bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Temperature and Photoperiod on a Virescent Mutant in Smooth Bromegrass1
Authors: Dunn G. M. , Ketel E. J. , Routley D. G. , Couture R. M.
Published: July 2010

Two growth chamber trials were conducted to determine effects of temperature and photoperiod on the phenotypic expression of a vireseent mutant of Bromus inermis. Maximum expression of the mutant occurred at low‐temperature short‐photoperiod, with a range in percent greening from about 17 for this treatment to 58 at high‐temperature long‐photoperiod. Significant differences were obtained for both temperature and photoperiod. At a constant 12‐hr photoperiod, temperature alone produced highly significant differences, with percent greening being approximately 83% at 27 C, 46% at 21 C, and 16% at 16 C.

Four vireseent, one yellow, and one normal green clone were analyzed for chlorophyll at four dates in the spring. Considerable variation was found in total chlorophyll and in rate of greening of the mutant clones in the field, but all except the yellow mutant contained approximately normal amounts of chlorophyll by June 13. Mutant and normal plants were etiolated in the dark, then analyzed for protochlorohpyll and carotenoid pigments. The mutants synthesized approximately as much protochlorophyll as normal plants. Carotenoid pigments were quite low in etiolated mutant seedlings, suggesting a possible genetic block in their synthesis rather than in chlorophyll.
Drying Effects on the Nylon Bag Digestibility of Alfalfa (Medicago sativa L.)1
Authors: Evans David W.
Published: July 2010

Vegetative and first‐flower stage alfalfa (Medicago sativa L.) was freeze dried and dried with forced air at temperatures ranging from 27 to 92 C to determine the effects of drying procedure on nylon bag digestibility. Results showed that exposure to 92 C (for periods from 2 to 48 hours) reduced the nylon bag digestibility of vegetative‐stage alfalfa, and that drying should be carried out at less than 62 C to equal digestibility of freezedried forage. Nylon bag digestibility of first‐flower stage alfalfa was only slightly affected by drying temperature, indicating that biochemical changes as alfalfa matures may prevent adverse digestibility response to high temperature and aging.
Induction of Germination of Impermeable Cottonseed by Electrical Treatment
Authors: Stone R. B. , Christiansen M. N. , Nelson S. O. , Webb J. C. , Goodenough J. L. , Stetson L. E.
Published: July 2010

Electric glow‐discharge and radiofrequency (RF) electricfield treatments were studied for inducing germination of impermeable cottonseed in selection 16‐B‐7 of Gossypium hirsutum L. Seed was exposed for 3 min in an evacuated glass tube chamber to the glow discharge established by application of 60‐Hz and 15‐ and 17.5‐kHz voltages to electrodes in the tube. Germination of impermeable cottonseed was increased from less than 10% to levels in the 60 to 90% range. Significant increases in germination were also achieved by exposure of seed to 40‐MHz electric fields of intensities ranging from 1.3 to 3.1 kilovolts/cm, but germination was not generally increased as much as by glow‐discharge treatments. RF treatments increased field emergence of a sawginned seed lot from 50 to 76%, but glow‐discharge treatments gave no significant increase for this seed lot. Glow‐discharge treatments offer a possible method for overcoming impermeability, but variation in cultivar response and seed storage conditions in relation to treatment needs further evaluation.
Prediction of Reactions to Maize Dwarf Mosaic Virus in Double‐Cross Hybrids Based upon Single‐Cross Reaction1
Authors: Zuber M. S. , Hilderbrand E. S. , Loesch P. J. , Keaster A. J.
Published: July 2010

We found a high correlation between predicted (as calculated from single cross data) and observed maize dwarf mosaic (MDM) ratings for 15 double crosses of corn (Zea mays L.). Predicted and observed grain yields were also highly correlated. Predicted MDM ratings for double crosses were negativdy correlated with predicted grain yields for double crosses, but the correlation coefficient was not as large between the observed MDM double‐cross ratings and observed grain yield for double crosses. In general, a nearly linear response in increased MDM rating values was observed both for the predicted and observed double‐cross performances with each additional substitution of a susceptible inbred parent for a tolerant one. Estimates of gca mean squares were nearly 40‐fold the sca value for MDM ratings; for grain yield the ratio was about 6‐fold. For the eight inbred lines we used in this study and under the levels of MDM infection encountered, our results suggest that tolerance to MDM may be conditioned by a few major genes in association with a modifier gene complex or by many genes with small additive effects.
Response of Perennial Sowthistle Selections to Herbicides1
Authors: Bell A. R. , Nalewaja John D. , Schooler A. B.
Published: July 2010

Perennial sowthistle (Sonchus arvensis L.) seed was collected from three fields in North Dakota and Minnesota. Plants grown from the seed in the greenhouse were treated with 2,4‐dichlorophenoxy acetic acid (2,4‐D), and 3,6‐dichloro‐o‐anisic acid (dicamba), or 4‐amino‐3,5,6‐trichloropicolinic acid (picloram). The range in response to the herbicides of perennial sowthistle from each field was similar with 0 to 8% of the plants tolerant and 68 to 92% susceptible. The range of response to herbicides was similar for greenhouse plants grown from clones collected throughout North Dakota, South Dakota, and Minnesota and for plants grown from seed collected in selected crop fields. The response of selected perennial sowthistle clones to herbicides in the field did not resemble the response obtained in the greenhouse. The number of live shoots per field plot after treatment with 1.68 kg/ha dicamba or 2,4‐D varied among selections from 0 to 8 and 3 to 12, respectively. Generally, the selections with the most live shoots per plot after herbicide treatment had a greater capacity for regrowth from creeping roots than did the selections with the least live shoots.
Heritability of Lowest Pod Height in Soybeans1
Authors: Martin R. J. , Wilcox J. R.
Published: July 2010

The feasibility of breeding for increased height of the lowest pod and associations between pod height and other agronomic characteristics of soybeans [Glycine max (L.) Merr.] was studied in progenies of high podding determinate strains crossed with normal podding indeterminate varieties. Heritability estimates for lowest pod height in two crosses were slightly greater than those for seed yield and seed size in the F2 generation and considerably higher than values for seed yield in the F3 generation. Heritability estimates for pod height in the third cross, although lower than in the other two crosses, were higher than estimates for seed yield in both the F2 and F3 generations.

Correlation coefficients for height of the lowest pod with date of flowering and maturity date indicated that the higher the height of the first pod, the later these plants flowered and matured. The lack of a close association of pod height with seed yield indicated that selections could be made for increased height of the lowest pod without affecting seed yield.
Reciprocal Differences in Tolerance to Seed‐Hydration Chilling in F1 Progeny of Gossypium hirsutum L
Authors: Christiansen M. N. , Lewis C. F.
Published: July 2010

We demonstrated heritable variability of injury response to chilling of imbibing seeds of Gossypium hirsutum L. Response to chilling of imbibing seed from reciprocal crosses of chilling‐tolerant and sensitive genetic lines was dependent upon the maternal parent. If the maternal parent of a cross is chilling‐susceptible, the F1 embryo was also susceptible.
Variability in Radiation Received by Small Plots of Sugarcane Due to Differences in Canopy Heights1
Authors: Tovey D. A. , Glasziou K. T. , Farquhar R. H. , Bull T. A.
Published: July 2010

Solar radiation receipt of isolated tall plots and embedded short plots of sugarcane (Saccharum hybrid) was calculated for several plot sizes and compared with that received by uniformly level plots. The differences in energy received were capable of causing serious errors when assessing mutual relationships between small plots of sugarcane or other tall row crops. Extrapolating from performance in small plots to expected field performance is likely to be invalid without adequate precautions in trial design.
Progeny Testing for Forage Yield in Tall Fescue, Festuca arundinacea, Schreb.1
Authors: Frakes R. V. , Matheson K. I.
Published: July 2010

Forage was harvested from parents, single‐crosses, open‐pollinated, polycross, and F2 progeny of 10 genotypes of tall fescue (Festuca arundinacea, Schreb.). All methods of progeny testing identified high. and low performing parents. The high yielding parent was involved in most of the high yielding crosses, and was present among the high yielding open‐pollinated and polycross progeny lines.
Inheritance of Semidwarfness in Several Wheat Crosses1
Authors: Romero G. E. , Frey K. J.
Published: July 2010

Inheritance of plant height in wheat Triticum aestivum L.) was studied by using single‐plant measurements from parental, F1 and F2 generations of nine crosses between three “normal‐height” (‘Napo 63,’ ‘Crespo 63,’ and ‘Bonza 63’) and three semidwarf (‘Sonora 64,’ ‘Son‐Sk‐A,’ and ‘Wt‐Nar’) pure lines. All crosses showed partial dominance for tallness over semidwarfness, with degrees of dominance varying from 0.12 to 0.90. Correlation of dominance values estimated in F1 and F2 was 0.83**.

Segregations in the F2 generation of the nine crosses showed the semidwarf lines Sonora 64, Son‐SK‐A, and Wt‐Nar differed from the normal‐height cultivars in alleles at one, two, and two loci, respectively. Three loci were involved in height inheritance among the 6 cultivars with alleles at the A‐a and C‐c loci each differentiating approximately 26 cm in plant height, and alleles at the B‐b locus differentiating 13 cm in height. Gene effects between loci were cumulative. The suggested genetic constitutions for the cultivars were: normal‐height parents (106 cm) = AABBCC; Sonora 64 (79 cm) = aaBBCC or AABBcc; Son‐Sk‐A (66 cm) = aabbCC or AAbbcc; and Wt‐Nar (53 cm) = aaBBcc.
Seedling Vigor of Open‐Pollination Progenies of Intra‐ and Inter‐Source Crosses of Birdsfoot Trefoil, Lotus corniculatus L.1
Authors: Conje A. M. , Carlson I. T.
Published: July 2010

Seedling vigor traits of open‐pollination seed from F1 plants of crosses within and between two diverse germplasm sources of birdsfoot trefoil (Lotus corniculatus L.) were studied under nonphotosynthetic conditions in a germination chamber. Parents of F1 plants were derived from ‘Empire’ and two Russian introductions. Seedling vigor (as measured by dry weight, hypocotyl length, radicle length, and total seedling length) was positively associated with seed size (r values ranged from 0.47 to 0.87). Progenies of crosses between the Empire and Russian sources exhibited a 5% increase in hypocotyl length at 7 days when compared with the average of progenies of intrasource crosses. Heterosis was not manitested for radicle length or seedling dry weight. Progenies of Empire crosses were superior in those two traits.
Genetic Analysis of the Crumpled Mutant in Cotton, Gossypium hirsutum L.1
Authors: Kohel R. J.
Published: July 2010

The mutant Crumpled is described, and the results of inheritance and linkage studies reported. The Crumpled phenotype is conditioned by a dominant allele at a single locus. The homozygous mutant genotype was assigned the gene symbols Crp Crp. Heterozygous Crumpled has an intermediate mutant phenotype. Linkage analysis established that Crumpled was independent of the marker loci cu, v1, gl1, fg, cl1, L0, R1, H2 R2, Y1, P1, Lc1 N, and Lg.
Genetic Analysis of the Depauperate Mutant in Cotton, Gossypium hirsutum L.1
Authors: Kohel R. J.
Published: July 2010

The depauperate mutant was conditioned by recessive alleles at a single locus, and the homozygous mutant genotype was assigned the gene symbols de de. Linkage analysis failed to detect any linkage association between depauperate and the marker loci cup leaf, virescent‐1, glandless bolls, frego bract, cluster‐1, Okra Leaf, Red Plant, Pilose, Petal Spot, Yellow Petals, Pollen Color, Brown Lint, Naked Seed, and Green Lint.
Effect of Time and Rate of Application of Two Growth Retardants on Growth, Flowering, and Yield of Upland Cotton1
Authors: Marani A. , Zur M. , Eshel A. , Zimmerman H. , Carmeli R. , Karadavid B.
Published: July 2010

Six experiments were conducted at four locations in Israel in order to evaluate the effect of two growth retarding chemicals, CCC and CMH, on plants of Upland cotton, Gossypium hirsutum L. When sprayed during the first week of flowering, CCC at 50 and CMH at 480 g a.i./ha retarded the increase in height of cotton plants without adversely affecting lint yield or quality. These treatments caused a small reduction in flower production, but this was not associated with a decrease in yield. In some of the experiments, the increase in plant height following treatment was reduced by as much as 50%. Application of CCC at the rate of 100 g a.i./h at the beginning of flowering significantly reduced lint yield in one experiment. Increasing the rate of CMH to 720 g a.i./ha produced no harmful effects.

When CCC or CMH were applied in the middle of the flowering period, they were less effective in reducing plant height. These results indicate that both CCC and CMH may be used to arrest excessive vegetative development of cotton plants, and that the optimum time of application is the beginning of flowering.
Heterosis and Combining Ability Estimates in Indian Mustard, Brassica juncea (L.) Czern. and Coss.1
Authors: Singh Shree P.
Published: July 2010

Heterosis and combining ability estimates were obtained for eight agronomic characters in Indian mustard, Brassica juncea (L.) Czern. and Coss. Highest heterotic values were found for yield. Six hybrids exceeded the performance of their best parents by an average of 49% over 2 years. Moderately high values were also found in certain crosses for number of primary and secondary branches and raceme length, but estimates, in general, were low for days to flower, plant height, silique length, and seeds per silique.

General combining ability (GCA) and specific combining ability (SCA) variances were important for all characters. The former was larger than the latter in all cases except for seeds per silique. Maternal and nonmaternal reciprocal variances were significant for days to flower and yield; only the former was significant for primary branches and silique length, and only the latter was significant for seeds per silique. Interactions for GCA ✕ years were significant for all characters; for SCA ✕ years for days to flower, number of primary and secondary branches, and plant height; and for nonmaternal ✕ years for days to flower and primary branches.
Influence of High Day and Variable Night Temperatures on Nitrate Reductase Activity of Young Corn (Zea mays L.) Plants1
Authors: Alofe C. Oluwole , Schrader L. E. , Smith R. R.
Published: July 2010

Sixteen corn (Zea mays L.) genotypes (a four‐parent diallel cross) were grown from seed for a month in controlled‐environment rooms in the University of Wisconsin Biotron. A high day (35 C) and three night temperatures (24, 16, and 7 C) were provided to study the influence of high day and variable night temperatures on nitrate reductase (E.C. 1.6.6.1) activity (NRA) in these genotypes. A 15‐hour photoperiod at 35 klux was provided. Plants were grown in vermiculite with nutrient solution.

Growth was fastest at a high night temperature of 24 C and slowest at 7 C, but NRA per g fresh wt (gfw) of leaf blades declined more rapidly at the high night temperature of 24 C than at 16 or 7 C and the decline was least rapid at 7 C. NRA per plant changed little at the 24 C night temperature during the first 21 days, but increased markedly thereafter. At 16 C, NRA per plant increased from 11 to 17 days, but decreased thereafter, whereas it increased at 7 C from 13 to 30 days in most genotypes.

Significant genotypic differences were observed at all night temperatures and at 9 of 10 samplings. At 24 C, levels of NRA of each reciprocal cross generally were intermediate with respect to levels of NRA in the two parental inbreds. However, in a few cases, one or both reciprocal crosses were higher than the midparent with respect to NRA. At 16 C, additional crosses were higher than the midparent with respect to NRA per gfw and per plant, though a few were intermediate in NRA as compared with their parents. At 7 C, NRA per plant generally was higher in the hybrids than in either parent.

Reciprocal effects were statistically significant in only 2 out of 10 samplings. General combining ability (GCA) effects were significant in eight samplings. In all samplings and at all temperature regimes, inbred ‘A632’ was the parent with most positive GCA effects.
Meiosis of Coronilla varia L.1
Authors: Berchtold D. J. , Cleveland R. W. , Risius M. L.
Published: July 2010

Meiosis in microsporocytes was studied in nine ‘Chemung’ plants, 14 ‘Penngift’ plants, and one S1 plant of crownvetch (Coronilla varia L.). All plants were tetraploid (2n=24), and 41% of the diakinesis cells had one or more multivalents (III's or IV's). Averages of pairing configurations were 0.8 I's, 10.7 II's, 0.1 III's, and 0.4 IV's per cell. Quadrivalents ranged from 0 to 5 per cell, compared to a theoretical maximum of 6. We concluded that C. varia had autotetraploid‐like meiotic chromosome behavior.

No differences were found between cultivars in mean frequencies of configurations per cell. However, plants within cultivars differed significantly in their frequencies of I's per cell (0.2 to 1.8), and in their proportions of cells free of I's or III's (33 to 94%). The mean chiasma frequency among all plants was 1.1 chiasmata per biva‐lent‐equivalent (range 1.0 to 1.3).

Laggards were present at meiotic anaphases. Chromosome numbers at TI were largely euploid (n = 12). No micronuclei occurred in pollen quartets, thus laggard chromosomes may have been included in TII nuclei. A first generation inbred plant was much more irregular in meiosis than other plants studied.

Cytomixis was a sporadic occurrence in microsporocytes of a few collections.
Alfalfa Pollen Production in Relation to Percentage of Hybrid Seed Produced1
Authors: Pedersen M. W. , Barnes D. K.
Published: July 2010

The relationship between different levels of pollen production and percentage crossing in alfalfa (Medicago sativa L.) was studied in both hand‐crosses in the greenhouse and bee‐pollinations in the field. White flower color was used as a genetic marker to determine the amount of crossing. Pollen production was rated in 4 classes: 1 = no pollen, 2= trace of pollen, 3 = moderate amount of pollen, and 4 = much pollen dehisced when the flower was tripped.

Greenhouse studies indicated that the amounts of sibbed and selfed (nonhybrid) seed were affected by the amount of pollen production in the male‐sterile seed parents. Three‐way random crosses among white‐flowered complete male steriles, white‐flowered sibling partial steriles, and unrelated purple‐flowered fertile plants were used to simulate pollination opportunities within a three‐way alfalfa hybrid. The type of seed produced on class 1 plants was 0% self, 2% sib, and 98% hybrid. The amount of self, sib, and hybrid seed produced on class 2, 3, and 4 plants were 3, 5, and 92%; 12, 27, and 61%; and 18, 40, and 42%, respectively.

Field studies were also conducted in which 36 crosses, segregating for varying degrees of male sterility, were assigned a pollen‐production index (PPI) by weighting each pollen‐dehiscence class according to its pollination effectiveness. The weighing factors for classes 1, 2, 3, and 4 were 0.0, 0.1, 0.6, and 1.0, respectively. PPI was negatively correlated with percent crossing for 2 years in a field test. The interaction between years and PPI did not significantly affect, crossing. PPI was significantly correlated with seed yield per plant in 1970, but not in 1971. The equation Ŷ = 98 −0.56x, where Ŷ = predicted percent hybrid seed and x = PPI, was arrived at for the prediction of the amount of pollen dehiscence allowable in the male‐sterile component of an alfalfa hybrid. A hybrid with 95% hybrid seed could not have a PPI of more than 5.4. A hybrid with 75% hybrid seed could not have a PPI of more than 41.1.
Use of Chromosomal Translocations to Determine Similarity of Maize Genotypes for Reaction to Maize Dwarf Mosaic1
Authors: Scott Gene E. , Rosenkranz Eugen E.
Published: July 2010

Reciprocal chromosomal translations involving breaks on chromosome 6 were crossed onto eight maize (Zea may L.) inbreds. Seven of these inbreds had been selected for their resistance to maize dwarf mosaic (MDM), and one for its susceptibility to this virus disease. The F2 seeds from each of these crosses were separated for endosperm type. Starchy and nonstarchy seeds were planted in separate rows in greenhouse flats. The seedlings were inoculated with maize dwarf mosaic virus (MDMV) by using an artist's airbrush. From our results, we concluded that all of the resistant inbreds tested (except possibly Tx601) possess a gene(s) for resistance on each arm of chromosome 6. Thus, these inbreds appear to have genes for resistance to MDM in common with each other and with GA209.
Tissue Cultures of Maize (Zea mays L.): Initiation, Maintenance, and Organic Growth Factors1
Authors: Green C. E. , Phillips R. L. , Kleese R. A.
Published: July 2010

Callus from 17 of 23 single crosses and 10 of 17 inbreds of Zea mays L. was isolated from mature embryos grown on Linsmaier and Skoog RM medium with 15 mg 2,4‐dichlorphenoxyacetic acid (2,4‐D) per liter. This callus growth was greatest from the first node of the seedling shoot; occasionally callus growth was observed from the radicle and coleoptile regions. All callus was easily transferred and maintained on media with 2 mg 2,4‐D/liter. Genetic variability for callus growth was observed among both single crosses and inbreds. Callus was initiated from 70% of 23 single crosses tested and from only 40% of the 17 inbreds tested. The most rapidly growing cultures were isolated from Oh51A ✕ Os420 which had a 20‐ to 25‐fold fresh‐weight increase during a 30‐day incubation at 30 C.

Cultures maintained on 2,4‐D did not require cytokinins for growth, nor was 2,4‐D effectively replaced by idoleacetic acid or α‐napthaleneacetic acid. Several complex media additives were studied and only 800 mg yeast extract/liter and 200 mg casamino acids/liter individually stimulated significant increases in fresh weight over unsupplemented media. The callus from Oh51A ✕ Os420 has been maintained for 20 months with transfer to fresh media every 30 days (representing 19 subcultures).
Leaf Pubescence and Cereal Leaf Beetle Resistance in Triticum and Avena Species1
Authors: Smith D. H. , Webster J. A.
Published: July 2010

Oats (Arena sativa L.) are not highly resistant to the cereal leaf beetle (Oulema melanopus (L.)) and do have pubescent leaves. Certain lines of A. sterilis L. are pubescent. Since this pubescence is not of the same length and density as that found in wheats resistant to the cereal leaf beetle, it was the purpose of this investigation to determine whether A. sterilis plants would produce a resistant reaction to the insect as measured by larval weight gain of first instar larvae and ovipositlon tests on seedling plants. The pubescent A. sterilis lines were significantly different from the susceptible check at the 10% level suggesting the possibility of further intensification of their resistance.
Effects of Inbreeding on Triticale Selected for Two Levels of Fertility and Chiasma Frequency1
Authors: Hsam S. L. K. , Larter E. N.
Published: July 2010

Two tritlcale (× Triticosecale Wittmack) populatlons, one with a high chromosomal chiasma frequency and high fertility level and the other with a low chiasma‐fertillty index, were selected from a bulk population of the cultivar ‘Rosner.’ Results indicated the lack of relationship between chlasma frequency and seed‐set upon in. breeding when selection was on the basis of a high chlasma‐fertility index. In contrast, a positive relationship was found to exist between these same two variables when selection was on the basis of a low chiasma‐fertility index. These results suggest that for early generation hybrids involving triticale amphiploids in which the chiasma‐fertility index is normally low, a response to simultaneons selection could be obtained. This would not,hold true, however, as the chlasma‐fertility index rose above some specific threshold.
Evaluating Growth Potential After Drought Stress1
Authors: Corleto Antonio , Laude Horton M.
Published: July 2010

Appraising the ability of plants to resume satisfactory growth after environmental stress is highly important, yet often the measurements made reflect only mortality or survival. How soon after soil‐drought stress the regrowth potential can be determined was studied in vegetative plants of annual ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (Lolium perenne L.). Differences in response to stress increased with time, with some not becoming apparent until 4 weeks after termination of stress. Annual ryegrass exhibited stimulation in growth when released from moderate drought stress, a behavior which has been reported in some other species.
Effect of Wide Plant Spacing on Six Cultivars of Upland Cotton1
Authors: Marani A. , Ephrat E. , Dor Z.
Published: July 2010

Six Gossypium hirsutum L. cultivars were compared under conditions of wide (40 cm) and normal (10 to 12 cm) spacing between plants, with 1 m between rows. Plant spacing had no significant effect on boll weight, boll retention, fiber length uniformity, or fiber strength or fineness. Lint percent was increased and fiber length was decreased by wide spacing, but there were no cultivar ✕ spacing interactions for these traits. Lint and seed cotton yields, boll number, and flower number (per unit area) were usually decreased by wide spacing, but significant cultivar ✕ spacing interactions were detected for these traits. ‘Acala 1517C’ and ‘Del Cerro’ were affected more strikingly than the other cultivars by plant spacing, probably because of their pyramidal plant‐type and short fruiting branches. The relative performance of genotypes for lint yield and associated traits, when evaluated under wide spacing, may therefore not be valid for more closely spaced plantings.
Anther‐Derived Haploids in Tobacco: Evaluation of Procedures1
Authors: Kasperbauer M. J. , Collins G. B.
Published: July 2010

Anther‐derived haploids are potentially useful in plant physiology and breeding programs. Techniques for largescale production of anther‐derived haploids were evaluated. Anthers were excised from immature floral buds that developed on tobacco (Nicotiana tabucum L.) plants in a greenhouse and in widely differing controlled environments. The anthers were cultured in Erlenmeyer flasks and petri dishes in several physical and chemical environments.

Haploid plants were successfully cultured from anthers that developed on plants grown under a wide range of light and temperature environments.

Numerous haploids were obtained from anthers cultured on different chemically‐defined nutrient formulations with and without auxin and c tokmin. Plantlets emerged earlier from anthers culturedr at 26 than at 21 C. Light was not essential for embryogenesis during anther culture; however, light was needed to prevent etiolation of the plantlets after emergence from the anthers. The simplest successful anther culture environment consisted of a stack of petri dishes under a plastic bag on an office desk.
Inheritance of Stem and Leaf Rust Resistance in Skorospelka 3b Wheat1
Authors: Gough F. J. , Merkle O. G. , Statler G. D.
Published: July 2010

Resistance of the Russian wheat (Triticum aestivum L.) cultivar ‘Skorospelka 3b’ to culture 111‐SS2 of Puccinia graminis f. sp. tritici is conditioned by two dominant independent genes, tentatively designated SrSo1 and SrSo2. The relation of SrSol and SrSo2 to genes with permanent designations in the Sr series was not established. The two genes are independent of a single gene for resistance to culture 70‐1 of P. recondita f. sp. tritici, Tests with selected cultures indicated that the gene for leaf rust resistance was Lr3.
Developmental Morhology of Seedling Subterranean and Rose Clover Leaves1
Authors: Raguse C. A. , Menke J. W. , Sumner D. C.
Published: July 2010

Ten morphologic stages of leaf development were described for seedling subterranean clover (Trifolium sub. terraneum) and rose clover (T. hirtum). The system is relatively simple to apply and has proved useful in field, greenhouse, and controlled‐environment studies that require a rapid, nondestructive means of monitoring growth responses to changes in plant environment.
Effect of Multiple Aleurone Layers on the Protein and Amino Acid Content of Maize Endosperm1
Authors: Nelson Oliver E. , Chang Ming Tu
Published: July 2010

The data from four F2 progenies from a cross of a normal endosperm, multiple aleurone maize (Zea mays L.) line with an o2/o2 single aleurone line were heterogeneous but do not disprove the hypothesis that the multiple aleurone phenotype is conditioned by a single dominant factor. This factor segregated independently of opaque‐2. In non‐opaque seeds, the effect of multiple aleurone layers on protein content of the endosperm or content of any amino acid was negligible. In o2/o2/o2 endosperms, the presence of multiple aleurone layers as compared to single aleurone layers increased slightly the content of all the amino acids that are increased in o2/o2/o2 endosperms as compared with O2/—/— endosperms. Most of the amino acids that were lower in o2/o2/o2 endosperms relative to O2/—/— endosperms were decreased further by the presence of multiple aleurone layers. We conclude that the multiple aleurone layer factor should be useful in breeding programs designed to utilize the opaque‐2 mutant.
Gene Effects Responsible for Inbreeding Depression in Autotetraploid Maize1
Authors: Rice J. S. , Dudley J. W.
Published: July 2010

Inbreeding depression was studied in autotetraploid maize (Zea mays L.). Experimental material included the original population, S2 through S4 generations derived by selling, and the sib 1 through sib 6 generations resulting from full‐sib mating in an open‐pollinated autotetraploid synthetic. The genetic model used was µ1 = µ + 6FβH + (4P0 + P1)γiii + P0γiii + P2γiiii, where µ1 is the mean of an inbred generation; µ is the mean of the noninbred generation; βii, γiii, and δiiii are interaction effects resulting from the presence in a genotype of two, three, and four alleles, respectively, identical by descent; and δiiii is the interaction effect resulting from the presence of two pairs of alleles identical by descent. F is the inbreeding coefficient (probability that two alleles are identical by descent); P0, P1 and P2 are the probabilities of obtaining genotypes with four alleles, three alleles, and two pairs of alleles identical by descent, respectively.

Least squares estimates of βii, γiii δiiii, and δiii,showed that for most characters, much of the depression could be accounted for by βii and βiiii,. These results were supported by multiple regression analyses ushig successively more complex models and measuring the sum of squares accounted for by each term in the model. It was concluded that the amount of inbreeding depression per unit of F in early generations of autotetraploids may differ for selfing and full‐sib mating. The significance of the results in terms of expected inbreeding depression in autotetraploid species is discussed.
Vegetative and Reproductive Development of Virginia‐Type Peanut Varieties in Different Stand Densities1
Authors: Cahaner A. , Ashri A.
Published: July 2010

The yield and reproductive and vegetative development of four Virginia‐type varieties of peanuts (Arachis hypogaea L.) differing in growth habit and plant size were tested under standard, medium, and high densities. The following parameters were studied in biweekly intervals during the season: plant size and dry weight; length of main branches and degree of branching; number and dry weight of pegs and pods at four maturity stages; and final yield and quality of mature pods.

Despite the size and growth habit differences between the varieties, there were no significant density ✕ variety interactions.

Increased stand density led to increased vegetative growth and more numerous reproductive organs at all maturity stages per unit area, but the yields of mature pods were equal in the three densities. Yield did not increase with density because crowding did not lead to earlier termination of pod setting. The presence of many maturing pods apparently arrested the maturation of a high proportion. Breeding and physiological research should be devoted to the production of varieties which terminate their pod setting early.
Inheritance of Genes Controlling Male‐Fertility Restoration in the Wheat Cultivar Primépi1
Authors: Miller J. F. , Schmidt J. W. , Johnson V. A.
Published: July 2010

The French winter wheat (Triticum aestivum) cultivar, ‘Primépi,’ is an effective source of male‐fertility restoration for Triticum aestivum (Zhuk.) Zhuk.—derived cytoplasmic male‐sterility. We studied and determined the number and action of restorer genes by observing fertility segregation in F2 and backcross populations involving crosses of cytoplasmic male‐sterile ‘Gage’ (cmst Gage) and Primépi. Observed data from both populations indicate that genes at two loci control fertility restoration. Complete restoration was expressed when both genes were present, either in the homozygous or heterozygous condition. The heterozygote or homozygote alone of either of the two genes was incompletely fertile, yielding seed set percentages less than 97%. One gene, heterozygous alone, may have contributed less fertility than the other gene and could be classified as minor. The high fertility levels achieved with the two restorer genes from Primepi indicate that this restorer would be valuable for hybrid‐wheat programs in latitudes similar to those of the Nebraska wheat‐growing area.
Prevention of Trifluralin Effect on Cotton with Soil Applied Lipids1
Authors: Christiansen M. N. , Hilton J. L.
Published: July 2010

Trifinralin (a, a, a‐ trifluoro‐2,6‐dinitro.N,N‐dipropyl‐ptoluidine) applied at 1 and 5 ppm as a soil‐incorporated surface‐horizon (7.6 cm) band reduced growth and fruiting of cotton (Gossypium hirsutum L.) in greenhouse culture. Soil‐incorporated D,a‐tocopherol or oleic acid reduced the herbicide effect. Surface injections of aqueous acetone solutlons of cottonseed oil as hill applications also reduced the trltluralln effect.
Analysis of the Genetic Relationships Between Several Yield Components Maize and Leaf Area at Specific Leaf Positions
Authors: Johnson G. R.
Published: July 2010

The genetic relationships among leaf area at individual leaf positions, several yield components (row number, kernels per row, and weight per 300 kernels), and yield in a set of maize (Zea mays L.) hybrids were investigated by a series of multiple regression models. The regression models determined, in sequence (1) the leaf positions that were the best linear predictors of the yield components, (2) additive and additive‐plus‐nonadditive genetic effects estimates of leaf area at the leaf positions selected in the first step, (3) estimates of yield components from regression on the additive and additive‐plus‐nonadditive leaf area genetic effects estimates obtained in the second step, and (4) the relationship of yield to the yield components estimated in step 3.

Yield was related to additive genetic variance for leaf area in the upper leaves through weight per kernel and to nonadditive variation in the upper and lower leaves via kernels per row. The relationships between yield and nonadditive leaf area effects in the upper leaves appeared to be dependent upon, and subordinate to, the relationship between yield and nonadditive leaf area effects fn the lower leaves. Though two distinct genetic pathways linking leaf area to yield via the yield components were evident, the two paths were not genetically independent but were negatively correlated
Genetic Basis of Culm Height Differences Between Two Forage Sorghum Cultivars1
Authors: Singh Shree P. , Drolsom P. N. , Senturia J. N.
Published: July 2010

Differences between the two cultivars ‘Rox Orange’ (RO) and ‘Early Sumac’ (ES) of forage sorghum. Sorghum bicolor (L.) Moench, for culm height, internode length, number of nodes, and days to flower were statistically significant. Analysis based upon the convolution approach suggests that these differences were monogenic for all characters except internode length. Our data suggest that both cultivars had similar height genotypes but differed at one of the maturity loci. Presumably the latter was responsible for differences in four characters between the two cultivars.

Each of the two cultivars appears to be recessive at two and dominant at two other loci for height, but specific identifications were not possible. The reasons for that are discussed.

Additive and dominance effects were exhibited, and overdominance was found for all characters except culm height. Only the dominance effect was shown for the latter.
Simulations of the Photosynthetic Rates of Three Selections of Grain Sorghum with Extreme Leaf Angles
Authors: McCree K. J. , Keener M. E.
Published: July 2010

Simulations were based on leaf angle distribution data taken by U. D. Havelka, during an experiment in which two “erect‐leaved” strains of grain sorghum (Sorghum bicolor (L.) Moench.) and one ‘normal‐leaved” variety, ‘Caprock,’ were grown in equidistant patterns at high and low densities (1.3 ✕ 105 and 5.2 ✕ 105 plants/ha). Data on leaf photosynthetic rate and solar irradiance were taken from the literature. At a leaf area index of 9, the calculated canopy photosynthetic rate of the most erect strain (P 407) was 10% greater than that of Caprock. At a leaf area index of 3, the rate for Caprock was slightly greater. The dry matter yields measured by Havelka at the end of his experiment differed by almost the same amounts. These differences, between “erect” and 'normal" genotypes, are much less than the maximum possible difference calculated by W. G. Duncan, using the same model of canopy photosynthesis but hypothetical leaf angle distributions.
Population Characteristics of Advanced Generations of an Alfalfa Synthetic Increased from Selfed, Single‐Cross, or Polycross Seed1
Authors: Bula R. J. , May R. G. , Garrison C. S. , Rincker C. M. , Dean J. G. , Elling L. J.
Published: July 2010

An alfalfa (Medicago sativa L.) synthetic, derived from four clones as selfed, single‐cross, or polycross seed, was increased 1 to 4 generations at four western and two north central U.S. locations. Plant populations of each increase were compared for various characteristics when grown at Lafayette, Ind., the area of adaptation of the clones, to determine what method of breeder seed synthesis would result in minimum deviation of population characteristics among the seed increases from the various locations.

Variations in fall regrowth height indicated a gradual population change toward taller plants and loss of winterhardiness with advancing generations of increase, regardless of method used to produce the breeder seed. Height of fall regrowth was greatest for populations derived from selfed seed and similar for populations derived from single‐cross and polycross seed.

Percentage of plants with purple flowers increased in the advanced generations, particularly those made at the western locations. Breeder seed derived from polycross seed at the two north central locations had percentages of plants with purple flowers similar to those of the first generation increases of the selfed or singile‐cross seed.

From a practical standpoint, these data indicate that seed multiplication of alfalfa synthetic cultivars can be accomplished using either selfed, single‐cross, or polycross seed as breeder seed with equally satisfactory maintenance of cultivar characteristics.
Effect of Tannin on In Vitro Dry Matter and Protein Disappearance in Sorghum Grain1
Authors: Schaffert R. E. , Lechtenberg V. L. , Oswalt D. L. , Axtell J. D. , Pickett R. C. , Rhykerd C. L.
Published: July 2010

The purpose of this investigation was to determine the effect of tannin and added urea on in vitro dry matter disappearance (IVDMD) and in vitro protein disappearance (IVPD) in sorghum (Sorghum bicolor (L.) Moench) grain. IVDMD of low and high tannin genotypes after 48 hours of fermentation was 72.5 and 46.4% respectively. The addition of urea increased IVDMD to 93.4 and 79.2% for the low and high tannin genotypes. IVPD of low and high tannin genotypes was not affected by urea and averaged 88.2 and 69.6%, respectively. After 96 hours of fermentation the IVDMD of low and high tannin genotypes was 93.8 and 85.8%, respectively, indicating a true difference in digestibiltiy of about 8 percentage units.

The major factor limiting the utilization of high tannin sorghum is apparently the availability of protein. Undigestible protein and tannin complex may account for more than half of the difference in IVDMD between low and high tannin genotypes.
General Combining Ability and Its Interaction with Environments in a 7 ✕ 7 Diallel Cross Population of Alfalfa1
Authors: Song S. P. , Walton P. D.
Published: July 2010

The relative importance of general combining ability (GCA) and specific combining ability (SCA) in the year of establishment and in the following year were studied for forage yield, plant height, days to flower, growth habit, vigor, and frost tolerance in a diallel cross population of alfalfa (Medicago sativa L.). For both years GCA was more important than SCA for most of the characters. The ratio of GCA to SCA was generally greater for plants in their second year. There were marked differences in the GCA effects of the seven clones. Clones selected from adapted cultivars produced progenies that performed relatively well; those selected from unadapted cultivars gave progenies that were found to be generally inferior in forage yield, vigor, and frost tolerance. Both days to flower and vigor showed appreciable genotype ✕ environment interaction.
Improved Technique for Evaluating Resistance of Corn to Corynebacterium nebraskense1
Authors: Calub A. G. , Schuster M. L. , Compton W. A. , Gardner C. O.
Published: July 2010

An inoculating instrument consisting of multiple needles imbedded in a cork and foam rubber was effective in evaluating corn (Zea mays L.) plants for reaction to leaf freckles and wilt disease caused by Corynebacterium nebraskense Schuster et al.

Inoculum concentrations of about l08 bacterial cells/ml in the foam rubber resulted in infection and excellent differentiation between resistant and susceptible lines in both the greenhouse and field, 5 to 7 days after inoculation. Seedlings were pricked by the instruments, one in each hand, from the base of the whorl to the tip of the leaves.

The correlation between ratings obtained with the pin‐prick method in the seedling stage and a syringe injection method at tasseling time was 0.977.
Elemental Composition of Developing Oat Plants1
Authors: Peterson David M. , Schrader L. E. , Youngs V. L.
Published: July 2010

The utilization of elements by oats (Avena sativa L.) and their distribution within the plant at various stages of development were of interest as background information for determination of fertility requirements, as data for determination of nutritional value of oats forage, and as a basis for further investigations on the physiology of elemental uptake and redistribution.

Shoots of two oat cultivars, ‘Dal’ and ‘Froker,’ were harvested at various intervals during development. Concentrations of P, K, Ca, Mg, Fe, Zn, Mn, and Al were determined by emission spectroscopy in leaf blades, culm plus leaf sheaths, and panicles. Sampling was from a measured plot size, and the amount of each element contained in each plant part per unit land area was calculated.

Phosphorus was the only element whose concentration increased with maturity in the panicle. In leaf blades, concentrations of Ca and Mg increased between 46 and 74 days after planting, and concentrations of Fe, Mn, and Al increased between 67 days and maturity. Because of increasing dry weight with maturity, the amount per hectare of most elements increased in the panicle, although the increase for K was slight. Amount of K (kg/ha) in the culm and leaf sheath fraction increased. Iron and Al amounts (g/ha) in leaf blades increased after panicle emergence. Of those elements measured, accumulation of K by the entire shoot was greatest, about 79 kg/ha at maturity. The amounts of P, Ca, and Mg accumulated were similar, approximately 20 kg/ha each. Microelement accumulation was greatest for Al (653 g/ha) and Fe (555 g/ha). Lesser amounts of Mn and Zn were contained in the shoots at maturity.

Cultivar differences were most pronounced for Mn concentration, which was considerably lower in Dal than in Froker in all plant parts.
Groat Protein Percentage in Avena Sativa L. Fatuoids and in a Fatuoid ✕ A. Sterilis L. Cross1
Authors: Lyrene P. M. , Shands H. L.
Published: July 2010

Groat protein percentages were compared for fatuoid and nonfatuoid plants from two plots of Avena sativa found to be segregating for spontaneous fatuoid mutations. Fatuoid plants averaged 3.0% higher in protein. The “fatuoid complex” of characters in A. sativa fatuoids, which includes spikelet shattering, awns, and rachilla pubescence, is closely paralleled by the “wild oat” complex of A. sterilis. In A. sativa ✕ A. sterilis crosses, progeny showing the wild‐oat traits average 2 to 3% higher in protein than those that do not. This figure was closely matched by the increased protein of fatuoids over nonfatuoids.

The gene which produces the fatuoid characters in A. sativa fatuoids was found to be allelic with the one producing the wild‐oat characters of A. sterilis. Evidence for this was the presence of shattering, awns, and rachilla pubescence in 12 F1 plants from the cross A. sativa ‘Garland’ fatuoid ✕ A sterilis PI 295932. In the F2, plants segregated in a ratio of 3 plants with spikelets like A. sterilis to 1 plant with fatuoid‐like spikelets. The two groups did not differ in groat protein percentage. The higher protein percentages associated with spikelet shattering and awns in A. sterilis and the fatuoids may be caused by these undesirable traits, and thus inseparable from them. If this is the case, A. sterilis and the fatuoids may prove less useful in protein breeding than originally thought.
Control of Stripe Smut and Flag Smut in Kentucky Bluegrass by a New Systemic Fungicide, Bay Meb 64471
Authors: Hardison John R.
Published: July 2010

A new systemic chemical, 1‐(4‐chlorophenoxy)‐3,3‐dimethyl‐1‐(1H‐1,2,4‐triazol‐l‐yl)‐2 butanone (BAY MEB 6447), controlled and possibly eradicated Ustilago striiformis (stripe smut) and Urocystis agropyri (flag smut) in infected plants of Poa pratensis ‘Merion’ after a single application to soil in the root zone. Effective dosages for complete control were 1 to 2 mg in 600 ml soil containing a single plant with 7 to 16 shoots. Plants cured of both smuts remained smut‐free for 16 weeks. Treated plants became darker green and apparently were only slightly affected by effective dosages of the chemical. BAY MEB 6447 is considered highly promising for control of stripe smut and flag smut in turf and in grasses grown for seed.