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An octoploid derivative, TA25, of 'Carsten V (Triticum aestivum L. em. Thell) x Agropyron intermedium, was found to be immune from wheat streak mosaic. Fj seed from crosses of TA25 x common wheat were exposed to 1000 and 2500 rads of fast neutrons. After a process of backcrossing and selection, three 43-chromosome addition lines and one 42-chromosome translocation or substitution line were obtained having immunity from wheat streak mosaic. An immune 44 chromosome line also was obtained from backcrossing and pedigree selection without irradiation. Both winter and spring type segregates occurred in all four derived lines. Additional index words: Triticum aestivum, Agropyron intermedium, Chromosome additions, Chromosome substitutions, Translocations.

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‘Hand’ wheat (Triticum aestivum L.) is high in protein, has excellent baking and dough handling properties, and is resistant to leaf rust (Puccinia recondita Rob. ex. Desm. f. sp. tritici) and stem rust (P. graminis f. sp. tritici Eriks. and Henn.). The pedigree of Hand is uncertain. However, it possesses a single gene, SrTt1, for resistance to stem rust as determined by an F2 analysis of crosses with stem rust tester lines. A study was conducted of Hand to determine the inheritance of high seed protein.Crosses were studied of Hand with ‘Centurk’ and an experimental line, TX62A2522‐8‐2, both low in protein, and of Hand with ‘WS1809’, a spring habit cultivar, and an experimental line, NE68513, both high in protein. Single plants of progeny rows of artificially vernalized seedlings of parents, F1, F2, F3 BCF1, and BCF2 were studied in the field. Hand differed from Centurk and TX62A2522‐8‐2 for protein level by one dominant gene for high protein which we have named PrHand. In NE68513*2/Hand, 21% of the BCF2 lines were higher in protein than NE68513 which derived recessive high protein from Atlas 66. Based upon dominance relations and transgressive segregation, we concluded that Hand and NE68513 have unlike genes for high percent seed protein.Transgressive segregation was not detected in the reciprocal backcrosses involving WS1809 and Hand. However, three selected progeny rows from WS1809/2*Hand averaged 2.1 and 0.8 percentage points higher than the means of the respective parents. Although not significantly different, that may suggest a difference in genes or alleles for high protein. Selections higher in protein than Hand were most prevalent in crosses involving only high protein parents, providing additional evidence that different genes were involved.