Evaluation of durum wheat genotypes at germination stage under salinity stress

Salinity is one of the most severe abiotic stress factors affecting plant growth and agricultural production worldwide. It strongly inhibits seed germination through osmotic stress, ion-specific effects, and oxidative stress. Durum wheat (Triticum durum Desf.) is a typical Mediterranean species very important for the Mediterranean areas, especially in drylands. Information on the genotypic tolerance to salt stress during the germination process are lacking in Sicilian durum wheat landraces. Limited literature work is documented so far on these genotypes so knowing their behavior can help breeding programs in the selection of salt tolerant varieties to achieve optimum wheat growth under saline condition.

The aim of this work was to investigate several durum wheat genotypes (11 landraces, 2 old varieties and 7 modern cultivars) for salt tolerance at germination and early growth stages.

Experiments were laid out in a two-factorial with four replications. Two-way ANOVA was performed and means were compared with Duncan’s multiple range test.

There were 3 salinity level (0, 50 mM and 100 mM) and 20 genotypes tested. Seven parameters were measured under laboratory conditions: germination, mean germination time, shoot length, root length, root number, shoot dry matter and root dry matter.

Genotype, concentration and their interaction showed significant differences in many of the parameters studied.

Remarkable germination (greater than 96%) were obtained by Timilia Reste Nere, Ciclope, Mongibello and Timilia Reste Bianche at the highest NaCl concentration; Rusticano, Ciclope , Simeto, and Mongibello are notable for the shorter mean germination time (range from 2,15 to 2,20 days). Among the landraces, Ciciredda and Urria showed good values of mean germination time. All the landraces have been reported for the better shoot length than modern varieties; Timilia Reste Bianche, Timilia Reste Nere, Ciciredda and Senatore-Cappelli are highlighted for the best performance for root length at 100 mM.

Raise of concentration determined an increase of the mean germination time and a decreasing trend for shoot length.