bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of Stocks within Long‐Time Inbred Lines of Maize in Testcrosses1
Authors: Fleming A. A.
Published: July 2010

The objective of these experiments was to determine the effect of seed stocks (sources) within long‐time inbreds of maize (Zea mays L.) on their performance in hybrids. Prior to increase, the inbreds were maintained by different breeders in several states. Seed stocks within the six long‐time inbred lines were compared in three‐way testcrosses.

Significant differences in the hybrids, depending on geographical source of the inbreds, were observed in 9 out of 10 agronomic characters: yield, ear height, plant height, time of silking, stalk lodging, erect plants, ears per plot, dropped ears per plot, and leaf position. No significant differences occurred in grain quality. Ear height had the most significant differences. Thus, genetic changes and shifts in gene frequency may be occurring constantly within an inbred. These changes may not only affect the performance of the inbred, but also of the hybrid in which it is used.
Seed Development Following the Mating of Trifolium repens ✕ T. uniflorum1
Authors: Chen Chi‐Chang , Gibson Pryce B.
Published: July 2010

About 17% of the ovules of Trifolium repens L. were fertilized by the male gametes of T. uniflorum L. following the mating of the two species; however, few if any of these would have developed into viable seeds. The hybrid embryo, although it grew more slowly than that of T. repens, differentiated normally or nearly so up to the 6th day after pollination. The hybrid endosperm, on the other hand, began to develop abnormally on the 4th day. By the 6th day, the endosperm was highly vacuolate. The appearance of the endosperm and the adjacent maternal tissues suggested that at this stage of development the endosperm had lost the ability to absorb and conduct nutrients. By the 8th day, the endosperm had disintegrated and the embryo appeared to be degenerating. These observations suggest that failure of the hybrid embryo to develop to a germinable condition following the mating of T. repens ✕ T. uniflorum is a result of starvation caused by abnormal development and, eventually, disintegration of the endosperm. Failure of the endosperm to nourish the embryo may be attributed to genetic imbalance of the endosperm itself, or to an unfavorable interaction of the endosperm with the maternal tissues.
Interactions of Alleles at Two Loci Regulating Fatty Acid Composition of the Seed Oil of Safflower (Carthamus tinctorius L.)1
Authors: Ladd S. L. , Knowles P. F.
Published: July 2010

Alleles affecting the fatty acid composition of the seed oil of safflower (Carthamus tinctorius L.) at the st (stearic acid) and ol (oleic acid) loci segregated independently. Increases in stearic acid percentage were accompanied by decreases in the percentage of oleic acid, linoleic acid, or both. In certain genotypes it appeared that cooler growing temperatures reduced the relative amounts of stearic and oleic acids while increasing linoleic acid.
Estimating Genetic Variance in Maize by Use of Single and Three‐way Crosses among Unselected Inbred Lines1
Authors: Wright J. A. , Hallauer Arnel R. , Penny L. H. , Eberhart S. A.
Published: July 2010

Unweighted least squares and maximum likelihood procedures were used and compared for the estimation of genetic variance for eight quantitative traits in maize (Zea mays L.). The genetic material was developed from unselected inbred lines isolated from a strain of Krug Yellow Dent maize. All possible single and 3‐way crosses were produced from 60 inbred lines, which traced back to 51 S0 plants. The mean squares from the diallel and triallel analyses were used in estimating the genetic components of variance.

Fitting the error and a six‐parameter genetic model showed that: 1) it was not possible to obtain realistic estimates of the epistatic components, although significant effects were detected in the analyses of variance; 2) the estimates of additive geuetic variance were significant for all traits for both estimation procedures; 3) the nonadditive components accounted for only a small proportion of the total genetic variance; 4) three iterations of the maximum likelihood procedure were sufficient to stabilize the estimates; and 5) the maximum likelihood procedure generally reduced the errors of the estimates.

For the two‐parameter genetic model the largest proportion of the total genetic variance was additive for all traits. The estimates of deviations due to dominance were larger than twice their standard errors for all traits in the two‐parameter model for the combined single and three‐way cross data. The frequency of significant interactions with environments was higher for the additive than for the dominance effects.
Influence of 2,3,5‐Triiodobenzoic Acid on Seed Yield of Lentils1
Authors: Muehlbauer F. J. , Miller D. G.
Published: July 2010

High rates of 2,3,5‐triiodobenzoic acid (TIBA) caused a dense‐appearing canopy that may increase the competitive ability of lentils (Lens culinaris L.). At high rates there was an increase in single pods per peduncle, a decrease in triple pods, and no change in double pods. Total number of pods per plant, seed per pod, seed per plant, and seed weight did not change. Yields were similar to the control at one rate (2.8 g/ha) of the chemical, while at other rates yields tended to be reduced.
Effectiveness of Selection in Successive Generations of Maize Inbred Progenies for Improvement of Hybrid Yield1
Authors: El‐Lakany M. A. , Russell W. A.
Published: July 2010

The F1, F2, F3, and F4 generations of 20 selected maize (Zea mays L.) inbred families were evaluated by testcross performance to determine the efficacy of selection in three successive segregating generations to improve combining ability for yield. Ten lines had high yield performance and 10 lines had low yield performance as determined by testcrosses of the F5 or F6 generation. The high‐performance families had F2's equal to, or better than, their F1 source, and nine families were improved by selection in the F3 or F4, or both. Five low‐performance families had F2 yields below those of the F1 source, and not enough gain by selection was realized to have the F4 at the yield level of the F1. The other five low‐performance families had F2 yields at least equal to their F1 source, but no further gains in yield were obtained by selection.
Influence of Unfilled Cotton Seed upon Emergence and Vigor1
Authors: Ferguson David , Turner John H.
Published: July 2010

The influence of cottonseed fullness upon emergence and seedling growth was studied under a minimal temperature of 17 C ± 1. Seeds of Acala SJ‐1 (Gossypium hirsutum L.) were sorted by X‐ray photography into four classes, or degrees of seed filling (50, 75, 90, and 100%).

Completely filled seeds were superior to partially filled seeds for total emergence, seedling survival, and early growth. Emergence and seedling survival were related more to seed fullness than to seed weight in this study. These data indicate that grading of planting seed based upon weight or size is not adequate to remove many inferior seeds.
Evaluation of Cross‐fertilization in Forage Crops1
Authors: Gorz H. J. , Haskins F. A.
Published: July 2010

In the improvement of forage crop varieties knowledge of the extent of cross‐fertilization is of value for (1) determining the extent and randomness of crossing in breeding procedures, (2) estimating varietal changes due to contamination and mechanical mixtures, and (3) evaluating effects of cross‐fertilization in the development and production of synthetic and hybrid combinations. Genetic markers can aid greatly in the evaluation of cross‐fertilization, and thus in the development and production of new varieties. Ideally, markers should be distinctive and readily detected in the seedling stage, conditioned by a single dominant gene with complete penetrance, and have no adverse effects on plant growth, zygote viability, or randomness of cross‐pollination.
Genetic Suppression of Shoot‐trichomes in Pearl Millet, Pennisetum typhoides1
Authors: Powell Jerrel B. , Burton Glenn W.
Published: July 2010

A new mutation in pearl millet, Pennisetum typhoides (Burm.) Stapf and C. E. Hubb that suppresses virtually all shoot‐epidermis trichomes is described. Hairs on blade and sheath, barbs along leaf margins, short hairs and claws on veins of upper and lower leaf surface, cilia on ligules, hairs on nodes, wooly hairs below base of panicle, rachilla hairs, and scabrous and pennate properties of bristles are suppressed. The plumose stigmas are modified into fork‐like stylar branches by the gene. Hair tufts at the apex of anthers, which have taxonomic significance, are absent. The trait is recessive and is inherited as a single gene pair.
Genetic Control of Root Fluorescence in Soybeans1
Authors: Fehr W. R. , Giese J. H.
Published: July 2010

We studied the genetic control of root fluorescence in soybeans [Glycine max (L.) Merr.]. Fluorescent roots emit a soft blue glow when exposed to ultraviolet light, while nonfluorescent roots exhibit the dark violet color of the light source. Two soybean varieties with fluorescent roots, 'Blackhawk' and 'Hawkeye,' and one variety with nonfluorescent roots, 'Minsoy,' were used.

Evaluation of F1 plants, F2 populations, and F3 families from the crosses Blackhawk ✕ Hawkeye, Blackhawk ✕ Minsoy, and Hawkeye ✕ Minsoy indicated that root fluorescence was controlled by a single gene. Fluorescence is completely dominant to nonfluorescence. The same allele for fluorescence is present in Blackhawk and Hawkeye. The symbol Fr will be used to designate the fluorescent gene.
Variability Associated with Sampling of Rhizobium japonicum Populations in Soybeans1
Authors: Vest Grant , Caldwell B. E. , Petersen H. D.
Published: July 2010

Five hundred nodules from the soybean [Glycine max (L.) Merrill] variety ‘Lee’ were serotyped each of 3 years. The Rhizobium japonicum [(Kirchner) Buchanan] strains in the nodules were classified into serogroups according to their serological reaction. Standard errors of the mean were computed for the predominant serogroups to determine the variability of the R. japonicum population within the field. R. japonicum variability was found to be greater within than between areas (blocks) in the field.
Growth Studies on the Sugarcane Plant. I. Effects of Temperature1
Authors: Mongelard J. C. , Mimura L.
Published: July 2010

Growth of four sugarcane (Saccharum officinarum L.) clones, as affected by two air and two root temperatures during a 28‐day period, is described. With all treatments dry‐matter production was found to be closely related to water consumption (r = 0.98), increase in height of the top visible dewlap (r = 0.95), and spindle growth rate (r = 0.91). The spindle, because of its rapid and constant growth rate, was found to be more reliable than the dewlap for obtaining short‐term (24‐hr) measurements of dry‐weight production. Leaf growth was affected more by low root temperature than by low air temperature. Low root temperatures reduced water consumption per unit leaf area. There was no effect of temperature on the transpiration ratio (water consumed per unit dry weight), but the increase in fresh weight/increase in dry‐weight ratio was about four times less under cool root conditions than under warm root conditions.
Meiosis of Trisomics of Diploid Alfalfa1
Authors: Buss G. R. , Cleveland R. W.
Published: July 2010

Several single primary trisomic plants (2n = 17) were produced by crossing a triploid (2n = 24) with several diploid plants (2n = 16). The diploid parents were Medicago saliva L., M. falcata L., and derivatives of hybrids of the two. The triploid was also a hybrid. The proportion of trisomic plants varied among families, averaging 13 and 34% when the triploid was used as the male and. fenmle parent, respectively. Double trisemics (2n = 13) occurred in 3X by 2X progenies only.

Chromosome pairing relationships at meiosis in microsporocytes were observed for 10 single primary trisomics. Mean numbers of trivalents per cell at MI differed significantly among plants, ranging from 0 to 0.47. Metaphase pairing behavior might be used in conjunction with other attributes to identify trisemics.

The trisomic condition did not impart distinguishing plant morphological characteristics.
Yields of S1 Lines from Original and Advanced Synthetic Varieties of Maize1
Authors: Genter C. F.
Published: July 2010

Four maize (Zea mays L.) synthetic varieties were selfed and approximately 200 S1 lines of each were grown in separate replicated yield trials with the parental populations to compare inbreeding depressions and yield distributions among the S1 lines. The four parental populations were (i) ‘iowa Stiff Stalk Synthetic,’ SSS, (ii) an advanced synthetic derived from SSS by seven cycles of recurrent selection based on half‐sib yield, SSS(HT)C7, (iii) ‘Virginia Corn Belt‐Southern Synthetic,’ CBS, and (iv) an advance synthetic derived from CBS by four cycles of recurrent selection for S1 yield, CBS(S)C4.

Inbreeding depression was lower for S1 lines from each of the advanced synthetics than for those of the corresponding original and was lowest for the S1 lines from SSS(HT)C7. Inbreeding depressions were 39.1 and 27.8%, respectively, for S1 lines from SSS and SSS(HT)C7, and 38.3 and 32.5%, respectively, for S1 lines from CBS and CBS(S)C4. S1 lines from SSS(HT)C7 averaged 9.3% higher in yield than those from SSS, although the range of yields was less at both extremes for lines from the advanced population. S1 lines from CBS(S)C4 averaged 27.2% higher than those from CBS with a comparable range of yields.

SSS(HT)C7 yielded slightly less than SSS. CBS(S)C4 yielded approximately 19% more than CBS. In all populations the maximum S1 yield approximated that of the parental source. Two S1 lines from CBS(S)C4 were comparable in yield to that of a double‐cross hybrid check variety. One effective means of increasing inbred line yields appears to be increasing the yields of parental source populations.
Additive Resistance to Stripe Rust in Wheat1
Authors: Henriksen G. B. , Pope W. K.
Published: July 2010

Under conditions of severe stripe rust (Puccinia striiformis West.) infestation at Moscow, Idaho in 1963‐65, progeny of crosses between the resistant wheat (Triticum aestivum L.) ‘Hussar’ and the wheats ‘Idaed’ (resistant) and ‘Dicklow,’ ‘Baart 46,’ ‘Federation,’ and ‘Lemhi’ (more or less susceptible) showed segregation of minor genes for additive levels of resistance, with the variety Lemhi contributing no genes for resistance.
Selection for Resistance to Anthracnose (Colletotrichum trifolii) in Four Alfalfa Populations1
Authors: Devine T. E. , Hanson C. H. , Ostazeski S. A. , Campbell T. A.
Published: July 2010

Three cultivars and one experimental population of alfalfa (Medicago saliva L.) were subjected to three cycles of recurrent phenotypic selection in the laboratory and greenhouse for resistance to anthracnose, caused by Colletotrichum trifolii Bain and Essary. The frequency of highly resistant plants in the cultivars ‘Glacier,‘ ‘Saranac,’ and ‘Vernal’ increased from 5, 5, and 1% to 82, 72, and 59%, respectively. The frequency of highly resistant plants in the experimental population MSHp6F, which had a higher initial level of resistance, increased from 20 to 88%. Highly resistant plants were characterized by the absence of lesions and acervuli. Rapid progress in selection and the bimodal distribution of the MSHp6F population series suggested that resistance in this population may be controlled by a single dominant gene. The distribution and selection progress in Vernal suggested a more complex mechanism for conferring resistance in this population.
Inheritance of Oleic and Linoleic Acids in Zea Mays L.1
Authors: de la Roche I. A. , Alexander D. E. , Weber E. J.
Published: July 2010

The difference in the levels of oleate and linoleate in the triglycerides of the related R84 and Illinois High Oil (IHO) maize (Zea mays L.) strains is determined solely by the In locus. A single locus controls the 20% difference in oleate and linoleate between C103 and R84. At least two loci control the levels of oleate and linoleate in C103 and IHO. Strong maternal effects are exhibited in the reciprocal F1's of C103 and R84. In contrast, no maternal effects were detectable in IHO ✕ R84 and C103 ✕ IHO.
Effects of Temperature and Photoperiod on Spring Wheat Pollen Viability1
Authors: Welsh J. R. , Klatt A. R.
Published: July 2010

Seven cultivars of spring wheat (Triticum aestivum L. em Thell.) including the cultivars ‘Chris,’ ‘Crim,’ their male‐sterile counter‐parts, the restorer ‘Dirk’ and the Fl′s of the male‐steriles ✕ Dirk were subjected to the nine combinations of 12‐, 14‐, and 16‐hour photoperiods and 24 C ‐ 7 C, 30‐13, .and 35‐18 day‐night temperature regimes. Pollen viability was based on stainable grains and seeds per spike were counted. The r value between pollen stainability and seed counts was 0.87.

Temperature had the greatest effect on pollen viability iu the experiment. In general, high temperatures reduced pollen viability. Photoperiod had minor effects with longer periods slightly reducing viability. Chris and Crim had the highest viabilities. The pollen viability of Dirk tended to drop sharply with high temperatures. The Fl′s were intermediate. Male‐sterile Chris had consistently low pollen viability. Male‐sterile Crim had quite viable pollen at low temperatures and short to medium daylengths, but low viabilities at other environments. Genotype ✕ environment interactions occurred only at the 14‐hour photoperiod where viabilities of Chris, Crim, and male‐sterile Crim were not reduced at high temperatures.
Interspecific Hybridization of Trifolium uniflorum L.1
Authors: Gibson Pryce B. , Chen Chi‐Chang , Gillingham J. T. , Barnett O. W.
Published: July 2010

Interspecific hybrids were obtained by crossing Trifolium uniflorum L. with T. repens L. and colchicine‐induced autotetraploid T. occidentale D. E. Coombe. The conclusion that the matings resulted in species hybrids was based upon morphological, cytological, and chemical evidence. The hybrids were vigorous plants, producedflowers, and varied in fertility. Multiple‐species hybrids of the three species were easily obtained. Trifolium uniflorum and T. occidentale have characteristics that possibly can be used to develop improved varieties of T. repens.
Twenty Years of Reciprocal Recurrent Selection with Two Synthetic Varieties of Maize (Zea mays L.)1
Authors: Penny L. H. , Eberhart S. A.
Published: July 2010

Five cycles of reciprocal recurrent selection in two synthetic varieties of maize (Zea mays L.) were summarized. Yields of the varietal cross and one parental variety were increased significantly, but the yield of the other variety de, creased slightly. Expected gain in the varietal cross yield, calculated from pooled heritabilities and selection differential, was 7.2% per cycle, but observed gain was only 1.7% per cycle.

In the sixth cycle, selection among S1 plants was substituted for selection among S0 plants. Selection within the randomly mated varietal cross was initiated for comparison with selection within the two parental varieties individually. Estimates of genetic variance within the parental populations in the sixth cycle were higher than for the three previous cycles, and genetic variance was higher within the randomly mated varietal cross than within the parental varieties.
A Geometrical Approach to Yield Models in Upland Cotton (Gossypium hirsutum L.)1
Authors: Maner B. A. , Worley S. , Harrell D. C. , Culp T. W.
Published: July 2010

Yield models were developed for selected Upland cotton (Gossyplum hirsutum L.) genotypes. Yield was equated with the volume of a rectangular parallellepiped having the following dimensions: bolls per square meter (X), seeds per boll (Y), and seed cotton per seed (Z). Axis (Z) was divided into its two fractions: lint per seed (L) and weight per seed (S). Yield components of selected genotylpes were expressed as a percentage of ‘Coker 201,’ when the variance was set at zero.

BolIs per square meter (X axis) had the gxeatest influence on yield. We expect that the greatest gain in yield improvement should come from exerting selection pressure on this character. Concurrent selection pressure should also be placed on seeds per boll (Y) and seed cotton per seed (Z) to maintain these components at levels similai to those of leading commercial varieties grown in the ecological area.
Inheritance of Resistance to Stem Rust in Six Durum Wheats1
Authors: Weeraratne Hector , Williams N. D.
Published: July 2010

We studied the inheritance of resistance to culture 111‐SS2 of Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henri. in six tetraploid wheats (Triticum turgidum L.). Seedling reaction was determined in the backcross‐F2 and F3 from crosses of six resistant wheats with the susceptible cultivar ‘Marruecos 9623.’ Three dominant genes conditioned resistance in each of the strains ‘C.I. 7805,’ ‘Acme,’ and ‘Beladi 116.‘ Two dominant genes and one recessive gene conditioned resistance in each of the cultivars ‘Arnautka’ and ‘Tremez Preto.’ Tremez Rijo had one dmninant and one recessive gene for resistance. Genes conditioning low infection types were epistatic to those conditioning high infection types. Lines having single genes for resistance were selected for each of the genes for resistance in Acme and ‘Tremez Rijo.’
Inheritance of Bud and Pod Color, Pod Attachment, and Growth Habit in Cowpeas1
Authors: Singh K. B. , Jindla L. N.
Published: July 2010

Genetic analysis showed that green bud color (Gr) in cowpeas (Vigna sinensis L.) was monogenically dominant over white (gr). Green pod color was dominant over white pod color and controlled by a single gene pair (G, g). Erect pod attachment E was monogenically dominant over drooping pod attachment e. Trailing growth habit was dominant over erect growth habit. This character is governed by three genes (T1, T2, and T3) that interact in such a manner that genotypes included in the categories T1‐T2‐T3‐, T1‐T2‐t3t3, and t1t1t2t2T3‐ have the trailing growth habit. All other genotypes have the erect growth habit.
Yield and Viability of Tobacco Seeds Produced under Heat and Light Reflecting or Absorbing Covers1
Authors: Burk L. G.
Published: July 2010

Seeds of tobacco (Nicotiana tabacum L.) were produced within cheesecloth bags and variously painted and unpainted wet‐strength kraft paper bags. Temperatures within these seed head covers were measured at noon on a typically warm day (30 to 34 C) and also on a relatively cool day (21 to 25 C). A treatment consisting of paper bags that had been painted black markedly reduced yield and germination. Highest temperatures were also encountered in the black bags. Lowest temperatures were measured in the cheesecloth bags from which the highest yield and germination of seeds were obtained. Bags painted silver possessed internal temperatures that were only 1 or 2 degrees higher than those measured under the cheesecloth bags. However, the yield from seed heads covered with bags painted silver was less than half of that obtained from those enclosed with cheesecloth. These data suggested further that light may have a beneficial effect on seed yield.
Studies of Nonrandom and Barren‐Type Sterility in Sorghum bicolor1
Authors: Jaisani B. G. , Drolsom P. N.
Published: July 2010

The frequency of nonrandom‐type sterile Sorghum bicolor (L.) Moench plants among the progenies of random‐type sterile plants in the S1, S2, and S3 generations decreased with advancing generations. The progenies of non‐random‐type sterile plants became more uniform, suggesting genetic control of such sterility.

Barren‐type sterility was observed in S1 S2, and S3 generation sorghum plants. The breeding behaviors of the segregating progenies suggested that this character was controlled by two gene pairs and that the double homozygous condition resulted in the expression of recessive barren‐type sterility. Fourteen progenies segregated for 15 nonbarren to 1 barren‐type sterile plants as expected. Eight progenies showed good agreement to a 3:1 ratio, and five progenies had an excess of barren‐type sterile plants. These findings further suggested that the genes governing barrenness are expressed only under certain environmental conditions.
Light Saturation, Photosynthesis Rate, RuDP Carboxylase Activity, and Specific Leaf Weight in Soybeans Grown Under Different Light Intensities1
Authors: Bowes G. , Ogren W. L. , Hageman R. H.
Published: July 2010

Higher light intensities during growth of ‘Wayne’ soybeans [Glycine max (L.) Merrill] resulted in increases in photosynthesis rate, light saturation intensity, RuDP carboxylase activity, and specific leaf weight. This light adaptation may explain the large reported differences in maximum photosynthesis rate and light saturation intensity for the soybean.
Some Metabolic Phenomena of Kentucky Bluegrass Under High Temperature1
Authors: Watschke T. L. , Schmidt R. E. , Carson E. W. , Blaser R. E.
Published: July 2010

Plugs of 10 Kentucky bluegrass (Poa pratensis L.) strains grown in a controlled environmental growth chamber for 4 weeks at 23 to 15 C, and these temperatures were shifted to 35 to 25 C for 4 additional weeks. Foliar production and carbohydrates were reduced rapidly at high temperatures. By the end of the 3rd week these reductions decreased as threshold carbohydrate levels were apparently approached. Photosynthesis differed among the strains at 35 C in normal air. Low oxygen concentrations inhibited photorespiration and caused nearly two‐fold increases in net photosynthesis. Dark respiration, measured with CO2‐free air, differed among the strains. Carbon dioxide compensation points were measured in a closed system and did not differ at 35 C. Bluegrasses with best growth at high temperatures generally had higher photosynthesis and lower respiration (both light and dark) than grasses with poor growth at high temperature. Management periods can influence tolerance; however, bluegrasses with genetically high photosynthetic efficiency should be selected for use in areas of high temperature stresses.
Effects of Seed Treatment with Fungicides and Systemic Insecticides on Stand of Cotton1
Authors: Minton E. B.
Published: July 2010

In 1967 the insecticide, 0,0,diethyl‐S‐2‐ [(ethylthio) ethyl] phosphorodithioate (disulfoton), did not affect cotton (Gossypium hirsutum L.) seedling stands when used with the fungicide combinations of tetrachloroisophthalonitrite (chlorothalonil) + p‐dimethylaminobenzenediazo sodium sulfonate (Dexon3) + 1,4‐dichloro‐2,5‐ dimethoxybenzene (chloroneb). However, it caused a slight reduction of the stand when used with chlorothalonil + N‐(trichloromethylthio)‐4‐cyclohexene‐l,2‐dicarboximide (captan), as compared to seed treated only with fungicides. In another test, stands from acid‐delinted seeds were not affected differentially by combination seed treatments of pentachloronitrobenzene + 3‐trichloromethyl‐5‐ethoxy‐l,2,4‐thiadiazole (formulated as Terracoat L213) and any of the systemic insecticides tested. However, stands from machine‐delinted seeds were lower consistently with the combined fungicide‐insecticide treatments, as compared to the fungicide treatment alone. In 1968 stands were increased by seed treatment with Terracoat L21 + disulfoton, or by the multiple‐fungicide treatment of Terracoat L21 + methyl mercury‐2,3‐dihydroxy propyl mercaptide and methyl mercury acetate (Ceresan L3), as compared to seeds treated with only Terracoat L21. When an emulsifiable formulation of Terracoat L21, as compared to the oil‐base seed treatment formulation, was used for seed treatment purposes, stands from the combination treatments were reduced.
Cytogenetics of Paspalum urvillei ✕ P. juergensii and P. urvillei × P. vaginatum Hybrids1
Authors: Burson Byron L. , Bennett Hugh W.
Published: July 2010

Paspalum urvillei, 2n = 4x = 40, was crossed with P. vaginatum, 2n = 2x = 20, and P. juergensii, 2n = 2x = 20. A morphologically different type of P. urvillei (480) was also crossed with P. vaginatum. Three P. urvillei ✕ P. vaginatum, five P. urvillei 480 ✕ P. vaginatum and 28 P. urvillei ✕ P. juergensii hybrids were produced. This represents a crossability of 0.7%, 1.3%, and 1.1%, respectively, which is high for this genus. All hybrids were 2n = 3x = 30. Meiosis in P. urvillei ✕ P. vaginatum and P. urvillei 480 ✕ P. vaginatum hybrids was very irregular with numerous laggards and micronuclei. Their mean pairing relationships were 1.89 II, 26.23 I and 1.25 II, 27.50 I respectively. P. urvillei ✕ P. juergensii hybrids had bivalent and univalent chromosome associations at meiosis with some laggards and micronuclei. The mean pairing relationships were 9.89 II and 10.29 I per cell. Chromosome pairing suggests a common genome in P. urvillei and P. juergensii but very little homology between P. urvillei and P. vaginatum. Megasporogenesis was normal in all hybrids. However, the functional megaspore generally deteriorated and an ovule without an embryo sac resulted. Sexual sacs in various stages of development were present in 1% of the ovules observed. None of the hybrids produced seed.
Performance of Sugarbeet Hybrids as Diploids and Triploids1
Authors: McFarlane J. S. , Skoyen I. O. , Lewellen R. T.
Published: July 2010

The pollen parents of two diploid sugarbeet (Beta vulgaris L.) hybrid cultivars were converted from diploids to tetraploids. The root yield of triploid hybrids produced with tetraploid pollinator 663 averaged about 10% higher than the equivalent diploid hybrids, but the sucrose concentration was reduced. The performance of triploid hybrids produced with the tetraploid pollinator 413 were similar to those of equivalent diploid hybrids. Bolting was less severe in the triploid hybrids than in equivalent diploid hybrids.
Variation In Kernel Plumpness, Lodging, and Other Characteristics in Six‐rowed Barley Crosses1
Authors: Nasr H. G. , Shands H. L. , Forsberg R. A.
Published: July 2010

Several generations of six‐rowed barley (Hordeum vulgare L.) crosses of parents with a wide range of morphological and agronomic characteristics were examined for breeding behavior. Parents used were wide‐kerneled ‘Larker’ and ‘X969‐3,’ intermediate‐kerneled ‘Dickson’ and ‘X1068‐1,’ and thin‐kerneled ‘Fraeg’ and ‘J2458‐1.’ The latter two are short and comparatively stiff strawed.

Population means for plumpness, test weight, and plant height resembled midparent values, indicating that gene effects were additive. Some population means deviated from midparent values for increased lodging and increased grain yield. For example, small‐plot yields of F3 lines of Larker ✕ X1068‐1 averaged 5,310 kg/ha (98.7 bu/a) in 1969, compared to 5,017 kg/ha for Larker.

Heritability estimates using variance components were high for kernel plumpness, intermediate to high for test weight and plant height, low to intermediate for lodging, and slightly lower for yield. Estimates obtained by the standard unit method were usually lower than those using variance components.

Predicted genetic advance for percent kernel plumpness ranged from 3.3 to 27.7%. The observed advances were close to the predicted in 6 of 11 high‐plumpness comparisons.
Further Selection for Lower Ear Height in Maize1
Authors: Acosta Alvaro E. , Crane Paul L.
Published: July 2010

The effectiveness of selection for lower ear height and the associated responses of four agronomic traits were evaluated. In a previous study two populations of maize (Zea mays L.), ‘Antigua 2D’ ✕ (BIO ✕ B14) and ‘ETO’ ✕ ‘CBC,’ were selected for lower ear height at a selection intensity of 50%. In this study they were submitted to two further cycles at 20% selection intensity. Evaluation was then made by means of topcrosses and populations per se. Ear height was reduced about 24% in both selected subpopulations during the four cycles, compared with the control subpopulations. Ear height of the control subpopulation in the ETO ✕ CBC population decreased about 3% per cycle compared with the original population. Plant height was reduced to a lesser degree. Lodging decreased in the selected subpopulation of Antigua 2D ✕ (BIO ✕ B14) population but not in the ETO ✕ CBC population. The selected subpopulations yielded progressively less than the control in each additional cycle of selection.
Environmental Effects on the Resistance of Rice Seedlings to Complete Submergence
Authors: Palada Manuel C. , Vergara Benito S.
Published: July 2010

The survival of rice seedlings (Oryza sativa L.) after complete Submergence in water decreased with increased duration of submergence; with increased depth, temperature, and turbidity of water; and with increased rates of N fertilization. Survival increased with high light intensity and plant carbohydrate content. Factors that influence the survival of submerged plants also determine the amounts of N and carbohydrate in the plant.
Genetic Control of Glycoflavone Production in Wheat1
Authors: Dedio W. , Kaltsikes P. J.
Published: July 2010

Two dimensional thin‐layer chromatography of three cultivars of hard red spring wheat (Triticum aestivum L. em. Thell.), their extracted AABB tetraploids, and two cultivars of durum wheat (T. turgidum L. var. durum) revealed at least 11 flavonoid compounds. Evidence from UV spectrophotometry, hydrolysis products, and Rf values indicated these to be glycoflavones with apigenin or luteolin bases. All cultivars exhibited similar chromatographic patterns, but quantitative variation was observed among them. The patterns of the extracted tetraploids were almost identical to those of their hexaploid counterparts, indicating considerable duplication of flavonoidsynthesizing genes.
Reciprocal Differences and Combining Ability for Corn Earworm Injury among Maize Single Crosses1
Authors: Widstrom N. W.
Published: July 2010

Reciprocal differences and combining abilities for corn earworm [Heliothis zea (Boddie)] injury were determined for single crosses among ten southern adapted maize (Zea mays L.) inbreds. Specific combining ability effects approached general combining ability effects in terms of their relative importance in conditioning resistance to injury by the corn earworm. Highly significant genotype‐environment interactions occurred for both general and specific combining abilities. Reciprocal effects were highly significant during one of 2 years but nearly disappeared in the combined analysis by way of a genotype‐environment interaction.

Constant parent regression (c.p.r.) analysis revealed significant amount of dominance for earworm injury, nearing the complete dominance level. The size of negative c.p.r., values for some inbreds suggested the presence of overdominance for resistance to earworm injury. In general, nonadditive effects appear to be nearly as important as additive effects in producing plant resistance. Reciprocal effects may interfere with identification of resistant genotypes through their interaction with specific enviromnents, but may normally be ignored as important genetic determinants. Consideration of the reciprocal differences and combining abilities obtained for these inbreds and crosses as selection criteria are discussed.
Effects of Two Diverse Environments on Seed Production Characteristics of Tall Fescue Hybrid Derivatives1
Authors: Buckner R. C. , Rincker C. M. , Burrus P. B. , Cressman R. M. , Garrison C. S.
Published: July 2010

Panicle emergence, anthesis and several components of seed yield of 42 S1 (Lolium perenne L. ✕ Festuca arundinacea Schreb.) × Festuca arundinacea Schreb. hybrid clones, grown at Prosser, Washington, and Lexington, Kentucky, were studied in two different years to evaluate seed production capabilities in widely diverse environments.

Clones differed at both locations for time of panicle emergence, date of anthesis, percent fertile pollen, number of panicles per clone, seed yield per clone, seed yield per panicle, percent fertile florets, and weight of 100 seeds. Total panicle production per plant at Prosser was approximately nine times greater than at Lexington, a factor that helped to explain the higher seed yields obtained at Prosser during both years.

The widely diverse environments resulted in significant differences between locations and significant clone and location interactions for most characters studied.

A correlation analysis between locations of means for characters of the 42 individual clones showed a highly significant association during both years for: (a) percent fertile pollen (r=0.87, r=0.80); (b) percent fertile florets (r=0.83, r=0.77); (c) seed per panicle (r=0.79, r=0.71); and (d) total seed yield per clone (r=0.67, r=0.72).
Yielding Ability and Competitive Influence in Hybrid Mixtures of Maize1
Authors: Kannenberg L. W. , Hunter R. B.
Published: July 2010

Ten short‐season commercial maize (Zea mays L.) hybrids were grown in pure stands and all possible equal‐proportion mixtures over a two‐year period at Guelph, Ontario. Differential stress was imposed by varying plant densities. Data were recorded for grain yields, ear moisture percentage and lodging percentage. Individual component data were collected in the second year.

No significant differences in grain yield were observed in either year among plant densities. Further, no differences were noted between observed yields of the mixtures and midcomponent means. This contrasts with many studies in self‐pollinated species.

Analysis of individual component data showed that the yield contribution of the components was disproportionate: hybrids that yielded highest in pure stands contributed more to a mixture than would be expected based on their pure stand yield and the lower yielding hybrids less than expected. These results suggest that natural selection in gene pools of cross‐fertilizing species would result in higher‐yielding genotypes. Ears of early maturing hybrids tended to dry more slowly when in mixtures and later hybrids more rapidly, relative to their drying rates in pure stands. Standability of mixtures was unrelated to respective standabilities of the various components in pure stands.
Studies on the Heritability of Gossypol in Leaves and Flower Buds of Gossypium1
Authors: Singh I. D. , Weaver J. B.
Published: July 2010

The inheritance of gossypol in cotton (Gossypium spp.) flower buds and leaves was studied in populations derived from three crosses of medium ✕ medium, high × low and high × high gossypol parents. Data from all three crosses indicated that a low gossypol level was dominant to a higher gossypol level. F2 frequency distributions suggested that more than one gene controls the expression of level of gossypol in flower buds. There was an indication of additive gene action although the possibility of geometric gene action was not ruled out. Estimates of broad‐sense heritability ranged from 73.0 to 86.0%.

Significant positive correlation values were found between the level of gossypol in the flower buds and leaves in four populations of Upland cotton. Thus we concluded that at least some of the genes responsible for the expression of the level of gossypol in the flower buds also control the level of gossypol in the cotton leaves.

Significant positive correlation values were obtained between the level of gossypol in the leaves and the number of glands on leaf, bract, and petal. Similarly, the correlation values between the level of gossypol in the flower buds and the number of glands on leaf and petal were positive and significant. Thus we concluded that the number of glands on leaves, bracts, and petals can be a useful breeding index for developing low or high gossypol lines of Upland cotton. The maximum number of glands per 5 mm disc occurred in the leaves and the minimum number in the bracts.
Selection for Early Flowering in Corn1
Authors: Troyer A. F. , Brown W. L.
Published: July 2010

Three late, serai‐exotic corn (Zea mays L.) synthetics were selected (5% level) for early silking by sib‐mating over a six‐generation period; then the seven cycles (including original forms) were compared in performance trials at three plant densities over 2 years. Virtually every ' trait measured changed significantly due to selection only for early flowering. Effect per cycle averaged: 1.00 q/ha yield increase; 1.2 points of percent H2O decrease; 2.8% stalk breakage increase; 7.2‐cm plant height decrease; 5.2‐cm ear height decrease; 1.8 days less to flower; and 0.3 days less silk delay. The decrease in silk delay suggests that the method may be useful in selecting materials for adaptation to high plant densities. We observed a maturity‐influenced cycle‐by‐year interaction for yield where early flowering cycles had a distinct advantage in a cool, short season.
Effects of Gibberellic Acid on Dwarfs of Lowland Switchgrass, Panicum virgatum L.1
Authors: Barnett F. L.
Published: July 2010

Dwarfs of lowland switchgrass, Panicum virgatum L., approached, but did not attain, normal vegetative growth when repeatedly sprayed with gibberellic acid. Treated dwarfs usually headed but required longer to do so than normal plants; untreated dwarfs usually failed to head. Panicles of treated dwarfs were abnormally compact and frequently failed to emerge completely; florets did not undergo anthesis. Treated dwarfs producd more culms than did untreated dwarfs or normal plants. Response to variations in application rate, absence of apparent tissue injury, and the close approach to normality attained in some instances suggested that essentially normal vegetative growth could be induced in dwarfs through carefully controlled application of gibberellic acid.
Plastom Control of Chloroplast Development in Cotton, Gossypium birsutum L.1
Authors: Kohel R. J. , Benedict C. R.
Published: July 2010

Developing chloroplasts in a variegated cotton (Gossypium hirsutum L.) mutant were examined. This plastom mutation leads to a block in chloroplast development at the primary lamellar stage and no grana development occurs. The synthesis of reductive‐pentose‐phosphate‐cycle enzymes was not impaired in this mutant.
Interacting Male Sterility‐Male Fertility Restoration Systems for Hybrid Wheat Research1
Authors: Maan S. S. , Lucken K. A.
Published: July 2010

We studied the behavior of several male fertility restoration systems in wheat involving cytoplasms from different species of Triticum L. and Aegilops L. and distinguished cytoplasms on the basis of nucleo‐cytoplasmic interactions. The genomes of Triticum aestivum L., varieties ‘Chris,’ ‘Selkirk’ and ‘Chinese Spring,’ and selections of T. durum Desf. and T. timopheevi Zhuk. were substituted into the cytoplasm of several species of Triticum and Aegilops by backcrossing. Also, cytoplasmic male‐sterile A‐lines of Chris and Selkirk were crossed with several R‐lines having male fertility restoring genes from different sources. R5 = (T. Zhukovskyi/3*T. aestivum ‘Justin’) and R6 = (T. boeoticum‐Ae, squarrosa amphidiploid/T, durum//Chinese Spring) gave fertile hybrids from crosses with A‐lines having cytoplasms of T. boeoticum Boiss., T. timopheevi, or T. Zhukovskyi Men. and Er., but R5 and R6 gave sterile hybrids with A‐lines having cytoplasms of T. araraticum Jakubz., T. dicoccoides var. nudiglumis Nabalek, or Ae. speltoides Tausch. Substitution of the T. timopheevi genome into Ae. speltoides cytoplasm resulted in malesterile plants. Of the six R‐lines used R5 and R6 restored male fertility and plant vigor to A‐lines with cytoplasm of T. boeoticum, produced stunted bushy plants from crosses with A‐lines having Ae. ovata cytoplasm, and showed that T. timopheevi and T. Zhukovskyi were cytoplasmically similar but differed from Ae. speltoides, T. aramticum, and T. dicoccoides var. nudiglumis. A method for producing single‐, three‐way, or double‐cross hybrids using interactions of two male sterility and male fertility restoring systems is proposed for hybrid wheat research. Thus, an R‐line can be used as an A‐Line for a cross with another R‐line.
Imbibitional Chilling Injury in Zea mays L. Altered by Initial Kernel Moisture and Maternal Parent1
Authors: Cal J. P. , Obendorf R. L.
Published: July 2010

The differential seedling growth of corn (Zea mays L.) hybrids after seeding at cold temperatures led to an evaluation of the effect of initial kernel moisture and parental lines on germination and seedling growth after cold imbibition. Low‐ and high‐moisture kernels were imbibed 0 to 21 days at 5C. Effects of cold during germination were evaluated by survival and growth of seedlings at 25C.

Imbibition of low‐moisture (6%) kernels at 5C resulted in aborted radicles, proliferation of seminal roots, and delayed seedling growth. For certain inbreds and crosses, prolonged exposure to 5C resulted in reduced survival. Sensitivity to imbibitional chilling was partially or totally reversed when initial kernel moisture was 13 or 16%. Cornell M‐3 was sensitive to chilling while Pennsylvania 290 was relatively tolerant, but certain parental lines of both hybrids were sensitive. Sensitivity of reciprocal hybrids indicated maternal effects.
The Influence of the Cytoplasm on Ear Number Expression in Corn1
Authors: Ellsworth R. L. , Peloquin S. J.
Published: July 2010

The influence of the cytoplasms on ear number expression on the main stalk was studied in the progeny of five inbred lines of corn (Zea mays L.). The F1, F2, and both reciprocal backcross generations were grown in two environments. The ears on the main stalk of each plant were visually enumerated using a scale of zero to six ears per plant. The nubbins were classified as a full ear when seed had developed to cover half of the cob and as zero if the cob was not half covered. By the use of Duncan's New Multiple Range Test, it was possible to demonstrate statistical differences between seven reciprocal pairs. On the basis of these comparisons it is suggested that the plant breeder interested in increasing ear number per plant could enhance the possibility for success by screening for beneficial cytoplasmic‐genotypic interactions.
Malting Characteristics of Hybrids among Six‐Rowed Winter Barleys Varying in Kernel Size1
Authors: Poehlman J. M. , Crook Wayne. J. , Standridge N. N.
Published: July 2010

We studied malting characteristics in parents and hybrids of six‐rowed winter barleys. A large‐seeded barley (Hordeum vulgare L.) selection was used as the maternal parent and crossed with seven cultivars and selections varying in kernel size. Seeds harvested from parents and hybrids were evaluated for malting quality. As an average over seven crosses, midparent heterosis was significant (5% level) for fine grind and coarse grind mall. extract. Kernel plumpness of the hybrids exceeded the midparent average although the difference was nonsignificant. Barley and wort nitrogen were significantly below the midparent averages. No heterosis for amylolytic activity was observed.
Chromosome Numbers in Eleven New Hemarthria (Limpograss) Introductions1
Authors: Schank S. C.
Published: July 2010

Chromosome counts, pollen stainability, and seed‐setting ability are presented for 10 new Hemarthria altissima (Poir.) Stapf et C. E. Hubb accessions from Africa and one native Hemarthria sp. from Argentina. Root tip smears confirmed that the basic chromosome number of this genus is x = 9. Nine of the introductions are diploid, 2n = 18, and two are tetraploid, 2n = 36. Pollen stainability and seed set indicate that all 11 introductions may be included in an intrageneric breeding program.