yard manure
Changes in seed characteristics during the domestication of the lablab bean (Lablab purpureus (L.) Sweet : Papilionoideae)
No full textMorphological, anatomical, physiological, and nutritional seed characteristics of the lablab bean ( Lablab purpureus) were investigated in 46 germplasm accessions, from wild through semi-domesticated forms to landraces and current cultivars. This study aimed to improve the understanding of the domestication process in this tropical crop legume. Wild accessions were distinguished by typical small, brownish and mottled seeds. Cultivated and semi-domesticated forms showed much wider variation in size, colour and shape. Most wild accessions had a thicker seed testa as well as a greater spread of germination over time and larger proportions of hard seeds than most cultivated and semi-domesticated accessions, which germinated more uniformly. Generally, wild accessions showed higher tannin and nitrogen values. In most characteristics, semi-domesticated accessions were intermediate. Not all cultivated accessions combined all typical features of the 'domestication syndrome'. This was particularly obvious in the dendrogram generated by cluster analysis from a relative domestication index calculated from seed mass and seed-coat texture for any pair of accessions. On the basis of seed characteristics of the germplasm studied, the crop is considered to have originated from Africa
Indigenous ecological knowledge of Borana pastoralists in southern Ethiopia and current challenges
No full textIndigenous ecological knowledge (IEK) of Borana pastoralists on strategies of sustainable resource utilization, forage species, ecological interactions, rangeland condition and trend was documented using discussions, a semi-structured questionnaire survey and analytical workshops. Traditional strategies of rangeland and water management were described and the most important forage species identified. Pastoralists' perceptions were compared across age, gender and site. There was a positive correlation between pastoralists' preference ranking of forage species and crude protein content of the species. IEK of men and women was complementary. The process of rangeland degradation was described as shortage of grass and decrease in density and frequency of highly palatable grass species, leading to low milk production and reduced conception rates in cows. The results confirmed that the IEK of these pastoralists could still provide the basis for sustainable resource utilization and rangeland rehabilitation. However, the young generation in the area had not only limited knowledge but also showed less interest to learn and apply the traditional resource management strategies. Therefore, there is high need to perpetuate, document and use this IEK for sustainable development. On the other hand, shortage of forage resources as a result of rangeland shrinkage (leading to rangeland degradation and woody plants encroachment), less application of IEK, the gap between traditional and formal systems, and trends of disobeying traditional rules and regulations were identified as current challenges for the Borana pastoralists
Tropical and subtropical forage germplasm conservation and science on their deathbed! 1. A journey to crisis
No full textRelationships between vegetation composition and environmental variables in the Borana rangelands, southern Oromia, Ethiopia
No full textTopography, climate and soil are the three important environmental abiotic factors that affect vegetation composition in rangelands. Determination of environmental factors that are responsible for the spatial distribution and abundance of vegetation is useful in ecological restorations and grazing land use planning. This study was conducted in the Borana lowlands to quantitatively explore relationships between vegetation composition and abiotic environmental factors. A combination of stratification and systematic random sampling techniques were employed to collect vegetation and environmental data in 58 plots of 500 m2 size. Redundancy Analysis (RDA) and Canonical Correspondence Analysis (CCA) were used to detect patterns of vegetation variation that were explained by the assessed environmental variables. CCA and RDA ordination diagrams revealed that the composition and distribution of both woody and herbaceous vegetation were mainly determined by altitude, soil pH, calcium, cation exchange capacity and magnesium. Density of woody plants was negatively correlated with altitude. Species richness was positively correlated with sand and altitude but negatively correlated with soil nutrients and clay content. It is concluded that the measured environmental variables significantly account for variation in the composition and distribution of the plant species composition in the Borana lowlands. Therefore, rangeland managers should incorporate environmental factors in planning and implementing restoration activities and planning grazing land use
Encroachment of woody plants and its impact on pastoral livestock production in the Borana lowlands, southern Oromia, Ethiopia
No full textEncroachment of woody plants has been among the major threats to the livelihoods of Borana pastoralists and their ecosystem. An approach that integrated vegetation survey and pastoralists’ perception was followed to study the impacts of encroachment of woody plants in the Borana lowlands, Ethiopia. Density of woody species was determined in 192 plots of 500 m2. Canopy cover of woody plants was estimated in 123 quadrates of 400 m2. Pastoralists’ perception was assessed through group discussions and a semi‐structured questionnaire. Results showed that plant density was 3014 woody plants ha−1. Cover of woody plants was 52%, indicating an increasing trend from ≤40% cover reported in the early 1990s. It was concluded that the increase of woody plants density and cover has crossed the critical threshold and has entered into the encroached condition. Principal components analysis (PCA) and redundancy analysis (RDA) also showed that woody plants were negatively correlated with herbaceous biomass. Commiphora africana, Acacia melliphera, A. drepanolobium, A. brevispica and Lannea rivae were among the dominant encroachers. RDA revealed that soil nutrients were positively correlated with woody plants density and cover. The pastoralists perceived that encroachment of woody plants had decreased the production of their grazingland. A ban on fire was perceived as the major factor that caused encroachment of woody plants. Re‐utilization of fire and strengthening of traditional rangeland management strategies are recommended
Tropical and subtropical forage germplasm conservation and science on their deathbed! 2. Genebanks, FAO and donors must take urgent steps to overcome the crisis
No full textRelationships between vegetation composition and environmental variables in the Borana rangelands, southern Oromia, Ethiopia
No full textTopography, climate and soil are the three important environmental abiotic factors that affect vegetation composition in rangelands. Determination of environmental factors that are responsible for the spatial distribution and abundance of vegetation is useful in ecological restorations and grazing land use planning. This study was conducted in the Borana lowlands to quantitatively explore relationships between vegetation composition and abiotic environmental factors. A combination of stratification and systematic random sampling techniques were employed to collect vegetation and environmental data in 58 plots of 500 m2 size. Redundancy Analysis (RDA) and Canonical Correspondence Analysis (CCA) were used to detect patterns of vegetation variation that were explained by the assessed environmental variables. CCA and RDA ordination diagrams revealed that the composition and distribution of both woody and herbaceous vegetation were mainly determined by altitude, soil pH, calcium, cation exchange capacity and magnesium. Density of woody plants was negatively correlated with altitude. Species richness was positively correlated with sand and altitude but negatively correlated with soil nutrients and clay content. It is concluded that the measured environmental variables significantly account for variation in the composition and distribution of the plant species composition in the Borana lowlands. Therefore, rangeland managers should incorporate environmental factors in planning and implementing restoration activities and planning grazing land use
- …
