bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Photoperiod and Light Intensity on Flowering in Sugarcane
Authors: James Norman I. , Smith Garry A. 
Published: July 2010

Photoperiods of 9, 11, and 14 hr drastically reduced the number of panicles that emerged in several sugarcane clones (Saccharum spp.), as compared to a photoperiod of 12.5 hr. A light intensity of 1399 lux tended to reduce the number of panicles that emerged more than light intensity of 86 lux when the photoperiod was 12.5 or 14 hr. The higher light intensity (1399 lux) caused significantly greater delay of panicle emergence than the lower light intensity (86 lux).Increasing the duration of the 12.5‐hr photoperiod from 0 to 12 weeks resulted in increased delay of panicle emergence; and 4 weeks of this treatment caused maximum delay when started as inflorescences were just beginning to form or were up to 1.25 cm long.
Effects of Various Dormancy‐Reducing Treatments on Seed Germination and Establishment of Indiangrass, Sorghastrum nutans (L.) Nash1
Authors: Geng Shu , Barnett F. L. 
Published: July 2010

Spikelets of indiangrass, Sorghastrum nutans (L.) Nash, from cultivars ‘Cheyenne,’ ‘Holt,’ and ‘Osage’ were subjected to various dormancy‐reducing treatments and subsequently tested for laboratory germination and field establishment. Dormancy‐reducing treatments were: prechilling, hull removal, prechilling followed by hull removal, and hull removal followed by prechilling.A cultivar‐by‐treatment interaction occurred in normal laboratory germination, suggesting cultivar differences in level of seed dormancy, type of seed dormancy, or susceptibility to caryopsis injury resulting from the treatments. Abnormal laboratory germination followed only treatments involving hull removal. Prechilling significantly increased establishment from Holt spikelets and resulted in a nearly significant (.05) establishment increase with those of Osage. Establishment from Cheyenne spikelets was unaffected by prechilling. Establishment from spikelets of all cultivars was significantly reduced following treatments involving hull removal, although in some instances those treatments significantly increased normal laboratory germination.Economic feasibility of prechilling, as a practical means of improving indiangrass establishment, was considered questionable. However, in laboratory tests prechillng did not seem to remove all dormancy, indicating work with other dormancy‐reducing treatments is warranted.Regression analyses indicated that field establishment was affected by seed set and caryopsis weight as well as by spikelet germination. When dormancy was reduced through prechilling, the effect of normal spikelet germination on fieId establishment was largely attributable to variation in seed set.Statistical complications deriving from use of intact spikelets were discussed.
Response of Hard Red Spring Wheat (Triticum aestivum L.) to Environments in Relation to Six Quality Characteristics1
Authors: Busch R. H. , Shuey W. C. , Frohberg R. C. 
Published: July 2010

Eight varieties of hard red spring wheat (Triticum aestivum L.) were evaluated by regression analysis for six bread quality characteristics to determine varietal response to environments. Means of all entries in each uniform nursery were used as environmental indexes for each characteristic. The linear regression coefficient allowed a comparison of predicted performance among varieties over a range of environments for each quality character‘Thatcher’ had the highest response and ‘Polk’ the least response while the six other varieties did not differ in their responses to environments for protein. ‘Manitou,’ ‘Selkirk,’ and Thatcher had high means and an undesirably high response to increasing ash environments. All varieties except ‘Waldron’ and Minn. II‐54‐30, exhibited a lower response to environments for mixogram score than for the other quality characteristics studied. ‘Chris’ exhibited a high response to increasingly good environments for loaf volume, whereas Selkirk had a below average response and a low mean.A minimum standard system of using check varieties with known environmental responses to aid in the evaluation of potential varieties for quality characteristics is proposed, based on the varieties' means and responses. Selkirk, Manitou, and Polk would provide the necessary number of checks for the evaluation of the six quality characteristics studied under most environments.
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.
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.
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.
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.
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.
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.
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.
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.
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.