Genetic variation of salt-stressed durum wheat ( Triticum turgidum subsp. durum Desf.) genotypes under field conditions and gynogenetic capacity

Abstract

Agriculture has new challenges against the climate change: the preservation of genetic resources and the rapid creation of new varieties better adapted to abiotic stress, specially salinity. In this context, the agronomic performance of 25 durum wheat (Triticum turgidum subsp. durum Desf.) genotypes (nineteen landraces and six improved varieties), cultivated in two semi-arid regions in the center area of Tunisia, were assessed. These sites (Echbika, 2.2 g l−1; Barrouta, 4.2 g l−1) differ by their degree of salinity of the water irrigation. The results showed that most of the agronomic traits (e.g. spike per meter square, thousand kernels weight and grain yield) were reduced by salinity. Durum wheat landraces, Mahmoudi and Hmira, and improved varieties, Maali and Om Rabia showed the widest adaptability to different quality of irrigation water. Genotypes including Jneh Kotifa and Arbi were estimated as stable genotypes under adverse conditions. Thereafter, salt-tolerant (Hmira and Jneh Khotifa) and the most cultivated high-yielding (Karim, Razzak and Khiar) genotypes were tested for their gynogenetic ability to obtain haploids and doubled haploid lines. Genotypes with good induction capacity had not necessarily a good capacity of regeneration of haploid plantlets. In our conditions, Hmira and Khiar exhibited the best gynogenetic ability (3.1% and 2.9% of haploid plantlets, respectively).

Comparative Genetic Analysis of Durum Wheat Landraces and Cultivars Widespread in Tunisia

“…The lines selected within Mahmoudi and Bidi landraces appear genetically related to one another, probably because both were introduced in Tunisia from Algeria. Mahmoudi is a landrace widely cultivated for its straw and grain yield, as well as its ability to produce a high yield under drought and heat stress conditions prevalent in southern Tunisia (Ayed and Slim-Amara, 2009 ; Ayed-Slama et al, 2018 ; Ouaja et al, 2021 ). Instead, Chili is an old cultivar introduced from France in the early 1930s with stable yield and a lower plant height; probably, these traits make Chili closer to modern cultivars than other Tunisian durum landraces.…”