bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Expressed Proteins in Fiber Fractions from Insect‐Protected and Glyphosate‐Tolerant Cotton Varieties
Authors: Sims Steven R. , Berberich Sharon A. , Nida Debbie L. , Segalini Lyra L. , Leach John N. , Ebert Christine C. , Fuchs Roy L.
Published: July 2010

The objective of this study was to determine the concentration of introduced proteins in the fiber fractions of transgenic cotton (Gossypium hirsutum L.) before and after processing. Two novel cotton varieties were developed by genetic transformation technology. One variety expressed the CryIA(c) insecticidal protein derived from Bacillus thuringiensis var. kurstaki. The second cotton variety expressed the CP4 EPSPS (5‐enolpyruvyl shikimate‐3‐phosphate synthase) protein, originally found in Agrobacterium sp., which confers tolerance to glyphosate herbicide. Levels of the CryIA(c) and CP4 EPSPS proteins in raw lint, combed lint, raw linters, and processed linter brown stock from these cotton varieties were analyzed by means of western blot, insect bioassay [for CryIA(c) protein only], or both. The CryIA(c) protein was present in raw linters (0.17 μg g−1), but it was not detected in either raw or combed lint. The CP4 EPSPS protein was detected at low levels (<0.5 μg g−1) in combed lint, but not in processed linter brown stock. Inactivation of the CryIA(c) and CP4 EPSPS proteins in the first processing step for linters indicates that these proteins will not be present in cotton linter products. Similarly, the typical heat and chemical processing of cotton lint should also denature any transgenic protein(s) present.
Molecular Markers Associated with Water Use Efficiency and Leaf Ash in Soybean
Authors: Mian M. A. R. , Bailey M. A. , Ashley D. A. , Wells R. , Carter T. E. , Parrott W. A. , Boerma H. R.
Published: July 2010

Water use efficiency (WUE) is an important trait that has been associated with drought tolerance of crop plants, and leaf ash (LASH) generally related to WUE. A restriction fragment length polymorphism (RFLP) map was constructed from a soybean [Glycine max (L.) Merr.] population of 120 F4‐derived lines from a cross of ‘Youngș × PI416937. The purpose of this research was to identify quantitative trait loci (QTL) associated with WUE and LASH in 36‐d‐old, greenhouse‐grown plants. The experimental design was a randomized complete block with six replications. Significant (P < 0.01) phenotypic differences were detected among the lines for both traits. A total of four and six independent RFLP markers were associated with WUE and LASH and if combined each group of markers would explain 38 and 53% of the variability in the respective traits. One marker locus (cr497‐1), on USDA Linkage Group J, explained 13.2% of the variation in WUE indicating the presence of a major QTL. The LASH was negatively correlated with WUE (r = −0.40**), and two QTL were associated with both WUE and LASH. For each of these QTL, the allele for increased WUE was associated with reduced LASH.
Inheritance of Host‐Controlled Restriction of Nodulation by Bradyrhizobium japonicum Strain USDA 110
Authors: Lohrke Scott M. , Orf James H. , Sadowsky Michael J.
Published: July 2010

The use of soybean [Glycine max (L.) Merr.] genotypes which specifically restrict nodulation by competitive indigenous Bradyrhizobium populations has been proposed as an approach to favor increased nodulation by more effective, inoculant‐quality strains. Soybean plant introduction (PI) PI 417566 restricts nodulation by Bradyrhizobium japonicum (Kirchner, Jordan) strains in serogroup 110. In this study, the interaction of PI 417566 with strains in serogroup 110 is being used as a model system to determine whether host‐controlled nodulation restriction can be used to alter the competitiveness of indigenous bradyrhizobia. The objectives of this study were to determine the type of inheritance and the number of genes in PI 417566 which condition restriction of nodulation by strain USDA 110 and whether this gene(s) could function to prevent nodulation of serogroup 110 strains under field conditions. Inheritance of host‐controlled nodulation restriction was determined by crossing P1417566 with the nonrestricting cultivars Agassiz and Evans. The nodulation phenotype of 126 F2 plants from Agassiz × PI 417566 and 44 F2 plants from Evans × PI 417566 was assessed in growth chamber studies. In the former cross, 98 nodulating and 28 non‐nodulating plants, and in the latter, 32 nodulating and 12 non‐nodulating plants were observed. In both cases, a Chi‐squared test indicated a good fit to a 3:1 segregation ratio, indicating that a single recessive gene conditions restricted nodulation in P1 417566. A 2‐yr field study utilizing F2:4 and F2:5 progeny from Agassiz × PI 417566 and F2:4 progeny from Evans × PI 417566 demonstrated that the lines had the ability to restrict nodulation by serogroup 110 strains under field conditions and that restriction occurred even in the presence of large numbers (5 × 1O7 cells/g soil) of added USDA 110.
Inheritance of Root Traits in Alfalfa
Authors: Johnson L. D. , Marquez‐Ortiz J. J. , Barnes D. K. , Lamb J. F. S.
Published: July 2010

Root growth patterns influence nutrient uptake, productivity, and persistence in alfalfa (Medicago sativa L.). Inheritance of traits affecting root growth patterns in alfalfa are not well understood. Objectives of this research were to determine the affects of plant spacing and geographic location on root traits in alfalfa, to determine the inheritance of seven root morphological traits of alfalfa, and to evaluate the association between root traits, fall dormancy, and seedling year herbage yield. Progenies of diallels and design II matings were planted during May 1991 at two locations in 30‐cm rows with 2.5 cm between plants within the row. Plants were evaluated for seedling year herbage yield and fall dormancy. During October 1991, they were dug and evaluated for taproot diameter (TD), lateral root number (LRN), lateral root diameter (LRD), lateral root position (LRP), fibrous mass (FRM), percentage of determinate taproots (PDT), and determinate taproot position (DTP). Border effects were determined by evaluating single plants from the ends of the plots separately from plants in the middle of the plots. Extra space on plot borders affected root morphology, but few progeny × border interactions were found. Location affected root morphology, and a few location × cross interactions were observed for TD and LRP. Additive genetic effects were important in controlling inheritance for TD, LRN, LRD, LRP, and FRM. These traits had moderate (45) to high (87) heritabilities. genetic variances were detected for PDT or DTP. Taproot diameter was the root trait most highly correlated with fall dormancy (0.46–0.50) and seedling year herbage yield (0.61–0.75). Selection for LRN, LRD, and FRM at one location with uniform plant spacing should be successful. Multiple location selection programs may be more appropriate for TD and LRP.
Grain Protein Determinants of the Langdon Durum‐dicoccoides Chromosome Substitution Lines
Authors: Deckard E. L. , Joppa L. R. , Hammond J. J. , Hareland G. A.
Published: July 2010

High grain protein content of durum wheat (Triticum turgidum L.) is important for improved cooking and nutritional quality. The development of a set of ‘Langdon’‐dicoccoides [LDN(DIC)] chromosome substitution lines offers an opportunity to develop new high protein durum cultivars. The objective of this research was to determine under field conditions the biological reason for the changes in grain protein content. The substitution lines studied included two LDN(DIC‐2A) lines; one each of the LDN(DIC‐4A), LDN(DIC‐4B), and LDN(DIC‐5B) lines; and three LDN(DIC‐6B) lines. The changes in accumulation and partitioning of dry weight (DW) and N as a result of substituting specific DIC chromosomes into LDN durum were consistent across the environments tested. Certain DIC chromosomes altered the accumulation ratio (total plant N/total plant DW), others altered the partitioning ratio (N harvest index/harvest index), and others appeared to alter both ratios to affect grain protein content. The major reason for the lower N contents of the 2A, 4A, and 4B lines was a decreased partitioning ratio, and the major reason for the higher N content of the 5B line was a higher accumulation ratio. The 6B lines were the only lines where the accumulation and partitioning ratios were always equal to or greater than LDN. The three 6B lines varied for the relative importance of changes in the accumulation and partitioning ratios to increase grain N content.
Sample Variation and Resource Allocation for Ergot Alkaloid Characterization in Endophyte‐Infected Tall Fescue
Authors: Adcock R. A. , Hill N. S. , Boerma H. R. , Ware G. O.
Published: July 2010

Ergot alkaloid concentrations vary among genotypes of endophyteinfected (E + ) tall fescue (Festuca arundinacea Schreb.). Because the ergot alkaloids are responsible for detrimental health disorders in grazing livestock, but the endophyte Neotyphodium coenophialum (Morgan‐Jones and Gams) Glenn, Bacon and Hanlin is mutualistic, development of E + tall fescue populations low in ergot alkaloid concentration may be a sustainable non‐toxic solution for livestock producers. Current techniques for screening ergot alkaloids in tall rescue are labor and equipment intensive and time consuming. The objective of this research was to determine the number of replications and locations needed to detect specified differences among treatments varying in alkaloid concentration. Six E + tall fescue genotypes were harvested twice at two field locations and one greenhouse location in 1 yr, and the number of replications and environments required to show specific treatment differences for alkaloid concentration calculated within harvest dates. Ergot alkaloid concentrations for the genotypes ranged from 488 mg kg−1 to 2504 mg kg−1 in the spring, and 219 mg kg−1 to 986 mg kg−1 in the summer. Genotypic variances were proportional to the mean; hence, data were subjected to a log10 transformation. Treatments harvested twice with differences of 50% of the experimental mean were detectable (P = 0.05) in experiments containing two replications grown at four environments, or two replications grown at three environments and harvested once when nontransformed or transformed data were used, respectively. Use of transformed data will be necessary to keep the number of observations per experimental unit manageable.
Marker‐Assisted Selection to Improve Drought Resistance in Common Bean
Authors: Schneider Kristin A. , Brothers Mary E. , Kelly James D.
Published: July 2010

Breeding for a quantitative trait like drought resistance would be facilitated by the development of a method of marker‐assisted selection (MAS) that is capable of identifying high performing genotypes in early generations. Two recombinant inbred populations were grown from 1990 to 1994 at eight locations in Michigan and Mexico under stress and nonstress conditions to identify random amplified polymorphic DNA (RAPD) markers associated with drought resistance in common bean (Phaseolus vulgaris L.) Six‐hundred random decamer primers were screened against the parents of the two populations, 50% of which were polymorphic. Seventy of these polymorphic primers were screened against each population. Using one‐way analysis of variance and multiple regression, four RAPD markers were identified in one population and five in another that were consistently and significantly associated with yield under stress, yield under nonstress, and/or geometric mean yield across a broad range of environments. To test the effectiveness of MAS for drought resistance, markers were used to select genotypes from either extreme. Yield data from three locations were examined to evaluate the effectiveness of these markerbased selections. Marker‐assisted selection in the Sierra/AC1028 population was found to be effective in Michigan under severe stress and ineffective in Mexico under moderate stress. The five RAPD markers used for MAS in the Sierra/Lef‐2RB population improved performance 11% under stress and 8% under nonstress, whereas conventional selection based on yield performance failed to increase performance. Response to conventional selection was three times greater in the Sierra/AC1028 population, supporting the conclusion that the effectiveness of MAS is inversely proportional to the heritability of the trait under examination.
Expression of Aluminum Tolerance Transferred from Atlas 66 to Hard Winter Wheat
Authors: Johnson James P. , Carver Brett F. , Baligar V. C.
Published: July 2010

Genetic improvement of acid soil tolerance of wheat (Triticum aestivum L.) adaptable to the Great Plains involves the transfer of AI tolerance from other gene pools. One hindrance may be the interaction of gene effect with genetic background. Aluminum‐tolerant nearisoĺines of hard red winter (HRW) wheat were selected on the basis of the hematoxylin assay using ‘Atlas 66’ as the source of tolerance. The objectives were to enumerate the genes for AI tolerance in these lines and to quantify their expression in artificial solution and natural soil media containing AI. Laboratory and growth chamber experiments were conducted with AI‐tolerant and AI‐susceptible near‐isolines of ‘Chisholm’ and ‘Century’. Segregation for hematoxylin staining score in populations derived from crossing the tolerant isoline with its recurrent parent indicated a single dominant gene was transferred from Atlas 66. This gene does not appear to be unique relative to ‘2180’. Dose‐response curves for relative root length (RRL) measured in solution culture confirmed differences in AI tolerance predicted by the hematoxylin assay. Each tolerant isoline showed a linear decline in RRL to increasing AI concentration (0.09–0.72 mM AI), while the susceptible isolines and recurrent parents showed a more acute curvilinear response. The tolerant isolines exceeded their recurrent parent by 19% (Chisholm) and 38% (Century) in RRL, measured in five acidic Appalachian soils. While the hematoxylin assay enabled selection of a dominant gene conferring increased root growth in response to AI, complete expression of tolerance from Atlas 66 was not achieved or was modified in these HRW backgrounds.
Cost‐Effective Transfer of Recessive Traits via the Backcross Procedure
Authors: Isleib T. G.
Published: July 2010

The backcross breeding method is often used to transfer recessive traits controlled by one or a few genes from one pure line to another. Guidelines are needed to help plant breeders to use backcrossing cost‐effectively. In a backcrossing program, a plant breeder may choose between methods with two or three stages per cycle. The two‐stage method utilizes alternate backcrossing and selfing to identify BCiSj plants with the recessive trait while the three‐stage method uses two sequential crosses followed by selfing. In the three‐stage method, nmin, the minimum number of plants required to recover at least one or two BCiSj plants in the ith cycle with a given probability (1 — α), is obtained by growing only one BCiSj plant for each of nmin BCiSo. Alternative values for the number of BCiSo plants (rib) and BCiSj plants per BCiSo (ns are present for α = 0.05 and α = 0.01 for traits controlled by one, two, three, or four recessive genetic loci. A method to compare the cost‐effectiveness of alternative values is presented for cases where the relative costs of crossing, selfing, and evaluation of Sj progeny are known. Unless time is the paramount concern, it is only in cases where the ressive trait is controlled by a single locus that it can be more cost‐effective to make two sequential crosses to the recurrent parent before selflng than to cross and self and then only if the cost of evaluating BCiSj plants is high relative to the cost of producing BCiSo plants. When using the three‐stage backcross method, the breeder can reduce the nb and increase ns if the cost of evaluating BCiSj plants is low relative to the cost of producing BCiSo plants.
Leaf Appearance in Cowpea: Effects of Temperature and Photoperiod
Authors: Craufurd Peter Q. , Subedi Madhu , Summerfield Rodney J.
Published: July 2010

Leaf appearance in crop plants is an important process involved in canopy development. The environmental control of leaf appearance has not been studied in cowpea [Vigna unguiculata (L.) Walp.]. This study was conducted to determine whether photoperiod has any effect on the rate of leaf appearance (RLA) and to determine the phyllochron and its base temperature in cowpea. Five genotypes from W. Africa were sown on nine occasions between 1990 and 1992 at Kano, Nigeria, (12°03′N). Plants were grown in pots under short (9.7–10.8 h d−1), natural (12.3–13.5 h d−1), and long (13.5–14.4 h d−1) day lengths and at mean daily temperatures of between 20.9 and 29.8°C. Eight genotypes, including the five genotypes grown in Nigeria, were also grown at seven mean temperatures ranging from 15.4 to 33.7°C in controlled environment glasshouses during 1994 in the UK. Leaf number on the main shoot was recorded every 2 to 3 d during the course of the experiments. No significant effects (P > 0.05) of photoperiod on RLA were detected in any genotype. Temperature significantly (P < 0.001) affected RLA in all genotypes. The relationship between RLA and mean temperature was similar in experiments in Nigeria and controlled environments. A comparison of the combined Nigerianand controlled environment data sets revealed significant (P < 0.01) differences between genotypes in the intercept but not in the slope of the relationship between RLA and mean temperature. The phyliochron, expressed as thermal time (0) per leaf, was therefore the same in all genotypes, 42°C d, above a base temperature that varied from 7 to 12°C. These values of the phyllochron and its base temperature are similar to those reported for other tropical legumes.
Photoperiodically Sensitive and Insensitive Phases of Preflowering Development in Rice
Authors: Yin Xinyou , Kropff Martin J. , Ynalvez Marcus A.
Published: July 2010

The time interval between sowing and flowering in rice (Oryza sativa L.) comprises three successive phases: a basic vegetative phase (BVP), a photoperiod‐sensitive phase (PSP), and a post‐PSP phase (PPP). The objective of this study was to estimate the length of the three phases in diverse rice cultivars to provide the basis for accurately predicting rice flowering dates. In greenhouse experiments, plants of 20 cultivars were transferred from short day (SD) (10 h d−1) long day (LD) (12.5 or 14 h d−1) or from LD to at various tim es aft er sowing. The duration of BVP varied greatly among cultivars ranging from 16.7 to 45.4 d. The indica cultivars exhibited an apparently longer BVP than the japonica cuitivars. The duration of PPP also varied among cultivars, from 18.0 to 37.2 d. For all cultivars, the length of the intervening PSP was shorter under SD conditions (3.6–24.1 d) than under LD conditions (10.5–76.5 d); the difference in PSP between SD and LD depended on the photoperiod sensitivity of the cultivar. The PSP under both SD and LD conditions did not necessarily end at panicle initiation (PI), but, on average, 4 to 5 d after PI. This study confirms the necessity to divide the entire preflowering period into the three phases for modeling purposes. Further studies are needed to elucidate the phenomenoinn some cultivars of a significant delay of flowering by early SD‐to‐LD transfers before PI.
Potential of RAPD Markers for Use in the Identification of Creeping Bentgrass Cultivars
Authors: Golembiewski Robert C. , Danneberger T. Karl , Sweeney Patricia M.
Published: July 2010

The production of RAPD markers is rapid and provides a reliable mechanism for generating an almost infinite number of polymorphisms useful in cultivar identification. The potential use of RAPD markers to identify bulk seed samples of 13 synthetic creeping bentgrass (Agrostis stolonifera L. var. stolonifera) cultivars was examined. Two seed lots were evaluated for five of the 13 cultivars. Eight of the 50 oligonucleotide primers screened produced unique polymorphic amplification fragments that identified 11 of the 13 cultivars. Two cultivars could not be identified because the amplification fragments that distinguished one seed lot were not present in the second seed lot of the same cultivar. These observed differences among seed lots were repeatable. The results demonstrate that RAPD markers have the potential to be a valuable tool for the identification of synthetic turfgrass cultivars as long as precautions are taken to account for the possibility of seed lot effect.
Amount and Quality of Chicory Herbage Ingested by Grazing Cattle
Authors: McCoy J. E. , Collins M. , Dougherty C. T.
Published: July 2010

Ingestive behavior of cattle (Bos taurus L.) grazing chicory (Cichorium intybus L.) has not been elucidated. Adult Angus cows were utilized to measure ingestive behavior over a range of allowances (2.53–5.17 kg cow−1 h−1) on vegetative chicory (cv. Grasslands Puna) growing on a Maury silt loam (fine, mixed, mesic, Typic Paleudalf) soil. A change‐over design employing difference procedures was used with tethered animals to evaluate allowance effects on forage quality of available, consumed and residual herbage as well as rate of biting and dry matter intake. Pre‐ and post‐grazing herbage mass and quality were determined in three 10‐cm strata above a 5‐cm stubble. Cattle consumed about 66% of the available herbage at each allowance level during a 1‐h grazing meal. In vitro dry matter disappearance (IVDMD) ranged from 719 to 746 g kg−1 across the three canopy strata prior to and after grazing. Nitrogen concentration increased from 26 to 47 g kg−1 from the lower to upper canopy stratum. Herbage intake rate increased from 1.7 kg h−1 at the lowest allowance to 3.6 kg h‐~ at the highest, in response to a linear increase in intake per bite. Biting rate was unaffected by herbage allowance. High dry matter intake per feeding station and a relatively low number of feeding stations visited per meal suggest that chicory was not grazed in distinct horizons. Together with high intake rates, the high and uniform quality of chicory canopies indicate that this species could be useful for livestock having high nutrient and dry matter intake requirements.
A Technique to Quantitatively Measure the Leaf Streaking Symptom of Russian Wheat Aphid Infestation
Authors: Miller Helen L. , Porter David R.
Published: July 2010

One of several symptoms of Russian wheat aphid (RWA) [Diuraphis noxia (Mordvilko)] damage in susceptible barley (Hordeum vulgare L.) is white or chlorotic streaking of the leaf. Current methods use several symptoms to qualitatively rate damage. We have developed a simple, inexpensive, and non‐destructive technique to quantitatively measure streaking. The technique uses a series of small contiguous circles photocopied onto a clear plastic sheet to help quantify the percentage of leaf streaked. Measurements of streaking can be done within a week after infestation, and require no other specialized instrumentation. The series of circles technique allowed us to confirm and quantify some previously observed patterns of the streaking response concerning location and amount of streaking in relation to aphid age, location, and feeding duration. This technique could be used in physiological and genetic studies of the plant's response to insect stress.
Effects of Heading Date on Agronomic Performance of Winter Wheat Isolines
Authors: Haro Edgar S. , Allan R. E.
Published: July 2010

Heading and photoperiod response are key processes affecting adaptiveness of wheat (Triticum aestivum L.). Few soft white winter (SWW) wheat cultivars of the U.S. Pacific Northwest (PNW) express early heading. Earliness offers several advantages including early harvest, reduced pre‐harvest sprouting loss, and increased operational efficiency. The objective of this study was to determine if early heading genotypes warrant greater breeding emphasis. Near‐isogenic lines (NILs) were developed by transferring early heading character from Early Blackhull and an Early Blackhull derivative to ‘Nugaines’ (NGN), an adapted PNW SWW cultivar. The NILs comprise a near‐continous range of phenotypes that head 0 to 10 d earlier than NGN. The parents and NILs were tested during two to four yr in three diverse field environments. Results showed that genotypes 3 to 7 d earlier than NGN warrant increased breeding emphasis because they had high yield potential across all environments and often had enhanced test weight, kernel weight and harvest index. The earliest NILs had limited yield potential in the cool‐moist medium growing season environment, but they had high yield potential in the temperate long‐growing season environment. Grain‐fill duration of NILs was strongly influenced by environment and only partially associated with heading date. Two early‐heading NILs were less sensitive to photoperiod than NGN, but less sensitivity was not a requirement for early heading. Rate of apical meristem development was partially associated with early heading date at the distinct blister‐like spikelet stage. Breeding programs centered in cool‐moist environments of the PNW should consider increasing emphasis on early heading SWW germplasm.
Maize Leaf Absorptance of Photosynthetically Active Radiation and Its Estimation Using a Chlorophyll Meter
Authors: Earl H. J. , Tollenaar M.
Published: July 2010

Recent evidence suggests that chlorophyll fluorescence techniques can be used to determine photosynthetic rates of maize (Zea mays L.) leaves much more rapidly than is possible with conventional gas exchange methods. However, the accuracy of such measurements depends directly on the accuracy with which leaf absorptance of incident photons in the PAR (photosynthetically active radiation) region can be estimated. Our objectives were (i) to monitor changes leaf ahsorptance in a typical maize crop over the growing season, and (ii) to determine if absorptance of maize leaves could be accurately estimated with a SPAD 502 hand‐held chlorophyll meter (Minolta Corporation, Ramsey, NJ). Leaves from six leaf positions were harvested on eleven dates between 55 and 134 d after planting. An integrating sphere and field‐portable spectroradio meter were used to measure reflectance and transmittance of leaf tissue samples at 5‐nm intervals between 400 and 700 nm, and a SPAD value was also determined for each sample. Greening of young leaves was associated with decreases in both reflectance and transmittance in the middle wavelengths of the PAR region, while leaf senescence was associated with increases in both reflectance and transmittance, primarily in the longer wavelengths of the PAR region. Leaf absorptance of incident photons in the PAR region by healthy, fully expanded leaves ranged from approximately 0.88 to 0.91; much lower values were observed for young, chlorotic, or senescing leaves. Regression analysis revealed a strong relationship (r2 = 0.98) between leaf absorptance and SPAD value, suggesting that the SPAD meter could be used to provide a rapid estimate of leaf absorptance in the field.
Transpiration Efficiency, Specific Leaf Weight, and Mineral Concentration in Peanut and Pearl Millet
Authors: Brown R. H. , Byrd G. T.
Published: July 2010

Transpiration efficiency (TE) is the weight of dry matter produced per unit of transpiration. If mineral nutrients are taken up in proportion to transpiration, then the concentration of minerals in dry matter may be predictive of TE. It has recently been reported that specific leaf weight (SLW) is also correlated with TE. Since both mineral concentration and SLW are easily and inexpensively measured, they may be valuable predictors of TE. Five experiments with 7 to 19 genotypes of peanut (Arachis hypogaea L.; C3 species) and four experiments with 9 or 10 genotypes of pearl millet [Pennisetum glaucum (L.) R. Br.; C4 species] were conducted to assess the predictive value of mineral concentration and SLW for TE. In peanut experiments, samples were also analyzed for C isotope discrimination (Δ). Plants were grown in pots in the greenhouse in sand, soil, and solution culture. Specific leaf weight, Δ, ash, and mineral element concentrations were determined at the end of the experiments. There was a strong negative correlation between Δ and TE in the four peanut experiments in which Δ was determined. Leaf ash concentration was negatively correlated with TE in four out of six comparisons for each of the species (r = −0.55 to −0.88). In peanut, Ca and Mg were negatively correlated with TE. No other elements were consistently related to TE in either peanut or pearl millet. The SLW was positively correlated with TE. Thus, both leaf ash and SLW were predictive of TE, but further research is needed to determine the physiological bases for the relationships and their general applicability.
Direct Classification and Selection of Superior Alleles for Crop Improvement
Authors: Sorrells Mark E. , Wilson William A.
Published: July 2010

The use of conventional breeding methods has resulted in consistent crop improvement within the cultivated gene pool by producing genotypes with new combinations of alleles that produce better phenotypes than either of the parents (transgressive segregation). Biotechnology has provided new methods to generate, identify, characterize, and manipulate genetic variation. Among these methods, marker assisted selection (MAS) with DNA markers has been applied in plant improvement programs. However, MAS is limited by the effort required to generate information about map location and breeding value of genes controlling important traits. Comparative genetic analysis across the domesticated grasses facilitates the identification and localization of gene sequences controlling specific traits of interest. The emerging databases of gene sequences will allow directed discovery of genes in higher plants and classification of alleles present within breeding germplasm. Identification of the genes controlling a trait and knowledge of their DNA sequence would facilitate classification of variation in the germplasm pool based on gene fingerprinting or characterization of variation in key DNA sequences. Classification of sequence variants at a targeted locus would substantially reduce the amount of work required to determine their relative breeding value and lead to the identification of superior alleles. Combining direct allele selection (DAS) with conventional selection, would allow more rapid and precise improvement of populations and breeding lines. Limitations of current technology can be minimized by transfer of genetic information across species, identification of highly variable genes, and focusing on the most important genes and traits for the species of interest.
HONEY: A Microcomputer Program for Plant Selection and Analyses of the Honeycomb Designs
Authors: Batzios D. P. , Roupakias D. G.
Published: July 2010

Selection in honeycomb designs, as it has been applied until now, is time consuming, subject to errors, and very difficult to apply when selection pressure is strong. Thus, a QBASIC computer program called HONEY was developed for honeycomb plant selection and analyses. The user may enter and edit data using the program. The program prints the arrangement of entries for the honeycomb design. Using the moving circle of selection, it prints the coordinates (row number and position in the row) of the high yielding plants and their yield. The user may select the desired selection pressure from a table appearing on the screen. The program gives the rank of the means of entries, the number of replications, the standard deviation, and the coefficient of variation. Following the selection process, an analysis of variance table is printed. HONEY runs on IBM‐PCs and compatible machines with 80286 or higher CPU and 640K RAM, running the PC‐DOS or MS‐DOS operating system.
Seed Protein and its Relationship to Soluble Sugars in Soybean
Authors: Hartwig Edgar E. , Kuo Tsung Min , Kenty Michael M.
Published: July 2010

Protein meal from soybean [Glycine max (L.) Merr.] contains the soluble sugars raffinose and stachyose. Because of these sugars, the quantity of soybean meal must be limited in rations to avoid flatulence in dogs (Canis familiaris) and digestive disturbances in baby pigs (Sus scrofa) and chicks (Gallus domesticus). Identifying soybean with a lower level of these sugars could lead to an increase in the quantity of soybean meal used in specific rations. As protein content of soybean seed is increased and oil is reduced, the total protein + oil + seed coat is greater than in standard type soybean. The residual portion is therefore reduced, and soluble sugars could account for a part of this reduction. Twenty standard type (high‐oil) soybean cultivars and breeding lines and 20 high‐protein breeding lines were grown in replicated trials on Sharkey clay (very‐fine, montmorillonitic, nonacid, thermic Vertic Haplaquept) at Stoneville in 1991 and 1992. Seed was analyzed for protein, oil, raffinose, stachyose, and sucrose. Range in protein content was from 387 to 537 g kg−1 dry seed and oil was from 145 to 216 g kg−1 dry seed. Range in g stachyose + raffinose kg−1 protein was 78.3 to 133.7. The correlation between protein and stachyose + raffinose was negative but nonsignificant. The g stachyose + raffinose kg−1 protein for the cultivar Forrest was used as a basis for comparison with the other genotypes evaluated. On this basis, the quantity of protein that might be used in a ration without changing the raffinose + stachyose level from that in Forrest ranged from 89 to 153%.
Cotton Leaf Age, Epicuticular Wax, and Nitrogen‐15 Absorption
Authors: Bondada Bhaskar R. , Oosterhuis Derrick M. , Norman Richard J.
Published: July 2010

Foliar N fertilization is sometimes used as a supplement to soil application in cotton (Gossypium hirsutum L.) production; however, information is lacking about the absorption of foliar‐applied N in relation to leaf age and epicuticular wax. A 2‐yr field study was conducted to examine the effect of leaf age and epicuticular wax on foliar‐applied 15N‐urea absorption and subsequent distribution within the subtended boll. Cotton (cv. Stoneville 506) leaves of different ages (20, 30, 40, and 60 d), at main‐stem node 10, fruiting position 1, were selected and treated with 15N‐urea solution using a paint brush. The 15N analysis of tissues 1 wk after treatment indicated that maximum absorption of 80% was achieved by 20‐d‐old leaves compared with 27 to 38% for 60‐d‐old leaves. As the leaves aged, 15N absorption decreased in concert with increased total wax concentration. A negative relationship between 15N absorption and total wax concentration of leaves of different ages (r2 = 0.97) suggested waxes were an important barrier to 15N absorption in older leaves. The subsequent translocation and distribution of 15N within the boll indicated that most of the absorbed 15N was retained in the 20‐d‐old leaf. As the leaves aged, more 15N was translocated to the subtended boll. Within the boll, most of the 15N was compartmentalized to lint and seed, and less was partitioned to the capsule wall, which implicated lint and seed as the major sinks. This study demonstrated that increased wax concentration during leaf aging was associated with reduced 15N absorption.
Root Characteristics and Hormone Activity of Wheat in Response to Hypoxia and Ethylene
Authors: Huang Bingru , Johnson Jerry W. , Box James E. , NeSmith D. Scott
Published: July 2010

Understanding the physiological mechanisms of hypoxia tolerance is important for developing hypoxia‐tolerant genotypes. This experiment investigated whether differential responses to hypoxia and ethylene exist in root characteristics, hormonal activity, and shoot growth for two wheat (Triticum aestivum L.) cultivars, Bayles and Jackson, differing in waterlogging tolerance. Rooting characteristics, ethylene production, cellulase activity, and shoot growth were determined after application of hypoxia and various concentrations of ethylene to the rooting medium in a growth chamber. Hypoxia limited root elongation for both cultivars but enhanced production of crown roots for tolerant Jackson. Hypoxia induced root aerenchyma formation and enhanced root ethylene production for both cultivars, but the response was greater for Jackson than Bayles. Ethylene effects on root growth and aerenchyma formation were similar to those observed for hypoxia treatment. All concentrations of ethylene (0.1, 1.0, and 5.0 μL−1) hastened the production of crown roots for Jackson but inhibited root elongation at the highest ethylene concentration (5 μL L−1). For sensitive Bayles, crown root production was promoted by the lowest concentration of ethylene, whereas root elongation was restricted at all levels of ethylene. Ethylene also promoted formation of aerenchyma in crown roots by increasing cellulase activity. This effect occurred earlier and was more dramatic for Jackson. The promoting effect of ethylene on aerenchyma formation was also more pronounced for newly formed than pre‐existing roots. The results showed that the effects of ethylene on roots varied with cultivar and ethylene concentration.
Sensitivity of Maize Hybrids to Chilling and Their Combining Abilities at Two Developmental Stages
Authors: Hodges D. Mark , Andrews Christopher J. , Johnson Douglas A. , Hamilton Robert I.
Published: July 2010

Maize (Zea mays L.), one of the most economically important plants grown in North America, is often subjected to cool conditions soon after sowing which can disrupt development. No studies on chilling sensitivity of maize at both germination and early growth developmental stages have been reported. To discern differences in chilling sensitivity between the germination and early growth phases, twelve hybrids originating from a complete diallel of four inbreds which differed in their sensitivity to chilling were subjected to laboratory screening tests at both these stages. Corresponding field trials were sown and parameters reflecting those evaluated in the laboratory were assessed. Estimates of general combining abilities and specific combining abilities were performed. Some lines that were initally chilling sensitive or tolerant at the germination stage altered their sensitivity to chilling at the early growth stage. This suggests that it is only possible to accurately evaluate chilling tolerance of maize by examining plants at both the germination‐emergence and early growth stages as these two stages may be under the control of different genetic factors. Furthermore, based on the physiological growth parameters assessed both in the laboratory and in the field, it is not possible to reliably predict hybrid maize cold tolerance from knowledge of the inbreds' responses.
Protein Body Formation and Immunocytochemical Localization of Globulins and Glutelins in Developing Rice (Oryza sativa L.) Embryos
Authors: Krishnan Hari B. , White Jerry A.
Published: July 2010

Rice (Oryza sativa L.) is one of the world's most important cereal crops. It plays a major role in human nutrition and its storage proteins have been thoroughly studied. Most of the research has concentrated on endosperm storage proteins. Embryo storage proteins have received only limited attention. Experiments were conducted to compare immunological relationships between the predominant endosperm globulins and those of the embryo. We examined the cellular and biochemical aspects of embryo storage proteins with light microscopy and transmission electron microscopy at three developmental stages. At 2 d after fertilization (DAF), embryos were globular in shape and were made up of actively dividing cells. These cells contained prominent vacuoles without any protein accumulation. At 6 DAF, the embryos had achieved distinct polarity, with cells at the basal region accumulating increasing amounts of starch and lipid. Moreover, these cells contained distinct types of vacuoles, most of which contained numerous dark‐staining protein inclusions. At 16 DAF, the embryo cells were filled with lipid bodies and contained prominent vacuoles that had accumulated substantial amounts of protein deposits. Antibodies raised against purified rice endosperm α‐globulin and against glutelin cross reacted with embryo proteins in Western blot analysis. However, the most abundant storage proteins of rice embryos did not react with these antibodies. Electron microscope immunocytochemistry revealed that proteins similar to α‐globulins and glutelins were deposited within the vacuoles. As in endosperm tissue, the glutelins and the α‐globulins were deposited within the same protein bodies. However, the embryo protein bodies were morphologically distinct from endosperm protein bodies. This study demonstrates the occurrence and localization of proteins similar to endosperm glutelins and globulins within the protein bodies of rice embryos.
Transgenic Corn Evaluated for Resistance to Fall Armyworm and Southwestern Corn Borer
Authors: Williams W. Paul , Sagers Jonathan B. , Hanten John A. , Davis Frank M. , Buckley Paul M.
Published: July 2010

Fall armyworm, Spodoptera frugiperda (J.E. Smith), and southwestern corn borer, Diatraea grandiosella Dyar, are important pests of corn, Zea mays L., in the southern USA. Germplasm lines with moderate levels of resistance to leaf feeding by these pests have been developed and released. Techniques for transforming corn have expanded opportunities for developing corn with higher levels of resistance and additional mechanisms of resistance to various insect pests. In this investigation, transgenic corn hybrids with insecticidal protein from Bacillus thuringiensis var. kurstaki were evaluated for resistance to fall armyworm and southwestern corn borer in field tests and laboratory bioassays. The transgenic hybrids sustained significantly less leaf feeding damage than the resistant check hybrids. Both survival and larval growth were reduced. Growth was also reduced when larvae were fed laboratory diets comprised primarily of lyophilized leaf or husk tissue. Southwestern corn borer larval survival on the transgenic corn hybrids was very low in both the field tests and laboratory bioassays. The high levels of resistance to fall armyworm and near immunity to southwestern corn borer of these transgenic corn hybrids provide the highest levels of resistance documented for fall armyworm and southwestern corn borer.
A Novel Statistical Approach to Analyze Genetic Resource Evaluations Using Capsicum as an Example
Authors: Cole‐Rodgers P. , Smith D. W. , Bosland P. W.
Published: July 2010

A novel statistical method is presented that allows quantitative and qualitative data to be combined for statistical analysis. Developing core subsets to increase the utilization and accessibility of germplasm resources is an important application of the method. Our objective was to determine if the normed binary scale statistical method would assist in identifying dissimilar accessions. Morphological characters that would be taken in field evaluations of Capsicum germplasm are used to illustrate the method. By combining both qualitative and quantitative data, one data set can be analyzed for dissimilarities among accessions. In addition, this method of analysis allows for the bounds of the limits to be reestablished if new trait limits are discovered. This method is applicable to any crop where quantitative and qualitative data has been collected.
Root‐Knot Nematode Resistance of F2 Cotton Hybrids from Crosses of Resistant Germplasm and Commercial Cultivars
Authors: Robinson Michael , Jenkins Johnie N. , McCarty Jack C.
Published: July 2010

The southern root‐knot nematode (RKN), Meloidogyne incognita (Kofoid and White) Chitwood, is a major pest of cotton (Gossypium hirsutum L.). A high level of resistance has been identified in eight germplasm lines; however, these lines are not as productive in yield as current cultivars. This study was conducted to determine the possibility of using F2 populations from crosses of these RKN resistant germplasm lines with five current cultivars as a means of combining RKN resistance with high yield potential. Two F2 populations were evaluated for their level of nematode resistance. Resistance in these F2 populations was greater than the cuitivar parents but less than the RKN resistant germplasm parents. The resistance level of the F2 population, however, was nearer the germplasm parenthan the cultivar parent, indicating that the F2 hybrids possess a useful level of resistance. Yield and fiber properties among the F2 hybrids indicated that by careful selection of parents, F2 populations that were equal in yield and fiber quality to the best of the cultivar parents could be produced. Results of this study indicate that F2 populations may provide a rapid way to combine high levels of RKN resistance with the higher yield and superior fiber properties of current cultivars.
Use of Irrigation in Selection for Soybean Yield Potential under Drought
Authors: Sneller C. H. , Dombek D.
Published: July 2010

The impact of selection in irrigated environments on improving seed yield in drought environments has not been extensively researched in soybean [Glycine max (L.) Merr.]. Our objectives were to evaluate cultivar × irrigation interaction, its impact on selection for yield in drought environments, and drought tolerance in soybean: drought tolerance being defined as better relative yield ranking in drought environments than in nondrought environments. Seven data sets were obtained from Arkansas trials of Maturity Group V cultivars. Each contained data from irrigated and nonirrigated trials from one location from two consecutive years with drought. Significance of genotype × irrigation interaction was determined for each set along with heritability of yield in both irrigation treatments and the genetic correlations of irrigated and nonirrigated yield from one year with nonirrigated yield in the other year. Rank correlations and crossover interactions between irrigation treatments were analyzed. The effect of selection in both irrigation treatments on yield in drought environments was simulated. Genotype × irrigation interaction was significant in six data sets. Entry‐mean heritability was higher in the irrigated trials (0.74) than in nonirrigated trials (0.37). Rank changes between irrigated and nonirrigated treatments rarely consisted of large yield differences. The genetic correlations of yield from irrigated and nonirrigated trials from one year with yield from nonirrigated trials in another year were nearly equal. The results indicated that selection from irrigated trials would improve yield in drought environments better than selection from nonirrigated trials. Drought tolerant reactions occurred in only 16% of the two‐cultivar comparisons. while several cultivars appeared tolerant, their yield in drought environments was not superior to several less tolerant cultivars. Nonirrigated trials may be useful in identifying a few unadapted cultivars.