Abstract:
The aim of this work was the obtaining of interspecific hybrids between wheat and wild Aegilops species as the female parent. The Aegilops genus is a potential genes source to genetic breeding for drought tolerance which causes considerable losses for wheat culture, in Algeria. For that, three durum wheat varieties (Oued Zenati, Waha and Hoggar) where crossed with two tetraploid Aegilops species (Aegilops geniculata Roth and Aegilops
triuncialis L.), crosses were realised for 5 years, to figure out parents having most crossability to obtain hybrids. Parents were also characterized for drought tolerance. Invitro mature embryos culture was undertaking, for raison of non hybrids germination in natural conditions. Hybrids were characterized by chromosomes numbering and using eleven microsatellites markers (SSRs) for molecular expression in comparison with their parents.
Results showed a great drought tolerance potential for Aegilops species and adaptation of wheat varieties to climatic conditions governing wheat culture areas. 81 interspecific hybrids were obtained. Aegilops geniculata/Oued Zenati crosses produced the higher hybrids number (54 hybrids as the rate of 5, 23%), followed by Aegilops triuncialis/Oued Zenati (18 as the rate of 3, 88%), crosses involving Aegilops species and variety Hoggar produced the less hybrids number. This direction of hybridization is advantageous, due to hybrid production without embryos rescue. However, lethality and abnormal hybrid development was observed at different stages, any plant hybrid could be generated. For Aegilops geniculata/Oued Zenati, chromosome number was establish to be 2n= 24. From eleven SSR markers, eight were found to be polymorphic, two of which Xbarc174 and Xwms332, had a big band number and better distinguished hybrids. Different patterns of markers expression were observed, even for hybrids having the same parents, where Xwmc25 and Xwms257 allowed characterization of 2BS chromosome fragmentation and elimination in two different Aegilops geniculata/Oued Zenati. These results indicate that maternal cytoplasmic inheritance took place in hybrid formation, and that postzygotic isolation mechanisms explain lethality and abnormal hybrids development, in this direction of hybridization. Searching within Aegilops, of accessions having more cross-ability to ensure hybrid regeneration and succeed such hybridizations.
