Agronomic Effect of Wheat-Rye Translocation Carrying Rye Chromatin (1R) From Different Sources

rived from Amigo have been recognized as the most favorable for yield (Lukaszewski, 1990; William and The confounding effect of wheat (Triticum aestivum L.) genetic Mujeeb-Kazi, 1993). T1BL·1RS resulted in higher grain background has been addressed as the major factor in inconsistent yield, kernel weight, and above-ground biomass (Carver agronomic performances of 1RS translocation. The objective of this study was to test the effects of centric translocations of chromosome 1 and Rayburn, 1994; Moreno-Sevilla et al., 1995a, 1995b). in various rye (Secale cereal L.) sources on agronomic performance However, the effects of 1RS translocation were not conof wheat grown in humid southeastern conditions in North America. sistent for grain yield. Significant reduction of grain Various 1R substitution, 1RS translocation, and 1RL translocation yield was reported by Singh et al. (1998). The advantage lines in ‘Pavon 76’ were evaluated for agronomic performance. The to grain yield of T1BL·1RS was reported in durum wheat 1RS translocation line was most favorable for agronomic performance (Triticum turgidum L.) only under moisture stress (Villawhen compared with those of substitution, 1RL translocation, and real et al., 1997). No significant advantage for grain yield controls. The 1RS significantly increased grain yield. However, the was reported in T1BL·1RS lines (Moreno-Sevilla et al., effect of source of rye chromatin was greater than its position effect 1995b; McKendry et al., 1996). The confounding effect in wheat genome. Among translocation lines, those with 1RS derived of wheat genetic background has been addressed as the from ‘E12165’ (CIMMYT) and ‘Amigo’ induced higher mean grain yield and T1DL·1RS derived from ‘BH1146/Blanco rye’ had the lowest major reason that the effects of 1RS translocation have grain yield. The mean grain yield of 1RL translocation lines was lower not been consistent for agronomic performance (Villathan that of 1R substitution. Thus, selection of 1RS source is important real et al., 1991, 1994; Moreno-Sevilla et al., 1995b; in producing constantly higher grain yield in 1RS translocation lines. McKendry et al., 1996). The objective of our study, Genetic recombination among different 1RS may also be used to therefore, was to determine the effect of 1RS and 1RL create more genetic variation. translocation and 1R substitution from different rye sources for agronomic performance grown under humid southeastern conditions. W translocation lines have been developed to increase useful genetic variation of the MATERIALS AND METHODS wheat genome and to reduce the amount of unwanted rye chromatin found in whole chromosome substitution Plant Materials lines (Lukaszewski and Gustafson, 1983; Zeller and Hsam, The tested rye chromatins were in the genetic background 1983; Pena et al., 1990). Translocations involving the short of Pavon 76, a white spring wheat from the International Maize arm (S) of 1R have been considered favorable for agroand Wheat Improvement Center (CIMMYT), Mexico. Varinomic performance because of the presence of genes ous chromosome substitutions and centric translocations were for resistance to powdery mildew (caused by Erysiphe transferred into Pavon 76 with at least seven backcrosses comgraminis DC. ex Marat f. sp. tritici), stem rust (caused pleted. Each wheat–rye substitution or homozygous translocaby Puccinia graminis Pers. f. sp. tritici), leaf rust (caused tion line was produced with a sister line containing the normal chromosome constitution, to serve as checks in field trials. by Puccinia recondita Rob. ex Desm. f. sp. tritici), and The original translocation chromosome T1BL·1RS for these stripe rust (caused by Puccinia striiformis West.) and experiments was taken from wheat cultivar Genaro 84, a line of high yield potential (Mettin et al., 1973; Zeller, 1973; the ‘Veery’ series from CIMMYT into which it was introduced Moonen and Zeven, 1984; McIntosh et al., 1993; Villafrom cv. Kavkaz (Rajaram et al., 1983). It was transferred to real et al., 1995; Carver and Rayburn, 1994). Pavon 76 by a series of backcrosses to 1B monosomics. All Superior grain yield has been achieved with T1AL·1RS monosomics for group 1 chromosomes of Pavon 76 were proand T1BL·1RS genotypes. The advantage of T1AL·1RS duced by backcrosses to the corresponding monosomics of cv. was high grain yield, above-ground biomass, number of INIA 66 obtained from Dr. R. Pienaar, University of Stellenspikes per square meter, and test weight (Meeteren and bosch, RSA, with 10 backcrosses completed. Sears, 1991; Villareal et al., 1996). T1AL·1RS lines deA complete chromosome 1R was identified in a breeding line of wheat E12165 (hereafter denoted by a subscript “e”) selected at CIMMYT from a triticale ( Triticosecale WittW. Kim and J.W. Johnson, Department of Crop and Soil Sciences, mack) wheat cross (Lukaszewski, 1993). It was transferred University of Georgia, Griffin Campus, Griffin, GA 30223; P.S. Baento Pavon 76 via backcrossing and moved via monosomic shift ziger, Department of Agronomy and Horticulture, University of Nefrom its original substitution for 1D to substitutions for 1A braska, Lincoln, NE 68583; A.J. Lukaszewski, Department of Botany and 1B. Once there, this chromosome was translocated by and Plant Science, University of California, Riverside, CA 92521; and centric breakage-fusion to group-1 chromosomes of Pavon 76 C.S. Gaines, USDA-ARS Soft Wheat Quality Laboratory, Wooster, with all six compensating translocations produced (LukaszewOH 44691. Received 12 Sept. 2003. *Corresponding author (jjohnson@ ski, 1993, 1997). The original of chromosome arms in this set of griffin.uga.edu). translocations is denoted by subscript “e” for arms of 1R from Published in Crop Sci. 44:1254–1258 (2004).  Crop Science Society of America 677 S. Segoe Rd., Madison, WI 53711 USA Abbreviations: E, environment; G, genotype.