bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Characters Within and Repeatability Between Years in Progenies of Four Sugarcane Crosses
Authors: Smith Garry A. , James Norman I.
Published: July 2010

We obtained phenotypic correlations among number of stalks, diameter of stalks, and Brix within and between plant cane and first ratoon crops of progenies of four sugarcane (Saccharum spp.) crosses. Repeatability of characters between crops was .611**, .551**, and .389** for .389** for number of stalks, diameter of stalks, and Brix, respectively. The associations among characters were relatively low within both crops (r = −.050 to .291**).

Joint distributions for each character in the plant cane and first ratoon crops indicated that selection of seedlings (in the plant cane crop) with 10 or more stalks, stalk diameter above 27 mm, and Brix greater than 110% of the mean would have increased the frequency of seedlings with these specified characteristics, in the resulting first ratoon crop, by 35, 25, and 20%, respectively.
Linkage of the Pa4 and Mla, Loci in Barley1
Authors: McDaniel M. E. , Hathcock B. R.
Published: July 2010

The Pa4 gene conditioning reaction to barley leaf rust (Puccinia hordei Otth.) in the cultivar ‘Gold’ (Hordeum distichum L. emend. Lam.) was found to be linked with the Mln gene conditioning resistance to powdery mildew (Erysiphe graminis D.C.f. sp. hordei Em. Marchal) in the cultivar ‘Cebada Capa’ (H. vulgare L.). The Pa4 locus was found to be 17.0 ± 3.5 crossover units from Mln on chromosome 5.
Pangolagrass (Digitaria decumbens Stent)
Authors: Oakes A. J.
Published: July 2010

The common name “pangolagrass” should be associated with only one clone of Digitaria decumbens Stent; i.c., USDA P.I. 111110.
Variety ✕ Environment Interactions in Cotton Variety Tests in the Delta of Mississippi1
Authors: Bridge R. R. , Meredith W. R. , Chism J. F.
Published: July 2010

Eight cotton varieties were evaluated at three locations for a 3‐year period to estimate the magnitude of variety ✕ environment interactions. The presence of a substantial variety ✕ location ✕ year interaction for lint yield, lint percentage, and weight per boll indicated that varieties showed differential responses when grown in different environments. With the exception of fiber elongation and 50% span length, the second order interactions were larger than either of the first order interactions; however, with the exception of lint yield, the magnitude of these interactions was small in comparison with the varietal components, and thus may be considered relatively unimportant. The lack of a significant variety ✕ location or a variety ✕ year interaction for all characters measured, indicated that neither locations nor years had any consistent effects on differential variety responses.
Polyembryony in Sorghum1
Authors: Ross W. M. , Wilson J. A.
Published: July 2010

Twin seedling pairs were isolated from Sorghum bicolor (L.) Moench at frequencies of 1:7,500 in crossed seed and 1:12,100 in selfed seed. The higher frequency from crossed seed probably was related to delayed pollination. Progenies of twins had no more twin seedlings than parental stocks. Twin types occurred in these ratios: vigorous‐vigorous, 48%; vigorous‐weak, 40%; and weak‐weak, 12%. Limited cytological analyses indicated that weak members may be a source of haploids.
Dry Inoculum for Inoculating Alfalfa with Colletotrichum Trifolii1
Authors: Campbell T. A. , Ostazeski S. A. , Hanson C. H.
Published: July 2010

Production and use of a dry anthracnose inoculum, which is as virulent and effective as wet inoculum, is described. Advantages are ease of storage, shipping, handling, and application; long shelf life; stability of culture; and low cost. Neither specialists nor specialized facilities are needed for production of inoculum or maintenance of virulent cultures. Dry inoculum is suited for screening large populations to isolate resistance.
Selection for Grain Yield and Components of Yield in Barley1
Authors: Rasmusson D. C. , Cannell R. Q.
Published: July 2010

A selection experiment in barley was performed to determine whether worthwhile increases in yield could be obtained by selecting among F4 families for the morphological components of grain yield. The data were used as a basis for examining relationships among yield and its components. Selection for number of heads resulted in changes in yield that were similar to those observed when selection was for yield itself. Selection for kernel weight was highly effective in altering yield in one of two populations. In contrast, yield was reduced in one population when selection was practiced for kernels per head. Thus, selection for yield through components was very effective in certain situations, but could not be recommended as a routine procedure. Genetic as well as environmental factors were responsible for the observed phenotypic correlations between the components of yield. These phenotypic correlations were unreliable as an indicator of the yield responses that occurred when selection was practiced for the components of yield. It was postulated that the optimum genotypic level for kernels per head and number of heads will vary depending on environment, but that the optimum. for kernel weight will be near its genetic maximum
Energetics of Early Seedling Growth in Corn (Zea mays L.)1
Authors: Cooper Clee S. , MacDonald Paul W.
Published: July 2010

Early growth of the corn seedling was studied in relation to its dependence on energy from endosperm and early photosynthetic tissue. Measurements were made of (1) endosperm utilization rate of seedlings grown in light and dark; (2) growth and leaf area of seedlings as affected by partial endosperm removal; and (3) photosynthesis (P), respiration (R), and 14CO2 uptake of seedlings as affected by endosperm excision at different ages. Endosperm utilization and growth rates were similar in light and dark until the two‐leaf stage l0 days after germination. Regression of root and shoot growth on age was 15.4 mg/day and of root and shoot growth on endosperm weight loss was .65 mg/mg. Partial removal of the endosperm at seeding resulted in decreased growth of roots and shoots and indecreased leaf area per seedling. Apparent P was negative at 9 days of age and was greatest for seedlings with endosperm excised. Apparent P was positive and similar at days 11, 12, and 13 for seedlings with endosperm excised and was positive, and increased from day 11 to day 13 for seedlings with endosperm. Energy obtained from CO2 fixation was not equivalent to that supplied by the endosperm until the 10th day. At this time seedlings had two fully emerged leaves. Absorption of 14CO2 was similar for seedlings with and without endosperm, and increased with age as a result of increased leaf area and increased absorption per unit of leaf area. Endosperm removal resulted in greater translocation of 14CO2 to seedling roots.
Alfalfa Chromosomes. II. Pachytene Karyotype of a Tetraploid Medicago sativa L.1
Authors: Gillies C. B.
Published: July 2010

The chromosomes of a tetraploid Medicago sativa L. (2n=4x=32) were analysed from cells at the pachytene stage of meiosis. Mean chromosome lengths, arm ratios, and the distribution of chromatic areas were used to construct an idiogram showing the distinguishing features of the karyotype. The chromosomes ranged in length from 18.1 to 26.0 microns, and the haploid complement totaled 335.8 microns. The complement consisted of six acrocentric or subacrocentric chromosomes, eight metacentric chromosomes, and two nucleolus organizing chromosomes which were much more chromatic than the rest of the complement. The individual tetraploid chromosomes were much shorter and more chromatic than those of diploid M. sativa and M. falcata. The chromosomes of the tetraploid idiogram could be classified into pairs on the basis of morphological similarities, but only three pairs were observed as quadrivalents at pachytene. The tetraploid's chromosomes seemed more similar to those of diploid M. sativa than to those of diploid M. falcata.
Relationship of Nitrate Reductase Activity to Grain Protein Production in Wheat1
Authors: Croy Lavoy I. , Hageman R. H.
Published: July 2010

Studies were conducted with field grown wheat (Triticum aestivum L.) with and without supplemental nitrogen to determine if nitrate reductase activity could be correlated with water soluble leaf protein, grain and grain protein (% and total) production. Nitrate reductase activity, nitrate, and water soluble leaf protein were determined at intervals throughout the life cycle of ‘Ponca’ and ‘Monon’ hard and soft red winter wheats, respectively. The major conclusions are, (a) nitrate content of the tissue was a major factor in controlling the level of enzyme activity; (b) nitrate reductase activity was related, though not numerically, to leaf protein content; (c) induction of nitrate reductase on a field scale, was achieved by supplemental nitrogen; (d) increased enzyme activity from supplemental nitrogen treatments was associated with increases in gram protein (% or total); (e) a significant correlation was found between the spring seasonal total of nitrate reductase activity (units of nitrogen reduced per hectare) and grain protein (kg/h) for both varieties; (f) this correlation is valid only for a specified genotype as Ponca required a higher level of enzyme activity to accumulate a unit of grain protein than Monon and (g) this observation suggests that Monon is more efficient in transporting reduced nitrogen from the vegetation to the grain than Ponca. Thirty‐two hard and soft red winter wheat varieties grown in a field nursery with low nitrogen fertility were evaluated for nitrate reductase activity; nitrate and water soluble leaf protein, grain and grain protein (kg/h) production. Average values of enzyme activity obtained from three fall and three spring samplings showed little variation among genotypes and no correlation with grain or grain protein production. However, selection of 16 of the varieties exhibiting highest nitrate reductase activity on November 12, when nitrate was in adequate supply, would have included 9 of the 13 varieties which ultimately produced significantly higher grain protein (kg/h).
Relative Performance of F1 and F2 Hybrids from Doubled Haploids and Their Parent Varieties in Upland Cotton, Gossypium hirsutum L.1
Authors: Meredith William R. , Bridge R. R. , Chism J. F.
Published: July 2010

Three doubled haploids were compared to their parent varieties in their ability to produce F1 and F2 hybrids, their interaction with locations, and the type of gene action involved. Doubled haploids were similar to their parent varieties in productivity of their crosses, interaction with locations, and type of gene action. Both F1 and F2 hybrids tended to give more consistent performances over all four locations than their parents. For lint yield, F1 hybrids were no better than the highest yielding parents. However, the F1 hybrids produced better combinations of yield and fiber properties. Lint yield and its components showed considerable dominance effects while fiber properties tended to be inherited in an additive manner. For the six crosses and nine characteristics studied, only one case of significant epistasis was detected.

The minimum within‐variety variability makes doubled haploids a useful tool in many genetic experiments. However, there is no indication that, in a cotton breeding program, doubled haploids differ from other varieties of similar genetic background.
Genetic Linkage in Soybeans. Linkage Group IV1
Authors: Weiss Martin G.
Published: July 2010

The genetic linkage between three loci in soybeans was determined and established as Linkage Group IV. The loci involved were V1, v1 (normal chlorophyll variegated leaves); Na, na (ovate, lanceolate leaflets); and P2,p2 (normal, minute pubescence or “puberulence”). The order of genes was shown to be v1‐na‐p2. The combined recombination value for v1 and na was 35.6 ± 0.9%, for na and p2 was 26.4 ± 1.4%, and random assortment of v1 and p2 occurred. Greater frequency of 4.seeded pods was shown to be a pleiotropic effect of the gene that causes narrow leaflets.
Combining Ability Estimates in Arachis hypogaea L. I. F1 Seedling Responses in a Controlled Environment1
Authors: Parker R. C. , Wynne J. C. , Emery D. A.
Published: July 2010

The feasibility of identifying superior parents of peanuts (Arachis hypogaea L.) by testing Fl hybrids grown under controlled conditions was investigated. Estimates of combining ability, maternal, and reciprocal effects among 15 F1 hybrids were determined for 17 seedling characters. Six lines of cultivated peanuts were crossed in all possible combinations to form a 6 × 6 complete diallel set. The lines included Valencia, Virginia, and Spanish types from three geographic regions of South America. Statistically significant variances were found for general combining ability for 11 of the 17 characters. Estimates of specific combining ability for three characters were statistically significant. The greatest portion of genetic variance was associated with general combining ability. Maternal and reciprocal effects were significant for two and one characters, respectively. Specific crosses among certain types had higher means than expected based on mid‐parent values for several characters.
On the Origin of Haploid/Diploid Twinning in Cotton1
Authors: Lee Joshua A.
Published: July 2010

Twin seedlings were recovered from a cross of the tetraploid cotton species, Gossypium barbadense L., (as female) with the wild diploid species, Gossypium davidsonii Kell., (as male). One of the embryos was clearly the result of interspecific hybridization. The other showed the characteristics of a polyhaploid and bore the same genetic markers as the female parent. Development of the polyhaploid from an unfertilized nucleus contributed by the mother plant was clearly indicated.
Effects of Mild Water Stress on Enzymes of Nitrate Assimilation and of the Carboxylative Phase of Photosynthesis in Barley1
Authors: Huffaker R. C. , Radin T. , Kleinkopf G. E. , Cox E. L.
Published: July 2010

The effects of water stress were determined on enzymes of nitrate assimilation, of the carboxylative phase of photosynthesis, and of dark CO2 fixation in the first leaves of Hordeum vulgare L. After water removal, decreased activity of nitrate reductase was detected at the same time that water potential decreased in the first leaves and growth of the second leaves ceased. Up to 58% of the nitrate reductase activity was lost during the 4‐day stress period. Nitrite reductase activity showed a tendency to decrease. Phosphoenolpyruvate carboxylase activity decreased 1 day later in the stress period and by only half as much as did nitrate reductase activity. Twenty‐four hours after rewatering, the activities of nitrate reductase and phosphoenolpyruvate carboxylase had recovered completely. This recovery occurred during the same time that water potential increased in the first leaves and elongation of the second leaf began.

Activities of phosphoribulokinase and ribulose‐l,5‐diP carboxylase were affected little by water stress. The reported rapid decrease in photosynthetic fixation of CO2 at the onset of water stress may be due less to changes in these enzyme levels than to restrictions in gaseous exchange by reduction of stomatal aperture. Concentrations of chlorophyll, soluble protein, and nitrate were slightly lower in the first leaves of water‐stressed plants.

The reduction in the activities of phosphoenolpyruvate carboxylase and, especially, nitrate reductase could be part of a biochemical adaptation to stress conditions, causing a decrease in synthetic capabilities so as to reduce overall energy requirements.
Distribution of a Trypsin Inhibitor Variant in Seed Proteins of Soybean Varieties1
Authors: Clark R. W. , Mies D. W. , Hymowitz T.
Published: July 2010

Studies on the polymorphic nature of the soybean trypsin inhibitor protein revealed that 20 out of 294 soybean (Glycine max [L.] Merrill) varieties sampled had Rf 0.92 electrophoretic bands, while the rest had Rf 0.95 bands. The frequency for Rf 0.92 was 0.07 and for Rf 0.95, it was 0.93.

Soybean varieties, whose origins were known, that had the Rf 0.92 band were from Japan or Korea, but not all soybeans from Japan or Korea had this band. Varieties with the Rf 0.95 band, the only type found in Chinesederived germ plasm, also came from Japan and Korea. Most of the varieties with the Rf 0.92 band are in Maturity Groups I through IV.
Single Height‐Gene Effects in Doubled Haploid Sorghum bicolor (L.) Moench1
Authors: Schertz K. F.
Published: July 2010

A comparison of short and tall sorghum, Sorghum bicolor (L.) Moench, determined the effects on morphological and agronomic characteristics of a single gene for height. Short doubled haploids, recessive at four major height loci (4‐dwarfs), were compared with tall mutant derivatives, recessive at three loci (3‐dwarfs) and dominant at one locus. The short and tall plants differed in height, internode length, leaf‐blade length, leaf‐sheath length, panicle width, and grain weight. Differences in height and internode length are due to a single gene difference. The other differences are either a direct effect or an indirect effect of this gene.
Effect of Seed Moisture on Temperature Sensitivity During Imbibition of Soybean1
Authors: Obendorf R. L. , Hobbs P. R.
Published: July 2010

Seeds of 12 soybean {Glycine max (L.) Merr.} varieties were equilibrated to 6% or 16% moisture before imbibition at cold (5 C) temperature, warm (25 C) temperature, or warm followed by exposure to cold. After imbibition, seeds were transferred to prewetted autoclaved soil mix in a greenhouse for 2 weeks. The number of seedlings surviving, height to apical bud, and dry weight of aerial parts without cotyledons were determined.

Imbibition of low moisture seeds at 5 C caused reduction in survival, dry matter accumulation, and height of seedlings, but no reduction was observed with high moisture seeds. When low moisture seeds were imbibed at warm temperature before exposure to cold, no reduction was noted. The effect of initial seed moisture on sensitivity to chilling during imbibition was reversible. while some varieties were tolerant to cold imbibition of low moisture seeds, other varieties had up to 75% reduction in survival, 38% reduction in dry matter accumulation per seedling, and 50% reduction in plant height when compared to warm imbibition. Imbibition treatments which resulted in greatest seedling injury also decreased the capacity of seedlings to utilize cotyledonary reserves. Our results suggest that adjusting seed moisture to 16% before seeding could improve seedling establishment of soybean in cold soil.
Frrequency and Distribution of Stomata in Barley1
Authors: Miskin E. , Rasmusson D. C.
Published: July 2010

Stomatal frequency on the lower surface of the flag leaves of 649 cultivars from the World Collection of Barley, Hordeum vulgate L., ranged from 36 to 98 stomata mm−5 with a mean of 64. Differences in stomatal frequency observed in the field were confirmed by a greenhouse experiment involving 50 cultivars. Among 20 cultivars examined for stomatal size, mean guard cell length varied from 41 to 56 μ. A negative correlation, ‐—.86, was obtained between stomatal frequency and size.

Stomatal frequencies of several cultivars decreased progressively from the flag to the lower leaves, with the flag leaf having approximately twice as many stomata mm‐2 as the basal leaves. Stomatal frequencies on the lower and upper surface of the flag leaves were similar. Stomata were not found on the lemma, and on the awn they were limited to two rows on the outer face. A single row of stomata extended down each side of the crease of the palea. Increased light intensity resulted in higher stomatal frequency, whereas temperature variations affected frequency very little.
Cytoplasmic Male Sterility in Rye (Secale cereale L.)1
Authors: Geiger H. H. , Schnell F. W.
Published: July 2010

Male‐sterile segregates were found in 1966 in four S1 lines derived from crosses between plants of Argentinian ‘Pampa’ rye, Secale cereale L., and a Hohenheim inbred line as pollinator. Progenies of sibbed and open‐pollinated male‐sterile S1 plants were crossed with four inbred lines in 1967. Various degrees of male sterility, ranging from 0 to 100%, were observed (1968) in the progenies of these crosses. Average male sterility varied substantially between progenies of different inbred lines. In 1969, offspring from backcrossing inbred lines to male‐sterile plants exhibited, with but few exceptions, complete male sterility. Backcrossing to male‐fertile (restored) segregates yielded varying proportions of male‐fertile, partially male‐sterile, and male‐sterile plants.

The results suggest a male sterility caused by interaction between Pampa cytoplasm and nuclear factors of the pollinator lines. Efficient restoration of pollen fertility by nuclear factors can be accomplished, but at present little can be said about its inheritance. The cytoplasmic male sterility should, for the first time, provide a means of large scale hybrid seed production in rye.
Prediction of Chemical Accumulation in Maize Double‐cross Hybrids from Single‐cross Data1
Authors: Craig W. F. , Thomas W. I.
Published: July 2010

Levels of potassium in the stover and the ear and of strontium in the stover of double‐cross corn hybrids, Zea mays L., were significantly correlated with the average level of accumulation of single‐cross parents. Similar correlations for phosphorus, calcium, magnesium, and zinc were not significant.
Inheritance of Hermaphrodite Pedicelled Spikelets of Sorghum1
Authors: Casady A. J. , Miller F. R.
Published: July 2010

Progenies of four Sorghum bicolor (L.) Moench crosses were studied to determine the inheritance of the hermaphrodite pedicelled spikelet character. The character was found to be controlled by a single pair of alleles, with the hermaphrodite pedicelled spikelet allele (hps) recessive to the non‐hermaphrodite pedicelled spikelet allele (Hps).
Comparison of Stresses Which May Limit Soybean Yields1
Authors: Mann J. D. , Jaworski E. G.
Published: July 2010

Hydroponically grown ‘Dare’ soybeans (Glycine max L.) were exposed to a number of discrete stresses at the time of flowering. Effects on initial pod set, subsequent pod abscission, and ovule growth were assessed. Lodging, when not associated with shading, did not lower pod set. Severe short‐term deficiency of calcium and nitrogen decreased pod set by one‐third. Temperatures above 40C caused severe pod abscission. Shading (63% of ambient) also caused abscission of half the pods. If plants were returned to short‐night conditions after 18 or 22 longnight cycles, flowering and initial pod set were similar to controls but ovule growth was markedly retarded. Thus, yield may be limited by high temperatures and by low light intensities, which cause pod shedding, or by inadequate night lengths which retard seed filling.
A Diallel Selective Mating System for Cereal Breeding1
Authors: Jensen N. F.
Published: July 2010

The author proposes a set of diallel selective mating procedures to serve as a supplement to conventional breeding systems for autogamous crops. The system uses multiple parent input into a central gene pool (population) which, through selective mating of individuals is advanced through successive generations. Mass and recurrent selection procedures are employed throughout on both the plant and seed portions of each plant generation. The system is designed to shift the attention of breeders from the present operating concept of employing germplasm sources discretely and sequentially in the formation of numerous populations. In contrast, the diallel and selective mating aspects of the new system force the simultaneous insertion of multiple genotypes into a few central populations.

The diallel selective mating system involves a planning phase and an implementation phase. The latter has four stages: a basic parent series of crosses (1) which set up the F1. diallel series of crosses (2) which when composited form P2; spaced P2 and subsequent P3, etc. provide the populations within which selective mating (3) is practiced on mass and recurrent selection principles. The final stage (4) is standard line selection from the various F5 composite populations.

Implementation of the concept of the broad working gene pool leads to a continuing state of open options and provides the opportunity and time for alternative solutions to difficult breeding problems. Specifically, the proposed arrangements provide for broad use of germplasm, simultaneous input of parents, creation of persistent gene pools, breaking of linkage blocks, freeing of genetic variability, and general fostering of genetic recombination.
Performance of Synthetics and Sib Lines in Fairway Crested Wheatgrass, Agropyron cristatum (L.) Gaertn.1
Authors: Knowles R. P.
Published: July 2010

Sixteen selected plants of crested wheatgrass (Agropyron cristatum (L.) Gaertn.) were used to form a 16‐clone synthetic, and alternatively two 8‐clone synthetics, eight fullsib lines and 16 half‐sib lines. Synthetics and sib lines were advanced to the second and third generation under isolation. Full‐sib lines showed yield declines of 9% in the second generation and 16% in the third generation; half‐sib lines showed vigor losses of 7% for the second generation and 12% for the third generation. Small losses in yield were shown for 8‐ and 16‐clone synthetics in the second and third generations. Single crosses of sib lines as well as topcrosses and synthetics of sib lines generally were not superior to second and third generations of synthetics. One single cross and several topcrosses of sib lines gave yields equivalent to the first generation of synthetics. Intercrossing second generations of 8‐clone synthetics gave a restoration of yield to the Syn. 1 level.
Incorporation of High‐Protein, Exotic Germplasm into Soybean Populations by 2‐ and 3‐way Crosses1
Authors: Thorne J. C. , Fehr W. R.
Published: July 2010

Exotic high‐protein parents were studied as sources of variability for protein, oil, and protein + oil in soybean (Glycine max (L.) Merrill) populations derived from 2‐ and 3‐way crosses. Random lines from homozygous 2‐way adapted × exotic and 3‐way (adapted × exotic) × adapted soybean crosses were evaluated. Significant genetic variability was detected for the three characters in each population. The high protein content of the exotic strains was transmitted readily to their offspring; and selection of high‐yielding, high‐protein strains from crosses involving exotic strains was possible.

Both 2‐ and 3‐way population means were determined primarily by additive effects, but instances of epistatic effects were noted. The rank of population means was predictable from parental performance.

Genetic variance estimates, heritabilities, and correlations between characters were similar for our 2‐ and 3‐ way populations. The 3‐way populations generally had significantly higher mean protein, oil, and protein + oil than the 2‐way populations and were more useful sources for selection of all characters. Selection for protein + oil was successful in increasing the protein level of the population while maintaining the oil content at the level of the unselected population.
A Chlorotic Mutation in Wheat1
Authors: Gustafson J. P. , Curtis B. C. , Youngman V. E.
Published: July 2010

A ‘corroded’ mutation was found in ‘Wichita’ wheat (Triticum aestivum L.) which was expressed as chlorotic bands bisecting the leaves. Genetic and environmental factors as well as histological effects of the mutation were studied. The mutation was controlled by a single recessive gene. The expression of the mutation was not inhibited by variations in temperature. The mutation was expressed under conditions of continuous light and continuous darkness.

A histological study showed that the plastids were the first to break down and disappear. Nuclear material was the next to disappear, followed by complete collapse of epidermal and parenehymatic cell walls. Walls of vascular bundles and sclerenchymatic tissue were the last to collapse.
Phenotypic Diversity for Agronomic Characters in Astragalus cicer L.1
Authors: Townsend C. E.
Published: July 2010

The phenotypic diversity for vigor, height, date of flowering, spread, and growth habit was evaluated in 20 accessions of Astragalus cicer L. Significant differences were found among the accessions for the characters measured. This indicated that progress could be expected from a breeding program. Simple correlation coefficients were calculated between vigor and the other characters. Height and date of flowering were highly correlated with vigor in the seedling year. The origin oE 11 accessions was traced to a single introduction (P.I. 66,515) made in 1926. There were significant differences among these 11 accessions for all characters measured; thus, the original introduction contained a large reservoir of germ plasm.
Some Sources of Variability in Boll and Fiber Properties of Cotton (Gossypium hirsutum L.)1
Authors: Meyer Vesta G. , Meyer James R.
Published: July 2010

Sources of variability in cotton fiber quality were studied by a series of experiments carried out over a period of several years. Homozygosity or heterozygosity of the individual plants or of the strain had only a small effect on variability. Environmental fluctuations were a major cause of variability within each variety, inbred line, or doubled haploid studied. Varieties differed in homeostasis, or buffering against environmental fluctuation, and homeostasis was not the same for all properties studied. It is suggested that cotton breeders can minimize the effects of environmental fluctuation on fiber quality, either by breeding and selection for buffering systems effective over a wider range of environments, or by breeding plants with a shorter season, so that they will not require adjustment to the unfavorable environment which lowers fiber quality of bolls developed just before frost.
Combining Ability Estimates in Arachis hypogaea L. II. Field Performance of F1 Hybrids1
Authors: Wynne J. C. , Emery D. A. , Rice P. W.
Published: July 2010

Estimates of heterosis and combining ability were made using 15 hybrid combinations grown under field conditions. The hybrids were produced by crossing in diallel six peanut (Arachis hypogaea L.) lines collected from three geographic areas of South America.

Of 17 characters, estimates of specific combining ability were significant for 16 and estimates of general combining ability were significant for 8. Specific combining ability was greater for yield and for most fruit characters.

Several of the crosses showed considerable heterosis when compared with mid‐parent means. Crosses of Virginia × Valencia type parents gave greater heterosis than other crosses for vegetative plant characters. However crosses of Valencia × Spanish type parents gave greatest heterosis for yield and fruit characters.

Comparison of field results with results obtained previously in a controlled environment indicated that the controlled environment may have limited use in predicting field performance of peanut hybrids.
Infertility of Cotton Flowers at Both High and Low Relative Humidities1
Authors: Hoffman G. J. , Rawlins S. L.
Published: July 2010

At either constantly low (25%) or high (90%) atmospheric relative humidity, cotton (Gossypium hirsutum L.) set very few bolls because the anthers failed to dehisce. Seed cotton yields were almost zero at both 25 and 90% relative humidity, whereas yields at 40 and 65% were 48 and 164 g/plant, respectively.
Effect of Chemical and Physical Treatment on Hard Seed of Penngift Crownvetch1
Authors: Brant R. E. , McKee G. W. , Cleveland R. W.
Published: July 2010

Various chemical and physical treatments were applied to hard seed of “Penngift” crownvetch, Coronilla varia L., in an attempt to make such seed permeable to water. Soaking for periods of up to 24 hours in acetone, benzene, chloroform, hexane, petroleum ether, anhydrous ether, ethyl alcohol, and t‐butyl alcohol had only slight effects on hard seed. However, the percentage of rotted seed increased. Treatment with enzymes such as hemicellulase and pectinase was likewise of slight value. Alternate freezing and thawing at temperatures as low as −80 C and dry heat treatment at 75 C had little effect on reducing the number of hard seed. Treatment with infrared heat lamps at temperatures of 85 to 100 C reduced hard seed content slightly but increased the percentage of rotted and firm seed appreciably. Treatment of 19 seed lots of Penngift crownvetch with sulfuric acid (18 N) for 15 min (with agitation) reduced hard seed from an average of 60% in the control to 11% in acid treated seed and increased readily germinable seed from 16% in the control to 75%. For the same lots, treatment in liquid N (two 2‐min dips separated by a l‐min interval) reduced hard seed to 15% and increased readily germinable seed to 65%. Treatment in boiling water (15 sec with agitation) reduced hard seed to 27% and increased readily germinable seed to 47%. Mechanical scarification reduced hard seed content to 4% and increased readily germinable seed to 78%. Scanning electron micrographs of seed scarified by either acid or mechanical means indicated that lumens of the macrosclereid cells were exposed, permitting imbibition of water. Seed subjected to differential thermal expansion in boiling water or liquid N had fissures penetrating the macrosclereid layer.
Comparative Performance of Obsolete Varieties and Current Varieties of Upload Cotton1
Authors: Bridge R. R. , Meredith W. R. , Chism J. F.
Published: July 2010

We evaluated 13 obsolete cotton varieties and three current commercial varieties for yield, agronomic, and fiber properties over a 2‐year period, (1967 to 1968), determine what genetic improvements the new varieties had over come of the older ones.

The current commercial varieties yielded approximately 112 kg/ha more lint than the best obsolete variety. Most obsolete varieties yielded 124‐448 kg/ha less lint than the commercial check varieties. These data indicated that varieties exhibiting increased yield potential had higher lint percentages, smaller bolls, smaller seed, and higher micronaire values. Increases in lint percentage have played a major role in increasing yield. Iriber properties of varieties currently grown were better than those of some old varieties, but inferior to those of others. Advances in fiber properties have not been as rapid as advances in yield.
Duration of the Grain Filling Period and Its Relation to Grain Yield in Corn, Zea mays L.1
Authors: Daynard T. B. , Tanner J. W. , Duncan W. G.
Published: July 2010

A Significant linear relationship was found among several corn (Zea mays L.) hybrids grown in 1966 and 1967 at Guelph, Ontario at several planting densities, between grain yield and effective filling period duration. Effective filling period duration (EFPD) is defined as final grain yield divided by the average rate of grain dry weight accumulation during the linear period of grain formation, and hence, is a relative measure of the length of the grain filling period. In each year yield differences among hybrids were more closely related to EFPD differences than to differences in the rate of ear dry weight accumulation. EFPD was unaffected by planting density. Results suggest that significant potential exists in corn for higher grain yields through a genetic extension of the length of the grain filling period.
A New Factor for Resistance to Common Bunt in Hexaploid Wheats1
Authors: Metzger R. J. , Silbaugh B. A.
Published: July 2010

A new gene, designated Bt10, conferred resistance to races T‐l and T‐15 of common bunt (Tilletia caries and T. foetida) in the wheat cross, (Triticum αestivum L.) PI 116306 (resistant)✕ ‘Elgin’ (susceptible) and to races T‐l and L‐9 in the cross PI 116301 ✕ Elgin. Bt10 confers resistance to all races of common bunt found in the Pacific Northwest States with the exception of race X‐l. The possibility of a loose linkage between Bt10 and the locus for glume color on chromosome IB is discussed.
Ineffectiveness of Nucleotides and Air Pressure Treatments as Substitutes for Vernalization of Winter Wheats1
Authors: Trione E. J. , Metzger R. J.
Published: July 2010

Neither uridine monophosphate nor air pressure (3.67 kg/cm2 for 5, 10, 15 days) treatments induced the development of apical meristems in three nonvernalized winter wheat cultivars (Triticum aestivum L.). Thus, these treatments cannot be used in place of cold treatments to satisfy the vernalization requirements of winter wheat.
Comparison of Expected Genetic Advance with Selection on the Basis of Clone and Polycross Progeny‐Test Performance in Alfalfa1
Authors: Hill R. R. , Pedersen M. W. , Elling L. J. , Cleveland R. W. , Graham J. H. , Frosheiser F. I. , Starling J. L.
Published: July 2010

Sixty‐seven alfalfa, Medicago sativa L., clones and their polycross progenies were evaluated for hay, seed, and chaff yields. The progenies were also evaluated in separate experiments for resistance to Corynebacterium insidiosum (McCull.) Jens.; Leptosphaerulina briosiana (Poll.) Graham & Luttrell; Pseudopeziza medicaginis (Lib.) Sacc.; Phoma herbarum West. f. medicaginis West, ex. Rab.; and Uromyces striatus Schroet. var. medicaginis (Pass.) Arth. Expected genetic gains with selection on the basis of clone and polycross progeny‐test performance were compared for each of the characters. Relative effectiveness of the two methods varied with heritability of the trait and the selection intensity permitted with each method; the polycross progeny test was favored with traits which had low heritability. Expected advance from selection on the basis of polycross progeny‐test performance was greater for hay, seed, and chaff yields, but expected advance with individual plant selection was greater for resistance to some of the pathogens.
Variation in the Content of Tryptamines in Clones of Phalaris Arundinacea L.1
Authors: Woods D. L. , Clark K. W.
Published: July 2010

A number of clones of reed canarygrass (Phalaris arundinacea L.) from two synthetic cultivars were examined by thin layer chromatography for the presence of substances reacting with Ehrlich's reagent. Approximately half of the clones examined appeared to be free of substances giving the blue color considered indicative of tryptamines, but in these tryptamine‐free clones a substance giving the pink color indicative of gramine was detected.
Inheritance of Seed Coat Color in Brassica campestris L. Variety Toria1
Authors: Ahmed S. U. , Zuberi M. I.
Published: July 2010

Four varieties of Brassica campestris L., ‘Toria‐A’, ‘Toria‐BP’, ‘Toria‐TP’ and ‘Toria‐7’, and their corresponding crosses and backcrosses were studied with respect to the inheritance of seed coat color. Chi‐square tests were performed to assess the results obtained. It was found that seed coat color was conditioned by a single gene and that reddish brown was completely dominant over yellow.
Leaf Area, Dry‐Matter Accumulation, and Carbohydrate Reserves of Alfalfa and Birdsfoot Trefoil Under a Three‐cut Management1
Authors: Greub L. J. , Wedin W. F.
Published: July 2010

‘Vernal’ alfalfa (Medicago sativa L.) and ‘Empire’ birdsfoot trefoil (Lotus corniculatus L.) were grown in the field in pure stands and cut three tinies before September 1. Alfalfa accumulated leaf area and dry matter (DM) more rapidly than trefoil during spring growth. After the first and second cuttings, leaf area initially accumulated more rapidly in alfalfa than in trefoil; but, by the third or fourth week, the leaf area index (LAI) values of trefoil exceeded those of alfalfa.

No consistent differences were found in mean net assimilation rate between the species. The greater LAI developed by trefoil was the main factor in the higher mean crop rates of trefoil compared with alfalfa after the first and second cuttings.

Residual leaf area remained on the trefoil stubble after the first two cuttings and may have contributed to the recovery. No residual leaf area remained on the trefoil stubble after the third cutting, and regrowth was initially slow. Trefoil increased leaf area rapidly and accumulated more aboveground DM than alfalfa during regrowth after the first and second cuttings.

The total nonstructural carbohydrate (TNC) levels alfalfa roots followed the characteristic depletion and accumulation cycles during all regrowths. Even though alfalfa was at 14% bloom at the second cutting, TNC levels had not been restored to the levels present at the time of first cutting when it was at 10% bloom. In contrast to alfalfa, trefoil root TNC levels declined during spring growth and remained at very low levels until late summer. The LAI values required to initiate net accumulation of TNC in alfalfa roots were 2.4 for spring growth and 1.6, 0.8, and 1.8 for regrowth after the first, second, and third cuttings, respectively.
Analysis of Growth Within Distinct Strata of the Soybean Community1
Authors: Koller H. R.
Published: July 2010

Growth analysis techniques were used to study components of dry matter accumulation within distinct strata of a field soybean [Glycline max (L.) Merrill] community at Lafayette, Indiana in 1968. An analysis was made of leaf area development and dry matter accmnulation in leaf, supporting, pod wall, and seed components of lower, middle, and upper main‐stem segments, and also the branches. Mathematical functions were selected to describe leaf area and dry weight vs. time relationships. Crop growth rate (CGR) and relative growth rate (RGR) were calculated for each plant fraction at each day of the growing season.

The lower main‐stem segment produced the most leaf area. However, due to abscission of lower leaves, the middle main‐stem segment had the most leaf area by the time of rapid seed development.

Approximately 36% of the total dry matter in lower and middle main‐stem segments and 47% of that in branch and upper main,stem segments was in the seed.

In each segment, the leaf component was first to reach peak CGR. This was followed in sequence by supporting, pod wall, and seed components. The time interval between vegetative and seed development decreased toward the top of the plant, resulting in a greater overlap of vegetative and seed growth.

Seed RGR did not vary due to position on the plant. Supply of assimilates, therefore, apparently limited seed growth to no greater extent at lower nodes than at upper nodes. In view of the decreased potential for photosynthesis toward the base of the soybean canopy, this suggests the occurrence of downward translocation of assimilates during pod filling.

Seed growth rate appeared to be controlled primarily by regulatory mechanisms within the seed, rather than by external availability of assimilates.
Leaf Development of Alfalfa at Several Temperatures1
Authors: Wolf D. D. , Blaser R. E.
Published: July 2010

Five leaf development indices were interrelated with leaf area, leaf weight, specific leaf weight (SLW), net carbon exchange (NCE), and petiole elongation of alfalfa (Medicago sativa L.). The summation of leaf indices to give leaf equivalents provides a time‐saving measure of the rate of leaf development, which may be closely correlated with rates of dry matter accumulation. The system cannot be used to measure leaf changes after full expansion. Leaf weight, SLW, and NCE per unit leaf area increased as leaves developed from emergence to full expansion. Increases were nearly linear and correlations among any two of the categories were highly significant. Plant development as shown by accumulated leaf equivalents at 10, 21, and 32 C was nearly linear and declined with each decrease in temperature. Fully expanded leaves were smaller in 32 than in 10 or 21 C environments.
Test Weight in Relation to the Physical and Quality Characteristics of Soft Winter Wheat (Triticum aestivum L. em Thell)1
Authors: Ghaderi Ardeshir , Everson E. H. , Yamazaki W. T.
Published: July 2010

Test weight is defined as the weight of grain that fills a given volume. It is the product of kernel density and volume of grain occupying the container. The latter component, when expressed as percentage of the volume of the container, is referred to as packing efficiency and was shown to be a cultivar characteristic. Of the two components packing efficiency has a greater effect on test weight when comparing soft winter wheats (Triticum aestivum L. em Thell).

There was a negative correlation between test weight and the kernel length‐width ratio (kernel shape). When the length‐width ratio remained constant, there was no increase in test weight when kernel volume increased. Kernel width was correlated more than length with kernel volume. Test weight and flour yield were not correlated within or among cultivars. Kernel protein was related to kernel size within cultivars.
Identification of Genes at the Ml‐a Locus in Barley for Resistance to Erysiphe graminis F. sp. Hordei1
Authors: Moseman J. G. , Jorgensen J. Helms.
Published: July 2010

The pathogenicity of haploid progeny from the cross of cultures CR3 and 63.5 of Erysiphe graminis [DC.] Merat hordei Em. Marchal was determined on 11 barley (Hordeum vulgare L.) varieties, each known to have a resistance gene at the Ml‐a locus. Different genes were shown to condition the pathogenicity of cultures CR3 and 63.5 on the ll varieties, indicating the corresponding resistance genes in those varieties are different. Genes in seven of the varieties — ‘Algerian,’ ‘Black Russian,’ ‘Ricardo,’ ‘No. 22,’ ‘Gopal,’ ‘Iso 20,’ and ‘Line 4831’ — had previously been designated Ml‐a through Ml‐a7. We propose the genes in varieties ‘Heil's Hanna,’ ‘Monte Cristo,’ ‘Iso 12,’ and ‘A222’ be designated Ml‐a8, Ml‐a9, Ml‐al0, and Ml‐a11, respectively.
Inheritance of a Light‐Quality Sensitive Character in Soybeans1
Authors: Kilen T. C. , Hartwig E. E.
Published: July 2010

Flowering of the soybean [Glycine max (L.) Merr.] cultivars ‘Lee’ and ‘Hill’ (insensitive to light quality) was delayed when grown in light from cool‐white fluorescent lamps at a 15‐hr photoperiod, or in natural daylight with the photoperiod extended to 15 hr by illumination with fluorescent lamps. ‘Arksoy’ and ‘Dorman’ (sensitive to light quality) flowered 28 to 30 days after emergence when grown under the same conditions. Flowering of all four cultivars was delayed when light from incandescent lamps supplemented that from the fluorescent lamps.

Progeny from the crosses Dorman ✕ Hill and Arksoy ✕ Lee segregated in the F2 generation at approximately 3 delayed:1 early when grown under fluorescent lamps alone, indicating that the light‐quality sensitive character acts as a monogenic recessive under these conditions. However, when F2 populations of the same two crosses were grown in short days of natural light extended with fluorescent lamps, the heterozygote was distinguished and a 1:2:1 ratio was obtained. F1 plants from crosses between light‐quality sensitive and insensitive types had flowering dates intermediate to the parents when grown in natural light extended with fluorescent lamps, but showed a response similar to that of the insensitive parent when grown in light from fluorescent lamps alone. Reciprocal backcross data gave additional support for one locus with two alleles for the light‐quality sensitive character. Bulk populations of Arksoy ✕ Lee and Dorman ✕ Hill that had been advanced in the field were grown under fluorescent lamps. The results obtained suggest that the light‐quality sensitive genotype is a poor competitor in a mixed population.