Evaluation of some bread wheat mutants for adult plant resistance to stem rust [electronic resource].

Includes references.

Stem rust disease is a drastic factor to bread wheat (Triticum aestivum, L.) production in Egypt and several countries in the world.
This study was carried out to evaluate twenty-two bread wheat mutant-lines in M5 and M6 generations as well as five check bread wheat
cultivars Gemmeiza11, Sids12, Sakha 93, Sakha94 and Morocco, for high yield and an adequate level of adult plant resistance to stem rust
under stress of the disease in the field. The epidemiological parameters; final rust severity (FRS%), average coefficient of infection (ACI)
and area under disease progress curve (AUDPC), were used to characterize adult plant resistance to stem rust in the tested genotypes,
as well as, some yield traits; grain yield, biological yield, No. of grains / spike and 1000-kernel weight were also recorded for the
studied genotypes. The results showed that Sakha94 (Sk94) cultivar and the nine mutant lines, i.e. (Mut1, Mut2, Mut11, Mut25, Mut26,
Mut28, Mut38, Mut59, Mut161), were resistant to stem rust. Negative correlation coefficient values existed between disease parameters
and yield traits under study, showing harmful effect of stem rust on plant characteristics. Grain yield showed negative and significant
correlation with ACI (r= -0.694**), AUDPC (r= -0.679**) and FRS% (r=-0.665**), while positive and significant correlation were found
with biological yield (r = 0.889**), number of grains/spike (r= 0.411*). The best mutant lines, having an adequate levels of adult plant
resistance to stem rust, combined with desirable yield traits could be introgressed into adapted Egyptian wheat cultivars; to develop
durable resistance to stem rust in wheat.
Keywords: Wheat, Mutations, Puccinia graminis f. sp. tritici, Adult plant resistance (APR), Gamma radiation.

Summary in Arabic.