bluuebunny/crossref_metadata_2025 huggingface dataset:
A Two‐Row Seeder for Water‐Seeded Rice (Oryza sativa L.) Plots1
Authors: Erickson J. R. , Fairbank J. P.
Published: July 2010

A floating two‐row seeder has been developed for waterseeded experimental rice (Oryza saliva L.) plots. Seed distribution and stand establishment are more uniform than that obtained through hand seeding. This improved seeder requires only two operators rather than the four previously needed.
Basic Proteins of Barley Seedlings as Affected by Temperature1
Authors: Thomason R. C.
Published: July 2010

Barley (Hordeum distichum L.) germinated at a series of four temperatures was found to contain seedling basic proteins which differed when separated in polyacrylamide gel by electrophoresis. The conclusion drawn from the observations is that the protein variation is the result of temperature treatment. It is suggested that the basic protein variation is an indication of physiological differences existing in the barley seedlings grown at the different temperatures.
Pseudo‐Self‐Compatibility in Red Clover (Trifolium pratense L.)1
Authors: Leffel R. C. , Muntjan A. I.
Published: July 2010

Pseudo‐sclf‐coinpatibility (PSC) in normally self‐incompatible angiosperms is attributed to environmental, chemical, or genetic causes. Vegetatively propagated clones or randomly selected red clover plants (Trifolium. pratense L.) were subjected to various treatments suggested in the literature as affecting PSC. PSC was a definite clonal characteristic. PSC of 30 of 45 clones tested was greatest at higher temperatures, 32 or 38C. Variation for PSC among world ecotypes ranging in origin from 5° to 69° latitude was limited. PSC was not affected by infection with alfalfa mosaic virus or bean yellow mosaic virus strain 204‐1. Applications of 10 ppm of napthalene acetamide or gibberellic acid as foliar and floral sprays did not affect PSC nor did wilting induced by reduction of soil moisture.
Influence of Oxygen, Sodium Hypochlorite, and Dehulling on Germination of Green Needlegrass Seed (Stipa viridula Trin.)1
Authors: Frank A. B. , Larson K. L.
Published: July 2010

Rcsearch was conducted to determine methods for reducing dormancy and tests for predicting germination of green needlegrass seed (Stipa viridula Trim). ‘Lodorm’ and native seed were used in the study. Dehulling new and after‐ripened 1967 seed increased germination 38.5 and 47.4 percentage units, respectively, and of new and after‐ripened 1968 seed by 57.3 and 77.9 percentage units, respectively. After‐ripening occurred independently of the lemma and palea and was nearly complete 8 months after harvest. Treating intact seed with sodium hypochlorite increased germination of 1967 after‐ripened seed from 42.6 to 87.9%, of 1968 new seed from 3.8 to 43.6%, and of 1968 after‐ripened seed from 12.8 to 72.0%. Germinating intact seed in an oxygen‐enriched atmosphere increased germination of 1967 after‐ripened seed from 57.8 to 86.6%, of 1968 new seed from 3.0 to 29.0%, and of 1968 after‐ripened seed from 13.5 to 71.2%.

The results obtained from dehulling, sodium hypochlorite, and oxygen treatments indicate that dormancy may be at least partially controlled by the following factors: impermeability of the lemma and palea to gas exchange, a mechanical barrier imposed by the lemma and palea which physically prevents coleoptile and radicle emergence, low seed vigor, or an oxidizable inhibitor present in the intact seed. Tetrazolium viability was a good predictor of germination of dehulled after‐ripened seeds.
Heterosis and Combining Ability in Diallel Crosses of Burley Tobacco, Nicotiana tabacum L.1
Authors: Legg Paul D. , Collins G. B. , Litton C. C.
Published: July 2010

Twelve burley cultivars of N. tabacum L., the 66 possible F1 hybrids among them, and the 66 F2 populations were evaluated during 1966‐69. Comparisons of the F1 hybrids with the parents indicated that heterosis values were small but significant for several characters. Two hybrids, ‘Ky 10’ × ‘Burley 37’ and Ky 10 × Experimental line 42, yielded more cured leaf than Ky 10, the highest yielding variety in the test. Percentages of inbreeding depression obtained from comparisons of the Fl and F2 generations in 1969 were also small, but they were significant for some characters.

Estimates of variances for general combining ability were significant for all seven characters studied. Specific combining ability variances were significant for days to flower, leaf width, and yield.
Relative Efficiency of 4×4 Balanced Lattice Squares Compared to Randomized Complete Blocks for Measuring Cotton Variety Lint Yields1
Authors: Krause G. F. , Mohanty S. , Sappenfield W. P.
Published: July 2010

The balanced lattice square experimental design was on the average 36% more efficient than a randomized complete block design based on total lint cotton (Gossypium hirsutum L.) data obtained from four locations in Missouri over 4 years. Efficiency varied with environment but was inconsistent over locations and years.
Response of Alfalfa (Medicago spp.) to Light Interruption of the Dark Period1
Authors: Massengale M. A. , Dobrenz A. K. , Brubaker H. A. , Bard A. E.
Published: July 2010

The influence of light interruption of the dark period on flowering and certain growth characteristics of alfalfa (Medicago spp.) was studied under field conditions at Tucson, Ariz.

One light interruption of 30 min in the middle of the dark period caused significant differences in flowering percentage, height, and dry‐weight production of specific cultivars. Alfalfa plants that were grown under light interruption had smaller crowns, flowered earlier and more profusely, and produced less dry matter compared to plants grown under natural daylength.

Seasonal temperatures influenced the effects of light interruption of the dark period. Differences between light treatments with respect to flowering were most evident during shorter natural daylengths which coincided with the cooler growth periods, while differences in production of dry matter were most evident when maximum and minimum temperatures were highest.

Light interruption of the dark period can be used to obtain more rapid and complete flowering of alfalfa under field conditions.
Selection for Persistence in ‘DuPuits’ Alfalfa1
Authors: Smith T. J.
Published: July 2010

The ‘DuPuits’ variety of alfalfa (Medicago sativa L.) rapidly loses plant stands when grown under field conditions in Virginia. Experimental strains from the interpollinated seed of surviving DuPuits plants obtained in one cycle of natural selection under field conditions were superior to DuPuits in persistence, yield, and resistance to southern anthracnose (Colletotrichum trifolii Bain and Essary). They also were equal in persistence to the check variety, ‘Williamsburg,’ and were superior in yield and anthracnose resistance.
Response of Soybean Genotypes to Spacing in Hill Plots1
Authors: Shannon J. G. , Wilcox J. R. , Probst A. H.
Published: July 2010

Experiments were conducted in a systematic design at 10 spacings ranging from 30 to 122 cm using determinate and indeterminate soybean genotypes (Glycine max.(L). Merrill) of both ‘Clark’ and ‘Harosoy.’ Yield and other characters were evaluated to determine the optimum spacing for evaluating maturity group II and IV soybean genotypes in hill plots. Competition between genotypes was also characterized.

Yield consistently increased as spacing between hills increased in all genotypes except the short determinate dt1. In general, the tall determinate, Dt2, and the indeterminate genotypes of each variety matured earlier and lodged least at the intermediate spacings. The dt1 determinates lodged little and tended to mature progressively later as distance between bills increased. Plants, in general, were taller at the closest spacing and progressively shorter as spacing increased. The genotypes of Harosoy differed in response to spacing for seed weight. Seed weight in dt1 increased as spacing between hills increased, while seed weight for Dt2 and indeterminate Harosoy tended to increase as spacing between hills increased. Seed weight in all the Clark genotypes tended to increase as distance between hills increased

Competition between the determinate and indeterminate genotypes within each variety revealed few significant differences for any character. Competitive effects on yield among genotypes diminished as spacing increased and were nonexistent at 65 cm between hills and beyond.
Effects of Potassium Nitrate on Germination and Respiration of Dormant and Nondormant Kentucky Bluegrass (Poa pratensis L.) Seed1
Authors: Maguire J. D. , Steen K. M.
Published: July 2010

Respiration rates for germinating ‘Cougar’ and ‘Newport’ Kentucky bluegrass (Poa pratensis L.) seed produced in 1965, 1968, and 1969 (freshly harvested) increased rapidly for 2 to 4 days after imbibition in 0.2% KNO3 and in water, then slowly increased for the remainder of a 7–day period. Cougar seed treated with KNO3 had higher respiration rates than water‐treated seed; only slight increases were obtained with KNO3‐treated New port seed. Seed from 1965 and 1968 took up oxygen more rapidly than the 1969 seed. Respiration rates of 1– and 4–month‐old Newport seed decreased rapidly 3 to 4 days after imbibition.

Germination tests of 1969 seed at 1 month after harvest after imbibition showed Newport seed to be more dormant than Cougar. KNO3 increased germination of 1–, 4– and 9–month‐old Newport seed but had no effect on Cougar seed.
Evaluation of Methods for Generation Advance in Bulk Hybrid Soybean Populations1
Authors: Empig L. T. , Fehr W. R.
Published: July 2010

We evaluated four methods of generation advance in bulk hybrid soybean (Glycine max (L.) Merrill) populations for their ability to maintain superior genotypes and genetic variability for economic traits and for their efficiency in sampling time. The methods used were single seed descent (SSD), restricted cross‐bulk (RCB), maturity‐group bulk (MGB), and cross‐bulk (CB).

Method means did not differ significantly at either location, and differences in genotypic variance among methods were not consistent in all crosses. SSD, RCB, and MGB maintained a similar number of high yielding lines, about twice as many as CB. SSD and MGB were the most effective methods in maintaining early lines. However, there were no differences among methods for the frequency of late segregates. SSD was about twice as effective for maintaining large‐seeded lines as the other methods. The four methods did not differ appreciably for the number of lodging resistant lines. RCB had the highest frequency of tall plants.

Comparison of the harvest time spent in obtaining samples for the next generation showed that CB was the fastest and RCB the second fastest method. SSD was more time‐consuming than CB and RCB. MGB was the most time‐consuming, since it required pulling plants at several different times to maintain subpopulations restricted in maturity.

SSD was the method least influenced by natural selection; therefore, it may be the most useful method in greenhouse or winter nursery environments where a genotype may perform differently than under field conditions in its area of adaptation.
Electrophoretic Patterns Among Alfalfa Seed Proteins from Selected Varieties, Experimental Stocks, and Species Accessions1
Authors: Bingham E. T. , Yeh K. J.
Published: July 2010

Seed proteins from 30 alfalfa varieties, several experimental stocks, and 26 species accessions of Medicago sativa and M. falcata were studied with basic gel disc electrophoresis. Protein patterns in general were basically similar in cultivated and wild materials, and at diploid and tetraploid levels. One major band was present in M. falcata and some varieties, absent in pure M. sativa accessions and some varieties, and segregating among individual varietal plants and experimental stocks. This band appeared under genetic control and could be useful to verify hybridization or in genetic analysis. Cultivated varieties were separated into four groups on the basis of the absence or presence and density of one main band. Varieties within a group could be further separated by visual density differences among several other bands, but not individually identified.
Flax Cultivars with multiple Rust‐conditioning Genes1
Authors: Flor H. H. , Comstock V. E.
Published: July 2010

Lines of seed.flax (Linum usitatissimum L.), each with a different gene for rust resistance, were developed by backcrossing to the cultivar ‘Bison.’ The monogenic Bison‐like lines were intercrossed to provide two‐gene segregates. Intercrossing two‐gene lines, with one gene in comtnon, develnped three‐gene lines. The selective pathogenicity of races of Melampsora lini (Ehrenb.) Lev., was utilized to identify plants that possessed the parental resistance genes. In a 3‐year trim (1966–1968) at Fargo, North Dakota, yield differences between 20 multiplegene cultivars and five commercial cultivars were not significant. Most of the experimntal cultivars would be satisfactory for commercial production.
Soaking Injury in Lima Beans1
Authors: Roos E. E. , Pollock B. M.
Published: July 2010

We investigated water uptake and ribonudease development in excised embryonic axes of lima beans (Phaseolus lunatus L. cv. ‘Thorogreen’) during the period 0 to 18½ hr after the start of imbibition. The impact of temperature, initial axis moisture, and submergence on these processes was studied. In general, ribonuclease development paralleled growth. However, under stress conditions enzyme formation was reduced to a greater degree than was growth. Submergence during the first 10 min of imbibition appeared tn condition the axes to reduced growth and ribonuclease development at a later period. Submergence during the growth period also had an adverse effect on these processes.
Abortive Terminal, A Cytoplasmically Inherited Character in Cotton, Gossypium hirsutum L.1
Authors: Quisenberry J. E. , Kohel R. J.
Published: July 2010

A mutant character was observed in a segregating population of Gossypium hirsutum L. The mutant seedlings failed to show apical growth, so the character was named “abortive terminal.” The abortive terminal condition was transmitted only through the maternal parent, and was not under the control of nuclear genes. Progeny tests using seeds from each boll of several individual plants demonstrated that the condition was transmitted only through certain bolls. Tests showed that it was probably not caused by viruses, bacteria, fungi, or visible cytological irregularities. We concluded that the abortive terminal was controlled by a mutant organelle in the cytoplasm.
Relative Efficiencies of Four Self‐Pollination Techniques in Alfalfa1
Authors: Barnes D. K. , Stephenson M. G.
Published: July 2010

We compared four techniques to self‐pollinate alfalfa, Medicago sativa L. The techniques included tripping flowers with a toothpick, tripping flowers with a toothpick having an emery paper tip, tripping flowers into a folded cardboard tag containing pollen, and rolling racemes between the fingers. Each of three people performed all four techniques on the same 60 plants. All plants had normal pollen production. The differences in relative effectiveness (average seeds per flower tripped) for the four techniques averaged over all personnel were not statistically different. A comparison of the relative efficiency (seed per man‐hour) indicated that rolling racemes between the fingers was about three times more efficient than the other methods of self‐pollination.
Physiological Changes in Barley Induced by Greenbug Feeding Stress1,3
Authors: Gerloff E. D. , Ortman E. E.
Published: July 2010

Quantitative amounts of greenbug (Schizaphis graminum Rondani) feeding stress on the first foliar leaf of barley (Hordeum vulgare L.) caused a severe detrimental decline in chlorophyll content and in the rate of photosynthesis. The stress produced an increase in the rate of respiration but no change in leaf area, fresh weight, or dry weight during 7 days of controlled infestation.
Genetic Male Sterility in Barley. III. Pollen and Anther Characteristics1
Authors: Roath W. W. , Hockett E. A.
Published: July 2010

Pollen staining, pollen and anther appearance, and anther size were observed in 18 genetic male sterile mutants in barley, Hordeum vulgare L. The stains used were 2,3,5‐triphenyltetrazolium chloride (TTC), acetocarmine, and iodine potassium iodide. Stain uptake with the vital stain TTC was not a good indication of selfing ability, but nonstainability indicated sterility. To facilitate allelism studies four groups of mutants were delimited: A. Selfing ability‐ms9; B. Near‐normal pollen and anther development but no selfing‐ms6, ms8, ms16; C. Extremely abnormal pollen and anther development‐ ms3, ms7; and D. Variable pollen and anther development‐ms1, ms2, ms4, ms5, ms10, ms11, ms11az, ms13, ms14, ms17, ms18, ms19. The two allelic mutants, ms11 and ms11az, behaved differently for pollen stainability and appearance and for anther size.
Cytogenetics of a Temperature‐Sensitive Albino Mutant in Smooth Bromegrass (Bromus inermis Leyss)1
Authors: Dunn G. M. , Nasiruddin M.
Published: July 2010

Tetrasomic inheritance was demonstrated for a temperature‐sensitiire albino mutation in smooth bromegrass, Bromus inermis Leyss. Evidence was obtained for both chromatid and chromosome segregation. The original mutant plant had 55 chromosomes, whereas the norma1 green parents had 56 chromosomes. Pairing was largely as bivalents, and the number of meiotic irregularities in this material did not exceed the number normally found in the species. The chlorophyll deficiency was probably due to a gene mutation rather than to gross chromosomal aberration. This study supports the two genomic model proposed for B. inermis, but does not exclude the three genomic model.
Photosynthetic Rates and Light Saturation Curves of Individual Soybean Leaves Under Field Conditions1
Authors: Beuerlein J. E. , Pendleton J. W.
Published: July 2010

The effects of leaf age and light acclimation on apparent photosynthesis (AP) rates of single attached leaves of highly productive, field‐grown, ‘Wayne’ soybeans (Glycine max L. Merr.) were determined. AP measurements were made on leaves at nodes along the main stem of plants 5 cm apart in 76‐cm rows (normal canopy plants) and on leaves at different nodes of widely spaced (76 cm ✕ 76 cm) plants without branches. The response to light in the range of 2,000 to 15,000 ft‐c of fully expanded leaves of the two types of plants was also measured.

The AP rates of upper and lower leaves of the normal canopy plants averaged 33 and 20 mg CO2/dm2/hour, respectively. AP rates of upper and lower leaves of spaced plants were equal and averaged 50 mg CO2/dm2/hour. Leaves from the upper part of normal, field‐grown canopy plants became light saturated at 10,000 ft‐c but the leaves of spaced plants were not light saturated at 15,000 ft‐c.
Genetic Variances in a Synthetic Variety of Maize Estimated by Two Mating Designs1
Authors: Sentz J. C.
Published: July 2010

Genetic parameters for a synthetic variety of maize (Zea mays L.) were estimated from Design I (D‐I) Design II (D‐11) matings. Corn borer and stalk rot resistance selection in derivation of lines had no effect upon mean yield or other traits in the D‐II reconstituted population.

Additive variance was significant with both designs and of primary importance for all traits. Dominance variance contributed 45% of the genetic variance for yield, but was relatively unimportant for other traits. Greater additive variance estimates with D‐II indicate some epistasis may exist for height and days to tassel. However, additive estimates were less with D‐II for yield, ear moisture, and ear diameter.

Genotype‐environment interactions were important for yield and ear moisture, but no consistent rdationships with their respective genetic components were obtained. In the absence of first‐order genotype interactions with years and locations, I pooled the interaction mean squares for D‐I analysis.

D‐I was less sensitive than D‐II for estimating genetic variances, particularly dominance variance. Although variance estimates were not large, expected yield increase with half‐sib progeny selection was 6.1 to 8.6%.
Selection in Two Seedling Crops of Four Sugarcane Progenies
Authors: James N. I. , Miller J. D.
Published: July 2010

Phenotypic correlations were obtained among stalk number, stalk diameter, and Brix, within and among the plant‐cane seedling crop, first‐ratoon seedling crop, and the plant‐cane clonal crop, in progenies of four sugarcane (Saccharum spp.) crosses. Associations among characters within crops were low.

The correlation coefficients for stalk number were .378** and .363** between the plant‐cane clonal crop and the plant‐cane and first‐ratoon seedling crops, respectively. Stalk diameter was more closely associated than stalk number between the plant‐cane clonal crop and the plant‐cane seedling crop (r : .618"*). Correlation coefficients for stalk diameter between the clonal crop and first‐ratoon seedling crop were heterogeneous among progenies and ranged from .406** to .673**. Stalk diametera ppearedto be a morer eliable selection criterion than stalk number, particularly in plant‐cane seedlings. Correlation coefficients for Brix among the crops were about equal to those for stalk number, indicating that the two characters were less reliable than stalk diameter, as sdection criteria.

Various culling levels imposed on the plant‐cane and first‐ratoon seedling crops indicated that effectiveness of selection was equal when the same selection pressure was applied in both crops. Results were similar with independent and simultaneous selection for the three characters. These data indicated that the most reliable selection criterion was stalk diameter. Stalk numberw as less reliable than either stalk diameter or Brix.

Selected populations could be obtained with high frequencies of segregates acceptable for stalk diameter. The trequency of segregates acceptable for stalk numbera nd Brix could be increased by selection, but populations with high frequencies of acceptable segregates could be obtained only when levels of acceptability were low.
Changes in Sugars, Starch, RNA, Protein, and Lipid‐soluble Phosphate in Leaves of Cotton Plants at Low Temperatures1
Authors: Guinn Gene
Published: July 2010

Cotton plants (Gossypium hirsutum L., cv ‘Westburn’) were severely injured when chilled at 5 C without prior hardening. Exposure to hardening temperatures of 15 C day and 10 C night prevented subsequent injury at 5 C. Sugars and starch increased during exposure to hardening temperatures, but RNA, protein, and lipid‐soluble phosphate decreased. Except for increases hi sugars, these changes in cotton during exposure to hardening temperatures are opposite changes which have been reported in plants that can be hardened to withstand subzero temperatures.
Response of Tobacco Budworm Larvae to Cotton Seedlings Carrying Various Combinations of Gland‐determining Alleles1
Authors: Wilson F. D.
Published: July 2010

Five‐ and 6‐day‐old larvae of the tobacco budworm, Heliothis virescens. (F.), discriminated among seedlings cotton, Gossypium hirsutum L., carrying the 4 true‐breeding combinations of the gland‐determining alleles Gl2 and Gl3. Seedling damage was least, and larval numbers were lowest on dimeric glanded, Gl2Gl2Gl3Gl3, intermediate on the 2 monomerics Gl2Gl2gl3gl3 and gl2gl2Gl3Gl3, and highest on glandless, gl2gl2gl3gl3, when readings were made 24 and 48 hours after infestation. Howevers, eedling damage was less at the second reading and numbers of larvae left on the seedlings were less at both readings in Gl2Gl2gl3gl3 than in the other monomeric line. Larval response was correlated both with the number of pigment glands in the cotyledonary petioles of the seedling, and with percent gossypol in seed meats of the genotypes studied. Results suggest that this bioassay technique may be useful in selecting seedlings with varying levels of gossypol. In fact, it may be possible to select seedlings by counting glands, without resorting to a bioassay. However, the effects of varied genetic background on gland number have not been studied. Also, the relationship of seedling resistance to mature‐plant resistance is not known. Several applications of this bioassay technique are discussed in relation to a number of other breeding, entomological, and genetic problems.
Diallel Crosses Among Burley Varieties of Nicotiana tabacum L. in the F1 and F2 Generations1
Authors: Matzinger D. F. , Wernsman E. A. , Ross H. F.
Published: July 2010

Burley F1 hybrids averaged 9.8% more yield than the parent varieties combined over 2 years. Heterosis was also expressed for increased total alkaloids, taller plants, more leaves, and larger leaves. Estimates of genetic variances indicated that additive genetic variance predomnated in the combined analysis. However, large genotype X year interactions existed for measures of heterosis and for estimates of genetic variances. These interactions were so large for yield that neither variance of general combining ability nor specific combining ability was significant in the combined experiments. Hybrids showing greatest heterosis and largest yield did not generally arise from the highest yielding parents per se. Variances arising from maternal and reciprocal effects were negligible.
Studies of F1 Hybrids Between Photoperiod Sensitive and Non‐sensitive Pennisetum Millets1
Authors: Bhardwaj Bhup D. , Webster Orrin J.
Published: July 2010

The F1 hybrids between crosses of ‘Tift 23A’ (cytoplasmic male‐sterile line Pennisetum typhoides (Burm.) and five populations of ‘Maiwa’ (P. maiwa Stapf and Hubb) were studied for various characteristics including restoration of male fertility. Tift 23A is day‐length neutral, short, and early maturing whereas Maiwa is day‐length sensitive, tall, and late‐maturing. Results indicate that genes for nonrestoration of cytoplasmic male sterility are present in Nigerian Maiwa populations, and that adapted A and B lines resistant to downy mildew can be produced. It also seems possible to develop high‐yielding, day‐length neutral, and day‐length sensitive strains from the segregating generations of Tift 23A ✕ Maiwa crosses.
Systematic Management of Early Generation Progenies1
Authors: Peterson C. J. , Vogel O. A. , Allan R. E. , Tate W. S.
Published: July 2010

Large populations of early generation progenies can be handled efficiently by using the systematic approach described herein. This method facilitates the application of automatic data processing machines to the printing of field books and field plot labels. Time spent on planting, harvesting, and preparing field books can be reduced by following the described procedure.
Relationships between Clover Root Curculio Injury and Severity of Bacterial Wilt in Alfalfa1
Authors: Hill R. R. , Murray J. J. , Zeiders K. E.
Published: July 2010

Alfalfa, Medicago sativa L., plants were exposed to larvae of the clover root curculio, Sitona hispidula (F.), and the bacterial wilt causal organism, Corynebacterium insidiosum (McCull.) H. L. Jens., in factorial combinations. Both factors significantly reduced top growth of alfalfa plants in the greenhouse, and a higher level of bacterial wilt was observed when S. hispidula was present than when it was absent.
A New Factor for Genetic Male Sterility in Sorghum Bicolor (L.) Moench1
Authors: Andrews D. J. , Webster O. J.
Published: July 2010

Male sterility, controlled at one locus, was discovered in 1963 at Sainaru after seed of a Nigerian sorghum had been irradiated with Co60. Crosses were made and the expression of the sterility remained stable in different genetic backgrounds and in a range of climatic conditions. Crosses with other reported genetic steriles indicate that the sterility found is governed by a new factor. The symbol ms7 is proposed.

The male sterility has been used to assist the breeding program by the development of a sorghum composite.
Artificial Selection for Seedling Drouth Tolerance and Association of Plant Characteristics of Lehmann Lovegrass1
Authors: Wright L. Neal , Brauen S. E.
Published: July 2010

Variability among lines of Lehmann lovegrass, Eragrostis lehmanniana Nees, was present for all plant and seed characteristics and responses studied. We reconfirmed the use of program‐controlled environment to consistently evaluate large numbers of seedlings and to select genotypes which are superior for seedling drouth tolerance. There was a lack of uniform association among lines for growth habit; foliage color; anther color; chromosome number; seed dormancy, weight, size, and color; and seedling drouth tolerance. No single characteristic is adequate as a criterion of selection for seedling drouth tolerance. However, we found that lines with nondormant seed of heaviest seed weight could be discarded as drouth susceptible lines before critical evaluation and selection for seedling drouth tolerance.
Evaluation of Synthetic Populations Developed from a Maize Variety (BSK) by Two Methods of Recurrent Selection1
Authors: Burton J. W. , Penny L. H. , Hallauer Arnel R. , Eberhart S. A.
Published: July 2010

The effectiveness of half‐sib selection with a doublecross tester and S1 selection per se was evaluated following four cycles of selection in BSK (the Krug Hi I syn. 3 strain of ‘Krug Yellow Dent’). Five populations, BSK CO, BSK(HT)C2, BSK(S)C2, BSK(HT)C4, and BSK(S)C4, were selfed, sibbed, and crossed in a diallel series. They were also test‐crossed to four single‐cross testers

The average of the four single‐cross testcross yields of the BSK (S) populations increased 10.6% during the four cycles, and the BSK(HT) populations increased 5.7%. The selfing series populations performed better than the testcross series populations when selfed, as indicated by a 38.7% increase for the BSK(S) bulk S1's compared with a 12.0% increase for the BSK(HT) bulk S1s. The populations per se increased 16.3% in the selfing series and 6.3% in the testcross series. The BSK(HT) × BSK(S) crosses exhibited heterosis, which indicated that the two methods developed populations that differed in gene frequency.

This study has shown that the mean yield and the general combining ability of BSK were significantly improved by four cycles of selection with both methods of recurrent selection, but S1 selection per se was more effective.
A Quantitative Genetic Study of Verticillium Wilt Resistance Among Selected Lines of Upland Cotton1
Authors: Verhalen Laval M. , Brinkerhoff L. A. , Fun Kwee‐Chong , Morrison Walter C.
Published: July 2010

A quantitative genetic study of the inheritance of resistance to verticillium wilt (Verticillium albo‐atrum Reinke and Berth.) was conducted among 10 selected lines of upland cotton (Gossypium hirsutum L.) utilizing the Jinks‐Hayman diallel analysis. Parents and F1's were studied in 1968 and 1969 at two locations in Oklahoma with the inclusion of F2 progenies in the second year.

General tests of the diallel assumptions revealed a partial noncompliance with those assumptions in this material. Epistasis did not appear to be a complicating factor herein, but significant genotype by environment interactions were found among parents from year to year for their additive and dominance components of variation. A significant portion of the dominance interactions could not be attributed to either years or locations.

All estimates of environmental variance and of additive genetic variance were significant, as were most estimates of dominance genetic variance. With one exception, estimates of additive variance were larger than the other parameters estimated in the same test. Wilt resistance displayed partial dominance except in one environment where overdominance was found to occur. Direction of dominance was toward greater susceptibility. The frequency of negative versus positive alleles in the parents was likely unequal and biased towards greater susceptibility. Narrow‐sense heritability estimates suggested that rapid genetic advances through selection could be made in most environments.
A Temperature‐Sensitive Leaf Necrosis Mutation in Hexaploid Oats1
Authors: Sadanaga K.
Published: July 2010

An induced mutation in hexaploid oats (Avena sativa L.), characterized by necrosis of the leaf sheaths and blades, is temperature sensitive. In tests in a growth chamber, the mutant phenotype was inhibited at 4 C night and 5.5 C day, but not at 9 C night and 11 C day temperatures. The threshold temperature probably lies between 4 and 9 C. F2 and F3 data indicated that penetrance of the dominant allele of the mutant gene In was variable. Segregation of F3 families fit a ratio of one normal to two segregating to 0.5 necrotic. The deficiency of the homozygous mutant genotype probably resulted from poor germination of In/In F2 seeds and from weak In/In F2 plants which produced few or no seeds. Necrosis began as a disorganization of mesophyll cells adjoining the epidermis.
Water Stress Effects on Photosynthesis and Stem Diameter in Soybean Plants1
Authors: Chen L. H. , Mederski H. J. , Curry R. Bruce
Published: July 2010

The use of a linear transducer for detecting the growth of soybean stems of plants undergoing and recovering from internal water stress was investigated. Continuous, simultaneous measurements indicate a close correspondence in the behavior of plant water stress, net photosynthesis and stem diameter. Plant water stress produces relatively large, transient changes in stem diameter which obscure the effect of water stress on real growth. The close correlation between changes in stem diameter, reflecting xylem tension, and leaf water stress indicates that the linear transducer would be useful for indicating changes in plant water stress.
Immunity from Wheat Streak Mosaic Virus In Irradiated Agrotricum Progenies1
Authors: Lay C. L. , Wells D. G. , Gardner W. S.
Published: July 2010

An octoploid derivative, TA25, of ‘Carsten V’ (Triticum aestivum L. em. Thell) ✕ Agropyron intermedium, was found to be immune from wheat streak mosaic. F1 seed from crosses of TA25 ✕ common wheat were exposed to 1000 and 2500 rads of fast neutrons. After a process of backcrossing and selection, three 43‐chromosome addition lines and one 42‐chromosome translocation or substitution line were obtained having immunity from wheat streak mosaic. An immune 44 chromosome line also was obtained from backcrossing and pedigree selection without irradiation. Both winter and spring type segregates occurred in all four derived lines.
Nodulation Response of Soybeans (Glycine max L. Merr.) to Application Rate and Placement of Combined Nitrogen1
Authors: Harper James E. , Cooper Richard L.
Published: July 2010

Uniform incorporation of ammonium nitrate (dispersed throughout a 30.5 cm soil column) impaired nodular development of soybeans (Glycine max L. Merr.) more than deep application (lower 10 cm of soil column) when ammonium nitrate was applied at a rate of 150 ppm N in growth chamber studies. Nodule fresh weight and haemoglobin content were decreased by nitrogen application, while nodule number was not as markedly affected, indicating an effect on nodule development rather than on root infection or nodule initiation. Greater nitrate content of roots and tops under dispersed nitrogen application, compared with deep application at the same rate, suggested that internal nitrate may be influencing nodulation. However, deep placement of 150 ppm combined nitrogen allowed greater root nitrate uptake than uniform incorporation of 50 ppm N, without concomitant inhibitory effects on nodulation. Nodulation response was not, therefore, strictly dependent upon internal nitrate content of the roots, indicating that application site may provide a means of partially alleviating the detrimental effect of combined nitrogen on nodulation.
Some Problems in Breeding Smooth‐Leaved Cottons1
Authors: Lee Joshua A.
Published: July 2010

Four alleles distributed at three independent loci impart varying degrees of smoothness to the leaves of upland cotton, Gossypium hirsutum L. Each of these alleles, when homozygous, and acting free of other smoothness alleles, confers a characteristic degree of smoothness. Certain interalldic combinations increase smoothness, whereas others do not. Some problems in breeding for smoothness are: (a) determining the degree of smoothness needed, (b) selecting the alleles necessary to impart that level of smoothness, and (c) recognizing the effects of the smoothness alleles in the background chosen, particularly in the heterozygous state. There is little reason to believe that individual smoothness alleles impart any undesirable traits other than possible susceptibility to thrips. However, certain allelic combinations might lower lint percent, and certain of the alleles could be linked to genes conditioning agronomically undesirable traits.
Inheritance of Crown Rust Resistance in Avena sterilis L. from Israel1
Authors: Fleischmann George , McKenzie R. I. H. , Shipton W. A.
Published: July 2010

The inheritance of resistance in four collections of Avian sterilis L. from Israel (D137, F169, F288, and F290) to races 239, 264, 290, 326, 330, and 332 of crown rust, Puccinia coronata Cda. vat. avenae Erikss, was investigated. Three of the collections (D137, F169, and F290) each had a gene conferring rust resistance to all six races, and these genes were independent. The gene in D137 was Pc35 while the genes in F169 and F290 were designated Pc45 and Pc46, respectively. Each of these three collections also contained an additional resistance gene. F169B and F290B were attacked by races 264 and 290, while D137B was attacked by these races as well as race 326.

Genetic analysis of F288 indicated that one gene (F288A) confers resistance to races 239, 290, 326, and 330 but not to races 332 and 264, while a second gene (F288B) confers resistance to race 239, but not to the other five races.

All the resistance genes from the four collections were dominant.
Winter Forage Production and in Vitro Digestibility of Some Phalaris Aquatica Introductions1
Authors: Hoveland C. S. , Anthony W. B.
Published: July 2010

Several unselected Phalaris aquatica L. plant introductions made nearly twice as much winter (Nov.‐Feb.) production as Kentucky 31 tall fescue (Festuca arundinacea Schreb.) or Auburn reed canarygrass (P. arundinacea L.) over a 4‐year period in central Alabama. Digestible dry matter of P. aquatica forage was high and superior to tall fescue in the spring. The wide range in winter productivity, growth habit, time of anthesis and summer dormancy make this species promising for breeding varieties adapted to the Lower Coastal Plain of the U.S.A.
Frequency of Cross‐Pollination of Soybeans After Seed Irradiation1
Authors: Beard Benjamin H. , Knowles Paul F.
Published: July 2010

Soybean [Glycine max (L.) Merrill] seeds of white‐flowered varieties were irradiated with 0, 5, 10, or 20 k rads of gamma rays and planted in rows bordered by purple‐flowered varieties of the same maturity. Honeybees were kept in the vicinity of the plots during the flowering period. Seedlings grown from seeds harvested from the white‐flowered plants were classified for hypocotyl color. The frequency of outcrossing varied with location, with varieties, and with treatment level of irradiation. Outcrossing in the nonirradiated populations varied from 0.30% to 3.62%. An increase of outcrossing, to as much as 11 to 14% in some cases, was observed in the irradiated soybeans. A mixture of the white‐ and purple‐flowered varieties in the same row increased outcrossing slightly over similar treatments with the varieties in separate rows. Seed treatment with ethyl methanesulphonate (EMS) increased outcrossing about the same as the irradiation. In this study a combination of mutagen‐treated seed plus large honeybee populations did not increase outcrossing over earlier reported frequencies from each used separately.
Heritability and Advance from Selection for Six Soybean Seed‐quality Characters1
Authors: Green D.E. , Luedders V.D. , Moraghan B.J.
Published: July 2010

Seed harvested from F3, F5, and F6 lines of six soybean [Glycine max (L) Merr.] crosses were evaluated for field emergence percentage and visually rated for defective seedcoat, wrinkled seedcoat, shriveled cotyledons, green cotyledons, and overall appearance. Correlations between field emergence percentage and the visually rated characters were low, although low incidence and severity of the visually rated characters were generally associated with high field‐emergence percentages. The overall rating generally was equal to any other rating as an indicator of relative field emergence.

Heritability estimates for field‐emergence percentage were low, due to low genetic variability for the character in the F5 and F6 generations and to the large error associated with estimating the field emergence potential of a seed lot. Estimates of heritability for the visual ratings generally were higher than for field emergence, with heritability of green cotyledons usually being lower than the other visually rated characters.

Selecting for high field‐emergence percentage resulted in no significant advance for the character. Advances from selection were somewhat higher for the visually rated characters. The results of this and previous studies suggest that the most efficient means of improving soybean seed quality in a breeding program is to use an overall visual rating and a laboratory germination test in which normal seedlings are counted early in the germinating period, probably at 5 days. An alternative method is to concentrate on improving visually rated characters by selection when environmental conditions cause adequate expressivity.
Heterosis and Combining Ability Estimates in F2 Flax Populations as Influenced by Plant Density1
Authors: Shehata A. H. , Comstock V. E.
Published: July 2010

Seed yield, its three components (bolls per unit area, seed size, and seeds per boll), oil content, and iodine value were studied in F2 populations of a diallel cross among nine cultivars of flax (Linum usitatissimum L.) at two locations and three plant densities.

Average heterosis for yield in F2 was 6% relative to the midparent values. Four F2 populations exceeded in yield the high‐yielding parent by 15 to 19%. One F2 population, ‘Russian’ ✕ C.I. 1664, exceeded by 5.5% the yield of ‘Marine’, the highest yielding cultivar. Varying plant density did not affect the magnitude of heterosis, mean oil percentage, iodine value, nor the estimates of combining ability. Plant density did have a significant effect on mean yields and on the yield components, and showed a significant interaction with genotypes for yield and bolls per unit area. In spite of the latter interaction, seven of the 36 F2 populations were among the highest 25% in yield in all three densities. The interactions of locations with genotypes were significant for most characters, which suggests that more than one test location should be used to evaluate hybrid flax populations. General combining ability effects were significant and much larger for all characters than were specific combining ability effects at all densities.
Effects of Chilling on Protein Synthesis and CO2 Fixation in Cotton Leaves1
Authors: Omran R. G. , Benedict C. R. , Powell Robert D.
Published: July 2010

Biochemical changes resulting from chilling of cotton seedlings (Gossypium hirsutum L. cultivar Paymaster) that had been subjected to 5, 10, and 25 C for 36 hours were studied. Incorporation of 14C amino acids into protein and fixation of 14CO2 immediately after chilling showed a great increase in protein synthesis and CO2 fixation. When protein synthesis was determined as a function of chilling duration at either 5 or 10 C, there was an increase in the amino acid incorporation following chilling up to 48 hours, but at 72 hours there was a sharp decrease. This result indicates that severe chilling injury caused sufficient damage to the metabolism of the plant to prevent the recovery processes from occurring. The observed stimulation in protein synthesis and CO2 fixation after chilling may be related to processes associated with recovery of tissue from the chilling damage.
Resistance in Soybeans to the lvlexican Bean Beetle. I. Sources of Resistance1
Authors: Van Duyn John W. , Turnipseed Sam G. , Maxwell James D.
Published: July 2010

World collections of soybean, Glycine max (L.) Merr., maturity groups VII and VIII, were screened for resistance to the Mexican bean beetle, Epilachna varivestis Mulsant, in 1968. Twenty‐three selections and five commercial cuhivars were intensively studied in 1969. In the field plants of PI 229358, PI 171451, and PI 227687 were highly resistant. Laboratory forced feeding tests showed that these three lines, were unsatisfactory as food even when no alternate food was available. Of the commercial lines tested ‘Bragg’ and ‘Nela’ demonstrated the least susceptibility.
Selection for Female Fertility and Seed Size in Male Sterile Intermediate Wheatgrass, Agropyron Intermedium (Host) Beauv.1
Authors: Schulz‐Schaeffer Jurgen , Kim Jae Ho
Published: July 2010

We selected for female fertility and seed size in strains of substitution backcrosses to the amphidiploids (AD) Triticum durum Desf. ✕ Agropyron intermedium (Host) Beauv. and T. durum ✕ A. trichopharum (Link) Richt. Among 77 second substitution backcross strains (SB2), 18 had high pollen sterility (81.5 to 100%) with some degree of female fertility. Seeds per spike in the SB2 varied from 0.78 to 10.48, with an average of 4.06. This compared with 4.30 to 13.67 seeds per spike in the AD. Lack of correlation between male and female sterility in the SB2 confirms the contention that the male sterility is cytoplasmic in nature. Thousand kernel weight (TKW) of 17 SB2 strains ranged from 3.39 to 10.06 g, with an average of 6.54 g. This compares with 3.98 g in A. intermedium.
An Automatic Darkbox to Induce Flowering in Short‐Day Plants in Midsummer1
Authors: Buron Glenn W. , Stansell J. R.
Published: July 2010

An inexpensive darkbox has been developed that will automatically provide short days. A 4‐week exposure to a 10‐hour day supplied by this unit will induce floral primordia in up to 140 3‐week‐old potted plants of pearl millet. Most “day neutral” and short‐day millets so treated and given temperatures of 35 to 40°C in the greenhouse will reach anthesis in the summer about 50 days after planting.
Selective Modification of Alfalfa toward Acclimatization in a Subarctic Area of Severe Winter Stress1
Authors: Klebesadel L. J.
Published: July 2010

A‐syn.B, a strain of variegated alfalfa (Medicago media Persoon) possessing exceptional adaptation to subarctic conditions, has been developed during the past two decades at the College Research Center in subarctic, interior Alaska (63.8° N. lat.). This strain was synthesized from persistent plants remaining after winters had eliminated the less hardy bulk of populations from numerous alfalfa cultivars in experimental field plantings.

A‐syn.B displayed significantly better winter survival in the field than 33 other strains from Canada, northern Europe, and the conterminous USA. Etiolated growth in autumn, an estimate of stored reserves, was expressed in greater amount and over a longer period by A‐syn.B than by ‘Rhizoma,’ ‘Rambler,’ or ‘Vernal,’ varieties that are considered extremely winter‐hardy elsewhere. A‐syn.B sustained less injury to artificial freeze stress than Vernal. This new strain is considered to represent selection for genotypes better adapted for reserve storage and coldhardiness development than midtemperate alfalfa varieties under the brief term of short photoperiods in the Subarctic prior to onset of winter.

Another Alaskan synthetic, A‐syn.A, derived from artificial crosses of M. media X M. falcata backcrossed to M. falcata, was superior to A‐syn.B in two of five tests and inferior to pure M. falcata in winter survival only in one test that was exposed to greatest winter stress. A‐syn.B was superior in winter survival to varieties of alsike, red, and strawberry clovers (Trifolium spp.), birdsfoot trefoil (Lotus corniculatus L.), crownvetch (Coronilla varia L.), and sainfoin (Onobrychis viciaefolia Scop.), and less hardy than two native Alaskan legumes.