bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Soybeans to End‐Trimming at Various Growth Stages1
Authors: Wilcox J. R.
Published: July 2010

Two soybean (Glycine max (L.) Merrill) cultivars in each of maturity groups I to IV were end‐trimmed at seven growth stages, from the first trifoliolate stage to maturity. Seed yield and seed size were recorded on two .3‐m sections at the ends of plots and on a 3‐m section in the center of plots. Data indicated that significant border effects in maturity groups II to IV, grown at Lafayette, Ind., extended more than .3‐m from the ends of plots. Border effects could be adequately controlled by trimming .6 m from each end of the plots when the top pods on plants were fully extended with seeds approaching full size for cultivars in groups I to III. Trimming would have to be delayed until leaves on plants were 30 to 50% yellow with a few falling for group IV varieties or strains. Plot yields could be adjusted to those of 4.9‐m rows trimmed at maturity by end trimming to 4.9 m at or before the first trifoliolate stage and multiplying plot yields by .874, .840, .796, and .755 for cultivars in maturity groups I to IV, respectively. Size of seed on plants at the ends of rows was increased only when end trimming was done at full bloom or as soon as flowering ceased.
Influence of Planting Date and Latitudinal Provenance on Winter Survival, Heading, and Seed Production of Bromegrass and Timothy in the Subarctic1
Authors: Klebesadel L. J.
Published: July 2010

Latitudinal ecotypes of bromegrass (Bromus sp.) and timothy (Phleum pratense L.), planted in rows at approximately 10‐day intervals from 20 May to mid‐September during two years in south‐central Alaska (61.5°N), were compared over the 12 planting dates for winter survival, heading, seed yield, and aftermath forage the following year.

‘Climax’ from Canada, and commercial and ‘Clair’ timothy from the conterminous USA, displayed poor winter survival, produced very few heads and negligible seed yields. ‘Achenbach,’ a variety of “southern‐type” smooth bromegrass (B. inermis Leyss.), sustained considerable winter injury in both tests, produced very low seed yields one year and none in the other. ‘Engmo’ timothy from northern Norway, two Alaskan bromegrasses—native B. pumpellianus Scribn. and ‘Polar’ (predominantly B. inermis ✕ B. pumpellianus)—and ‘Manchar’, a “northern‐type” smooth bromegrass from the Pacific Northwest, displayed excellent winter survival when seeded earlier than mid‐July to mid‐August.

B. pumpellianus and Polar bromegrass produced highest seed yields of all grasses compared. The native bromegrass produced higher seed yields than Polar with planting dates prior to mid‐June; with later planting they were about equal. Both produced most heads and highest seed yields with May planting the previous year, declined precipitously in both yield characters with planting dates between May and early August, and produced no heads with later planting. Manchar bromegrass headed much less than B. pumpellianus or Polar, producing mostly sterile culms. Different planting dates prior to early July had little effect on Engmo timothy heading and seed yields the following year, but later planting until September resulted in progressively less heading and lower seed yields.

Percent crude protein in aftermath forage was inversely related to forage yield and seed production.
Effects of Border Row Competition on Strain Performance and Genetic Variance in Soybeans1
Authors: Thorne J. C. , Fehr W. R.
Published: July 2010

We evaluated the performance of six soybean (Glycine max (L.) Merr.) strains in three border row competition regimes. Strains ✕ competition regime interaction was significant for yield, but the component of variance was small compared to the component for among strains. Estimates of genetic variance for yield and canopy width were inflated when intergenotypic competition was present. Smaller estimates of genetic variance were observed in intergenotypic competition regimes than in pure stand for maturity and lodging. Competition response for yield was related to maturity, but other factors also were involved.
Effects of Male‐Sterile‐Inducing Cytoplasm in Sorghum Hybrids1
Authors: Quinby J. R.
Published: July 2010

Two sorghum (Sorghum bicolor L. Moench) hybrids with male‐sterile‐inducing cytoplasm were compared with versions of the same hybrids in normal cytoplasm. Malesterile‐inducing cytoplasm caused a 1/2‐day delay in flowering and a 3‐cm greater plant height. Tillering and width of the largest leaf were not influenced significantly by the different cytoplasms. The two cytoplasms appeared to have no significantly different effect on grain yield.
Evaluation of a Rapid Technique for Measuring Soluble Solids in Corn Stalks1
Authors: Campbell D. K. , Hume D. J.
Published: July 2010

Soluble solids in corn (Zea mays L.) stalks were measured by multiplying the refractometer reading in percent Brix of a small sample of expressed juice by the moisture lost in drying a stalk sample. This method was evaluated by comparison with total sugar determination by the Shaffer‐Somogyi method on the same samples. For individual internodes sampled over the growing season the correlation was r = +0.93**. The ratio of total sugars : soluble solids over a range of genotypes and populations varied from 0.48 to 0.66

More rapid estimates of soluble solids in the stalk were obtained by sampling one internode near the ear with the refractometer and multiplying the Brix reading by the moisture lost in drying the entire stalk. Results obtained by using refractometer readings from the ear internode, the internode above the ear, and the internode below the car were highly correlated (r = +0.92**, +O.SO*+, and 0.90**, respectively) with the total sugar content of the stalks.

The refractometric technique was an inexpensive, rapid means of determining levels of soluble metabolites in corn stalks and also provided useful estimates of total sugar levels.
Winter Hardiness in Oat Populations Derived from Reciprocal Crosses1
Authors: Muehlbauer F. J. , Marshall H. G. , Hill R. R.
Published: July 2010

Significant differences in freezing resistance and winter hardiness occurred between the F3 populations of certain reciprocal crosses in oats (Avena sativa L. and A. byzantina K. Koch). Heritabilities were high and selection for both freezing resistance and winter hardiness should be effective. Specific combining ability of parents and differences among F3 lines within crosses were important sources of variation for winter snrvival, but general combining ability, maternal effects, and reciprocal effects over all populations were relatively unimportant. The contribution of parents was consistent over locations, but lines within crosses were inconsistent over locations. Transgressive segregation for winter hardiness was common in the F3 populations derived from crosses between the winter and spring parents.
Texas Marker‐1. Description of a Genetic Standard for Gossypium hirsutum L.1
Authors: Kohel R. J. , Richmond T. R. , Lewis C. F.
Published: July 2010

An inbred line (TM‐1) was developed at the Texas Agricutural Experiment Station as a standard reference cotton (Gossypium hirsutum L.) for genetic and cytogenetic experimentation. Its origin and development is described. The results of a performance test of several advanced generations of the inbred were used to characterize the agronomic properties of the line and to evaluate the effects of inbreeding.
Photosynthesis of Plant Parts of Alfalfa Canopies1
Authors: Wolf D. D. , Blaser R. E.
Published: July 2010

Radioactive carbon from CO2 assimilated by upper leaves of alfalfa, Medicago sativa L., was not detected later in lower leaves. This suggests that the old leaves in dense canopies (low light intensity) were not parasitic. Net carbon exchange (NCE) and specific leaf weight (SLW) were highest for upper leaves and lowest for bottom leaves. NCE of petioles and stipules contributed 0.6 and 0.9% of total NCE of an alfalfa canopy. The upper steur under normal light conditions was near light compensation, while 8% of the photosynthate from leaves appeared to be respired by the lower stem tissue. The data suggest that models for predicting plant growth may need to include respiration from stems of plants in late growth stages. The data do not support the concept that respiration is a linear function of increased leaf area index.
Influence of Cowpea Chlorotic Mottle Virus (Soybean Strain) on Agronomic Performance of Soybeans1
Authors: Harris H. B. , Kuhn C. W.
Published: July 2010

Host reaction to a soybean [Glycine max (L.) Merrill] strain of cowpea chlorotic mottle virus (CCMV‐S) was studied at Experiment, Georgia, in 1968 and 1969. Symptoms in soybean cultivar ‘Davis’ were leaf mottling with light and dark green areas, reduced plant height and vigor, slightly crinkled leaves, and a tendency for leaves to be abnormally upright. Yields from inoculated plants were reduced 20 and 31% in 1968 and 1969, respectively. Seed quality was reduced in 1968 and seed weight in 1969. Inoculation of 18 resistant cultivars produced only local necrotic lesions, whereas seven susceptible cultivars exhibited systematic mottling. One cultivar exhibited veinal necrosis.
Can Losses from Wheat Stem Rust be Eliminated in North America?1
Authors: Knott D. R.
Published: July 2010

Permanent control of wheat stem rust in North America may be possible by managing the evolution of the pathogen through appropriate use of both general and specific resistance. Methods of breeding for rust resistance can be classified into those that put selective pressure on the rust and those that minimize selective pressure. It is proposed that rust be controlled in North America by assigning genes for specific resistance to particular areas, perhaps three in number, and by concentrating on general resistance in the overwintering area.
Genotypic Stability Analysis and Its Application to Potato Regional Trials
Authors: Tai George C. C.
Published: July 2010

This paper presents a method of genotypic stability analysis for regional variety trials. Based on the principle of structural relationship analysis, the genotype‐environment interaction effect of a variety is partitioned into two components. They are the linear response to environmental effects, which is measured by a statistic α̂, and the deviation from the linear response, which is measured by another statistic λ̂ A perfectly stable variety has (α, λ)=(‐1, 1) and a variety with average stability has (α, λ) = (0, 1).

Seedlings in three series of potato maincrop regional trials were analyzed for the genotypic stability of their marketable tuber yields. The results showed that the highest yielders were unstable, while the seedlings with average stability had about the same yielding ability as the check varieties.
Response of Corn (Zea mays L.) to Population Pressure1
Authors: Fery Richard L. , Janick Jules
Published: July 2010

The response of field and sweet corn (Zea mays L.) to population pressure was investigated using square and row spacing arrangements with population levels ranging from 2,375 to 151,957 plants per ha (961 to 61,496 plants per acre). Grain yield per unit area peaked at a finite population level, while total top yield appeared to be asymptotically related to plant population. Of the various models tested only the “modified reciprocal” equation w −θ = Ap + B, where w = yield per plant, p ‐= plant population, and θ, A, and B are constants, adequately described the response of both grain and total top yield per plant to changes in plant density. The constant θ can be estimated using α from the relation Wtotal = Wαgrain as yield changes with plant density. The constant α may be useful both as a selection criterion in breeding for increased yield and as a parameter in population and plant distribution studies.
Relationship Between Tannin Levels and Nutritive Value of Sericea1
Authors: Cope W. A. , Burns J. C.
Published: July 2010

One low‐tannin sericea synthetic strain (Lespedeza cuneata (Dumont) G. Don) was compared with high‐tannin strains over different years, harvests, and test locations for in vitro dry matter disappearance (IVDMD). Concentrations of fiber and lignin were determined for representative samples of both low‐tannin and high‐tannin strains. Increments of a water‐soluble purified tannin fraction, “sericin,” were added to samples of one lowtannin and one high‐tannin strain for IVDMD analysis. The low‐tannin strain was consistently about 25% higher in IVDMD than high‐tannin sericea over years, harvests, and locations where mean values varied widely. There were only small differences among high‐tannin strains for IVDMD. The low‐tannin strain was quite similar to two high‐tannin strains in fiber and lignin concentrations. The results strongly support the conclusion that tannin was the cause of IVDMD difference between lowand high‐tannin genotypes. IVDMD of both low‐ and high‐tannin sericea decreased progressively with added increments of sericin. Both tannin and sericin were effective in limiting the IVDMD of sericea forage.
Two Major Genes for Time of Flowering and Maturity in Soybeans1
Authors: Bernard R. L.
Published: July 2010

Two independent gene pairs affecting time of flowering and maturity in soybeans (Glycine max (L.) Merr.) were identified and studied in a common genetic background developed by backcrossing to the commercial variety ‘Clark.’ E1, a gene for lateness linked to pubescence color (T t), was transferred from strain T175, and e2, a gene for earliness, from T245. The late allele at each locus was partially dominant in most combinations. Flowering and maturity dates for the homozygotes based on 2 years data at Urbana, Ill., are summarized below as number of days earlier (−) or later (+) than Clark.

Strain
Genotype
Flowering
Maturity

Clark
e1 E2
0
0

Clark‐E1
E1 E2
+23
+18

Clark‐e2
e1 e2
− 7
−14

Clark‐E1 e2
E1 E2
+ 9
+ 1
Increasing Seed Weight in Wheat and Its Effect on Yield, Yield Components, and Quality1
Authors: Knott D. R. , Talukdar B.
Published: July 2010

High seed weight was transferred from ‘Selkirk’ to ‘Thatcher’ spring wheat Triticum aestivum L., by backcrossing. On the average the backcross lines with high seed weight outyielded Thatcher. However, their yield varied considerably depending on the degree of compensation in the other yield components, seeds per spike and spikes per plot. Weight per seed was positively correlated with yield and negatively correlated with number of kernels per plot. The number of kernels per spike showed a high negative correlation with the number of spikes per plot. Some of the highest‐yielding backcross lines appeared to be equal to Thatcher in milling and baking quality.
Effect of the Number of Parents on the Mean and Variance of Synthetic Varieties1
Authors: Hill R. R.
Published: July 2010

The effect of the number of parents per synthetic on the mean and variance of synthetic varieties was studied for diploid and autotetraploid species. The mean of synthetics with a small number of parents each will usually be less than the mean of the source population from which the parents were chosen, and the mean of the synthetics approaches the mean of the source population as the number of parents per synthetic increases. The genetic variance among the means of the synthetics decreases as the number of parents per synthetic increases, and the decrease is more rapid for the nonadditive than the additive portion.

The findings indicated the following: (1) Selection among experimental hybrids or synthetics utilizes genetic variance more efficiently when the number of parents per experimental variety is small. (2) Hybrids make slightly more efficient use of nonadditive genetic variance than synthetics with a comparable number of parents, and most of the advantage of hybrids would be lost with one generation of seed increase. (3) Most of the progress in development of medium to broad‐based synthetics results from selection of the parents and very little additional gain would be expected from selection among medium to broad based combinations of the selected parents.
Alternate Row Multistrain Culture in Soybeans1
Authors: Lin C. C. , Torrie J. H.
Published: July 2010

Alternate row multistrain culture was studied in the soybean (Glycine max L. Merrill) separately for maturity groups I and II using four Genotypes in each group. Two spacings between rows, 46 and 91 cm, were used during three years, 1965, 1966, and 1967. Seed yield averaged over genotypes was significantly greater when a genotype was bordered by other genotypes than when self bordered for group I genotypes only in the narrow but not in wide row plantings. Seed yield of alternating row plantings was lower than that of the best component with the exception of group I with narrow rows. Increases in seed yield of alternating rows of two genotypes as compared to the mean of pure stands were generally greater for single than for double alternating rows. Variance components for genotype combinations ✕ years indicated that the yield of alternating row plantings of two or three genotypes were more consistent from year to year than those of pure stands.
Gene Action for Yield Components and Plant Height in a Spring Wheat Cross1
Authors: Chapman S. R. , McNeal F. H.
Published: July 2010

Means and variances for the parental, F1 F2 and single
backcross generations were used to analyze quantitative
genetic variation in the wheat (Triticum aestivum L.) cross ‘Henry’ × ‘Lemhi 53’'. In both 1967 and 1968, epistatic effects were non‐significant in the inheritance of number of spike lets and kernel weight. Additive gene action had the greatest effect on number of spikelets; both additive and dominance types of gene action influenced kernel weight. In 1967, highly significant epistatic effects were detected in the inheritance of number of heads, yield and plant height. In 1968, epistatic effects were nonsignificant for these traits. When epistatic effects were significant, the metrical value of the F1 markedly exceeded the value of the higher parent.
Simulation of Growth and Yield in Cotton: Respiration and the Carbon Balance1
Authors: Hesketh J. D. , Baker D. N. , Duncan W. G.
Published: July 2010

Rates of respiration and dry matter accumulation were measured for growing squares (floral buds), bolls, and leaves of cotton, Gossypium hirsutum L. After assuming a “maintenance respiration” and a “growth respiration”, it was possible to derive an equation whereby such components of respiration could be estimated from regression analysis of transformed experimental data. New values for the efficiency of conversion of photosynthate into dry matter were estimated for leaves, squares and bolls; such values ranged from 50 to 69%. The theory, experiments described, and results from cotton offer hope for better descriptions of respiration for growing organs of other plant species. Such information is urgently needed for the development of management models depending on predictions on effects of environment on plant growth.
Resistances to Water Transport in Soybean, Bean, and Sunflower1
Authors: Boyer J. S.
Published: July 2010

The resistance to water transport in whole plants and plant segments was measured by a transient flow method for soybean (Glycine max L. (Merr.) var. ‘Harosoy’), bean (Phaseolus vulgaris L. var. ‘Bountiful’), and sunflower (Helianthus annuus L. var. ‘Russian Mammoth’). The resistance to water transport in whole soybean plants was twice that of sunflower and bean. The high resistance in soybean was caused by a high resistance in the root tissue external to the root vascular tissue. The data indicate that leaf water potential will have to drop about twice as far in soybean as in sunflower or bean to maintain a given rate of water transport to the leaf evaporating surface.
Alfalfa Chromosomes. III. Medicago Glomerata Balb. Pachytene Karyotype1
Authors: Gillies C. B.
Published: July 2010

The pachytene idiogram of Medicago glomerata Balb. was found to be almost identical to that published for M. sativa L., only two arm ratio means and two chromosome length means differing significantly between the two species. The M. glomerata idiogram was also similar to a M. falcata L. idiogram, although in this case there were greater differences. Hybrids between M. glomerata and both M. sativa and M. falcata had normal pachytene pairing. Hence M. glomerata may be a common ancestor of both M. sativa and M. falcata.
Variability and Relationships Among Characters in Zea mays L. Synthetics with Improved Protein Quality1
Authors: Dudley J. W. , Lambert R. J. , Alexander D. E.
Published: July 2010

We measured means, genetic variances, heritabilities, and correlations among characters on half‐sib families (ear‐to‐row progenies) from four opaque‐2 (o2) and two floury‐2 (f12) maize (Zea mays L.) synthetics. Syn. D.O. o2 and SSSS o2 were higher in percent lysine (of whole kernel), g lysine/100g protein (g L/100g P), yield, and lysine/plot, but lower in percent protein and kernel density than fl2 versions of the same synthetics. Genetic variances for all characters except g L/100g P were higher in fl2 synthetics. Estimates of heritability suggested that improvement in lysine percent would require breeding efforts similar to those necessary to increase yield. Correlations obtained suggest that simultaneous selection for grain yield and percent lysine would be possible, and that increases in percent lysine would result from increases in g L/100g P and not from increased percent protein. Correlations between kernel density and yield were not significant.
Anomalous Fertilization in Diploid‐Tetraploid Crosses in Maize1
Authors: Sarkar K. R. , Coe E. H.
Published: July 2010

Diploids with 10 heterozygous gene markers on 10 chromosomes were crossed reciprocally with two lines of tetraploid maize (Zea mays L.). Analyses of four tetraploids obtained from 54,250 fertilizations from marked 2n ✕ 4n crosses showed that in each case the diploid set from the female originated by exact duplication of a reduced gametophyte, probably by doubling or by fusion of two reduced female nuclei. No 4n sectors or unreducedmegaspore events were found. Up to eight possible cases of megaspore fusion and parthenogenetic development of diploid sporophytes were detected in the same 2n ✕ 4n cross, but no case was detected of diploid female gametes arising without meiotic assortment.

Three tetraploids were recovered from 41,660 fertilizations in 4n ✕ marked 2n crosses. Analyses of these showed that they probably arose from fertilization of the diploid egg by a diploid male nucleus originating from restitution in the second division of microsporogenesis or, less likely, from concurrent fertilization by two haploid nuclei from two pollen tubes.

The easiest and most efficient procedure to obtain triploids from diploid‐tetraploid intercrosses is to use tetraploid females and to screen for plump kernels.

To explain the occurrence of occasional plump kernels in either 2n ✕ 4n or 4n ✕ 2n crosses, we propose specific ploidy level of the endosperm, 3n or multiples of 3n, for proper endosperm development. Earlier hypotheses of a definite ratio between embryo and endosperm ploidy level in seed development are rejected, since seed development is found to be independent of the ploidy level of the embryo.
Physiological Basis for Genotypic Variation in Net Photosynthesis of Oat Leaves1
Authors: Criswell J. G. , Shibles R. M.
Published: July 2010

The net CO2 exchange rate of flag‐leaf blades of 20 oat (Avena spp.) genotypes was measured by infrared gas analysis in 1968 and 1969. Net photosynthetic rate and rate of CO2 efflux into CO2‐free air in light differed significantly among genotypes. Rankings were consistent across years. The CO2 compensation point was the least variable of the factors measured, and it was not related to net photosynthetic rate. A positive correlation between net photosynthesis and CO2 efflux was found; genotypes showing high CO2 efflux rates were concluded to have a lower resistance to CO2 diffusion between leaf respiratory sites and the external atmosphere. Differences in diffusion resistances, particularly the residual or mesophyll resistance, seemed to explain best the differences in net photosynthesis.

Mean genotypic net photosynthetic rates were correlated with mean specific leaf dry weights (g dry weight dm‐2 leaf area). That mean residual resistance values were negatively correlated with mean specific leaf dry weight values indicates that internal leaf morphology or biochemical factors associated with morphological characteristics of the oat leaf may be associated with genotypic differences in net photosynthesis.
Effect of Date and Rate of Seeding on the Performance of Triticale in Comparison to Wheat1
Authors: Larter E. N. , Kaltsikes P. J. , McGinnis R. C.
Published: July 2010

Triticale hexaploide Lart. cult. ‘Rosner’ and Triticum aestivum L. cult. ‘Manitou’ were sown on four dates and at eight rates in separate, 2‐year experiments at the University of Manitoba. Of the two cultural factors examined in this experiment, date of seeding had a far greater impact on yield than did rate of seeding. Delayed seeding severely reduced grain yields from triticale relative to yields from wheat. When the seeding date was delayed from April 20th (earliest date in this experiment) to May 5th (which corresponds to the general date of seeding for the area), yields for triticale were reduced 16% compared to 9% for wheat. In terms of comparative yield potentials of the two species, this delay resulted in an overall reduction in the yield advantage of triticale over wheat from 34% to 24%.

The optimum rate of seeding for triticale was 100 kg/ha. Seeding rates of 68 to 102 kg/ha (1 to 1 1/2 bu/ac) are recommended for wheat in western Canada. Kernel weights of both species were reduced with increased seeding rate however, their protein content was not affected.
Analysis of a Dominant Gene for Male‐Sterility in Upland Cotton, Gossypium Hirsutum L.1
Authors: Weaver J. B , Ashley Terry
Published: July 2010

Two male‐sterile plants were found in the cotton (Gossypiutn hirsutum L.) variety ‘Acala 1517D’ in 1968. F1 hybrids produced from these plants produced a 1:1 ratio of male‐sterile to fertile plants. Self‐pollinated seed from fertile plants produced all fertile offspring. Additional crosses made onto male‐sterile plants continued to produce approximately a 1:1 ratio of male‐sterile to fertile plants. A double haploid technique is proposed for producing homozygous dominant male‐sterile plants. The gene symbol Ms7 is proposed for this new dominant malesterile gene.
Comparison of S1 with Testcross Evaluation for Recurrent Selection in Maize1
Authors: Carangal V. R. , Ali S. M. , Koble A. F. , Rinke E. H. , Sentz J. C.
Published: July 2010

We made S1 and testcross progeny evaluations for two cycles of recurrent selection for grain yield in a 13‐line maize (Zea mays L.) synthetic. In the first cycle we evaluated 60 lines at four locations in 1 year. For the second cycle we evaluated 68 lines in three trials during 2 years. Selection intensity was 17% in both cycles.

Genetic variance for grain yield in the first cycle was significantly greater for selfed progeny in comparison with testcross evaluation, but decreased in the second cycle. Variability for ear moisture, broken stalks, and root lodging was increased with both selection procedures. S1 selection for grain yield gave greater improvement in the population per se, and was equal to testcross selection for general combining ability improvement. However, one second‐cycle testcross progeny exceeded the highest‐yielding parental line testcross.

Genotypic correlations were greater between related and nonrelated testcrosses than between S1 and either testcross. However, several selections were common to both S1 and testcross procedures. Second‐cycle correlations were significantly lower than first‐cycle values.
Effects of CCC on Tillering and Flowering of Uniculm Barley1
Authors: Bokhari U. G. , Youngner V. B.
Published: July 2010

Effects of (2‐chloroethyl)trimethyl ammonium chloride (CCC) on the uniculm mutant of barley (Hordeum vulgare L.) were studied at several concentrations applied as a soil drench. Individual plants were grown in 15‐cm pots well spaced on a greenhouse bench. Treated plants were shorter and darker green than untreated. Control plants consisted of a single shoot, but treated plants showed increased tillering with increasing CCC concentration. A high percentage of the additional tillers produced spikes. Microscopic examination of young untreated plants showed tiller primordia were present in most leaf or leaf primordia axils. Growth of these was promoted by CCC. Supernumerary spikes were observed on some treated plants that appeared to result from an interaction of cool temperatures and short days with CCC treatment. A greater grain yield on treated plants resulted directly from the greater number of tillers.
Genetics of Resistance to Brown Planthoppers and Green Leafhoppers in Oryza sativa L.1
Authors: Athwal D. S. , Pathak M. D. , Bacalangco E. H. , Pura C. D.
Published: July 2010

The genetics of resistance of several rice cultivars (Oryza sativa L.) to the brown planthopper, Nilaparvata lugens (Stål), and to the green leafhopper, Nephotettix impicticeps (Ishihara), was studied in the greenhouse. Two testing techniques were developed and employed. In one, 7‐day‐old seedlings were infested with insects and then classified on the basis of insect injury. In the other a known number of insects were caged on tillers of 6‐weekold plants and insect survival was used as the criterion for classification. The resistance of ‘Mudgo,’ ‘Manavari CO22,’ and ‘Dalwa Sannam MTU15’ to the brown planthopper was controlled by single dominant genes that appeared to be allelomorphic. Another cultivar, ‘Karsamba Red ASD7,’ possessed a single recessive gene for planthopper resistance that was either allelic or closely linked to the locus that conditions resistance in the other three cultivars. The field reaction of F4 lines of a cross between Mudgo and a susceptible cultivar was strongly correlated with the greenhouse reaction, and aparently the same gene controlled planthopper resistance at different stages of growth. Resistance to the green leafhopper in the cultivars ‘Pankhari 203,’ ‘ASD7,’ and ‘IR8’ also was controlled by single genes that were nonallelic and dominant. The planthopper resistance of Mudgo, and the leafhopper resistance of Pankhari 203 were independently inherited as was the resistance of ASD7 to the two insects.
Soluble Proteins of Alfalfa, White Clover, and Birdsfoot Trefoil1
Authors: Rommann, L. M. , Gerloff E. D. , Moore R. A.
Published: July 2010

Total soluble protein and perceut Fraction 1 protein of birdsfoot trefoil (Lotus corniculatus L.), white clover (Trifolium repens L.), and four varieties (‘Teton,’ ‘Travois,’ ‘Vernal,’ ‘Ladak’) of alfalfa (Medicago sativa L.) were investigated using polyacrylamide gel electrophoresis. Plants were grown in a growth chamber under 2 day lengths and were harvested at prebud, bud, and bloom stages of growth.

Statistically significant differences in total soluble protein content were shown among varieties and among species. However, no statistically significant difference in percent Fraction 1 protein, measured as a percentage of the total soluble protein, could be detected among birdsfoot trefoil aud three varieties of alfalfa. Both birdsfoot trefoil and Teton alfalfa were significantly lower in percent Fraction I protein than Vernal alfalfa and white clover. Minor differences in percent Fraction 1 protein due to species, day length, or stage of growth and their interactions do not appear sufficiently large to be a primary factor in the etiology of bloat.

Qualitative differences in lipoprotein staining patterns were evident among species, varieties, and between clones within a variety (or species) with the exception of birdsfoot trefoil. Visual quantitative differences could also be easily detected.
Comparative Study of Five Genotypes of Pearl Millet Under a Range of Photoperiods and Temperatures1
Authors: Begg John E. , Burton Glenn W.
Published: July 2010

The growth and development of five genotypes of pearl millet, (bulrush millet) Pennisetum typhoides (Burm.) Stapf and C. E. Hubb., were compared under controlled environment conditions at three photoperiods (12, 14 and 16 hr., where the solar radiation received was 10 hr. in all treatments and this was extended with low intensity incandescent light), and at two day/night temperature regimes (36/28 C and 28/20 C). The genotypes behaved as facultative short‐day plants, flowering at all photoperiods, though much earlier with short days. At the 12‐hr. photoperiod, there was relatively little effect of genotype or temperature on anthesis date. Although the solar radiation received was the same in all treatments, the yield was at least doubled under long photoperiods (14‐ and 16‐hr) in three genotypes. With the increase in photoperiod there was also an increase in the number of tillers and the number of leaves on the main stem. The results are considered in the context of the development of forage types for use in warm temperate regions.
Prediction of Protein Efficiency Ratio of Peas from Their Albumin Content1
Authors: Bajaj S. , Mickelson Olaf , Lillevik H. A. , Baker L. R. , Bergen W. G. , Gill J. L.
Published: July 2010

Strains of peas (Pisum sativum L.) with higher protein efficiency ratios (PER) contained more albumin N than those of lower PER, as determined by rat bioassay. For data from 21 strains of peas with a range in albumin N from 0.53 to 1.06%, a quadratic function of the albumin N content had a high coefficient of correlation (R = 0.949) with PER. Such an equation provides a simple and accurate method for the evaluation of protein quality (as determined by PER) of peas. The selection of varieties of peas containing more albumin may be important for future plant breeding improvement of PER values of peas.
Inheritance of Tolerance to Soil‐Borne Oat Mosaic Virus in Oats1
Authors: Byrd B. W. , Graham Doyce , Byrd W. P.
Published: July 2010

Information was obtained on the reaction of segregating populations of oats (Avena byzantina C. Koch and Avena sativa L.) to soil‐borne oat mosaic virus, Marmor terrestre var. typicum. Bulk F3 lines were evaluated at two locations that had natural mosaic infestation in the soil. Frequency distributions of mosaic scores indicated that tolerance to OMV was a quantitative character. Heritability estimates based on progeny means ranging from .59 to .88 indicated that a large portion of the variability in tolerance to the virus is heritable. A heritability estimate based on individual plots was lower. Estimates of expected genetic advance indicated that selection of 5% of the more tolerant lines would result in lower mosaic scores, although the resulting scores would not approach the tolerant parent. Evaluation for tolerance at one location was a reliable indication of tolerance at the second location.
Stage of Development Descriptions for Soybeans, Glycine Max (L.) Merrill1
Authors: Fehr W. R. , Caviness C. E. , Burmood D. T. , Pennington J. S.
Published: July 2010

We developed stage of development descriptions which we believe apply to all soybean (Glycine max (L.) Merr.) genotypes grown in any environment. The descriptions apply to single plants or a community of plants and are precise and objective.

Vegetative and reproductive development are described separately. Vegetative stages are determined by counting the number of nodes on the main stem, beginning with the unifoliolate node, that have or have had a completely unrolled leaf. Reproductive stages Rl and R2 are based on flowering, R3 and R4 on pod development, R5 and R6 on seed development, and R7 and R8 on maturation.

The stage descriptions should enhance soybean research by standardizing descriptions of soybean plant development. The system also will be used by the soybean hail insurance industry for stage determination in adjustment of losses.
Inheritance of Kernel Weight in Six Spring Wheat Crosses1
Authors: Sun P. L. F. , Shands H. L. , Forsberg R. A.
Published: July 2010

Four spring wheat [Triticum aestivum L. em. Thell. ssp. vulgare (Vill, Host) Mac Key] cultivars, ‘Henry,’ ‘Thatcher,’ Wis. 255, and C.I. 12633, contrasting parents for kernel weight, were intercrossed in six combinations to estimate gene effect parameters, the extent of heterosis, and heritability for this character.

Hayman's (6) three‐ and six‐parameter models utilizing generation means were used to estimate gene effects. Additive and dominance effects were more consistent and important in determining kernel weight than epistatic effects. However, epistasis was detected in at least 1 year in all crosses where the parents were of different kernel weight classes. Parents and environment influenced the expression of epistasis. Additive ✕ additive and deminance ✕ dominance types of epistasis were more important than additive ✕ dominance effects.

Heterosis, calculated as the percentage increase of F1 above midparent performance, ranged from −4.3 to 31.2%. Heterosis was greater in crosses of more distantly related parents and it usually occurred with significant dominance and one or more significant epistatic effects. Broad sense heritability estimates for kernel weight ranged from 51 to 85% over crosses and years, with one exception (9%).
Third Phase in the Yield Evaluation of Synthetic Varieties of Maize1
Authors: Hallauer Arnel R.
Published: July 2010

Nine synthetic maize (Zea mays L.) varieties, 36 variety crosses, and four single‐cross hybrids were evaluated for yield at eight Corn Belt locations in six states. This is the third phase of a program for sequentially evaluating the yield potential of synthetic varieties developed as improved sources of breeding material. ‘Iowa Stiff Stalk Synthetic #2’ ✕ ‘Pa. Intermediate Synthetic’ and ‘Iowa Stiff Stalk Synthetic #2’ ✕ Iowa Long Ear Synthetic' were the high‐yielding variety crosses. They approached the yield level for two of the single‐cross hybrid checks. The stability parameters showed the regression coefficients to be sirnilar, and the variety crosses had lower deviation mean squares. ‘Iowa Two‐ear Synthetic’ was the highest‐yielding variety per se, and Iowa Stiff Stalk Synthetic the lowest, which agrees with previous phases of testing. Iowa Synthetic #2 and ‘Tuxlan’ included exotic germplasm and yielded as well per se and in crosses as Iowa Stiff Stalk Synthetic. Midparent heterosis in the third phase was 14%.
Initiation of Inflorescences in Cool‐season Perennial Grasses1
Authors: Canode C. L. , Maun M. Anwar , Teare I. D.
Published: July 2010

The objectives of this paper are to discuss pertinent literature and to present some recent research concerning induction of the vegetative primordia and initiation of floral development in perennial cool‐season grasses. The amount of exposure to short photoperiod and cool temperatures under field conditions necessary for induction of three forage grasses and four cultivars of Kentucky bluegrass (Poa pratensis L.) was studied. Plants were moved from the field at 15‐day intervals from September 15 to March 15 and grown under long photoperiod and warm temperatures for the production of inflorescences.

The number of inflorescences produced indicated that a high level of induction for smooth bromegrass [Bromus inermis (Leyss.)], crested wheatgrass [Agropyro desertorum (Fisch. ex. Link) Schult.], and orchardgrass (Dactylis glomerata L.) had been reached by October 15, November 1, and November 15, respectively. The four Kentucky bluegrass cultivars showed a significant linear response to exposure. Inflorescence production increased as the exposure time increased. Seed production for Kentucky bluegrass cultivars followed essentially the same pattern as inflorescence production in response to exposure. The time required for inflorescence emergence for all cultivars and species had a negative association with the length of exposure to inductive conditions. If the rate of inflorescence emergence was used as the index, induction intensity was increasing up to March 15.

Observations of dissected tillers at weekly intervals indicated the initiation of floral development for smooth bromegrass by February 12, and for orchardgrass and crested wheatgrass by February 19. The apices of the Kentucky bluegrass cultivars show a transition to floral primordia by January 22 for Delta and by February 5, 12, and 26 for Newport, Cougar, and Merion, respectively. Transition of vegetative apices to floral development occurred under conditions of cold temperature and short photoperiod for all species and cultivars.
Variation and Selection for Preharvest Seed Dormancy in Safflower1
Authors: Zimmerman L. H.
Published: July 2010

Selection for preharvest seed dormancy had two aspects: selection for low or no germination in the head at maturity, followed by selection for short‐term seed dormancy as shown by high germination after a period of seed storage. No domestic safflower (Carthamus tinctorius L.) had 20% or less germination in the head; however, a high frequency of wild Carthamus species did. Short‐term dormancy was also found in wild species. Selections of Carthamus palaestinus Eig, which readily interbreed with domestic safflower, had as little as 7% germination with seeds stored for 3 weeks after harvest and as much as 100% with seeds stored for 19 weeks.
Amylolytic Activity in Leaves of a Tropical and a Temperature Grass1
Authors: Karbassi Parviz , West S. H. , Garrard L. A.
Published: July 2010

Amylolytic activities of leaf extracts of ‘Pangola’ digit grass (Digitaria decumbens Stent.) were determined after imposing low night temperature treatments known to reduce growth. Comparisons were made between the activities of leaf extracts of Pangola and those of orchardgrass plants (Dactylis glomerata L.) that were subjected to the same treatments. Treatment of Pangola, a tropical species, with 10‐C night temperature markedly reduced the starch‐degrading activity of leaf extracts, whereas this was not the case with orchardgrass, a temperate species that is little affected by 10‐C night temperature. In addition, a low incubation temperature during enzyme assay reduced the amylolytic activity of Pangola extracts more than that of orchardgrass. These results suggest that the reduction of growth of Pangola by suboptimal night temperatures is at least partially due to a depression of amylolytic activity.
Inheritance of Heading Date, Plant Height, and Kernel Weight in Two Spring Wheat Crosses1
Authors: Bhatt G. M.
Published: July 2010

Inheritance of heading date, plant height, and kernel weight was studied in two crosses of spring wheats (Triticum aestivum L.) involving three cultivars, ‘Timgalen,’ ‘Sonora 64A,’ and ‘Eagle.’ Means and variances were estimated for six populations: P1, P2, F1, F2, and the two first backcrosses, B1 and B2. Estimates of heritability and genetic advance indicated that considerable progress could be made by applying selection pressures for the three characters. Gene action appeared to be primarily additive in the expression of these characters.
Crosing Relationships between Synthetic Lotus Amphidiploids and L. corniculatus1
Authors: Somaroo B. H. , Grant W. F.
Published: July 2010

A total of 236 trispecific hybrids were obtained from 15 out of 22 different cross combinations attempted between 12 Lotus amphidiploids and the cultivated tetraploid L. corniculatus. The relative ease with which these crosses have been produced, without resort to embryo culture, indicates that the transference of desirable germplasm from diploids to tetraploid L. corniculatus by means of experimentally produced amphidiploids can be accomplished without too much difficulty. Generally, the self‐fertile amphidiploids were more suitable as seed parents than the self‐incompatible L. corniculatus. From the crossing relationships of the various amphidiploids and L. corniculatus, it appears that L. japonicus and L. alpinus are more closely related to L. corniculatus than to the diploid taxa L. filicaulis, L. schoelleri, L. krylovii, and L. corniculatus var. minor. The highest percentage of successful crosses (85.15%) was realized when the amphidiploid (L. japonicus ✕ L. alpinus)2 was crossed with L. corniculatus.
Cytokinin Content and Kernel Size of Barley Grain as Affected by Environmental and Genetic Factors1
Authors: Michael G. , Seiler‐Kelbitsch H.
Published: July 2010

The cytokinin activity in barley (Hordeum vulgare L.) caryopses (determined by the soybean [Glycine max (L.) Merr.] callus assay method) decreases very rapidly after pollination. Small caryopses, whether genetically determined, resulting from de‐awning of spikes, or from damage by high water content of soil after pollination, matured earlier and had lower cytokinin activity. Differences in cytokinin content were detected earlier than those in grain size. The results suggest that plant growth substancs such as cytokinins participate in the regulation of grain size, possibly by influencing accumulation processes and the duration of the filling period. It is probable that roots also play a role in regulating grain size by supplying the spikes with plant hormones.
Secondary Dormancy in Cotton1
Authors: Taylor R. M. , Lankford M. K.
Published: July 2010

This study was undertaken to evaluate the effect of low temperature and high soluble salts on the germination of cotton (Gossypium hirsutum L.) seeds. Stress conditions consisting of either low germination temperature (13 C) or high concentrations of soluble salts (18,000 ppm) in the germination substrate, induced a secondary dormancy in newly harvested cotton seeds. Seeds from seven cotton‐producing states responded similarly, and dormancy under identical conditions decreased as the seeds aged. Three‐year‐old seeds showed little or no dormancy under either salt or cold germination conditions.
Inheritance of a Trypsin Inhibitor Variant in Seed Protein of Soybeans1
Authors: Hymowitz T. , Hadley H. H.
Published: July 2010

Soybean [Glycine max (L.) Merrill] seeds from the backcross ‘Harosoy3’ ✕ T245 were analized for electrophoretic banding pattern of SBTI‐A2. Harosoy produced a fast‐moving band at Rf 0.79 and T245 produced a slowmoving band at Rf 0.75. All seeds having either fast or slow bands bred true in the next generation. Seeds having both fast and slow bands produced progenies in a ratio of 26 fast:50 fast and slow:24 slow. Our evidence confirmed that a single locus with two codominant alleles, which we designate as Ti1 and Ti3, controls the two protein forms.
Photoperiod and Temperature Manipulation Induces Early Anthesis in Pearl Millet1
Authors: Hellmers Henry , Burton Glenn W.
Published: July 2010

The time requited for anthesis and head development by two inbred lines of pearl millet, Pennisetum typhoides (Burm, Staph, and C. E. Hubb), Tift‐23 and Tift‐31 was shortened by manipulating temperature and photoperiod regimes. Growth and development rates over a range of temperatures and photoperiods were determined using the controlled environment facilities in the Phytotron at Duke University. These studies showed that high day and night temperatures of 32 and 29 C, combined with long days (16 hours) of high light intensity, favored growth and that early flowering could be induced with 8‐hr days. Early anthesis and full head development were attained using 32‐C day with 29‐C night temperatures and the following photoperiod sequences: 21 days with a long photoperiod, 16 hrs; then 15 days with a short photoperiod, 8 hr; followed again by long days. This procedure resulted in anthesis in 45 to 48 days from date of planting, compared to previously reported times of 56 to 67 days.
Morphology and Technique for Crossing Lens esculenta Moench
Authors: Wilson V. E.
Published: July 2010

Small size, fragility, and cleistogamous nature of lentil (Lens esculenta Moench.) flowers made manual crossing difficult. Study of the morphological characters and development of flower buds showed that the optimum stage for successful manual crossing occurs as the petals reach one‐half to three‐fourths the length of the calyx lobes. This development occurs during stigma receptiveness but prior to anther dehiscence. Temperatures between 15 and 25 C and relative humidity above 50% favored manual crossing in the greenhouse. Crossing attempts made in the field were unsuccessful.