Identification and differentiation of Ficus carica L. cultivars using inter simple sequence repeat markers

Information on germplasm diversity and relationships among elite materials is fundamentally important in crop improvement. The main objectives of our study is to determine the level of genetic diversity inter fig-tree cultivars using inter simple sequence repeat (ISSR) markers. Fifty-seven local Tunisian figtree cultivars were fingerprinted with ISSR marker. A total of 33 alleles were detected. A high level of genetic diversity was identified inter cultivars. The clustering grouped the studied cultivars into four clusters with no correlation to geographical origin

Polyploidy induction of Tunisian Trigonella foenumgreaum L. populations

Polyploidy plays an important role in plant evolution and constitutes an important mechanism of diversification and creation of genetic variability. Artificial polyploidy can be induced using the colchicine. The aim of this study was to determine the Trigonella foenum-greacum (2n= 16)  population which resists better to colchicine treatment and which has the highest rate of polyploid formation among 38 populations collected from different Tunisian regions. The comparative study between treated and control plants showed significant increases (p < 0.05) for the parameters survival rate, rate of malformed leaves appearance, stem height and seeds number by pod. The 38 treated populations showed significant variations (p < 0.05) between them for the parameters survival rate, branches number, stem height and seeds number by pod. Results also showed that treatment of the shoot meristem by colchicine allowed to obtain diploid (2n= 16) and mixoploid plants having mixoploid branches (4n = 32 and 2n= 16) and branches entirely tetraploid (4n = 32). The obtained rate of mixoploidy was 65.79% of treated plants. Among the 38 analyzed fenugreek populations, the population 15 of Menzel Temime presented the highest rate of mixoploids formation and survival rate to colchicine treatment.Key words: Fenugreek, induction of chromosome doubling, mixoploidy, colchicine, Tunisia

Natural genetic variation in Calligonum Tunisian genus analyzed by RAPD markers

The Calligonum genus is one of the most economically important resources of the Tunisian desert, playing an important role in the lives of desert local population. A great range of genetic diversity could be seen in diverse populations of this genus which are spread all over Tunisian areas. DNA-based molecular markers are playing increasingly important role in the analysis of genetic diversity in wide range of plants. This study is an attempt to collect, compile and collate information on the existing natural genetic diversity, at intra-specific and inter-populational levels in Calligonum genus (C.azel, C.arich and C.comosum). This study deals with 16 genotypes of Calligonum (Polygonaceae) collected from different regions of Tunisian desert using random amplified polymorphic DNA (RAPD) marker. In total, 46 polymorphic bands amplified by 4 random primers, with the polymorphic rate of 89.06% were recorded. The commercial software package SPSS 16 was used to develop similar matrices based on the Dice coefficient which is defined as 2a/2a+u, where “a” is the number of positive matches and “u” is the number of non-matches. From the analysis, it is imperative that predominantly obligate out breeding behavior of Calligonum genus, helps these diverse accessions to spread and occupy specific geographical niches in the Tunisian arid regions.Key words: Calligonum, genetic diversity, Inter-specific variation, RAPD marker, Tunisian desert

Genetic diversity assessment of Lawsonia inermis germplasm in Tunisian coastal oases by ISSR and RAPD markers

Genetic relationships were estimated among 25 germplasm belonging to Lawsonia inermis L. using RAPD and ISSR markers. These markers were implemented in analyses of principal coordinates (PCO), unweighted pair group mean average (UPGMA). Results showed that the L. inermis L. germplasm divided on three groups based on RAPD data. However, using the ISSR data, all studied germplasm were grouped in one group which is divided on three sub-groups, exception four germplasm. The overall mean genetic similarity based on ISSR data ranged from 0.1 to 0.83 and from 0.07 to 0.83 based on RAPD data. The PCO applied on 25 germplasm using ISSR markers showed three groups constituting the three sub-groups obtained in dendrogram based on UPGMA method. Based on RAPD data, the PCO and dendrogram defined three groups; only one group seemed to be the same in the two applied analyses. The groups obtained based on ISSR and RAPD were independently from their geographical origin. Therefore the ISSR and RAPD molecular markers show two genetic grouping of L. inermis L. germplasm which would be as the first step to understand and to conserve these resources characterizing by genetic erosion in these localities