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CROP BREEDING, GENETICS & CYTOLOGY

Covariation for Microsatellite Marker Alleles Associated with Rht8 and Coleoptile Length in Winter Wheat

^a 4008 Throckmorton Hall, USDA-ARS, Department of Agronomy, Kansas State University, Manhattan, KS 66506
^b 368 Agricultural Hall, Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078

^* Corresponding author (gbai{at}agron.ksu.edu).

	ABSTRACT

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
Wheat (Triticum aestivum L.) cultivars with greater coleoptile elongation are preferred in low-precipitation dryland regions and in early-planted management systems of the Great Plains, but the presence of GA3 (gibberellin)-insensitive dwarfing genes tends to restrict coleoptile elongation. The agronomic value of Rht8 and the discovery of its diagnostic microsatellite marker, Xgwm 261, have accelerated breeders' interest in Rht8 as an alternative dwarfing gene. Our objectives were to determine allelic distributions at the marker locus in contemporary samples of hard winter and soft red winter wheat relative to samples of Chinese accessions from a Rht8-rich geographic region, and to compare coleoptile elongation in the presence or absence of Rht8 determined by the Xgwm 261 marker. The 165-bp (primarily hard winter wheats) and the 174-bp (primarily soft red winter wheats) alleles of Xgwm 261 were most frequent. About 8% of all U.S. accessions carried the 192-bp allele diagnostic for Rht8, compared with 64% of the Chinese accessions. Coleoptile length varied among accessions from 4.4 to 11.4 cm. Frequency distributions for 192- and non-192-bp genotypes showed no advantage of the 192-bp allele to coleoptile elongation. None of the 192-bp genotypes from the Great Plains showed greater coleoptile length than ‘TAM 107’, a hard red winter cultivar without Rht8 often chosen over contemporary cultivars for its greater emergence capacity with deeper seed placement. Since coleoptile elongation may be controlled by several quantitative trait loci, identifying only the presence of 192-bp allele of Xgwm 261 may be misleading if the primary motivation for its deployment is to increase coleoptile length in a semidwarf plant type.

	INTRODUCTION

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
IN ENVIRONMENTS where successful crop establishment is hindered by poor seedling emergence, wheat breeders are challenged by the need to improve coleoptile elongation in the presence of GA3-insensitive dwarfing genes, which tend to restrict it. Although coleoptile elongation is under polygenic control (Singhal et al., 1985; Rebetzke et al., 1999, 2001), a major QTL that maps directly to the Rht (Reduced height)-B1 locus (formerly Rht1) and another QTL on chromosome arm 4BL may account for the majority of genotypic variation in coleoptile length measured at 11 to 19°C (Rebetzke et al., 2001). This restriction provides an incentive to winter wheat breeding programs to use alternative dwarfing genes in the low-precipitation dryland regions of the Great Plains and Pacific Northwest, where deep seed placement is needed to reach moist soil to initiate germination (Budak et al., 1995; Schillinger et al., 1998).

In the southern and central Great Plains, there is further incentive for long coleoptile because winter wheat is seeded early as a dual-purpose crop for forage and grain production. Deep seed placement and reduced coleoptile elongation in the predominately hot soils can combine to have a potentially devastating impact on stand establishment (Stockton et al., 1996). Historically, earlier-planted wheat produces lower grain yield than later-planted grain-only wheat (Epplin et al., 2000). Hence, poor stand establishment translates, in part, to reduced profitability of both components of the dual-purpose system, estimated to account for the majority of the area seeded in Oklahoma (Epplin et al., 1998).

Two strategies may be followed to achieve adult-plant height reduction without the negative consequences of reduced coleoptile elongation. One might be to generate populations void of Rht-B1b (formerly Rht1) and Rht-D1b (formerly Rht2) and select phenotypically for minor height-suppressing genes. Removal of these genes in bread wheat near-isogenic lines produced only minor increases (less than 28%) in height, but substantially greater increases (up to 65%) in coleoptile length (Trethowan et al., 2001). Independent expression of plant height and coleoptile length in non-Rht1 or non-Rht2 populations should allow divergent selection responses for these traits, i.e., shorter height, longer-coleoptile genotypes, in the same population (Rebetzke et al., 1999; Trethowan et al., 2001). A second strategy might be to introduce GA-responsive dwarfing genes, such as Rht8, Rht9, and Rht12, that may not reduce coleoptile elongation, though their phenotypic detection may be more challenging (Worland et al., 1994; Worland and Snape, 2001).

Following its debut in the Japanese cultivar Akakomugi, a relatively weak height-reducing allele at the Rht8 locus gained attention from southern European, Russian, and Chinese breeding programs targeting semidwarf stature in lieu of GA-insensitive Rht genes. In near-isogenic backgrounds, this allele has shown moderate reductions in plant height, and additional reductions when combined with the closely linked photoperiod-insensitive, height-reducing gene, Ppd-D1 (Worland et al., 1998). Other GA-responsive genes, Rht9 and Rht12, have not gained a similar level of popularity because of their negative associations with grain yield (Worland and Snape, 2001). The discovery of a microsatellite marker, Xgwm 261, 0.6 cM from the Rht8 locus has made it possible to detect allelic variants that confer varying degrees of height reduction or promotion. The 192-bp allele of Xgwm 261 is indicative of the more commercially favorable Rht8 allele, while the other alleles of Xgwm 261 marker locus are considered associated with various levels of height promotion (Korzun et al., 1998).

The agronomic value of Rht8 and the discovery of its diagnostic marker have ignited breeders' interest in Rht8 as an alternative dwarfing gene. As expected, Rht8 is concentrated in regions where it was first introduced and subsequently spread through Italy to additional countries: Bulgaria, Greece, Yugoslavia, Ukraine, and China (Worland et al., 1998, 2001). The distribution of Rht8 in North American gene pools is not extensively characterized, though the gene has been found in a few cultivars (Ahmad and Sorrells, 2002). A more extensive survey of the Great Plains gene pool is justified given that cultivars featuring Rht8 as the primary dwarfing gene might potentially have greater success in early-planted management systems or in High Plains dryland environments.

Breeding programs throughout the Great Plains occasionally introduce germplasms from Europe and Asia where Rht8 is known to occur, if not predominate relative to other dwarfing genes. Thus, we hypothesized that the Xgwm 261 192-bp allele diagnostic of Rht8 could be identified in advanced breeding lines and cultivars originating from European programs. Because soft red winter (SRW) wheat is sometimes used by hard winter wheat breeders in interclass hybridizations, this germplasm pool might serve as a more useful Rht8 provider than germplasms from international programs. The objectives of this study were to (i) determine allelic distributions at the Xgwm 261 locus in contemporary samples of hard winter and SRW wheat, (ii) compare those distributions to a genotypic sample (Chinese landraces and cultivars) from a Rht8-rich region of the world, and (iii) compare coleoptile elongation in the presence and absence of the Xgwm 261 192-bp allele.

	MATERIALS AND METHODS

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
Plant Materials
The study involved a primary set of 135 wheat accessions, mostly from the USA and China. The U.S. accessions included 80 hard winter wheat (primarily hard red winter, HRW) and 25 SRW experimental lines and cultivars. Selection of contemporary hard winter wheat cultivars was based on their commercial importance to the southern and central Great Plains. Additionally, we evaluated a historical set of 12 HRW cultivars previously assessed for adaptation to a dual-purpose system (Khalil et al., 2002), and all hard winter experimental lines and check cultivars tested in the 2001 Southern Regional Performance Nursery. The SRW genotypes included experimental lines from the University of Illinois and some entries submitted to the 1997 Uniform Eastern Soft Red Winter Wheat Nursery and the 1997 Five-State Advanced Nursery. Pedigree and origin of a total of 135 accessions are listed in Appendix 1.

Accessions from other sources were selected based on their putative Rht8 genotype, including the Italian cultivars Mara and Funo, and the experimental lines ARS96329, ARS96339, and ARS96342 (Schillinger et al., 1998). Others were selected on the basis of their coleoptile elongation potential, including the Australian experimental lines PH179 and PH18 (G.J. Rebetzke, personal communication, 1997) and a selection from ‘Sturdy’, TX9129-962 (K. Porter, personal communication, 1998).

Molecular Marker Analysis
DNA was isolated from bulked leaves of two to three seedlings by the CTAB procedure (Saghai-Maroof et al., 1984). Microsatellite marker Xgwm 261 from chromosome 2DS was analyzed for all accessions in an IR²–4200 DNA sequencer (LI-COR Inc., Lincoln, NE) by labeling one primer with an infrared (IR) fluorescence dye. Each 10 µL PCR sample contained 30 ng DNA, 1x PCR buffer, 0.25 mM dNTP, 2.5 mM MgCl₂, 0.5 pmol each of labeled and unlabeled SSR primers, and 1 unit of Taq polymerase. The following touchdown thermal profile was used for SSR amplification: 5 min at 95°C, 5 min at 68°C, and 1 min at 72°C for five cycles, in which the annealing temperature was lowered by 2°C per cycle; five more cycles with 2 min annealing time in which the temperature was lowered by 2°C per cycle; and 25 cycles in which the annealing temperature remained constant at 50°C. Five minutes at 72°C was used for the final extension. Molecular sizes of the SSR fragments were determined by comparison with the DNA size standard (LI-COR Inc., Lincoln, NE) by RFLPscan software (Scanalitics, Inc., Fairfax, VA).

Coleoptile Length Measurement
Seeds for the coleoptile length measurements were obtained from greenhouse-grown plants and germinated 60 d after harvesting. Coleoptile length was measured following the method of Hakizimana et al. (2000) with some modifications. Fifteen uniform seeds per accession were spaced 1 cm apart and about 7 cm from the bottom of a germination towel (no. 76 germination paper; Anchor Paper Co., St. Paul, MN). Each towel contained a different accession. The towel was folded at about 5 cm from the bottom, placed inside wax paper, rolled loosely, and secured with a rubber band. The wrapped towels were arranged vertically on a metal rack, set in distilled water to wet the germination towels thoroughly, and then drained of excessive water. The samples were covered with black plastic and placed in a cold room at 4°C for 2 d to interrupt any dormancy. The samples were incubated in a growth chamber at 100% relative humidity and 15°C for 7 d, followed by 6 d at 20°C. This procedure was conducted six times for all accessions, with re-randomization of entries in each replicate.

Means comparisons were performed for coleoptile length between allelic classes of Xgwm 261 using a t test. Frequency distributions for coleoptile length were compared among allelic classes of Xgwm 261 (192-bp, 165-bp, or all allelic classes excluding 192-bp allele) on the basis of the Kolmogorov-Smirnov test (Steel et al., 1997).

	RESULTS AND DISCUSSION

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
Allelic Variation at Xgwm 261 Locus
Microsatellite Xgwm 261 was highly polymorphic among the 135 accessions examined in this study. The microsatellite primers amplified nine SSR fragments that varied in size from 165 bp to 212 bp (Table 1). One hundred sixteen accessions amplified a single fragment, 15 accessions (13 from the HWW class) amplified two SSR fragments of different sizes, and four accessions from the HRW class amplified three SSR fragments of different sizes. Among these microsatellite alleles, the 165-bp fragment occurred with greatest frequency (39%), followed by 174-bp (17%), 192-bp (16%), 210-bp (14%), and 197-bp (10%) fragments (Table 1). The 184-, 194-, 202-, and 212-bp fragments were most uncommon (<3%). Among the nine SSR fragments, eight were detected in the hard winter accessions, and only four fragments were detected in each of the other accession types, indicating that the polymorphic level of microsatellite Xgwm 261 was highest among the hard winter accessions in this study.

The majority of the 80 hard winter accessions contained the 165-bp allele, whereas the majority of the 25 SRW accessions contained the 174-bp allele. These two alleles prevailed in more limited samples of U.S. wheat cultivars (Worland et al., 2001; Ahmad and Sorrells, 2002), but differentiation of the predominant U.S. hard and soft wheat classes at Xgwm 261 was not possible in those surveys. These alleles were also found in the highest frequency among CIMMYT-derived semidwarf wheat accessions (165 bp) and in United Kingdom, German, and French wheat gene pools (174 bp) (Worland et al., 1998). Their worldwide prevalence in regions outside of southern Europe, Japan, and China is attributed to a possible compensatory effect on plant stature in the presence of GA-insensitive Rht genes and photoperiod-insensitive genes (Worland et al., 1998). Their hypothesis may also explain the dominance of the stronger height promoting 165-bp allele among predominately photoperiod-insensitive winter wheat cultivars adapted to the arid environment of the Great Plains, where extreme height reduction would be unacceptable. We found the 165-bp allele consistently among ancestors of modern Great Plains cultivars, such as ‘Turkey’, ‘Kharkof’, ‘Triumph 64’, and ‘Scout 66’. In addition, the 210-bp allele only appeared in modern Great Plains cultivars and formed the second largest genotypic group in the class, suggesting this allele may offer some selection advantage to modern cultivars in this region.

The diagnostic marker allele for Rht8 (192 bp) was found in only six HRW accessions and two SRW accessions, representing 6% of the total accessions in both classes. From the HRW class, accessions carrying the 192-bp allele included ‘TX97D6377’, ‘G97380’, and ‘HG-9’. Cultivars 2163, Ok102, and 2137 (with 50% of its parentage from 2163) were heterogeneous for the 192-bp allele and either the 174- or 165-bp allele. Though present in low frequency, the germplasm with 192-bp allele appears to be scattered among hard winter wheat breeding programs in the Great Plains. In the SRW class, the 192-bp allele was limited to two highly related experimental lines from Illinois, IL 94-2426 and IL 95-2909 (also heterogeneous for the 165-bp allele). However, on the basis of the available pedigrees, we are neither able to determine the origin of Rht8 in these U.S. accessions carrying the 192-bp allele nor affirm the presence of Rht8 in these accessions because the 192-bp allele is a linked marker to Rht8, not part of the gene.

In contrast to the two U.S. gene pools, the majority (76%) of Chinese accessions contained the 192-bp allele (Table 1), which is consistent with Worland et al. (2001). Most of these accessions had Funo or a relative of Funo in their pedigrees, indicating a high possibility of Rht8 in these accessions. These results confirm the value of Chinese germplasm as a potential Rht8 donor. Of particular interest was the Chinese cultivar, Sumai 3, which we found to contain the 192-bp allele contributed from Funo. If not by design, then certainly by accident, Rht8 introgression has already commenced in many wheat breeding programs that targeted Sumai 3 as a source of Type II resistance to Fusarium head blight caused by Fusarium graminearum Schwake [teleomorph Gibberella zeae (Schwein.)] (Bai et al., 2003). We would expect this to be the case in U.S. wheat because of introduction of Sumai 3 as a scab resistant parent in winter or spring wheat breeding programs.

We evaluated several other accessions thought to have Rht8 or long coleoptile potential (Table 1, "Other genotypes"). Two Italian cultivars, Funo and Mara, and one Australian line having Mara as one of its parents, PH 18, contained the 192-bp allele. We could not confirm that three soft white winter experimental lines, ARS96329, ARS96339, and ARS96342, contained the 192-bp allele, which were previously claimed to have Rht8 (Schillinger et al., 1998). This could result either from the absence of Rht8 in these selections, or from recombination between Rht8 and the marker locus. Although TX9129 was selected from Sturdy for its greater coleoptile elongation, that characteristic is not attributable to Rht8.

Coleoptile Elongation and Xgwm 261 192-bp Allele
Coleoptile length was measured with moderate repeatability among the 135 accessions, as estimated by the intraclass correlation coefficient of 0.40 ± 0.04. Hakizimana et al. (2000) reported slightly higher repeatability of 0.6 to 0.7 among 15 HRW genotypes. A 7.0-cm range in coleoptile length was found among individual accessions, and their mean was 8.2 cm. The longest coleoptile was 11.4 cm for Chinese cultivars Wannian 2 and F 60096. The shortest was 4.4 cm for HRW cultivar ‘2180’. Chinese accessions tended to have longer coleoptiles than U.S. accessions, yet considerable overlap occurred among U.S. and Chinese cultivars (Table 1). Genotypes with the Xgwm 261 locus varied in mean coleoptile length from 7.9 cm (genotypes carrying 165-, 197-, and 210-bp alleles) to 8.8 cm (192-bp genotypes).

Frequency distributions for coleoptile length were generated for 192-bp genotypes, all genotypes lacking the 192-bp allele, and for the more common genotype with the 165-bp allele (Fig. 1) . Only the non-192-bp distribution departed from normality (P < 0.01, Shapiro-Wilk test). However, these distributions did not differ significantly on the basis of the Kolmogorov-Smirnov statistic. An obvious association between greater coleoptile length and the presence of the 192-bp allele could not be detected from these results and visual examination of the distributions. Several accessions that contained the 192-bp allele had no greater coleoptile length than those that did not (Fig. 1), especially those in the HRW and other genotypes classes (Fig. 1).

View larger version (18K): [in this window] [in a new window]   Fig. 1. Distributions for coleoptile length of wheat accessions containing only the 192-bp allele (A, n = 26), of all accessions not containing the 192-bp allele (B, n = 121), or of accessions strictly containing the 165-bp allele (C, n = 46) of the microsatellite marker Xgwm 261.

Appendix 1.

Allelic identity for microsatellite Xgwm 261 and mean coleoptile length of 135 wheat accessions.

Cultivar Origin Source Pedigree Fragment size (bp) Mean coleoptile length Hard winter wheat 2137 USA PI 592444 Pioneer, KSU W2440/W9488A//2163 165, 192  6.4 2157 USA Pioneer, KSU Caprock/B 86//Sc 3212 165  7.4 2158 USA Pioneer Unknown 165  9.1 2163 USA Pioneer, KSU Pioneer line W558/5/Etoile de Choise//Thorne/Clarkan/3/CI15342/4/Pur 4946A4-18-2 174, 192  6.5 2174 USA Pioneer, OSU IL 71-5662/PL 145//2165 165  8.6 2180 USA PI 532912, Pioneer TAM W-101/Pioneer W603//Pioneer W558 165  4.4 Above USA CSU TAM 110*4/FS2 165  8.4 AP502CL USA AgriPro, CSU TXGH12588-26*4/FS2 165  9.7 Chisholm USA PI 486219, OSU Sturdy sib/Nicoma 165  7.8 CO970498 USA CSU Ogallala/Halt 210  8.2 CO970531 USA CSU Ike/Halt 210  8.2 CO970547 USA CSU Ike/Halt 165, 210  6.9 CO970940 USA CSU Yuma/T-57//Lamar/3/4*Yuma/4/NEWS16 165  7.1 Coronado USA AgriPro Mustang/W80-425//COMP76B-1-84-1/SW74-8A-47 212  6.8 Custer USA OSU F29-76/TAM 105//Chisholm 165  7.6 Cutter USA AgriPro KS84063-9-39-3//TAM-200/W81-296 210  7.7 Dumas USA AgriPro F2SPS-102/TAMW-101//RPB/Mustang/W80-425/Comp. Sel. 165  6.9 Enhancer USA Goertzen Seed HT43H-331-9 (Nebraska winter hardy selection) 165  9.2 G1878 USA Goertzen Seed Hawk//Sturdy/Plainsman V 165  9.2 G97209 USA Goertzen Seed Karl 92/G525/Arlin 165  7.7 G97380 USA Goertzen Seed GSR2500/Plainsman V//KARL92 192  7.4 HG-9 USA Hardeman Grain   & Seed TAM 200 outcross selection 192  9.1 Ike USA PI 574488 KSU Dular/Eagle//2* Cheney/Larned/3/Colt 212  7.7 Intrada USA PI 631402 OSU Rio Blanco/TAM 200 197  8.1 Jagger USA PI 593688 KSU KS82W418/Stephens 165, 212  7.5 Kalvesta USA Goertzen Seed Oelson/Hamra//Australia215/3/Karl 165  7.8 Karl 92 USA PI 564245, KSU Plainsman V/3/Kaw/Atlas 50//Parker *5/Agent 165, 210  7.1 Kharkof Ukraine PI 5641 Landrace from Ukraine 165  7.5 KS920709-B-5-2 USA KSU ABI 86*3414/X84W063-9-39-2//Karl 92 210  7.5 KS920946-B-15-2 USA KSU T67/X84W063-9-45//Karl 92 210  7.7 KS98HW151-6 USA KSU Arlin//TA2460/*3 TAM107 165  9.1 KS98HW220-5 USA KSU Arlin/Yuma 165  7.4 Lakin USA PI 617032 KSU KS89H130/Arlin 165  7.8 Lockett USA PI 604245 TAM TX86V1540/TX78V2430-4 165  8.2 NE97465 USA UNL SD3055/KS88H164//Colt*2/Patrizanka 210 10.2 NE97V121 USA UNL N87V106/OK88767 165, 210  7.7 NE98466 USA UNL KS89H50-4/3/Brl//Sxl/Benn 210  7.0 NE98564 USA UNL Colt/Cody//Yuma 165, 210  7.3 NE98632 USA UNL Niobrara/5/Aiv/Nbr/Bolal//Hiplains/3/Lov6/4/Redland 165  7.3 NI98439 USA UNL Benn/BRL//X10927 592-1-5 165  7.7 NW97S218 USA USDA-ARS   Lincoln KS85W663-1-1/Karl 92 210  7.6 NW97S278 USA USDA-ARS   Lincoln Pronghorn/Arlin 197  7.2 Ogallala USA AgriPro TX81V6187//OK711252/W76-1226 197, 210  7.6 Ok102 USA OSU 2174/Cimarron 165, 192  7.5 OK93P656-RMH3299 USA OSU W0405D/HGF112//W7469C/HCF012 165  6.6 OK94P549-99-6704 USA OSU HBY756A/Siouxland//2180 202  7.6 OK96705-99-6745 USA OSU 2180/OK88803//Abilene 165  7.0 OK96717-99-6756 USA OSU Abilene/2180//Chisholm 165  7.7 OK98680 USA OSU Odessa 06/Mesa 212  7.6 Onaga USA AGSECO 165  7.7 Scout 66 USA CItr 13996 UNL Composite of 85 selections from Scout, CItr 13546 165, 210  7.9 T001X USA Trio Seed Hybrid 165, 174, 210  7.9 T002X USA Trio Seed Hybrid 165, 174, 210  7.3 T003X USA Trio Seed Hybrid 165, 174, 210  7.5 T122 USA Trio Seed Tecumseh/5627//T91 165  7.3 TAM 105 USA CItr 17826, TAM ‘short wheat’ Sturdy composite bulk selection 165  7.8 TAM 107 USA PI 495594 TAM TAM 105*4/Amigo 165  9.6 TAM 110 USA PI 595757 TAM (TAM 105 *4/Amigo)*5/Largo 165  9.9 TAM 111 USA TAM TAM 107//TX78V3620/CTK78/3/TX87V1233 194  8.8 TAM 202 USA PI 561933 TAM Siouxland outcross 197  7.9 TAM 302 USA PI 605910 TAM Probrand 812/Caldwell//TX86D1310 (TAM 300 sib) 165  8.0 TAM W-101 USA CItr 15324, TAM Norin 10/3/Nebraska 60//Mediterranean/Hope/4/Bison 165, 210  7.3 Thunderbolt USA AgriPro OK711252A/W76-1226//KS90WGRC10 165  8.2 Tomahawk USA AgriPro Ironstraw S4 210  7.3 Tonkawa USA OSU F29-76/TAM 105//Chisholm 165  7.1 Trego USA PI 612576 KSU KS87H325/Rio Blanco 197  7.1 Triumph 64 USA CItr 13679 OSU Danne Beardless Blackhull/3/Kanred/Blackhull//Florence/4/Kanred/Blackhull//Triumph 165  9.2 Turkey Ukraine/Russia Landrace 165  8.9 TX 95A1161 USA TAM TAM W-101//NE78488/Veery 165  7.5 TX97A0122 USA TAM TX88V4328/TX87V1613//TX87V1233-1 165, 197  7.5 TX97A0219 USA TAM TX71562-6*4/AMI*4//LGO/3/NE86582 165, 210  8.1 TX97A0244 USA TAM TAM 105*4/AMI*5//LGO/3/Sturdy 165  8.6 TX97D6377 USA TAM HBG026+NE78659*Arkan/2180 192  7.6 TX97V2838 USA TAM U1254-1-5-2-1/TX81V6582 197  7.8 TX98D1170 USA TAM TX89D1253*2/TTCC404 165  8.3 TX98V9315 USA TAM U1254-4-7-2/Dong Xie 4 197  8.1 TX98V9618 USA TAM U1254-1-8-1-1/TAM-202 197  8.0 TX98V9930 USA TAM U1254-7-9-2-1/TX86A5616 165, 197, 210  7.3 Venango USA Goertzen Seed HBE 1066-105/HBF0551-131 210  8.1 Vona USA CItr 17441, CSU II 21183/CO 652363//Lancer/KS 62136 165  6.6 Soft red winter wheat Bacup USA PI 596533 Nuy Bay/Pioneer 2375//Marshall 165  9.3 Cardinal USA Ohio State Univ. Logan*2/3/Va63-5-12/Logan//Blueboy 165  8.8 Clark USA PI 512337 Beau Caldwell sib/67137B5-16/4/Sullivan/3/Beau//5517B8-5-3-3/Logan 174  8.1 Ernie USA PI 584525 U M Pike/MO9965/3/Stoddard/Blueboy//Stoddard/D1707 174  8.6 Foster USA PI 593689 UK Coker65-20/Arthur/4/Chul* 8CC//VA68-22-7/Abe/3/VA72-54-14/Tyler//Suwon 92/Arthur//Arthur/VA 70-52-2 174  7.6 Freedom USA Ohio State Univ. GR876/OH217 165  8.5 IL 93-2283 USA UI Tyler/Caldwell//Auburn/Wheeler 174  8.1 IL 94-1549 USA UI Auburn/Ark38-1/Arthur/Blueboy 174  8.6 IL 94-1909 USA UI Fillmore/Amigo//Tyler/Howell 174  7.9 IL 94-2426 USA UI Roland/4/Coker 68-15/3/IL69-1751/5/IL70-2227-1/McNair1003/2/Howell 192  9.2 IL 94-6280 USA UI Tyler/Caldwell//Auburn/Wheeler 174  8.7 IL 95-1966 USA UI Tyler/Howell/3/Howell//Oasis/Arkansas38-1/4/Auburn/3/Rosen//Arthur/Blueboy 174  7.0 IL 95-2066 USA UI IN7688G1/3/Caldwell//Spritzer Agrotriticum/LRC40/4/P79424H1-20-2-74 174  7.9 IL 95-2909 USA UI Freedom/6/Roland/4/Coker 68-15/3/IL69-1751/5/Roy/4/Coker 68-15/3/IL69-1751 165, 192  8.8 IL 9634-24851 USA I P76788G2-5-494/5/Caldwell/4/Coker68-15/3/IL69-1751/6/Caldwell/Tyler//Auburn/7/Ning 7840 174  7.5 Kaskaskia USA PI 602969 UI (IL70-2255/CI13855//McNair48-23)/(Arthur/Blueboy//TN1571)//Pike/Caldwell 174  7.0 MO 94-193 USA 97FSAN MO 11728/Becker 174  7.6 MO 94-312 USA 97FSAN Pioneer brand 2551/Caldwell 174  8.9 OH 552 USA 97UESRWN Pur71761A4-31-5-33/VA68-26-331/6/Thorne*5/199-4/5/Thorne/4Taylor*2/2/Norin 10/Brevor/3/unknown parent 174 10.5 OH 569 USA 97FSAN Pur71761A4-31-5-33/VA68-26-331/6/Thorne*5/199-4/5/Thorne/4 Taylor*2/2/Norin10/Brevor/3/unknown parent 174 10.9 P91193D1-10-2 USA 97UESRWN 851423/INW9853 174  7.7 PA8769-158 USA 97UESRWN Titan/Caldwell 174  7.8 PB 2555 USA Pioneer Coker 68-16/MoW 7140//Pioneer Brand W521 165  8.7 Pontiac USA PI 573038 AgriPro Magnum/Auburn 174  7.8 Roane USA PI 612958 VA Tech VA 71-54-147/Coker 68-15//IN6 5309C1-18-2-3-2 202  6.1 Chinese accessions Cultivars Chuanyu 35050 China Chuanyu 5/Chuanyu 9461 192, 212  7.9 Dwarf Sumai 3 China JAAS Sumai 3/Tom Thumb//Tom Thumb 192  6.4 F 5114 China JAAS LongXi 18/(Avrora/Anhui 11//Sumai 3) 165  9.9 F 5125 China JAAS Fufan 904/(Avrora/Anhui 11//Sumai 3) 165 10.4 F 60096 China JAAS Jinzhou 1/Sumai 2 192 11.4 Fumai 3 China PI 447405 Orofen/Funo 192  9.4 JG 1 China PI 531193 Mayo/Armadillo//Yangmai 3/Avrora/Ningmai 3 192  9.7 Ning 7840 China PI 531188 Aurora/Anhui 11//Sumai 3 192 10.4 Ning 8026 China PI 531189 Avrora/Sumai 3//Yangmai 2 192  8.1 Ning 8331 China PI 53119 Yangmai 4/(Avrora/Anhui 11//Sumai 3) 192  8.7 PC-2 China CIMMYT Unknown 174 10.2 Sumai 3 China JAAS Funo/Taiwan Wheat 192 10.6 Sumai 49 China JAAS N7922/(Aurora/Anhui 11//Sumai 3) 192  9.9 Wannian 2 China PI 447403 Selection of Mentana 192 11.4 Wuhan 3 China CIMMYT Unknown 192  9.9 Xianmai 1 China PI 481544 Ardito/Tevere//Wannian 2 174 11.2 Yangmai 1 China PI 447404 Selection of Funo 192  8.2 Landraces CaiZiHuang China PI 447402 Landrace from Jiangsu 197  9.8 FSW China JAAS Landrace from Fujian Province 184  9.8 NTDHP China PI 462149 Landrace from Jiangsu 194 11.1 Wangshuibai China PI 462141 Landrace from Jiangsu 194 11.3 WZHHS China JAAS Landrace from Zhejiang Province 192 11.0 Other genotypes ARS96329 USA 174  9.2 ARS96339 USA 174 10.1 ARS96342 USA 174 10.3 Funo Italy PI 213833 Duecentodieci/Demiano 192  8.2 Mara Italy PI 244854 Autonomia A/Aquila sib I 192  7.9 PH179 Australia Skua/Shortim 165  5.9 PH18 Australia Insignia/Skua//Shortim/Mara 192  8.8 TX 9129 USA Selection from Sturdy 165  9.3

97UESRWN = 1997 Uniform Eastern Soft Red Winter Wheat Nursery; 97FSAN = 1997 Five State Advanced Nursery; UK = Univ. of Kentucky; UI = Univ. of Illinois; OSU = Oklahoma State Univ.; KSU = Kansas State Univ.; TAM = Texas A&M Univ.; CSU = Colorado State Univ.; UNL = Univ. of Nebraska, Lincoln; CIMMYT = International Maize and Wheat Improvement Center; JAAS = Jiangsu Academy of Agricultural Sciences, Nanjing, China.

Mean of six replicates.

	NOTES

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 
Research funded by the Oklahoma Wheat Research Foundation and the Oklahoma Agricultural Experiment Station. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

Received for publication June 25, 2003.

	REFERENCES

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION REFERENCES

 

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