Assessment of Inter-Specific Diversity of the \u3cem\u3eHedysarum\u3c/em\u3e Genus in Tunisia

In Tunisia, many grassland and pasture species were menaced by genetic erosion. Thus, we were interested in the Hedysarum species which constitute a very important phytogenetic patrimony able to produce forage and restore destroyed pasture land especially in arid and semi-arid areas. In order to facilitate fodder improvement, we investigated the phenetic relationships among Hedysarum species using rDNA intergenic spacer (IGS) polymorphism

Towards an optimal sampling strategy for assessing genetic variation within and among white clover (Trifolium repens L.) cultivars using AFLP

Cost reduction in plant breeding and conservation programs depends largely on correctly defining the minimal sample size required for the trustworthy assessment of intra- and inter-cultivar genetic variation. White clover, an important pasture legume, was chosen for studying this aspect. In clonal plants, such as the aforementioned, an appropriate sampling scheme eliminates the redundant analysis of identical genotypes. The aim was to define an optimal sampling strategy, i.e., the minimum sample size and appropriate sampling scheme for white clover cultivars, by using AFLP data (283 loci) from three popular types. A grid-based sampling scheme, with an interplant distance of at least 40 cm, was sufficient to avoid any excess in replicates. Simulations revealed that the number of samples substantially influenced genetic diversity parameters. When using less than 15 per cultivar, the expected heterozygosity (He) and Shannon diversity index (I) were greatly underestimated, whereas with 20, more than 95% of total intra-cultivar genetic variation was covered. Based on AMOVA, a 20-cultivar sample was apparently sufficient to accurately quantify individual genetic structuring. The recommended sampling strategy facilitates the efficient characterization of diversity in white clover, for both conservation and exploitation

Amplified Fragment Length Polymorphism (AFLP) is useful for finding markers associated with QTL for architectural trait in Hedysarum coronarium L.

Amplified fragment length polymorphism (AFLP) has been proposed as a valuable tool for finding mol- ecular markers linked to QTL controlling architectural trait. Segregation of polymorphic AFLP frag- ments was followed in F 2 offsprings Hedysarum coronarium derived from two native wild accesions crossing: Jebel Zit × El Haouaria, which had previously characterised by morphological and AFLP mark- ers. A comparison of profiles from the morphologically contrasted parental individuals and F 2 offspring has been assessed using five AFLP primer combinations. These generated 178 bands revealed by silver- stained denaturing polyacrylamide gels, of which 150 were polymorphic. Several AFLP markers appeared to be implied in the orthotropic form that can assist the selection and improve Hedysarum for- age crop