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Information of the genetic diversity of the threatened tree species in any region of the world may contribute to the creation of effective strategies for their preservation and future use. Nowadays, molecular markers have proven to be invaluable tools for assessing genetic resources of tree plants by improving understanding of the users with regards to the distribution and the extent of genetic variation within and among species. Recently developed marker technologies allow the uncovering of the extent of the genetic variation in an unprecedented way through increased coverage of the genome. Markers have diverse applications in plant sciences, but certain marker types, due to their inherent characteristics, have also shown their limitations. A combination of diverse marker types is usually recommended to provide an accurate assessment of the extent of intra-and inter-population genetic diversity of naturally distributed plant species on which proper conservation directives for species that are at risk of decline can be issued. Here, specifically, natural populations of forest trees are reviewed by summarizing published reports in terms of the status of genetic variation in the pure species. In general, for out bred forest tree species, the genetic diversity within populations is larger than among populations of the same species, indicative of a negligible local spatial structure. Additionally, as is the case for plants in general, the diversity at the phenotypic level is also much larger than at the marker level, as selectively neutral markers are commonly used to capture the extent of genetic variation. However, more and more, nucleotide diversity within candidate genes underlying adaptive traits are studied for signatures of selection at single sites. This adaptive genetic diversity constitutes important potential for future forest management and conservation purposes.

This review paper focuses some basic aspect of the taxonomic, biology, cultivation, chemical composition, bio-diesel potential, medicinal values and uses of Jatropha curcas Linn. The genus Jatropha is distributed throughout the tropics and sub-tropics growning in marginal lands and is a potential biodiesel crop worldwide. Due to its adaptability to marginal soils and environments the cultivation of Jatropha curcas is frequently mentioned as the best option for producing biodiesel. The seed oil can be used as a feed stock for biodiesel. Alternatively Jatropha oil is used in soap, glue or dye industry. The seed cake is rich in nitrogen and phosphorus and can be used as manure. Ash from the roots and branches of Jatropha curcas L. is used as cooking salt, and as lye in dyeing. The dark blue dye extracted from the bark of Jatropha is a useful dye. The plant parts and its oil along with its latex used for different reasons such as pesticides, anti-inflammatory activities, wound healing, lighting (lamp), bio-gas production, fertilizer and other purposes. The objective of this review paper focuses some basic aspect of the taxonomic, biology, cultivation, chemical composition, bio-diesel potential, medicinal values and uses of Jatropha curcas Linn.

The present study was conducted on 36 white lupin (Lupinus albus L.) genotypes to estimate the genetic variability, broad sense heritability and genetic advance. The genotypes were grown in Randomized Complete Block Design with three replications at Research Site of Madda Walabu University and Gasera farmers' farm land in southeastern part of Ethiopia in 2017. Data were collected on 18morpho-agronomic quantitative characters. The collected data were adjusted to mean values and the mean values were standardized to mean of zero and unity variance in order to minimize biases due to differences in scales of measurement and then subjected to analysis of variance using SAS 9.2software. The combined analysis of variance showed very highly significant (p<0.0001) and highly significant (p<0.01) differences among the studied genotypes for all characters, except for the traits number of primary branches (NPB) and pod thickness (PT) at both experimental sites. This indicated the existence of variability and hence the potential for selection and improvement for those characters other than NPB and PT. Wide range of variability was observed among the genotypes. The maximum performance value (9711.0 Kg ha-1) for the trait seed yield per hectare was observed on the genotype AC.26637; whereas the minimum (787.6Kg ha-1) was exhibited by the accession AC.239051. The phenotypic coefficient of variation (PCV) was greater than that of genotypic coefficient of variation (GCV) for all the traits indicating the influence of environmental variation to the total variation. Higher values of h 2 % were observed for the traits such as days to flowering (98%), pod length (97%) and seed yield per plot (SYP) (97%). Some traits, such as hundred seed weight and SYP showed high values of genetic advance as percent of mean. Hence, these traits can be used to improve white lupin through application of selection and other breeding methods.

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