bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Soybean Cultivar Ranking and Selection for Yield with AMMI and Full‐Data Performance Estimates
Authors: Sneller Clay H. , Dombek Don
Published: July 2010

The additive main effects and multiplicative interaction (AMMI) estimate of genotype performance removes genotype × environment interaction (GEI) noise that is intrinsic to full‐data estimates of genotype performance in specific environments, thereby producing estimates that may be more predictive of future performance than full‐data estimates. Our objectives were to (i) compare genotype rankings based on AMMI and full‐data estimates of performance, and (ii) compare the yield of genotypes selected by the two sets of estimates. Five data sets, each containing data from two consecutive years, were constructed from yield trials of Maturity Group V soybean [Glycine max (L.) Merr.] cultivars conducted at five locations. The AMMI and full‐data estimates of genotype performance were calculated for each location and year in each data set. Rank correlations were calculated between the AMMI and full‐data estimates. The yield of the top 15% of all genotypes and the top genotype, as ranked by each method in each location and each year, were compared in the other year of the data set. All correlations between AMMI and full‐data estimates were significant within each environment, and both estimates appeared equally predictive of future genotype rankings. The yields of genotypes selected based on either set of estimates were essentially equivalent in nonmodeling years. There was no advantage or disadvantage to either method of estimating genotype performance. Apparently, the GEI patterns incorporated in the AMMI estimates in our study were not repeatable enough across years to produce estimates that were more predictive of future performance than full‐data estimates.
Linkage Relationships among Genes on Wheat Chromosome 5A That Condition Resistance to Hessian Fly
Authors: Ohm H. W. , Sharma H. C. , Patterson F. L. , Ratcliffe R. H. , Obanni M.
Published: July 2010

Hessian fly [Mayetiola destructor (Say)] is a serious pest of wheat (Triticum ssp.) in many wheat growing areas of the world. A number of genes (H1‐H26) that confer resistance to Hessian fly have been described. The linkage relationships of many of these genes, which are useful in breeding wheat for resistance to Hessian fly, are unknown. Testcross analyses were made in tetraploid durum wheat(Triticum turgidum L.) and tested to biotype D of Hessian fly to determine the linkage relationships among genes H9, H10, H12, H14, H15, H16 and HI7, all conferring resistance to biotype D. Also, monosomic 5A plants of susceptible cultivar Chinese Spring were crossed as seed parents to Purdue wheat (T. aestivum L. em Thell.) lines carrying gene H10 or H12. Testcross analyses indicated that six of these genes appear to occupy a single linkage block on wheat chromosome 5A in the order H9 to H15, HIO, H17, H16, and H12. Gene H14 did not appear to be within the linkage block H9 to H12. Additionally F2 plants derived from 41‐chromosome F1 plants and F1 families derived from F2 resistant plants were tested against biotype D. F2 segregation deviated significantly from 3 resistant : 1 susceptible and F3 families from resistant F2 plants deviated significantly from 1 resistant: 2 segregating for both crosses involving H10 and H12. Thus, monosomic analyses provided additional evidence that genes H10 and H12 are likely on chromosome 5A. Linkage between these genes would not seriously limit efforts to pyramid them in breeding for resistance to the Hessian fly because the linkage values are more than 20 centimorgans.
A Strategy to Breed Low‐Protein Barley with Acceptable Kernel Color and Diastatic Power
Authors: Goblirsch C. A. , Horsley R. D. , Schwarz P. B.
Published: July 2010

Grain protein content is an important malt quality trait in barley (Hordeum vulgare L.). A source of low‐protein used by the North Dakota six‐rowed barley breeding program has been the cultivar Karl. No cultivars with Karl in their pedigree have been released from this program because all low‐protein lines have had unacceptably dark kernel color, low diastatic power (DP), or both. The objective of this study was to determine why low‐protein cultivars with acceptable kernel color, DP, and grain protein content have not been developed and to suggest a strategy to breed such cultivars. To fulfill these objectives, the following grain protein content, kernel color, and DP data were collected from three crosses: broad‐sense heritability estimates, expected and observed gains from selection, genetic correlations between the three traits, and the correlated response of a trait when selecting for another trait. Low to medium heritability estimates for all traits, low genetic correlation between traits, and the small expected correlated changes in DP when selecting for decreased grain protein content or a brighter kernel color suggest it should be possible to identify low‐protein lines with acceptable kernel color and DP. Using independent culling, DP of selected lines in all crosses was similar when either grain protein content or kernel color was the first trait selected; therefore, either trait could be used as the primary selection trait. A strategy for developing low‐protein cultivars with acceptable kernel color and DP would be to use independent culling in F2:3 or F3:4 families in which grain protein content or kernel color would be the first trait and DP would be the last trait selected. The population size needed to select such lines needs to be greater than the I00 to 200 F2:3 or F3:4 families currently used by the North Dakota six‐rowed barley breeding program.
Inheritance of Sugarcane Ratooning Ability and the Relationship of Younger Crop Traits to Older Crop Traits
Authors: Milligan S. B. , Martin F. A. , Gravois K. A.
Published: July 2010

The inheritance of ratooning ability and the relationship of traits among crops in sugarcane (Saccharum spp. hyb.) has not been well examined. Ratooning ability (RA) was defined as the second ratoon(SR) crop yield percent of the plant cane yield. A replicated 4‐yr test at four locations of 37 genotypes was studied for two three‐crop cycles. Broad‐sense single‐plot heritabilities for RA were low (H ≤ 17%), while the genetic coefficient of variation of RA was largest for sucrose yield and cane yield (GCV ≈ 14.5%), and smallest for stalk diameter (GCV = 1.5%). Cane and sucrose yield RA demonstrated the largest potential for gain, while stalk weight, stalk diameter, and stalk length showed the least. Except for sucrose and cane yield and stalk number, other traits were highly correlated between plant cane and SR crops (r ≥ 0.78). Stalk number in the younger crop was the only trait significantly correlated to ratoon crop cane yield (r = 0.56), suggesting that selection for stalk number in the younger crops would enhance older crop yields. The results indicate that SR crop yields could be predicted by first ratoon crop yields. However, the best improvement of SR yields would be realized by selection in the SR.
Screening Methods to Develop Alfalfa Germplasms Tolerant of Acid, Aluminum Toxic Soils
Authors: Dall'Agnol M. , Bouton J. H. , Parrott W. A.
Published: July 2010

Soil acidity and aluminum (Al) toxicity are major problems limiting performance of alfalfa (Medicago saliva L.) in many parts of the world, but neither an effective screening procedure nor a tolerant cultivar is available. The objective of this study was to evaluate different screening methods for selection of acid soil tolerant alfalfa germplasms in the greenhouse during 1991–1994. The general screening methods included selection in unlimed soil, selection in unlimed soil containing a limed germination layer, selection for either tolerance or sensitivity to acid soil stress with Al toxicity in tissue culture, selection in unlimed soil with tandem selection for Al tolerance in tissue culture, and selection in unlimed soil containing a limed, fertilized germination layer with tandem selection for Al tolerance in tissue culture. All selected populations and checks were evaluated during 1994 in greenhouse cups containing the following soil treatments: (i) cups filled with unlimed soil, (ii) cups filled with limed soil, and (iii) cups filled with unlimed soil containing a germimation layer of limed soil. Most of the selected populations possessed better root and shoot growth than the original base population (GA‐TE) in unlimed soil, but only the population selected in unlimed soil showed better root and shoot growth in unlimed soil with a limed germination layer. No population had poorer performance than GA‐TE in limed soil. Selection in cell culture for Al toxicity tolerance did not improve tolerance per se, but selection for Al sensitivity enhanced sensitivity. In terms of success, resources, and time, screening in unlimed soil was the most effective method to improve acid soil stress tolerance.
Relationship between Bacterial Streak and Black Chaff Symptoms in Winter Wheat
Authors: Tillman B. L. , Harrison S. A. , Russin J. S. , Clark C. A.
Published: July 2010

Disease symptoms caused by Xanthomonas campestris pv. translucens (J.J.R.) Dye occur on leaves (bacterial streak), spikes (black chaff), and peduncles of wheat (Triticum aestivum L. em. Thell.). Bacterial streak‐black chaff has become prevalent in semi‐tropical regions and cultivar resistance is the best control method. The objective of this work was to determine the relationship between bacterial streak and black chaff symptoms on wheat. In field tests during 1991 to 1994, black chaff severity and bacterial streak severity were not correlated among 15 soft red winter wheat cultivars and advanced lines or 387 wheat cultivars and germplasm accessions. Greenhouse tests during 1993 to 1994 showed that ‘Florida 304’ was susceptible to bacterial streak, but resistant to black chaff. In contrast, ‘Coker 9877’ was susceptible to black chaff, but moderately resistant to bacterial streak. The cultivar Terral 101 was resistant to both black chaff and bacterial streak, whereas LA85426 was susceptible to both diseases. Wheat genotypes may be resistant to black chaff but susceptible to bacterial streak or vice‐versa. This may have caused the lack of correlation between black chaff and bacterial streak in the field. The results indicate that breeders cannot select indirectly for resistance to bacterial streak by selecting for resistance to black chaff. Since yield loss is related to bacterial streak but not to black chaff, wheat should be evaluated for resistance to bacterial streak and not black chaff.
Selection for Biological Nitrogen Fixation and Nitrogen Utilization in Birdsfoot Trefoil
Authors: Ehlke N. J. , Vellekson D. J. , Lyman B. E.
Published: July 2010

Birdsfoot trefoil (Lotus corniculatus L.) is a perennial forage legume which has a lower rate of biological nitrogen fixation (BNF) than alfalfa (Medicago sativa L.). In this study, we evaluated the gain from two cycles of recurrent selection in the glasshouse in three germplasms of birdsfoot trefoil using traits associated with improved BNF or N utilization. For improved BNF, selection was based on morphological traits correlated with the acetylene reduction assay (ARA) in a nil‐N soil environment. For improved N utilization, selection was based on increased top dry weight production in a N‐rich soil environment. The 12 selected populations and the three parental populations were evaluated in two growth chambers in a completely randomized design with four replicates. The chambers were watered three times per week with 100 mL of a modified Hoagland's solution containing either 0.0 (nil‐N environment) or 10.7 (N‐rich environment) mM N. At 8 and 14 wk after seeding, the plants were individually scored for nodule mass and fibrous roots, top dry weight, ARA rate, and N yield. Correlated trait selection for improved BNF as measured by the ARA produced populations with larger plants, more fibrous roots, and greater nodule mass resulting in a 56% increase in ARA in the nil‐N environment. In the N‐rich environment, the populations selected for improved BNF showed a significant increase in nodule mass and a 79% increase in ARA rate. Selection for improved N utilization resulted in larger plants with more fibrous roots, larger nodule mass, higher N yield and a 77% increase in ARA in the N‐rich environment. In the nil‐N environment, the populations selected for improved N utilization had larger, root systems, slightly better nodulation, and produced larger plants which resulted in a 58% increase in ARA rate. Correlated trait selection for traits which support BNF or N utilization could significantly improve the performance of birdsfoot trefoil in environments with fluctuating N availability.
Canopy Photosynthesis, Growth, Yield, and Boll 15N Accumulation under Nitrogen Stress in Cotton
Authors: Bondada B. R. , Oosterhuis D. M. , Norman R. J. , Baker W. H.
Published: July 2010

Comprehensive knowledge concerning the influence of pre‐plant fertilizer N rates on canopy photosynthesis, growth, and yield of cotton (Gossypium hirsutum L.) is lacking, while no research has been conducted on boll 15N accumulation from foliar‐15N fertilization. Field studies were conducted on long‐term N fertilizer plots on Loring silt loam (fine‐silty, mixed, thermic Typic Fragiudalt) to investigate how varying levels of pre‐plant fertilizer‐N applied to soil affected lateseason canopy photosynthesis, growth, yield and foliar applied‐15N accumulation by bolls in the top, middle, and bottom portions of the canopy. Four pre‐plant soil incorporated fertilizer N treatments were imposed: 0, 55, 82, and 110 kg N ha‐1. Plant height, number of main‐stem nodes, and first fruiting branch node were increased by increasing soil‐N regime. Leaf number, leaf area, boll number, and dry weights of leaf and boll were higher in the middle of the canopy than in the top or bottom portions. Lint yield was strongly associated with soil N and canopy photosynthesis, and the photosynthetic capacity of the canopy was proportional to availability of N. To determine boll 15N accumulation from fofiar fertilization, three foliar‐N sprays with the last fofiar‐N spray consisting of 15N was applied in each pre‐plant fertilizer N regime. The middle canopy bolls accumulated significantly more 15N than those in the upper or lower canopy. This study extended previous cotton N studies by showing that yield differences due to N can largely be explained by variation in canopy photosynthesis and plant size, and provided new information on differential 15N accumulation by bolls positioned in different portions of the canopy.
Genetic Variation for Seedling Vigor Traits in Rice
Authors: Redoña E. D. , Mackill D. J.
Published: July 2010

Seedling vigor is important for stand establishmet in direct‐seeded rice (Oryza sativa L.) culture. Genetic variation for, heritability of, and relationships among seedling vigor traits in 27 diverse rice cultivars and two segregating populations from crosses between low‐ and high‐vigor cultivars were studied. Growth chamber slantboard tests were conducted at 18° and 25°C. In a greenhouse test, entries were seeded directly in standing water. Field tests, conducted during 2 yr, used drill‐seeding. Genotypic differences were highly significant for all growth chamber, greenhouse, and field seedling vigor traits. Groupwise, temperate japonicas and indicas were more vigorous than tropical japonica types. Italica Livorno and Black Gora were the most vigorous cultivars across traits. For shoot length in the slantboard test, temperate japonica cultivars showed lower response to higher temperature than tropical japonicas and indicas. Response of root length was pronounced in tropical japonicas. Based on correlation analyses shoot weight, shoot length, and coleoptile length in slantboard tests best predicted greenhouse and field seedling vigor. Heritabilities of slantboard traits were estimated in two segregating populations. Heritability for shoot length, the most important trait, was high (0.80)in the cross Labelle/Black Gora and low (0.26) in the cross Labelle/Italica Livorno. The slantboard test was a reliable screening procedure for seedling vigor, and promising donors were identified for incorporation to breeding programs.
Cotton Response to Seasonal Patterns of Flower Removal: I. Yield and Fiber Quality
Authors: Jones M. A. , Wells R. , Guthrie D. S.
Published: July 2010

Cotton (Gossypium hirsutum L.) yield and quality can be affected by altered fruiting patterns related to the abscission of fruiting forms. This field study quantified the effects of flower removal during various stages of reproductive development on subsequent yield development, boll development, and fiber properties. Effects of early‐, mid‐, and late‐season flower loss on cotton reproductive development was determined. Various flower removal treatments were imposed on two cultivars at Clayton, NC, during 1991 and 1992. Early flower removal treatments (3rd week and earlier) delayed boll development, but no significant reduction in yield was found at season's end. Later flower removals (4th week and later) significantly reduced total fiber yields (13–33%) compared with early‐season removals (1st, 2nd, and through 3rd week) and no removal. Boll weight was positively correlated with fiber properties and was related to the amount of competition among developing bolls. The largest bolls resulted from treatments that had the largest negative effect on yield. Micronaire was the only fiber variable affected by flower removal, with increased values associated with later removal. Data indicate that late‐season flower losses (4th week and later) are the most injurious to yield, with significant yield reductions occurring from even the least severe, late‐season removal treatment of 6th week and later flowers. Early loss (3rd week and earlier) of fruit can be tolerated if the season allows sufficient time for compensatory reproductive growth and if further losses due to plant stress or insect damage are controlled.
Flowering of Berseem Clover Types in Response to Vernalization
Authors: Fairbrother T. E.
Published: July 2010

Winter hardiness of ‘Bigbee’ berseem clover (Trifolium alexandrinum L.) was reported to differ between plants grown from certified seed and breeder seed. Winter growth form also differed, with plants from breeder seed forming a rosette and plants from certified seed elongating. To determine if growth form differences were due to a change in vernalization response, imbibed seeds of Bigbee certified and breeder seed and certified ‘Multicut’ were vernalized at 2°C for 0 to 6 wk in weekly increments. Seeds from all treatments were simultaneously germinated and grown in a greenhouse under 18‐h daylength. Days to flowering, node at first flower, and the number of nodes below 5 cm at flowering were recorded. Replicated experiments were conducted with germination dates of 17 Aug. 1992 and 25 Feb. 1993. The regression of days to flowering and node at first flower on vernalization period was significant for Bigbee certified and breeder seed. Response slopes of Bigbee plants grown from certified and breeder seed differed from each other for all variables. As vernalization period decreased, plants from Bigbee breeder seed flowered later and at a higher node than plants from Bigbee certified seed. Vernalization had no effect on days to flowering or node at first flower for Multicut. Variation in vernalization response between Bigbee breeder seed and certified seed indicated that a change occurred during the production of certified seed. Multicut and Bigbee certified seed may have less winter grazing tolerance than Bigbee breeder seed since there were fewer nodes near the soil line to support regrowth.
Temperature, Nitrogen, and Carbon Dioxide Effects on Spring Wheat Development and Spikelet Numbers
Authors: Frank A. B. , Bauer A.
Published: July 2010

Spring wheat (Triticum aestivum L.) responds favorably to elevated atmospheric carbon dioxide concentration ([CO2]) at optimum temperatures. Predictions are for air temperatures to increase as global [CO2] increases. Since spring wheat grain yields generally decline as temperature increases, there is a need to understand the effects of both [CO2] and temperature on spring wheat growth, development, and yield potential. Objectives were to evaluate combinations of [CO2], air temperature, and applied N levels on leaf and apex development, spike components, tiller numbers, dry matter, plant height, and water use in spring wheat. ‘Amidon‘ spring wheat was grown in controlled environment chambers at all combinations of 350, 650, and 950 μL L−1 [CO2], 0, 100, and 300 kg N ha−1, and 14/18°C and 22/26°C night/day air temperatures. Temperature affected the Haun stage by growth degree‐days (GDD) relationship more than N or [CO2]. The phyllochron in GDD was greater for plants grown at 22/26°C (433 GDD) than at 14/18°C (345 GDD). The Haun stage at apex double ridge and terminal spikelet increased as applied N and [CO2] increased. Fertile spikelet numbers increased as [CO2] and N level increased at 14/18°C, but at 22/26°C, spikelets increased as N increased and decreased as [CO2] increased. Fertile spikelets were greatest at 14/18°C 18°C and 650 μL L−1 [CO2]. Results suggest that at elevated [CO2] and adequate soil water, air temperature is more important than [CO2] in controlling grain yield potential. Because wheat yield potential at higher temperatures decreased as [CO2] increased, a northly shift in the spring wheat growing areas may occur if global temperatures increased in concert with [CO2].
Genetic Relationships within Old U.S. Soybean Cultivar Groups
Authors: Lorenzen L. L. , Shoemaker R. C.
Published: July 2010

Before hybridization programs began in the 1930s, new soybean cultivars in the USA were primarily plant introductions from Japan, China, and Korea, or “off type, pure line” selections from existing U.S. cultivars. These “off type, pure‐line” selections were sometimes thought to have arisen as mutations. Current study of this hypothesis is difficult because numerous accessions with names similar or identical to“pre ‐1930” cultivars occur in the USDA soybean germplasm collection. This study was conducted to determine if selections made from old cultivars were likely derived from mutation and to determine the genetic diversity between accessions with the same or similar old cultivar names. One hundred‐six old entries, which belonged to 17 cultivar groups, were analyzed at between 37 and 50 RFLP loci. “Group” was defined as all accessions with a similar common name, and subsequent selections made from them. Genetic diversity values suggested that mutation did not appear to play a key role in the derivation of selections from most old cultivars. Mutation may have contributed to selections made from Habaro, Mandarin, and Wilson, but this could not be determined unambiguously. AK was previously known to be a heterogeneous seed mixture, and the old cultivar Manchu was suspected as such. The RFLP analysis supported the hypothesis that both AK and Manchu were introduced as a heterogeneous line. Most old cultivars with the same or similar common names could be easily distinguished by genotypic (RFLP) or phenotypic diversity. In 44 instances, phenotypic diversity values between two members of a group equalled zero. In only four cases were genotypic diversity values unable to resolve differences between the two accessions.
Crown Morphology Relationships among Alfalfa Plant Introductions and Cultivars
Authors: Marquez‐Ortiz J. J. , Johnson L. D. , Barnes D. K. , Basigalup D. H.
Published: July 2010

The alfalfa (Medicago sativa L.) crown is an important morphological structure because of its association with regrowth, yield, and persistence. The objectives of this research were to evaluate variability for crown morphological traits among 1067 plant introductions (P.I.s) and 110 North American cultivars, to determine the association between crown morphological traits and germplasm sources, and to compare the association between crown morphological traits and fall dormancy classes for North American alfalfa cultivars. The P.I.s and the cultivars were grown in separate field studies at Rosemount, MN, during 1989 and 1990, respectively. Plots consisted of one 3.5‐m‐long row for P.I.s, and one 1.8‐m‐long row for cultivars. They were seeded in May and the plants were dug in October. Plants were individually evaluated for crown depth, crown width, number of crown stems, crown stem width, and number of crown buds. Variation was observed among both P.I.s and North American cultivars for all crown traits. Discriminant analysis of crown traits was effective at separating germplasm sources from diverse geographic origins. The crown traits of germplasm sources from less diverse origins appeared similar. Discriminant analysis of crown traits separated highly dormant (fall dormancy = 1) cultivars more effectively than semi‐dormant and non‐dormant cultivars. Only number of crown buds had a meaningful correlation (−) with fall growth. Variation observed for crown traits among alfalfa germplasm sources indicated that selection for specific crown modifications could be effective.
Allozyme Variation in Accessions of Russian Wildrye
Authors: Wei Jun‐Zhi , Campbell William F. , Wang Richard R.‐C.
Published: July 2010

Many accessions in a gene bank collection lack adequate genetic characterization. To measure genetic variability in Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski; 2n = 2x = 14; NsNs] for effective management and utilization of germplasm resources, 160 plants representing 11 accessions of this outcrossing species from five countries were analyzed by starch gel electrophoresis. Ten enzymes revealed 14 putative and scorable loci, of which 11 were polymorphic (on average, 66% of loci were polymorphic and 2.6 alleles were found per locus). High levels of isozyme diversity were found mainly within accessions. Fixation of the Idh allele occurred in accessions from Russia, Turkey, and China, whereas polymorphisms at that locus existed in accessions from Mongolia and Iran. Allelic variation at the locus Ak‐1 was only detected in accessions of Russian origin. A large amount of allelic diversity occurred at most polymorphic loci. Approximately 90% of the allelic diversity existed within accessions. Most of the accessions, except one from Turkey, were genetically similar. Accessions collected from Russia and Mongolia were closely related, except for accession JA 251, which is closely similar to PI 499558, an accession from Xingjiang, China.
Yield and Germinability of Seed from Irrigated and Nonirrigated Early‐ and Late‐Planted MG IV and V Soybean
Authors: Heatherly Larry G.
Published: July 2010

Drought stress in the midsouthern USA reduces yield of soybean [Glycine max (L.) Merr.] planted in May and June and sometimes affects germination of harvested seed. Irrigation often increases yield, and may also increase seed germinability. Field experiments were conducted on Sharkey clay (Vertic Haplaquept, very‐fine, montmorillonitic, termic) in 1992, 1993, and 1994 at Stoneville, MS. The objective was to determine the effects of earlier‐than‐normal (April) and normal (May) planting dates on yield and germinability of harvested seed of Maturity Group (MG) IV and V soybean cultivars grown in nonirrigated (NI) and furrow‐irrigated (I) environs. In 1992, germination of seed of all cultivars harvested from the NI (14–73%) and I (36–77%) 15 April plantings was lower than that of seed harvested from the 27 May plantings. In 1993 and 1994, germination of all harvested seed averaged more than 90%. Without irrigation, seed yield from the April plantings exceeded that from the May plantings every year. The difference was greatest in 1992 (3170 vs. 2190 kg ha−1) and least in 1993 (1432 vs 1295 kg ha−1). In 1992, the 4195 kg ha−1 average yield with irrigation from the 15 April planting exceeded the 2979 kg ha−1 average yield from the 27 May planting. In 1994, yield of all irrigated cultivars in the 21 April planting equalled or exceeded the yield of the same cultivars planted on 13 May. Yields of MG V cultivars were equal to or greater than those of MG IV cultivars in both I and NI plantings in all years. These results demonstrate that April vs. normal May plantings of both MG IV and V cultivars can increase yields when grown with and without irrigation in the midsouthern USA.
Growth, Photosynthesis, and Water Relations of Wheat Grown on Acid Soil Amended with Coal Combustion By‐Products
Authors: Zaifnejad M. , Clark R. B. , Ritchey K. D. , Baligar V. C. , Parrish D. J.
Published: July 2010

Aluminum toxicity often reduces plant growth on acid soils, and coal combustion by‐product (CCBPs) can partially mitigate acid soil effects. Columns containing acidic (pH 4.7) Lily soil (Typic Hapludult) were amended in the upper 15 cm with CCBPs, lime, or both. Amendments were, in grams per kilogram, (i) none (Check); (ii) 3.98 dolomitic limestone (Lime); (iii) 15.88 high‐gypsum flue gas desulfurization by product (FGD); (iv) 3.98 + 15.88 combination of Lime + FGD; (v) 15.88 high‐gypsum FGD by‐product containing −6% Mg(OH)2 (FGD + Mg); and (vi) 6.45 fluidized bed combustion by‐product (FBC). The soil columns were leached with 138 cm of deionized water. Wheat (Triticum aestivum L., ‘Arthur’) was grown in the columns for 34 d with no additional water. Plants grown in Check and FGD treatments had lowest and similar shoot and root dry matter (DM) and leaf area. Leaf areas and DM for FBC, FGD + Mg, Lime, and Lime + FGD plants were similar and 13 to 17 times higher than for Check plants. Total root length (RL) was highest for FBC plants, which was about six‐fold higher than FGD plants, while total RL of plants grown with other amendments was about half that of FBC plants. Specific RL was highest for FGD plants. Plants grown on Lime, Lime + FGD, FGD + Mg, and FBC treatments had higher leaf photosynthetic rates, chlorophyll, and ET and lower leaf temperatures than Check and FGD plants. Even though DM of FGD plants was low, they had the highest leaf relative water content (RWC) and leaf water potential (LWP). Amendments increased soil pH and reduced acid soil stress. Higher mineral nutrient concentrations were noted in shoots of plants grown on amended soil, except for the FGD plants, which had lower Mg and higher B than considered optimal. Some but not all CCBPs benefitted plants grown on acid soil.
Aluminum Tolerance of 1BL.1RS and 1AL.1RS Near‐Isolines in Soft Red Winter Wheat
Authors: McKendry A. L. , Tague D. N. , Somers D. J.
Published: July 2010

Some cultivars containing the 1BL.1RS wheat (Triticum aestivum L.)‐rye (Secale cereale L.) translocation are presumed tolerant to aluminum (AI) toxicity, but whether this tolerance is due to genes 1RS or to genes in the wheat genome is not clear. A set of backcross‐six, F2‐derived F4 near‐isolines containing either the ‘Kavkaz’‐derived 1BL.1RS or ‘Amigo’‐derived 1AL.1RS translocation were developed in five soft red winter wheat backgrounds at Columbia, MO between 1988 and 1992. The presumed contribution of 1RS to Al tolerance expressed in solution culture was measured using a split‐plot design, replicated four times. Seedlings were grown for 4 d in an aerated, low‐ionic‐strength, hydroponic solution at pH 4.0 containing no phosphorus. Whole‐plot treatments included 1 mg L−1 Al as AlCl3 and a zero Al control. The longest seminal root of each seedling was measured and averaged across seven seedlings per isoline. Root tolerance index (RTI), calculated as the mean seminal root length in the Al treatment divided by the mean seminal root length in the control, provided a measure of Al tolerance. Higher RTI values indicated greater Al tolerance. Mean RT1 values for each background, averaged across 1AL.1RS and 1BL.1RS isolines, ranged from 0.63 in ‘MO 11728’ to 0.24 in ‘Caldwell’. 1AL.1RS significantly reduced Al tolerance in ‘Becker’, Caldwell and ‘MO 10501’, but had no effect on A1 tolerance in MO 11728 and ‘Pioneer 2551’. 1BL.1RS had no effect on Al tolerance in any genetic background. Neither the Kavkaz‐ nor the Amigo‐derived 1RS segment contained genes for AI tolerance when grown in solution culture, and improved AI tolerance previously reported in 1BL.1RS cuitivars was due to coincidental major genes on the wheat genome.
Alcohol‐Soluble Proteins and Protein Body Formation in the Endosperm of Tall Fescue
Authors: Krishnan Hari B. , White Jerry A. , Sleper David A.
Published: July 2010

Alcohol‐soluble proteins (prolamins) are the predominant storage proteins in the endosperm of most of the cereals. Prolamins are deposited within membrane bound structures called protein bodies. Our objective was to determine if there is some commonality in protein body formation between agronomically important cereals and grasses. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) of alcohol‐soluble proteins from tall rescue seeds revealed abundant proteins ranging in size from 73 to 23 kDa. Immunoblot analysis using wheat (Triticum aestivum L.) prolamin antiserum revealed limited antigenic homology between wheat and tall rescue (Festuca arundinaceae Schreb.) prolamins. The amino acid composition of tall rescue alcohol‐soluble proteins showed a high concentration of glutamine and proline residues, similar to those found in several cereal prolamins. Uitrastructural studies of the endosperm cells of tall rescue seeds at 15 d after anthesis revealed the presence of numerous vacuoles that contained protein inclusions. Extensive rough endoplasmic reticulum was seen during this developmental stage. The endoplasmic reticulum, which was often dilated, gave rise to numerous, small vacuole‐like structures. At 20 d after anthesis, the rough endoplasmic reticulum contained flocculent material within the lumen of the dilated areas. Protein aggregates were surrounded by numerous vesicles whose membranes were studded with ribosomes. Organized membrane lattices were seen at the surface of protein bodies and at the junctions where small protein bodies were fusing with larger ones. Protein A‐gold immunocytochemistry employing wheat prolamin antiserum specifically localized the alcohol‐soluble proteins within the protein bodies.
Breeding for Grain Yield Stability Using Full‐Sib Family Recurrent Selection in Sorghum
Authors: Chisi M. , Bramel‐Cox P. J. , Witt M. D. , Claassen M. M. , Andrews D. J.
Published: July 2010

Sorghum [Sorghum bicolor (L.) Moench] is generally grown unpredictable environments, where the genotype × environment (GE) interaction is large. Recurrent selection can be used to select genotypes adapted to all these environments. This study evaluated the potential gain from selection of full‐sib families for grain yield stability across diverse environments using various selection criteria. These criteria were mean productivity, a rank summation index, a selection index, and scores from the principal component analysis of the G × E matrix. One‐hundred full‐sib families were derived from a broad‐based population of sorghum, KP9B. The full‐sib families were evaluated at three locations, Garden City and Hesston, KS, and Mead, NE, in 1991 and 1992. The experiment involved two replications of a block‐in‐replication design with five blocks of 20 entries each. The interaction of the full‐sib families with the individual environments was high. The use of mean productivity, rank summation, and selection index using a subset of the environments to select for genotypes with a consistent, high yield across the environments or stability was predicted to be ineffective. The GE interaction matrix was partitioned into three significant (P < 0.05) principal components. Cluster analysis of the genotype's three principal component scores grouped the full‐sib families into five groups that differed in their response to the six environments as characterized by differences in their mean standardized grain yield and bloom date in each individual environment and overall. This technique described the types of full‐sib family responses to the test environments and identified a yield response that could be considered as stable.
Teosinte Cytoplasmic Genomes: II. Performance of Maize Hybrids with Teosinte Cytoplasms
Authors: Edwards Jode W. , Coors James G.
Published: July 2010

Alien cytoplasm substitution effects on quantitative agronomic characters in maize breeding germplasm have been studied many times, but few cytoplasmic effects have been found. This research was conducted to evaluate the importance of nuclear sources of variation often confounded with cytoplasmic effects, and to study effects of substituting teosinte cytoplasms into Zea mays ssp. mays hybrids. Cytolines were developed by transferring 11 cytoplasms to maize inbreds A619 and W23 by at least six generations of backcrossing. Reciprocal testcrosses were made between cytolines and three testers as well as between A619 and W23 and the same testers. Nuclear effects on reciprocal cross differences and effects of incomplete recovery of cytoline nuclear genotypes were large enough to cause bias in estimates of cytoplasmic effects, had appropriate comparisons not been available to account for these sources of variation. The 11 teosinte cytoplasms reduced grain yield by an average of 0.20 Mg ha−1 or 2.2%. Cytoplasmic effects averaged across all cytoplasms and hybrids were not significantly different from zero for any other trait. One of 11 cytoplasms studied had stable effects on hybrid performance. Four additional cytoplasms had appreciable effects that varied widely with the nuclear genotype. Direct substitution of any of these cytoplasms into maize hybrids would not likely be of great benefit because desirable effects were generally small and difficult to predict in different nuclear‐cytoplasmic combinations.
Genetic and Cytogenetic Analyses of Russian Wheat Aphid Resistance in Triticale × Wheat Hybrids and Progenies
Authors: Nkongolo Kabwe K. , Lapitan Nora L. V. , Quick James S.
Published: July 2010

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is a serious pest in wheat (Triticum aestivum L.). Four Russian triticale (X Triticosecale Wittmack) lines, PI 386148, PI 386149, PI 386150, and PI 386156, have been the most resistant triticales to the RWA in several screening tests. Resistance is controlled by a single dominant gene at a common locus in the three triticale lines PI 386148, PI 386149, and PI 386156. However, expression of these resistance genes in a wheat background and the inheritance of resistance in PI 386150 have not been determined. The objectives of this study were (i) assess the transmission and the expression of RWA resistance in triticale × wheat hybrids, (ii) to determine the inheritance of resistance in PI 386150, and (iii) to identify the rye chromosome(s) from Secale montanum Guss. associated with RWA resistance. Advanced generations from crosses between PI 386148 triticale × ‘Lamar’ wheat and P1386150 triticale × Lamar were produced and the progenies screened to determine their reaction to the RWA. All F1 plants derived from both crosses were resistant indicating that resistance is dominant in both triticale lines. C‐banding and in situ hybridization with the pSc119.1 probe, a rye‐specific DNA probe, showed that chromosome 4Rmon was associated with resistance in PI 386150. The results of this study should facilitate the transfer of the resistance gene(s) from these triticale lines into wheat.
Associations among Characters Related to Yield Sink Capacity in Space‐Planted Rice
Authors: Kato Tsuneo , Takeda Kazuyoshi
Published: July 2010

Yield sink capacity, a maximum size of sink organs to be harvested, has been one of the objectives in crop breeding for increasing yield. This study investigated associations among characters related to yield sink capacity of rice (Oryza sativa L.). Two populations of recombinant inbreds (RI), which differed in their genetic variance for grain size, were examined in four environments. Genetic and environmental correlations were estimated with an analysis of variance on the data obtained from single plants. Filled grain percentage showed a high negative genetic correlation with yield sink capacity in a RI population with smaller grain size variation (r = −0.96). This correlation was not so high in another RI population with larger grain size variation (r = − 0.49). Hence, genetic variation in grain size could reduce the negative genetic relationship between filled grain percentage and yield sink capacity. In both RI populations, filled grain percentage showed negative genetic correlations with the traits for number of spikelets on secondary branches (SB) and a positive genetic correlation with number of primary branches (PB) per panicle. The number of PB per panicle did not show positive genetic correlations with the traits for number of spikelets on SB. These findings suggest that spikelets on PB, which generally produce well‐ripened grains, can be increased by increasing the number of PB per panicle, without overproducing spikelets on SB. Thus, rice cultivars could be developed bearing panicles with both a large spikelet number and a high filled grain percentage.
Soybean Growth and Agronomic Performance in Response to the Long‐Juvenile Trait
Authors: Tomkins Jeffrey P. , Shipe Emerson R.
Published: July 2010

A long‐juvenile (LJ) trait that delays flowering has been incorporated into temperate soybean [Glycine max (L.) Merr.] genotypes for adaptation to short‐day conditions. Growth and agronomic effects of the LJ trait as influenced by maturity group are not well documented. A study was undertaken in which five LJ near‐isoline pairs in Maturity Groups IV, V, and VI were evaluated at early (late April), normal (late May), and late (late June) sowing dates near Pendleton, SC (34° N lat) in 1993 and 1994. Growth stages, plant morphology, and agronomic characteristics were determined. Extended periods of vegetative growth in response to the LJ trait resulted in one to three additional V‐stages and increased branch growth during the vegetative period. The LJ trait lengthened the period between flowering and pod set (R1 to R5) 38, 17, and 11% at early, normal, and late sowings, respectively, in Maturity Group IV isolines and shortened it 18 and 12% at early and normal sowings for Maturity Group VI isolines. The period of seed fill (R5 to RT) was unaffected by the LJ trait. The LJ trait influenced reproductive morphology and plant seed yield distribution with responses being affected by maturity group. Seed yield in response to the trait increased 43 and 16% at early and normal sowings in Maturity Group IV isolines and 22% at early sowings in the Maturity Group V isoline. Seed quality of LJ genotypes in Maturity Group IV isoline pairs was improved 49 and 35% at early and normal sowings. Our results indicate that maturity group influences growth and agronomic responses related to the LJ trait and that early maturing genotypes are more suited for its introgression to maximize potential benefits of the trait.
Theoretical Comparison of Recurrent Selection Methods for the Improvement of Self‐Pollinated Crops
Authors: Goldringer I. , Brabant P. , Gallais A.
Published: July 2010

Choosing a recurrent selection strategy depends on the resources of the breeder and on the efficiency of the possible selection schemes. An experimental comparison is difficult and time consuming, but a theoretical comparison may provide some guidelines. This study was conducted to compare theoretically the efficiency of different recurrent selection methods of improving the line value of a population, in this case, of self‐pollinated crops. We considered five methods that are well adapted to breeding autogamous species: single‐doubled‐haploid descent selection with a 4‐yr (SDH1) or 5‐yr cycle (SDH2); selection on S1 family (S1; selection on S2 bulk (S2B) and on S2 family (S2F); and two other methods‐selection on half‐sib progeny (HSP) and full‐sib family (FSF)‐ used for the improvement of per se or combining ability values. Analytical expressions for the corresponding expected genetic advances (per growing season) were derived and compared according to the values of the narrow sense heritability and the variance components in an inbred system. SDH1 always appeared as the most efficient method. SDH2 and S2F were the next best methods for realistic values of parameters. S1 efficiency was restricted to very high heritabilities and additive variances. Gain due to higher gene fixation in the S2 families balanced the short cycle of S1. As the proportion of non‐additive and environmental effects increased, SDH2 became more efficient than S2F, and S2F more efficient than S1. S2B was always the least efficient except when the possibility to reduce the between‐plot environmental variance through a larger plot size was taken into account. In that case, S2B could be more efficient than S2F for medium to low heritabilities. HSP and FSF appeared only marginally as the second or third most efficient methods. SDH is the best method to improve autogamous crops even though cycle length is 5 yr; however, if haplo‐diploidization technologies are not available or are too expensive, a selection scheme based on S2 family may be the most economical method.
Spatial Analysis Improves Precision of Seed Lot Comparisons
Authors: Clarke F. R. , Baker R. J.
Published: July 2010

Spatial analysis, by least squares smoothing, was compared with randomized block analysis of data from field trials of 50 seed lots of spring wheat (Triticum aestivum L. cv. Katepwa) and of 40 seed lots of spring barley (Hordeum vulgare L, cv. Harrington). Spatial analysis reduced standard errors (SED) of differences for grain yield, but not for stand density. For grain yield, least squares smoothing reduced the SED by 11 to 53% in four spring wheat trials and by 24 to 34% in three spring barley trials. Improved precision is expected to affect correlations between trials. For spring wheat, the inter‐trial correlation increased from 0.40 to 0.60 in one trial, from 0.03 to 0.41 in another, and had little effect in the remaining four of six pairs of wheat trials. For barley yield, the inter‐trial correlation increased from 0.25 to 0.36 in one of three pairs of trials, and decreased from 0.28 to −0.06 or from 0.22 to −0.05 in the other two. In the spring wheat trial with largest spatial variability, least squares smoothing, first‐order autoregressive residuals, and the iterated Papadakis' methods gave similar reductions in SED (53–63%) and adjusted means that were highly correlated (r > 0.94). Row‐column analysis gave little reduction in the SED. A multiplicative model reduced the SED, but adjusted means were poorly correlated with those of other methods (r > 0.78). Simulation showed that an incomplete block analysis could have provided nearly the same improvement in precision as spatial analysis. Our results confirm that spatial or incomplete block analyses can improve the efficiency of field trials.
Inheritance of Low Production of Striga Germination Stimulant in Sorghum
Authors: Vogler R. K. , Ejeta G. , Butler L. G.
Published: July 2010

Host‐plant resistance to the parasitic weed Striga (Striga spp. Lour.) is a manifestation of one or more potential mechanisms. One of the better understood mechanisms of resistance against Striga by sorghum [Sorghum bicolor (L.) Moench] is low production of compounds by the host root that Striga seeds require as stimulants for germination. A recently developed, efficacious laboratory screening technique, the agar gel assay, distinguishes resistance to Striga among sorghum cultivars based on the capacity of their root exudates to stimulate Striga seeds to germinate in a water agar medium. This study was conducted to determine the inheritance of low stimulant production in sorghum by the use of the agar gel assay. F1, F2, and backcross progenies between resistant sorghum line ‘SRN‐39’ and three susceptible lines, ‘Shanqui Red’, ‘P‐954063’, and ‘IS 4225’, were evaluated for stimulant production. Segregation ratios indicated that low stimulant production is inherited as a single, nuclear, recessive gene which is largely additive in action.