Tebra Triki

The Use of ISSR and RAPD Markers for Genetic Diversity among South Tunisian Barley

Random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) were assayed to determine the genetic diversity of 80 barley specimens from South Tunisia. The ISSR primers showed variation in the percentage of polymorphism, band informativeness (Ib), and resolving power (Rp). The percentage of polymorphism is 66.67%, the average Ib ranged from 0.24 to 0.39, while Rp ranged from 0.74 to 1.16. In RAPD analysis, three primers yielded a total of 17 scorable bands, which are all polymorphic. The three polymorphic primers exhibited variation with regard to average band informativeness (AvIb) and resolving power (Rp). RAPD and ISSR marker systems were found to be useful for the genetic diversity among the barley specimens. The two dendrograms obtained through these markers show different clustering of 80 barely specimens, but we noted that some clusters were similar in some cases. A poor correlation (𝑟=0.12) was found between both sets of genetic similarity data, suggesting that both sets of markers revealed unrelated estimates of genetic relationships. Therefore, the ISSR and RAPD molecular markers show two genetic grouping of studied barely specimens.

Storage protein contents and morphological characters of some Tunisian pomegranate (Punica granatum L.) cultivars

Abstract The Tunisian pomegranate is much appreciated for its fruit production in the Mediterranean Basin. Seeds contain 17% proteins on a dry—weight basis. Punica granatum accumulates globulins and albumins as major storage proteins, respectively 43% and 32% of total storage proteins. Results indicate that the globulins are made of two groups of subunits with PM between 38 and 54 kDa, and two subunits of 13 and 18 kDa. Albumin represents three groups ranged respectively from 58 to 116 kDa, 33 to 46 kDa and 15 to 23 kDa. The glutelin (16%) form three subunits groups respectively with 37 kDa (1st group), 21 and 23 kDa (2nd group) and 14 kDa (3rd group). The least presented fraction, prolamin, represents a small proportion (9%) composed of one group of three subunits of 15, 20 and 24 kDa.

INFLUENCE OF VARIOUS PHYSICAL PARAMETERS ON ANTHER CULTURE OF BARLEY

This study describes the effect of some parameters on anther culture of barley to optimize the plant regeneration condition of this species. The embryo formation and plant regeneration from anthers of three barley cultivars (‘Igri’, ‘Saida’ and ‘Libya’) were investigated. The effects of length of flag leaves, stage of microspore development, and pre-treatments (mannitol or cold pre-treatment) of anthers were investigated. Results showed significant responses. Anthers at the mid uninucleate to mid-late uninucleate stage gave the best anther culture response showing 80, 60, and 30% anther development in ‘Igri’, ‘Saida’ and ‘Libya’ barley cultivars, respectively. The use of mannitol (0.3 M) or 20 days cold pre-treatments showed the best results for embryo and green-plant production.

Création de variétés tolérantes au stress abiotique chez l'orge (Hordeum vulgare L.) par culture d'anthères

Abstract The study aims the creation of the pure barley variety, tolerant to the abiotic stress by anther culture. This study was concerned two variety of barley: cultivar Ardhaoui, selected for their best tolerance to the abiotic stress (salt and drought) collected from Tunisia, and cultivar Arige, from Syria, sensitive for the two types of stress. The androgenic aptitude was evaluated in the parents (Ardhaoui and Arige) and their hybrids (F1) by anther culture. The stage of setting in anther culture was given on the basis of morphological and cytological criteria. The result shows that the capacity of regeneration of cal differs from a genotype with another (it varies from 50% at the hybrids with 40% in the parent Arige). Following the results, it is important to announce that the rate of albinism which we observed is height, it especially exceeds 70% from Ardhaoui; it can be explained by the combination of several factors. Finally we can deduced that the majority of the regenerated planted are diploid (70%).