Understanding the Effect of Rye Chromatin in Bread Wheat

and Meinel, 1994; Moreno-Sevilla et al., 1995a; McKendry et al., 1996). The 1RS.1BL translocation is one of the Most experiments on 1RS translocations in wheat (Triticum aestimost frequently used alien introgressions in wheat vum L.) cannot separate the effects of introgressions of rye (Secale breeding programs throughout the world (Braun et al., cereale L.) chromosome arm from the absence of corresponding wheat chromosome arms. The objective of this research was to determine 1998). It was derived from the Russian cultivars ‘Authe contribution of individual wheat and rye group 1 chromosome rora’ and ‘Kavkaz’ (Zeller and Hsam, 1984). The arms. Five group 1 ditelosomics, six substitutions, and 16 translocations 1RS.1AL translocated wheats derived from ‘Amigo’ of 1R in wheat were compared with appropriate controls. All ditelohave also been extensively used in wheat breeding prosomics were significantly different from controls for 100-kernel weight grams in the USA (Graybosch, 1995; 2001). (100-KW), flour protein content (FP), Mixograph peak time (MT) and Although the 1RS introgressions have conferred tolerance (MTO), and sodium dodecyl sulfate sedimentation (SDSS) broad adaptation, high yields, and yield stability, they volume. Among the long arms, 1DL was the most important for endhave frequently demonstrated unsatisfactory end-use use quality and 1AL the least important, ranking even below the 1RL quality, especially diminished mixing tolerance, dough tested. The contribution of all short arms was low. Substitutions of stickiness, reduced loaf volume, and poor crumb grain 1R negatively impacted agronomic performance with the long arm being entirely responsible for this effect. Among translocation lines, when compared with wheats with a standard chromothose with 1RS.1BL had the highest yield and those with 1RS.1DL some constitution (Dhaliwal et al., 1990, Burnett et al., the lowest. Negative impact of all translocations of 1RS on the end1995; Lee et al., 1995; Seo et al., 1995). Carver and use quality was far greater than the absence of the corresponding 1S Rayburn (1995) indicated that the 1RS.1BL translocaarms of wheat. Translocation 1RS.1AL was the least detrimental to tion lines had, on average, increased grain protein conquality and 1RS.1DL the most detrimental. Both the source of the tent and decreased dough mixing properties and SDS rye chromatin and its position in the wheat genome affected agronomic sedimentation volumes. Moreno-Sevilla et al. (1995b) performance and quality. These results suggest that it may be possible determined that the 1RS.1BL genotypes from the ‘Rawto create new translocations of 1RS in wheat with improved perforhide’ background had a higher protein content, similar mance. Translocation of 1RS to 1AL is preferred from a quality point mixing time, and lower mixing tolerance than 1B genoof view; that to 1BL appears more beneficial for agronomic performance. types. Shepherd et al. (1992) indicated that the 1RS.1DL translocation had much weaker dough properties than the equivalent rye arm in a 1RS.1BL translocation in the same background. On the other hand, Graybosch I of rye chromatin into wheat through et al. (1993) have shown that the 1RS.1AL translocation wheat–rye chromosomal substitutions and translocawas less detrimental to the bread-making quality of tions have increased the genetic diversity of bread wheat wheat than the 1RS.1BL translocation. Consequently, cultivars for various characters (Zeller and Hsam, 1984). the 1RS.1AL translocation was considered a better way The chromosomal translocations of the short arm of to utilize rye genes in the genetic improvement of wheat rye chromosome 1R to the long arm of wheat group 1 (Graybosch et al., 1993). chromosomes are of particular interest to wheat breedThe quality defects associated with 1RS introgresers. The 1RS arm carries genes for resistance to diseases, sions in wheat may be a consequence of a change in the arachnids, and insects (McIntosh, 1984; Zeller and protein composition, especially reduced dough glutenin Hsam, 1984). Translocations of 1RS to the wheat chroconcentration, resulting from the removal, through the mosome arms 1AL and 1BL have been the most extensubstitution by 1RS, of one short arm of a group 1 sively used because, in addition to the resistance loci, chromosome of wheat. These arms carry loci-encoding they positively affect agronomic traits including yield gliadins and low molecular weight glutenins that have performance, yield stability, and wide adaptation (Raa direct effect on end-use quality of wheat. Alternajaram et al., 1984; Villarreal et al., 1991; William and tively, the quality defect may also be a consequence of Mujeeb-Kazi, 1993; Carver and Rayburn, 1994; Schlegel the presence of rye secalins in these lines (Dhaliwal et al., 1990; Graybosch et al., 1993; Lee et al., 1995), or a A.M. Kumlay, P.S. Baenziger, and K.S. Gill, Dep. of Agronomy and combination of both factors. Because the presence of Horticulture, and R.A. Graybosch, USDA-ARS, Univ. of Nebraska, a 1RS translocation in wheat is concomitant with the Lincoln, NE 68583; D.R. Shelton, Wheat Marketing Center, 1200 N.W. absence of the replaced wheat arm, the two effects canNaito Parkway, Suite 230, Portland, OR 97209; A.J. Lukaszewski, Dep. of Botany and Plant Science, Univ. of California, Riverside, not be easily separated. Minor detrimental effects of CA 92521-0124; D.M. Wesenberg, USDA-ARS, Aberdeen, ID 83210. the removal of the short arms of wheat group 1 chromoContribution no. 13724 from the Nebraska Agric. Res. Div. Received 7 June 2002. *Corresponding author ([email protected]). Abbreviations: FP, flour protein content; GVW, grain volume weight (test weight); GY, grain yield; HD, days to heading; 100-KW, hundredPublished in Crop Sci. 43:1643–1651 (2003).  Crop Science Society of America kernel weight; MT, Mixograph peak time; MTO, Mixograph tolerance; SDSS, sodium dodecyl sulfate sedimentation. 677 S. Segoe Rd., Madison, WI 53711 USA