bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographical Patterns of Phenotypic Diversity in a World Collection of Durum Wheats1
Authors: Jain S. K. , Qualset C. O. , Bhatt G. M. , Wu K. K.
Published: July 2010

More than 3,000 durum wheats (Triticum turgidum L. durum group) from the USDA world wheat collection were grown in the field and classified for leaf sheath glossiness, glume pubescence and color, awn color, kernel color, and basal spike node fertility. The entries were grouped by geographic origin, and frequencies of the various phenotypes were examined. Variation for all characters was found, and usually within each geographic region. The number of entries in the collection was very small from some areas known to be important sources of germplasm, pointing to the importance of intensifying efforts in germplasm exploration and conservation. The Shannon‐Weaver diversity index (H') was used to examine overall genetic divergence on a country and regional basis. In collections of substantial size, Ethiopia and Portugal had the greatest diversity (H' = 0.87 and 0.86), and Turkey, Bulgaria, and the United States had significantly less diversity (H' = 0.50, 0.42, and 0.39). Based on the characters studied and the relatively small collection evaluated, the centers of diversity seem to be Ethiopia, the Mediterranean region, and India.
Influence of Lint Percentage, Boll Size, and Seed Size on Lint Yield of Upland Cotton with High Fiber Strength1
Authors: Culp T. W. , Harrell D. C.
Published: July 2010

Our major objectives in breeding cotton (Gossypium hirsutum L.) have been to change negative genetic associations between lint yield and fiber strength, and lint yield and length. We also find an association between low lint percentage and extra‐long (above 35 mm) fiber length. With the introduction of the C 6‐5 breeding line into the cotton breeding program at the Pee Dee Exp. Stn. in South Carolina in 1955, the latter association was broken.

Through a program of hybridization and selection, lint percentage and lint yield of the PD fines were raised 5 and 12%, respectively. The introduction of C 6‐5 germplasm was accompanied by increases in seed and boll size. The selection of the line, AC 241, caused a reduction in boll and seed size; however, this line has fruit and seeds somewhat larger than desired. We are currently pursuing a program to reduce boll and seed size through hybridization of PD lines with southeastern commercial cottons.
Variability of Floral Characteristics Influences Honey Bee Visitation to Soybean Blossoms1
Authors: Erickson E. H.
Published: July 2010

Group O‐III cultivars of soybean, Glycine max (L.) Merr., screened for floral variability (e.g. flower size, color, abundance, cleistogamy, aroma, ncctar production, and blossom sequence) demonstrated a continuum between extreme limits for most of these factors. Cultivars potentially attractive to honey bees (Apis mellifera L.) were ranked from high to low, based on their rate of nectar secretion. The responses of late flowering under fluorescent light and temperature insensitivity at flowering (noncleistogamic) were found to be associated with higher production of nectar, which suggests possible methods of screening for potential bee attractiveness. The effect of weather in Wisconsin on the flowering and bee visitation for one soybean cultivar was studied in detail. Here, flowers failed to open and nectar secretion ceased at daily mean ambient temperatures below 21 C.
Reaction of Diallel Crosses of Maize In T and N Cytoplasms to Bipolaris maydis Race T1
Authors: Scott Gene E. , Futrell M. C.
Published: July 2010

Diallel crosses among eight corn (Zea mays L.) inbreds that differed for their response to Bipolaris maydis (Nisikado and Miyake) Shoemaker race T (Helminthosporium maydis Nisikado & Miyake race T), were made both on Texas male sterile (T) and on normal (N) cytoplasms. These crosses were evaluated for their reaction to inoculation with B. maydis race T both as seedlings in the greenhouse and as plants in the field.

Single crosses produced in N cytoplasm were heavily infected by spores of the fungus in greenhouse tests but extensive lesions did not develop, and the fungus caused relatively little damage. Differences for disease ratings among the hybrids in the N cytoplasm were not significant either in the greenhouse or in the field. Crosses in the T cytoplasm responded differentially to this fungus. Except for crosses with Mp305 as one of the parents, the average disease severity for all crosses with a given parental line was as expected, based on the original evaluation of the parents as lines. However, disease ratings on the crosses in the greenhouse did not agree well with those obtained in the field.

Crosses produced in T cytoplasm yielded 69% of their normal counterparts in 1972 and 22% in 1973. Differences were noted among hybrids produced in the T cytoplasm. The most resistant hybrid yielded 63% of its normal counterpart in 1973 while the most susceptible hybrid yielded only 1% of its normal counterpart. Thus, we found that necular gene resistance could overcome part, but not all, of the susceptibility associated with T cytoplasm to this disease.

Additive genetic variances accounted for most of the differences among hybrids produced in T cytoplasm. However, nonadditive and reciprocal variances were significant for some characteristics.
Plant Height, Protein Percentage, and Yield Relationships in Spring Wheat1
Authors: Pepe John F. , Heiner Robert E.
Published: July 2010

Two hard red spring wheat (Triticum aestivum L. em Thell.) semidwarfs, 'Era' and 'Chris Mutant,' with different dwarfing genes, were hybridized and 126 F5 progeny lines were studied to determine the relationship among the variables plant height, yield, and protein percentage. Of these 126 lines, 26 were tall (> 90 cm), 89 were semidwarf (60 to 90 cm), and 11 were dwarf (< 60 cm). The lines were divided among five yield nurseries grown in 1972. Tall vs. semidwarf comparisons were available in three of the nurseries, and the fifth nursery contained nine families of sister lines that differed in plant height (F3‐derived F5 families).

Phenotypic correlation coefficients and coefficients of determination for the three characters showed that plant height did not influence grain yield or protein percentage of the lines derived from this cross. The only apparent association was the highly inverse relationship between yield and protein percentage. The inverse yield protein percentage relationship found in high‐yielding lines appeared to result from a complex interaction between source and sink and not from an association with plant height.
Forage Nutritive Value and Palatability of 12 Common Annual Weeds1
Authors: Marten G. C. , Andersen R. N.
Published: July 2010

Our objective was to determine whether or not some broadleaf (forb) and grass weeds that commonly are found in newly established stands of perennial forage crops have sufficient quality to be considered satisfactory forages.

We determined the relative palatability of 12 weed species in comparison to oats (Avena sativa L.) in a grazing study with sheep. In each of 3 years, we estimated, by laboratory analyses, the nutritive value of these 12 weed species grown in field studies.

Six weed species, yellow foxtail [Setaria glauca (L.) Beauv.J, barnyardgrass [Echinochloa crusgalli (L.) Beauv.], green foxtail [Setaria viridis (L.) Beauv.], redroot pigweed (Amaranthus retroflexus L.), Pennsylvania smartweed (Potygonum pensylvanicum L.), and common lambsquarters (Chenopodium album L.) were as palatable to sheep as was oats. Four weed species, giant foxtail (Setaria faberi Herrm.), wild mustard [Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes)], giant ragweed (Ambrosia trifida L.), and common cocklebur (Xanthium pensylvanicum Wallr.) were unpalatable. Two species, common ragweed (Ambrosia artemisiifolia L.) and velvetleaf (Abutilon theophrasti Medic.) were classed as interacters; i. e. some sheep found them palatable, whereas other sheep refused to graze them. Palatability was not associated with nutritive value, indicating that sheep lacked “nutritional wisdom.”

Redroot pigweed, common lambsquarters, and common ragweed had nutrient composition and digestibility essentially equivalent to that of high quality alfalfa (Medicago sativa L.). Giant foxtail and Pennsylvania smartweed were less digestible than alfalfa. Giant foxtail, yellow foxtail, and barnyardgrass contained more acid detergent fiber and less crude protein than alfalfa. Ten of the 12 weed species were more digestible than oats forage. Nine of the 12 contained more crude protein than oats.

All of the 12 weed species contained adequate minerals to meet the requirements of ruminants, although the species differed considerably in mineral concentration. The grasses contained less than half of the calcium of the forbs, and the grasses usually contained less magnesium than the forbs.

Tests for anti‐quality components (alkaloids, nitrate, and mineral unbalances) revealed only a few potential animal toxicities due to mineral imbalances of some of the weeds if they were fed as sole rations.

We conclude that some of the common annual weeds found in new stands of perennial forages growing in fertile soils do not decrease the nutritive value of hay or pasture if utilized at relatively early stages of maturation.
Pollen Movement Within and Between Rows to Male‐sterile Soybeans1
Authors: Boerma H. R. , Moradshahi A.
Published: July 2010

Soybean (Glycine max (L.) Merr.) pollen movement was studied by evaluating the frequency of outcrossing on white‐flowered (recessive) male‐sterile plants sampled at various within and between‐row distances from a purple‐flowered (dominant) pollen source. In 1973, five 2.75‐m within‐row segments from 0.0 to 13.75‐m and three between‐row distances from 2‐m to 9‐m were evaluated. The data indicated a linear reduction (from 8.3 to 1.4%) in the amount of purple‐flowered progeny as both within and between‐row distances increased.

In 1974, six 6.1‐m within‐row segments from 0.0 to 36.6‐m and 12 between‐row distances from 1.0 to 23.0‐m from the purple‐flowered pollen source were evaluated. The 1974 results indicated that with between‐row distances of at least 7‐m and within‐row distances of at least 12 to 18‐m from the pollen source, little pollen contamination would occur. The percentage of purple‐flowered progeny found at these distances or beyond averaged 0.4%. These results indicated that most outcrossing occurred with surrounding plants, and thus intermating blocks of soybeans could be located adjacent to other soybean experiments or commercial plantings without high levels of pollen contamination.
Parameters for Determination of Damage to Sweet Corn Genotypes from First and Second Generation European Corn Borer1
Authors: Carlson J. R. , Andrew R. H.
Published: July 2010

This research was designed 1) to determine infestation techniques and parameters best suited for assessment of relative resistance to European corn borer, (Ostrinia nubilalis Hbn.) among adapted sweet corn (Zea mays L.) hybrids, and 2) to study the interrelationships of first and second generation damage, host maturity, and environment. Four egg masses placed in the whorl and on the ear shoot were used to simulate egg laying by first and second generation corn borer adults, respectively, at Arlington, Wis. in 2 years. Husk ratings and ear tunnel counts were used to measure both first and second generation damage. Tip ratings and ear indexes were used to further evaluate second generation damage. Simple phenotypic correlations were obtained among damage parameters and maturity and Spearman's rank correlations were used to investigate the consistency of the data across years.

Differences following first generation infestation in the whorl stage of development usually were not significant or consistent. Use of husk damage ratings, ear tunnel counts, and ear damage indexes following second generation infestation of ear shoots gave significant and consistent measures of hybrid differences in two markedly different seasons. First and second generation measurements of damage were not significantly related. For the hybrids included in these trials, maturity was negatively and consistently correlated with all second generation damage parameters.
Recurrent Selection for Rind Thickness in Maize and its Relationship With Yield, Lodging, and Other Plant Characteristics1
Authors: Davis Stephen M. , Crane Paul L.
Published: July 2010

This study attempted to evaluate the effectiveness of recurrent selection in increasing the stalk rind thickness in a synthetic population of maize (Zea mays L.) and determine the associated response of lodging and several other characters to selection for rind thickness. Three cycles with a selection intensity of 10% and effective populations of 883, 891, and 1054 were completed on an individual plant basis. The rind thickness of all cycles were not compared in a single year.

Lodging decreased from 24.2 to 20.7% after two cycles of selection in topcrosses of the selected populations with five single‐crosses and from 25.7 to 19.1% after three cycles of selection in the populations per se. Grain yield decreased with selection for rind thickness from 64.3 to 50.9 quintals/ha in the populations per se and from 67.9 to 64.7 quintals/ha in the topcrosses. No substantial changes occurred in grain moisture at harvest, percent stand, ear height, nor plant height.
Changes in Nitrogen and Carbohydrate Fractions in Developing Oat Groats1
Authors: Peterson David M. , Smith Dale
Published: July 2010

We determined changes in total N, soluble α‐amlno N, protein fractions, amino acids, and carbohydrate fractions, in developing primary groats of six cultivars of spring oats (Avena sativa L.). Concentration of total Increased during development in groats of all cultlvars. Initial values at 4 days after anthesis ranged fxom 2.02 to 2.56% (dry wt basis), whereas at maturity total N concentrations were 2.44 to 3.04%. Total nonstructural carbohydrates also increased with development, ranging from 56.4 to 61.2% initially and attaining concentrations of 60.4 to 71.3% at maturity. Concentrations of soluble aamino N and fructosans were initially high (0.25 to 0.40% and 12 to 19%, respectively) but declined to trace levels by maturity. Protein fractionation revealed that the proportion of globulins increased from about 28% to 55% of protdin recovered and that of prolamlns from about 2% to 11% during maturation. Proportions of albumins and glutelins decreased with groat maturation. Changes in amino acid composition, such as the decline in lysine and threonine and increase in glutamic acid with maturation, could usually be explained by the changing proportions of the protein fractions. Amino acid composition generally was similar among these six cultivars. It was concluded that genetic improvement in amino acid balance of oats would be unlikely to occur by a lowering of the prolamin concentration.
Cross‐fertilization in Seed Production in Relation to Forage Yield of Alfalfa1
Authors: Kehr W. R.
Published: July 2010

Experiments were conducted to determine the relationship between percentage of cross‐fertilization in alfalfa, Medicago sativa L, seed production, and forage yield, and to determine the competitive relationships between plants of hybrid and nonhybrid origin at three seeding rates. The percentages of cross‐fertilization in seed production were measured by classifying the flower color of progeny from white‐ and yellow‐flowered markers that were planted with blue‐ and purple‐flowered materials. Seed lots that varied from 30 to 91% of hybrid origin were seeded in replicated field plots to study yield and other traits, and to provide plants that were dug and classified for flower color.

Percentage of cross‐fertilization in seed production was not significantly correlated with forage yield of alfalfa in any of three experiments. The percentages of plants of hybrid origin that became established in the field by the fall of the seeding year, from a spring seeding, were highly correlated with percentages of cross‐fertilization in seed production in two experiments, with r values of 0.758 to 0.924, significant at the 1% level. In the fall of the first harvest year, the average percentages of plants of hybrid origin were 81, 87, and 90% in plots seeded at 4.5, 9.0, and 13.4 kg/ha, respectively. These percentages exceeded the average percentage of cross‐fertilization in seed production by 29 to 38%. In the fall of the second harvest year, the average percentages of plants of hybrid origin were 95 and 96% in plots seeded at 9.0 and 13.4 kg/ha, respectively.

The percentages of plants of hybrid origin were significantly different for, and increased with, seeding rate by the fall of the year of seeding in one experiment and by the fall of the first harvest year in another experiment.
Effects of Low and High Saponin Selection in Alfalfa on Agronomic and Pest Resistance Traits and the Interrelationship of these Traits1
Authors: Pedersen M. W. , Barnes D. K. , Sorensen E. L. , Griffin G. D. , Nielson M. W. , Hill R. R. , Frosheiser F. I. , Sonoda R. M. , Hanson C. H. , Hunt O. J. , Peaden R. N. , Elgin J. H. , Devine T. E. , Anderson M. J. , Goplen B. P. , Elling L. J. , Howarth R. E.
Published: July 2010

Six alfalfa (Medicago sativa L.) cultivars, ‘DuPuits,’ ‘Ladak,’ ‘Lahontan,’ ‘Ranger,’ ‘Uinta,’ and ‘Vernal’ were selected for low and high saponin concentration and tested at various locations for seven agronomic traits and resistance to six diseases, five insects, and two nematodes. Although the selection for saponin concentration was effective, none of the agronomic traits (yield, foliage color, frost damage, lodging, digestibility, fraction I protein, and soluble protein) was consistently affected by the selection. High saponin concentration retarded the in vitro growth of southern blight (Sclerotium rolfsii Sacc.) but had very little effect on any of the other disease organisms studied: anthracnose (Colletrotrichum trifolii Bain); bacterial wilt (Corynebacterium insidiosum (Mc‐Cull.) H. L. Jens.); common leafspot (Pseudopeziza medicaginis (Lib.) Sacc.); downy mildew (Peronospora trifoliorum deBary); and phytophthora root rot (Phytoph‐thora megasperma Drechs.). High saponin concentration was also correlated with resistance to pea aphids (Acyr‐thosiphon pisum (Harris)) but had no appreciable effect on chalcids (Bruchophagus roddi (Gussakovsky)), clover root curculio (Sitona hispidulus (F.)), spotted alfalfa aphid (Therioaphis maculata (Buckton)), alfalfa weevil (Hypera postica (Gyllenhal)), northern root‐knot nematode (Meloildogyne hapla Chitwood), or stem nematode (Ditylenchus dipsaci (Kühn) Filip.). Significant correlations among the pest resistance traits suggest the possibility of linkages or pleiotropic factors.
Effects of Yield Components on Lint Yield of Upland Cotton with High Fiber Strength1
Authors: Harrell D. C. , Culp T. W.
Published: July 2010

Seeds/boll, lint/seed, and bolls/m2 were determined for several PD breeding lines and check cultivars of Upland cotton, Gossypium hirsutum L., representative of distinct breeding stages in the simultaneous improvement of lint yield and fiber strength. These yield components were calculated from seed cotton yield, boll size, seed size, and lint percentage measured on the stocks in one or more tests conducted for at least 3 years on the Pee Dee Experiment Station, Florence, S.C. from 1956 to 1972. The objective of the present study was to determine the influence of each component on lint yield and its breeding implication in improvement programs.

Most southeastern commercial cultivars averaged 36 seeds/boll as compared with 33 for PD lines. Seeds/boll can be increased by crossing PD lines with southeastern commercial cultivars and selecting for this characteristic. It might be possible to increase lint yields of PD lines by increasing seeds/boll, which should increase seed surface area for greater lint production. Lint/seed advanced slightly as lint percentages were improved in early developed PD lines. Lint/seed was increased significantly after the introduction of the C 6‐5 breeding line because lint percentage and seed size advanced greatly. This component has not influenced yield of recent PD lines appreciably because boll size has declined and lint percentage has remained relatively constant. Bolls/m2 has been the major component contributing to lint yields of PD lines. Except for the rapid increase in lint yield from the higher level of lint percentage and larger bolls and seeds derived from C 6‐5, increases in lint yields have paralleled increases in bolls/m2 We suspect that we will be concerned more with maintaining, rather than increasing, bolls/m2 as we develop future PD breeding lines.
Observed and Predicted Response to Selection for Protein and Yield in Peas1
Authors: Pandey Shivaji , Gritton E. T.
Published: July 2010

Few reports of selection for seed yield and seed protein concentration, two important traits in peas, are available in the literature. This study involved the effect of selection for protein in the F2, F3 and F4 and for seed yield in the F3 and F4 generations of four pea (Pisum sativum L.) crosses grown in the field nursery. Mean protein of all progeny in each population was generally lower than the higher parent and tended toward the lower parent. Seed yield/plant values were generally higher than the midparent and tended toward the higher parent. Narrow sense hecitability values estimated through the parentprogeny regression method varied with crosses and generations, and were generally greater for protein (17 to 56%) than for seed yield (0 to 41%).

The observed change from selecting for higher % protein ranged from ‒0.84 to 5.85% of the population mean and was generally less than that predicted (2.07 to 5.54%). The observed decrease (‒0.75 to ‒7.05%) in the same trait for negative selection was generally greater than that predicted (‒2.18 to ‒4.62%). The relationship between observed increase in yield from selection (3.22 to 12.53%) and that predicted (0.00 to 19.25%) was variable, but the observed decrease (‒1.93 to ‒17.25%) was generally greater than that predicted 0.00 to ‒17.65%).

Correlations between protein and seed yield were small and inconsistent, suggesting that selection for either trait would not necessarily influence the level of the other. Selection for the two traits appears to be effective even in early generations. The amount and rate of progress would be influenced by choice of parents and selection intensity.
Modified Vitreous Endosperm Recom‐Binants from Crosses of Normal and High Lysine Sorghum1
Authors: Singh Shree P.
Published: July 2010

Modified recombinants with varying degree of kernel vitreosity were obtained in crosses between normal and high lysine Ethiopian sorghum [Sorghum bicolor (L.) Moench] lines. The opaque and translucent fractions of the modified types had floury and vitreous endosperms, respectively. Although the protein content of these modified selections, in general, was relatively lower than their normal and high lysine parents, the lysine values in protein were comparable to that of high lysine parents. Therefore, it seems possible to breed for modified types with good quality protein in sorghum.
Abnormal Starch Granule Formation in Zea Mays L. Endosperms Possessing the Amylose‐Extender Mutant1
Authors: Boyer C. D. , Daniels R. R. , Shannon J. C.
Published: July 2010

Starch isolated from Zea mays L. kernels homozygous for the endosperm mutant amylose‐extender (ae) is composed of normal, nearly spherical granules and abnormal types ranging from spherical granules having extensions of amorphous or optically isotropic starch to very long slender amorphous granules. Normal endosperm cells undergo a developmental sequence of nuclear enlargement, initiation of small spherical granules closely associated with the nucleus, granule enlargement, granule movement away from the nucleus, and continued granule enlargement to cellular maturity. Endosperm cells from the ae mutant undergo a similar developmental sequence except that movement of the spherical granules away from the nucleus is followed by a secondary initiation of abnormal granules in close association with the nucleus. Later in physiological development some of the earlier produced granules develop amorphous extensions. Numbers of abnormal granules increase with physiological age of cells. Endosperm cell maturity gradients in ae kernels are similar to those previously reported for normal kernels.
Developing Greenbug Resistant Lines from the KP2BR Sorghum Breeding Population1
Authors: Starks K. J. , Eberhart S. A. , Casady A. J. , Webster O. J.
Published: July 2010

Tests were designed to determine the possibilities of obtaining resistant lines from breeding populations as an alternative for insecticides for the control of the greenbug, Schizaphis grominum (Rondani). The KP2BR Sorghum bicolor (L.) Moench breeding population, developed from diverse germplasm, was random mated before selecting for resistance to the greenbug among seedlings in the greenhouse. To produce 135 S5 lines, selection was done in each of five generations (half‐sib or S0, S1, S2, S3, and S4). For comparison, six F5 lines derived from individual resistant ✕ susceptible crosses were selected in three generations (F2, F3, and F4). The S5 lines from KP2BR had as high greenbug resistance as the better parental sources, but none of the F5 lines were as resistant. Withinplot variance for some S5 lines exceeded the estimate of within plot environmental variance, which suggested residual genetic variation. Breeding populations offer an alternative to the widely used practice of introducing insect (or other pest) resistance into new parental lines by backcrossing.
Gibberellic Acid‐controlled Sex Expression of Corn Tassels1
Authors: Hansen D. J. , Bellman S. K. , Sacher R. M.
Published: July 2010

Foliage of corn (Zea mays L.) was sprayed with gibberellic acid (GA3) in an attempt to regulate sex expression of corn tassels. Complete suppression of staminate development would facilitate hybrid seed production. Tassels of inbred lines ‘A619’ and ‘Gaspd Flint’ became pistillate, male sterile, or remained male fertile depending on the time of GA3 application. Maximum pistil development within the tassel occurred when 5 mg/plant of GA3 was applied 8 or 9 days prior to the start of microspore meiosis. Complete male sterility without pistil development was observed when applications were made 1 to 3 days before the onset of meiosis. Sex expression of the tassel was not altered when GA3 treatments were made after the start of meiosis. Ear sex expression was not modified by any of the treatments. Stem weakness accompanied pistillate expression within the tassel and the stem either broke or was incapable of holding the plant in a verticle position. GA3 treatments altered stem and peduncle elongation but did not change total plant height. The precise timing needed to obtain male sterility without stem weakness reduces the utility of GA3 for hybridizing large populations. Plants in a normal field population do not reach this time frame at an uniform rate.
Structural Composition and in vitro Dry Matter Disappearance of Brown Midrib Corn Residue1
Authors: El‐Tekriti Ramadhan A. , Lechtenberg V. L. , Bauman L. F. , Colenbrander V. F.
Published: July 2010

The purpose of this research was to determine the effect of the brown midrib‐3 (bm3) gone on lignin percentage and in vitro dry matter disappearance of corn (Zea mays L.) stems and leaves sampled after grain harvest. Brown midrib‐3 and nearly isogenic normal corn hybrids were grown under field conditions at two locations and sampled at approximately 3, 6, and 9 weeks after grain harvest. An additional normal source represented by a commercial hybrid was also grown at one location. The stover portion of the plants was separated into leaves and stems. Samples were analyzed for structural composition and in vitro dry matter disappearance (IVDMD) using detergent solution and rumen fermentation techniques.

The lignin percentage in leaves averaged 5.8 and 7.1% for bm3 and normal plants at the first location. IVDMD of the leaves at this location averaged 57.1 and 49.8%. Lignin percentage in stems averaged 5.4 and 11.6% for bm3 and normal plants. IVDMD of stems averaged 59.2 and 43.0%. The composition of commercial hybrid plants was similar to that of normal plants. At the second location, leaf lignin averaged 6.6 and 8.1% and IVDMD was 56.0 and 50.2% for bm3 and normal genotypes. Lignin averaged 7.0 and 12.4% and IVDMD averaged 50.1 and 39.0% for bm3 and normal stems.

Lignin percentage increased and IVDMD decreased after grain harvest. However, differences between bm3 and normal genotypes were nearly as great at the last sampling as at the first, indicating that the differences in composition and digestibility of corn stover caused by the bm3 gene persist in the plant residue long after the grain has been harvested.
Inheritance of and Interrelationships among Maize Kernel Traits and Elemental Contents1
Authors: Arnold J. M. , Bauman L. F.
Published: July 2010

Combining ability for concentrations and g/200 kernels of P, K, Mg, Fe, Zn, oil, and protein, and for kernel weight, volume, and density in a six‐parent diallel of maize (Zea mays L.) inbreds was examined. Correlations among certain variables were computed. Significant variation was detected among GCA effects for concentrations and g/200 kernels of all kernel constituents except K concentration but among SCA effects only for oil concentration. GCA and SCA effects were significant for kernel weight, volume, and density. Highly significant correlations were found between P and K, P and Mg, and K and Mg concentrations.
Simple, Rapid Assay for Screening Nitrogen‐fixing Ability in Soybean1
Authors: Wacek T. J. , Brill Winston J.
Published: July 2010

The ability of Rhizobium to fix N2 in legume root nodules is a property that requires a great deal of further study. A rapid assay for N2‐fixing ability that can be used for screening many plants certainly will be utilized for work on this important symbiosis. We have modified the acetylene‐reduction technique to assay for N2 fixation in nodulated legumes. Inoculated seedlings are grown in sterile conditions in small vials capped with plastic bags. The vials contain vermiculite wetted with an N‐free medium. The effectiveness assay is completed within 2 weeks after seedlings have germinated and several thousand seeds can readily be tested in 1 month. Nitrogen‐fixing ability is monitored by observing the reduction of acetylene to ethylene by gas chromatography. Cultivars of soybean, Glycine max (L.) Merr., were assayed with this technique and major varietal differences were found. Nitrate and ammonium prevent nodulation and acetylene reduction in the effectiveness assay. Results from screening soybean cultivars and introduction lines may have value for plant‐breeding programs and host‐Rhizobium interaction studies. This effectiveness assay is useful for screening mutant plants or rhizobia that have defects in their ability to synthesize factors responsible for the establishment of an N2‐fixing root nodule.
Evaluation of a Vertical‐Pull Technique in Population Improvement of Maize for Corn Rootworm Tolerance1
Authors: Rogers R. R. , Russell W. A. , Owens J. C.
Published: July 2010

Two maize (Zea mays L.) breeding populations were evaluated for rootworm tolerance by use of the vertical‐pull technique. This technique should be an effective method for selection to reduce root lodging in populations under rootworm infestations. Variance component estimates for genotype‐environment interactions were small relative to genotypic variance. Error variance, however, was substantial in both populations. Expected gains from selection suggest that an optimum allocation of resources for evaluation trials would be three replications at one to two locations and three to five plants per plot.
In vitro Dry Matter Digestibility in Timothy (Phleum pratense L.) Cultivars of Different Maturity1
Authors: Koch D. W.
Published: July 2010

Ten named timothy (Phleum pratense L.) cultivars varying in maturity were compared to common timothy for in vitro dry matter digestibility (IVDMD) in 1973 and 1974. Early cultivars had significantly higher IVDMD at early heading compared with later maturing cultivars. The lower IVDMD of later‐maturing cultivars at early heading was offset by the slower daily decline in IVDMD. At early anthesis there was little difference among cultivars in IVDMD. The time interval between early heading and early anthesis varied from 11 to 16 days for the earliest and latest maturing timothy cultivars, respectively. Days from initial heading to initial anthesis was highly correlated (r = −0.71) with daily decline in IVDMD. Results indicate selection for relatively early maturity at initial heading should improve chances for increased IVDMD in timothy.
Induction of Useful Short Stature and Early Maturing Mutants in two Japonica Rice Cultivars1
Authors: Rutger J. N. , Peterson M. L. , Hu C. H. , Lehman W. F.
Published: July 2010

Short stature and early maturing mutants were induced in two japonica rice (Oryza sativa L.) cultivars by 60Co gamma irradiation. Frequency of useful mutants in the M2 generation grown from bulked seed of M1 plants was 1.89% in ‘Calrose’ and only 0.62% in ‘Colusa.’ The most promising mutant was the short stature Calrose selection D7.

D7 was about 25 cm shorter than its parent cultivar Calrose. In 11 large‐plot tests conducted over 2 years, D7 equaled the yield of the tall check cultivar ‘CS‐M3’ (a cultivar similar to Calrose), was 35 cm shorter and had more lodging resistance. The short stature of D7 was controlled by a single recessive gene.

Two early maturing Calrose mutants, D18 and D31, may be useful as germplasm sources of early maturity. One short stature, early Colusa mutant, D38, may also be useful as germplasm.

Several different short stature phenotypes were induced in Calrose. When Calrose M1 plants from the 25 kR treatment were handled in a pedigree fashion, nearly 10% of the M1 plants produced mutants possessing some degree of short stature.
Recurrent Selection for Shifting Gene Frequency of Seed Weight in Panicum antidotale Retz.1
Authors: Wright L. Neal
Published: July 2010

Effectiveness of recurrent phenotypic selection with restricted intercrossing by random mating through succeeding cycles to isolate genotypes of heavy and light seed weight of blue panicgrass, Panicum antidotale Retz., was investigated. Increased frequency of desired genotypes and isolation of separate genepools for extremes of seed weight were effected. Most effective estimate of selection intensity was calculated as the difference between mean of resource populations and mean of sample populations. Frequency of resource populations showed trimodal distribution. Bimodal frequency distributions were found for first four cycles of sample populations of light seed weight. Monodal frequency distributions were found for sample populations of heavy seed weight. Sixth cycle frequency distributions showed that sample populations of heavy and light seed weight were separated. Findings suggested that the biological limit was approximately 38.0 mg/100 seed for light seed weight and 135.0 mg/100 seed for heavy seed weight of plants selected from the resource populations investigated.
Protein and Lysine Content of Grain, Endosperm, and Bran of Wheats from the USDA World Wheat Collection1
Authors: Vogel K. P. , Johnson V. A. , Mattern P. J.
Published: July 2010

The effects of relative amounts and the protein and lysine concentrations of kernel components on whole grain protein and lysine in wheat (Triticum aestivum L.) were studied. Wheats from the USDA World Wheat Collection that differed in whole grain protein and lysine content were compared. The correlation of grain protein with endosperm protein was r = 0.98, showing that whole grain protein percentages accurately reflect endosperm protein content in wheat. The correlation of grain and endosperm lysine percentages was lower. Endosperm percent protein had the largest effect on grain lysine content of any of the factors tested. The combined effect of percent of bran, bran percent protein, and bran lysine (% of protein) on whole grain lysine content was great as the effect of endosperm lysine (% of protein). Wheats with high grain lysine content do not always have high endosperm lyslne content. Differences were detected among the wheats studied for endosperm and bran protein and lysine content.
Effects of UV‐B Radiation on Net Photosynthesis of Some Crop Plants1
Authors: Van T. K. , Garrard L. A. , West S. H.
Published: July 2010

Thirteen crop plants were subjected to an enhanced ultraviolet “B” (UV‐B) radiation (280 to 320 nm) regime that simulated a 0.19 atm cm ozone level, solar angle 55° (approximately 50% ozone depletion at 30° N latitude), to determine their susceptibility to photosynthetic impairment. As evidenced by net CO2 uptake and dry weight measurements, these plants exhibited a wide range of response to enhauced levels of UV‐B radiation. These species were classified either as “sensitive” (pea, Pisum sativum L.; collard, Brassica oleracea L., var. acephala; cabbage, Brassica oleracea L., var. capitata; soybean, Glycine max L.; and oat, Avena sativa L.), “moderately sensitive” (tomato, Lycopersicum esculentum L.; sorghum Sorghum bicolor L.; rye, Secale cereale L.; and rice, Oryza sativa L.), or “tolerant” (corn, Zea mays L.; digitgrass, Digitaria decumbens Stent.; pearl millet, Pennisetum americanum (L.) K. Schum.; and peanut, Arachis hypogaea L.) in respect to their sensitivity to UV‐B radiation. Plants grown in growth chambers with the same UV‐B enrichment but a lower irradiance of visible light (50 W.m‐2) showed greater photosynthetic impairment than did greenhouse‐grown plants. This was postulated to be due to photorepair under greenhouse conditions.
Resistance of Male Sterile Wheat to Ergot as Related to Pollination and Host Genotype1
Authors: Darlington L. C. , Mathre D. E.
Published: July 2010

This study was undertaken to determine if susceptibility of cytoplasmically male sterile spring wheat (Triticum aestivum L. em Thell.) to ergot [Claviceps purpurea (Fr.) Tul.] is influenced by pollination and host genotype.

Inoculation at various times after hand pollination showed that resistance was established in some lines within a few hours after pollination. The development of resistance after pollination was more rapid in some lines than others, but most lines were nearly immune by 7 days after pollination. Inoculation of diallel crosses between lines that developed resistance quickly after pollination and those that developed resistance slowly indicated that the resistance factor was maternally controlled.
Cytoplasmic Homology between Aegilops squarrosa L. and A. cylindrica Host.1
Authors: Maan S. S.
Published: July 2010

Fully fertile plants of normal vigor, normal chromosome number, and normal meiotic pairing resulted from substitution backcrosses involving autotetraploid Aegilops squarrosa L. (4x=28;DDDD) or A cylindrica Host. (2n=28;CCDD) as the females, and Triticum aestivum L. em Thell. as the recurrent male parent. However, the addition of a D‐genome chromosome to the T. durum Desf. nucleus was necessary to obtain alloplasmic T. durum with A. squarrosa or A. cylindrica cytoplasm. These 29‐chromosome plants had complete female fertility, but they produced a large proportion of shriveled, inviable seeds (or semilethal seedlings), and a few plump, viable seeds from crosses with euplasmic T. durum. They had sporadic partial seed set on selfed heads. Most of the plump seeds again produced 29‐chromosome plants. Apparently, shriveled, inviable seeds had 28‐chromosome zygotes. These nucleo‐cytoplasmic interactions indicate cytoplasmic homology between A. squarrosa and A. cylindrica.
Nitrate Reductase Activity in Heat (Drought) Tolerant and Intolerant Maize Genotypes1
Authors: Pal U. R. , Johnson R. R. , Hageman R. H.
Published: July 2010

The objective of this work was to determine if stability of enzyme activity under heat stress might be associated with differences in heat or drought tolerance in corn (Zea mays L.) inbreds in the seedling stage. Three heat (drought) tolerant and three intolerant inbreds that had been field evaluated were obtained from Pioneer Hi‐Bred International, Inc. and were used to test the effect of assay temperature on three cytoplasmic enzymes [nitrate reductase (NR), glyceraldehyde‐phosphate dehyrogenase (NAD), and ribonuclease] and two chloroplastic enzymes [nitrite reductase and glyceraldehyde‐phosphate dehydrogenase (NADP+) (phosphorylating)]. Only NR and trite reductase exhibited a differential genotypic temperature response. NR (in vivo and in vitro) from three tolerant and one intolerant inbreds was inhibited less at 40 to 45 C than the other two intolerant inbreds. This is consistent with field evaluation of these genotypes during vegetative development. When all inbreds were grown at 40/21 C day/night temperature for 19 days, four inbreds (three tolerant and one intolerant with anomalous NR sensitivity to high temperature) accumulated proportionately more dry weight than the two intolerant inbreds. In vitro and in vivo (with NO3‐ in the infiltration medium) assays of the temperature‐treated seedlings showed no differential genotypic effect. However, the in vivo (without NO3‐ in the infiltration medium) activity declined in a manner consistent with growth response, suggesting involvement of a “metabolic” NO3‐ pool. Although maintenance of NR activity under temperature stress is associated with heat or drought tolerance during the vegetative stage, the simplest selection criterion may be plant growth rate in response to temperature stress.
Changes in the Zinc‐65 Distribution in Corn Root Tissue with a Phosphorus Variable1
Authors: Youngdahl L. J. , Svec L. V. , Liebhardt W. C. , Teel M. R.
Published: July 2010

A corn (Zea mays L.) hybrid sensitive to a phosphoruszinc interaction was grown hydroponically in the greenhouse at several P levels in the presence of 65Zn, to determine if P affected the distribution of Zn within the root and affected Zn movement into the cytoplasm. Lyophilized root tissue was serially extracted with chemical and enzyme extractants. High P was found to increase the amount of 65Zn in the ethanol‐soluble fraction and pectate fraction of the cell wails. This binding of Zn to the cell wall may reduce the amount of Zn available for transport to the upper portions of the plant, resulting in Zn deficiency.
Factors Affecting Selection for Seed Coat Thickness in Fababeans (Vicia faba L.)1
Authors: Rowland G. G. , Fowler D. B.
Published: July 2010

Smaller seed size in fababeans (Vicia faba L.) would make seeding easier and more economical. However, the seed coat contains 89% of the seed crude fiber and it is imperative that any reduction in seed size be accompanied by at least a corresponding reduction in the seed coat contribution. Therefore, this study was initiated to evaluate the factors affecting variation in seed coat thickness in fababeans.

Analysis of seven varieties of fababeans grown at three locations in Saskatchewan in 1973 revealed significant differences in seed coat thickness due to cultivars, locations, replicates within locations, and seeds within cultivars times replicates within locations. Variance components from this analysis were utilized to estimate the numbers of locations, field replicates, seeds, and measurements per seed coat required for detection of specified differences in seed coat thickness. These estimates indicated that the largest number of measurements were required within seed coats and among seeds within cultivars. The position of the seed on the plant had no effect on seed coat thickness. Seed weight and seed coat thickness were not correlated within varieties but were highly correlated among varieties (r = 0.70).
Variation in Lipid Composition Among Strains of Oats1
Authors: de la Roche Ian A. , Burrows V. D. , McKenzie R. I. H.
Published: July 2010

Significant relationships were detected between lipid content and total fatty acid composition of seed from Avena sativa L. With increasing lipid content, the proportions of palmitic and linoleic acid decreased while oleic acid Increased. The relative proportions of acyl lipid classes (especially phospholipids and triglycerides) were also affected; high lipid strains contained a greater proportion of triglyceride and a lower proportion of phospholipid. Although the fatty acid composition of these two lipid classes was distinctly different in each strain, both exhibited similar shifts in fatty acid composition with changing lipid content.
Sorghum Root Morphogenesis and Growth. II. Manifestation of Heterosis1
Authors: Blum A. , Jordan W. R. , Arkin G. F.
Published: July 2010

Manifestations of heterosis in sorghum [Sorghum bicolor (L.) Moench] aerial growth and grain yield are well documented. Heterosis in sorghum roots has not been reported. This study compared three grain sorghum hybrids (‘Combine Kafir‐60’ ✕ ‘Combine 7078’, Combine Kafir‐60 ✕ ‘Tx 2536’, and ‘Wheatland’ ✕ Tx 2536) and their parents, in order to determine if and how heterosis is manifested in root morphogenesis and growth. Plants were grown in hydroponics in the greenhouse until 40 days after emergence. Measurements were made on leaf area, length of seminal and adventitious roots, initiation rate of adventitious roots and root volume.

Heterosis (advantage of the hybrid over its best parent) was significant in all hybrids for length of the seminal root, growth rate of adventitious roots, and root volume. Heterosis in root volume was probably a result of promoted number and growth of lateral root branches. Consistent heterosis was not revealed in number of adventitious roots per plant, nor in seminal and adventitious root dry matter.

The results are discussed in terms of current concepts of heterosis in sorghum. Possibilities for the development of some selection criteria for root improvement are suggested.
Yield‐component Analysis of Oat Isolines that Produce Different Grain Yields1
Authors: Brinkman M. A. , Frey K. J.
Published: July 2010

A series of early and midseason isolines of oats (Avena sativa L.) contain specific crown‐rust resistance loci, which were associated with significant grain‐yield deviations when tested in rust‐free conditions. To delineate specific causes for these yield deviations, yield components were measured in the isolines and their recurrent parents in six rust‐free environments.

Increased grain yields in both isolines with the crownrust resistance allele from CI 8079, an Avena sterilis L. strain from Israel, were due primarily to significantly increased tiller production. A 3.0% increase in spikelets per panicle also contributed to the increased yield of CI 9170, the early‐maturing isoline.

Although each donor parent was associated with contrasting yield‐component expressions in the early and midseason backgrounds in the remaining isoline sets, causes of deviant yields were evident. An increase in panicle number contributed to grain‐yield advantages of isolines derived from CI 7171, while seed weight improvement was the most important contributor to yield improvement in the midseason isoline. The significant yield reductions of X5501 and CI 9192, the early and midseason isolines with crown‐rust resistance derived from Arena strigosa Schreb., were caused primarily by fewer spikelets per panicle.