Frequency and Distribution of Genes For Necrosis and Chlorosis in Tetraploid Species of Triticum

Five hundred and sixty six different accessions belonging to 14 tetraploid species of Triticum were studied for frequency and distribution of genes for necrosis and chlorosis in them. The study showed a high frequency (70%) of Ne1 gene in 4x wheats; they were either of the genotype, Ne1 ne2 or ne1 ne2. Ne2 carriers were completely absent. All the strains of T. aethiopicum, T. ispahanicum, T. abyssinicum, T. palaeocolchicum, T. timopheevii and T. araraticum studied were found to be noncarriers. A high prevalence of Ne1 was observed in T. durum, T. polonicum, T. pyramidale and T. turanicum. while Nclm was predominant among the strains of T. earthlicum and T. dicoccoides. Only one strain of T. dicoccoides was found to carry Nei w The Ch1 carriers were met with only in T. dicocceum (81%) and T. dicoccoides (26%). The results indicate thatChl carrying emmer wheat is involved in the origin of T. miacha.