Agro-morphological traits assessment of Tunisian male date palms (Phœnix dactylifera L.) for preservation and sustainable utilization of local germplasm

Date palm (Phœnix dactylifera L.) like other crop species in the arid Mediterranean region is being threatened by genetic erosion and climate change. Therefore, the understanding and assessment of the diversity extent of this species is a primary requisite for preserving these crop resources. This study was designed to quantify the potential of Tunisian male date palms using a set of agro-morphological characteristics i.e. flowering traits, inflorescence morphology and pollen quality. The flowering time traits exhibited a trend of precocious phenotype at emergence spathe trait and the dominance of the full-season phenotype at the opening date. At inflorescence morphology, all observed traits expressed wide ranges which reflected the broad variability of the evaluated male genotypes. Significant difference was recorded for the majority of the examined traits with a high significant variation in the tree quantitative traits: Spathe Total Length, Spathe Maximum Width and Length to the brunched part. Pollen viability ranged from 51.10% to 98.75% while the germination rate was between 0.90% and 70.50%. Our phenotypic investigation has allowed the identification of males with desirable agronomic traits which have been genotyped using 18 nuclear SSR markers and a chloroplast minisatellite for preservation and effective utilization purposes.

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 molecular markers linked to QTL controlling architectural trait. Segregation of polymorphic AFLP fragments was followed in F2 offsprings Hedysarum coronarium derived from two native wild accesions crossing: Jebel Zit x El Haouaria, which had previously characterised by morphological and AFLP markers. A comparison of profiles from the morphologically contrasted parental individuals and F2 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 forage crop.

[Syndrome associating: osteopetrosis, tubular acidosis, mental retardation and cerebral calcifications due to carbonic anhydrase II deficiency. Apropos of 3 cases in the siblings]

Three new cases of a syndrome including osteopetrosis, tubular acidosis, mental retardation and cerebral calcifications are reported in the same sibship. This rare syndrome has an autosomal recessive inheritance and is due to carbonic anhydrase II deficiency. Fractures and mild sensorial manifestations were noticed in 2 cases. Mental deficiency and otitis were present in the 3 cases. Blood count and phosphocalcic metabolites were normal. A proximal tubular acidosis was present in each case. The radiological features were specific: cerebral calcifications were present in all cases since the age of 2 1/2 years; osteocondensation and bone modeling were predominant in long bones metaphyses. Alcalinization improved the height growth.