Selection of Tolerant Lines to Salinity Derived from Durum Wheat (Triticum durum Desf.) in Vitro Culture
The genetic variability is considered as the major principle of plant breeding for durum wheat. This variability can be induced in vitro by selection pressure exerted by stress factors such as salinity in order to regenerate the vitro plantlets tolerant. This study aims in the first step in the regeneration of plantlets tolerant to salinity from mature embryos culture derived from two Tunisian durum wheat varieties: improved (Razzek) and landrace (Jenah Khotifa (JK)) varieties. The tolerance evaluation to salt stress was applied in vitro (100 mmol∙l−1 NaCl) and was based on various parameters. Our results showed that JK variety was distinguished by a stable response for all parameters tested: average weight of callus (368.1 mg for control and 307 mg under salt stress), callus regenerated percentage (36.6% for control and 35.7% under salt stress) and green shoots number/callus (17 for control and 17 under salt stress). This stability of response translates the adaptability of this variety to salinity. In order to fix regenerated JK plantlets in single generation and obtain HDs homozygous stable lines, in vitro gynogenesis technical is tested for this genotype. The Evaluation of gynogenetic capacity focused on about 1200 unfertilized ovaries of JK and was based on its ability to induction, differentiation, development of green shoots, and haploid plantlets regeneration. JK showed good tolerance to salinity and a relatively good response to gynogenesis.