bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Planting Pattern on Estimated Digestibility of Smooth Bromegrass1
Authors: Ugherughe P. O. , Drolsom P. N. , Davis J. R. 
Published: July 2010

Digestibility estimates of most forage grasses in the early stages of breeding programs are based upon samples obtained from spaced plants in nurseries rather than from solid stands as grown on farms. The purpose of this research was to examine the relationship between digestibility estimates of spaced plants and solid stands of smooth bromegrass (Bromus inermis Leyss.).Whole plants and plant parts of 30 smooth bromegrass genotypes were evaluated for digestibility for 2 years. The acid‐pepsin and the modified two‐stage in vitro digestion techniques were used with three sampling dates each year.In both years, genotypes differed significantly in stem, leaf, and panicle acid‐pepsin dry matter disappearance (APDMD) at each harvest under the two planting patterns, except for the first harvest of solid stands in the 2nd year. No differences were found among genotypes for whole plant APDMD under solid stands for each of the three harvests in 1978. Spaced plant harvests differed significantly in APDMD in the 2 years while there were no significant differences in APDMD among harvests of solid stands in 1978. Among the plant parts at the first harvest, the APDMD of leaves and stems correlated best with whole plant APDMD, with leaves the highest.
Comparison of Inbred vs. Single‐cross Testers and Estimation of Genetic Effects in Sunflower1
Authors: Miller J. F. , Hammond J. J. , Roath W. W. 
Published: July 2010

The objectives of this study were to determine relative effectiveness of inbred versus single‐cross testers in identifying combining ability of inbred sunflower (Helianthus annuus L.) lines; to determine whether epistasis was significant in the genetic systems controlling selected traits; and to evaluate the importance of additive and dominance variance for traits not influenced by epistasis. The hybrids evaluated in this study were formed by crossing the inbred lines RHA 274 and RHA 278, and their single‐cross, RHA 274/RHA 278, to 10 randomly selected female inbred lines. The design used was a variation of the triple testcross, an extension of the Experiment III design.The interaction of female ✕ restorer parent was significant, indicating that the three testers did not rank the female lines identically for yield. However, the three testers did identify three of the top four lines when a 40% selection criterion was applied. For oil percentage, the interaction of female ✕ male parents was nonsignificant indicating that the three testers gave very similar rankings. Utilizing any one of the three testers will differentiate or identify high‐yielding potential female lines for yield and oil percentage in a population improvement or inbred development program.Epistasis was a minor factor in the overall genetic variation for all traits studied in these sunflower lines. Additive variances were most important, with dominance variances important only for yield. The estimate for degree of dominance for yield (0.62) indicated that partial dominance predominated, an observation with significant implications for breeders in countries that primarily use open‐pollinated cultivars. Improvement by development of high‐yielding synthetics or open‐pollinated cultivars should be continued. The results also indicate that breeders should develop population improvement schemes that utilize the large additive portion of genetic variance detected in this study.
Genetic and Soil Moisture Effects on the Branching‐Root Trait in Alfalfa1
Authors: McIntosh M. S. , Miller D. A. 
Published: July 2010

The inheritance of the branching‐root trait in alfalfa, Medicago saliva L., was studied in diallels at two field locations. Diallel progenies of seven clones were grown in spaced plantings at Champaign‐Urbana and Brownstown, Illinois. Roots of 6‐month‐old alfalfa branched more at Brownstown than Champaign‐Urbana. At Champaign‐Urbana significant differences were found for general but not specific combining ability. At Brownstown, differences were significant for specific combining ability but not for general combining ability. General combining ability × location interaction also was significant. Reciprocal and selfing effects were not important at either location. Regression estimates of offspring on S1 parent were 0.128 and 0.002 for the Brownstown and Champaign‐Urbana locations, respectively.A greenhouse experiment was conducted to determine whether moisture stress contributes to the genotype × environment interaction for the branching‐root trait. Progeny of six crosses, whose parents represented a wide range in rooting habit, were grown in pots with soil moisture levels increased daily to − ⅓) bar onto 50% of the − ⅓ bar moisture level. Low moisture levels resulted in plant stress exhibited as a decrease in plant height and dry weight. Plants grown in the low moisture regime also had a lower incidence of branching roots. The genotype × moisture interaction was nonsignificant. Among moisture‐stressed plants, height and weight were positively correlated with root branching (r = 0.81 and 0.60, respectively. Both are significant at the 0.01 level.). For unstressed plants, only plant weight was significantly correlated with the branching root habit (r = 0.49, significant at the 0.05 level.).
Yield Stability of Forage Sorghum in Northeastern Brazil1
Authors: Faris M. A. , de Araujo M. R. A. , de A. Lira M. 
Published: July 2010

Ten forage sorghum [Sorghum bicolor (L.) Moench] selections, one commercial sorghum cultivar, and one local maize (Zea mays L.) cultivar were grown in replicated trials at 12 locations in the semi‐arid tropics of northeastern Brazil for 3 years. Superiority of some of the new selections in forage dry matter production over the commercial cultivar and corn check was demonstrated.The combined analysis revealed that entries (G), environments (E), and the G × E interaction were highly significant. However, some nonlinearity existed which necessitated transformation of the data to the logarithmic scale which gave better fitting regression lines. Two of the highest yielding entries possessed the greatest stability. The results showed that better data interpretation came from the log transformed data and that stability parameters should be considered in selection among high yielding cultivars.
Critical Stages of Development for Defoliation of Soybean1
Authors: Fehr W. R. , Lawrence B. K. , Thompson T. A. 
Published: July 2010

One objective of our research was to define the most critical stages for defoliation of indeterminate and determinate soybean [Glycine max (L.) Merr.] strains. The second objective was to determine if yield loss from defoliation at R4.5 could be predicted by the average of loss at R4 and R5 and if loss at R5.5 could be predicted by the average of loss at R5 and R6. Response to 100% defoliation for an indeterminate cultivar, ‘Beeson,’ and a determinate experimental strain, A72‐407R, was evaluated at Ames, Iowa during 3 years. The strains were defoliated at R4 (full pod), R4.5, R5 (beginning seed), R5.5, and R6 (full seed).The indeterminate strain had an average yield loss across stages of 59% compared with 80% for the determinate strain, but the strain × stage interaction was not significant. The most critical stage for defoliation varied among environments, but was either R5 or R5.5 for both strains. The average yield loss at R4.5 of 72% was slightly greater than the average of loss at R4 and R5 of 68%. The average yield loss at R5.5 of 80% was significantly greater than the average of loss at R5 and R6 of 69%. Yield response to defoliation at R4.5 and R5.5 should be considered in estimating yield reduction from factors that cause defoliation of soybeans.
Monogenic Male‐sterility in Rice: Induction, Identification and Inheritance1
Authors: Singh R. J. , Ikehashi H. 
Published: July 2010

Monogenic male‐sterility has not been utilized so far in the improvement of rice (Oryza sativa L.) because it is not available to breeders in an agronomically useful genetic background. The objective of this study was to induce male‐sterility in a widely grown rice cultivar ‘IR36.’One hundred grams each of dried seeds of the rice cultivar IR36 were treated with 0.2, 0.4, 0.8, 1.2, and 1.6% concentrations of ethyleneimine for 1 or 3 hours to obtain monogenic male‐sterile mutants. Seed treatments with higher concentrations and longer durations had greater reductions in the percent seed germination than treatments with lower concentrations and shorter durations. Treatments for 1 hour with 0.4% and for 3 hours with 0.2% concentrations reduced seed germination to 69 and 30%, respectively, and were considered more satisfactory than other treatments. In four M2 progenies, male‐sterile plants with normal meiosis were crossed with control IR36 and segregation in F2 indicated that one recessive gene controlled inheritance for male‐sterility in each of these lines. The male‐sterile plants showed high seed set from outcrossing. Possible use of recessive genes for male‐sterility in rice improvement was discussed.
Inheritance of Bean Seed Globulin Content and its Relationship to Protein Content and Quality1
Authors: Mutschler Martha A. , Bliss F. A. 
Published: July 2010

Globulin‐1 (G1) protein, the major storage protein fraction of common bean, Phaseolus vulgaris L., was measured in mature seed using rocket immunoelectrophoresis. Percentage total protein was measured by infrared reflectance. Heritability estimates were calculated for the protein traits and seed yield, and correlations between traits were determined using parental, F2 and F3 populations.Among the six parents grown in the field in 1977, ‘Endogava Z.N.’ had the highest percentage protein (27.8% protein), while PI 229815 produced the most G1 protein (136.5 mg G1/g flour). Both were low yielding, producing 12 and 13 g seed/plant compared to the highest yielding parent, ‘Bonita’ that produced 66 g seed/plant. Bonita showed the most favorable combination of traits, with levels of 24% protein and 108 mg G1/g flour, in addition to high yield. ‘Swedish Brown’ and WI 74‐2047 had the lowest levels of total protein, (17.4 and 18.5%, respectively) as well as G1 protein (75 and 61 mg/g flour, respectively).Analyses of 5 of the 15 F2 populations derived from crosses among the six parents were presented in detail. Inheritance of both percentage protein and mg/g flour was quantitative with broad sense heritability estimates ranging from 0.19 to 0.65 and 0.37 to 0.95, respectively. Narrow sense heritability estimates ranged from 0.59 to 0.86 and 0.43 to 0.74 for percentage protein and mg G1/g flour, respectively in four populations.Mean F2 values of populations resulting from crosses between parents that differed widely for protein amounts were usually intermediate between the two parents. The average values of the five F2 populations resulting from one common parent produced rankings similar to those based on parental values for percentage protein and mg G1/g flour.Moderate positive correlations between mg G1/g flour and percentage protein were observed in F2 and F3 populations. There was no correlation between yield and mg G1/g flour and low negative correlation between yield and percentage protein. No obvious consistent relationship between available methionine and G1 content was seen, perhaps because of variation in other constituent fractions or the confounding effects of seed tannins. Implications of genetic manipulation of protein fractions and total protein on protein quality improvement are discussed.
Inheritance of Dwarfness in Three Oat Crosses and Relationship of Height to Panicle and Culm Length1
Authors: Marshall H. G. , Murphy C. F. 
Published: July 2010

A stiff‐strawed, dwarf oat (Avena sativa L.) line (CI 8447) was crossed to its parental line (NC 2469), a medium‐height cultivar (‘Otee’), and a tall cultivar (PI 258595). All F1 plants were semidwarf for plant height, and all F2 distributions for height were skewed toward the dwarf‐parent mean. Variation for plant height was continuous in the F2 populations from all crosses, but F3 families were readily classified into discrete dwarf, tall, and segregating families. The ratios of parental to segregating families fitted those expected for a model with a difference for one gene. The continuous variation for plant height in the F2 and minor variation within parental type F3 families was attributed to minor effects of modifying genes plus environment. The symbol Dw‐7 was assigned to the single, partially dominant gene. This gene may be useful in developing semidwarf, lodging‐resistant cultivars.In all three crosses, panicle and culm length were correlated with total plant height and the relationship was linear.
A Genetical Scheme for Isolating Cotton Cultivars1
Authors: Lee Joshua A. 
Published: July 2010

When the diploid cotton (Gossypium davidsonii Kell.) species, is crossed with cultivars of the tetraploid species, G. hirsutum L. and G. barbadense L., the hybrid embryos abort, or the seedlings become necrotized and moribund shortly after germination. A complementary lethality intereaction is indicated, the cultivated cottons contributing the factors Le1 and Le2, whereas G. davidsonii contributes at least one factor, Ledav.A rare genotype in G. barbadense is le1le1le2le2. Crosses between plants of this genotype and G. davidsonii yield viable triploids. Using the technique of hexaploid bridging, I transferred Ledav from G. davidsonii to the cross‐compatible stock, 15‐4. The resulting stock—genotype le1le1le2le2LedavLedav—is not cross‐compatible with a series of cultivars of G. hirsutum and G. barbadense.Utilizing the le and Ledav alleles, I produced stocks of G. hirsutum that proved to be genetically isolated from a series of G. hirsutum cultivars under both greenhouse and field conditions. The use of the le ‐ Ledav genetical system for isolating cotton cultivars grown for special purposes, such as gossypol‐free seeds, is discussed.
Description and Evaluation of a near Infrared Reflectance Spectro‐Computer for Forage and Grain Analysis1
Authors: Shenk J. S. , Landa I. , Hoover M. R. , Westerhaus M. O. 
Published: July 2010

Near infrared (NIR) reflectance has been proposed as a procedure to determine the nutritive value of forages and feedstuffs. A Neotec model 6100 scanning monochromator interfaced to a PDP‐11 minicomputer was used for this study. Instruments of this type are called spectro‐computers. Ten computer programs developed at University Park, Penn. were used to operate and test the instrument. The scanning range of the spectro‐computer was from 1,100 to 2,500 nm. Wavelength accuracy was ± 1.0nm, wavelength precision ± 0.01 nm, stray light <0.10%, and system peak to peak and root mean square noises were 0.33 × 10‐3 and 0.05 × 10‐3, respectively, expressed as log (1/R). This high level of monochromator performance permits the spectro‐computer precision to compare favorably with that of the standard laboratory procedures.Two hundred forage samples were used to test the accuracy of the spectro‐computer system. These samples represented a broad array of species and mixtures, stages of maturity, and harvest locations. Protein and in vitro dry matter disappearance were predicted best with NIR data treated as log of 1/R, resulting in standard errors of prediction of 0.96 and 3.18%, respectively. Other quality parameters were predicted better when the log (1/R) NIR data were transformed to the second derivative. They were acid detergent fiber ± 1.99%, neutral detergent fiber ± 2.27%, lignin ± 1.13%, cellulose ± 1.27%, Ca ± 0.16%, P ± 0.04%, and K ± 0.37%.Further study of the prediction of protein in 90 Canadian wheat (Triticum aestivum L.) samples resulted in a prediction error of 0.17%. We believe this spectro‐computer system is suitable for use in forage and grain analysis.
Leaf Photosynthesis, Leaf Permeability, Crop Growth, and Yield of Short Spring Wheat Genotypes Under Irrigation1
Authors: Fischer R. A. , Bidinger F. , Syme J. R. , Wall P. C. 
Published: July 2010

Because of the expected importance of photosynthetic activity to yield, the relationships of leaf photosynthetic traits to crop growth rate and yield in 48 genotypes of spring wheat, were examined under irrigation in northwest Mexico. There were three tall and 33 short (Norin 10‐derived) bread wheats (Triticum aestivum L.), eight short durum wheats (T. turgidum L.) and four triticales (X Tritosecale Wittmack). Photosynthetic activity (A) and leaf permeability viscous air flow (LP) were measured weekly using 14CO2, uptake and an air flow porometer, respectively.Genotypic effects on A (range 14.7 to 20.4 mg CO2 dm‐2 hour ‐1) and LP (range 5.7 to 11.1 permeability units) were highly significant but species effects were small and nonsignificant. Looking now exclusively at the short bread wheat group, A was unrelated to specific leaf weight or to LP. A on the first sampling at 4 weeks before anthesis and preanthesis crop growth rate (g ‐2 day‐1) were weakly correlated (phenotypic r = 0.42, significant at the 0.05 level), and both these traits were positively correlated with mature plant height (r = 0.56, significant at the 0.01 level, and 0.68, significant at the 0.05 level, respectively). A was also positively correlated with crop growth rate during grain filling (r = 0.46, significant at the 0.01 level) and with yield (r = 0.45, significant at the 0.01 level; yield range 516 to 860 g m‐2). These correlations arose because of the positive influence of days to anthesis on all three traits and probably reflect an increase in sink size (more kernels ‐z) with later anthesis. Yield was positively correlated with LP (r = 0.56, significant at the 0.01 level); the correlations remained significant (r = 0.46, significant at the 0.01 level) after allowance for the negative effect of plant height on both (LP was unrelated to anthesis date). While the cause of this correlation may be indirect, the testing of LP as an early generation selection criterion is suggested. Effects of major Norin 10 dwarfing genes on these relationships are discussed.
Recurrent Selection for Resistance to Iron Deficiency Chlorosis in Soybeans1
Authors: Prohaska K. R. , Fehr W. R. 
Published: July 2010

The objective of our study was to evaluate the use of recurrent selection by S1 testing for development of a soybean [Glycine max (L.) Merr.] population with improved resistance to iron‐deficiency chlorosis on calcareous soil. An intermated population was developed with the 10 most resistant cultivars or experimental lines and the 10 most resistant plant introductions available in 1975. Each cycle of selection required 1 year and included the growing of S0 plants in Puerto Rico during the winter to obtain 100 S1 lines, evaluation of the S1 lines for chlorosis score on calcareous soil in Iowa, selection of the 10 most resistant lines before flowering, and recombination of selected lines for the next cycle of selection. Progress from selection was evaluated by comparing the mean performance of the parents for the cycle 0, 1, and 2 populations on calcareous soil in four Iowa environments.There was a significant linear improvement in mean chlorosis score from cycle 0 to 2. The average genetic gain per cycle and year of 0.2 units was 9% of the cycle 0 mean. The highest frequency of resistant lines was from the cycle 2 parents. Genetic improvement in the population indicated that resistance to iron‐deficiency chlorosis is influenced by genes with additive effects. The results also indicated that early‐generation testing of F2‐derived or S1 lines should be effective in development of cultivars with the desired level of resistance.
Contribution of Husk Leaves to Maize Grain Yield1
Authors: Cantrell R. G. , Geadelmann J. L. 
Published: July 2010

Mechanical detasseling is a common procedure in hybrid seed production of maize (Zea mays L.) and is often accompanied by loss of leaves. No one has examined the potential of husk leaves, i.e., laminae extending from the husk, to compensate partially for leaf area lost during detasseling. We investigated the contribution of husk leaves to grain yield in three environments under normal conditions and under stress induced by partial defoliation prior to anthesis. The study involved four inbreds and two hybrids of early Corn Belt dent maize with high husk leaf area. Treatments consisted of a check, removal of the tassel plus the top two leaves prior to anthesis, and removal of all tissue above the uppermost ear prior to anthesis. Also, the husk leaves were either left intact (check) or removed when they are fully extended.Reduction in grain yield due to the removal of only the tassel and the top two leaves averaged 9.2% over all genotypes. Removal of all tissue above the uppermost ear caused an average yield loss of 50.2%. The decrease in yield due to complete husk leaf removal was significant for four of the six genotypes, and the average reduction was 2.6% (1.2 q/ha). The contribution of the husk leaves to grain yield was similar across the various detasseling treatments. Therefore, selection of seed parent inbreds for husk leaf areas similar to those we studied would not greatly offset yield reductions caused by mechanical detasseling.
Inheritance of Ineffective Nodulation and Non‐nodulation Traits in Alfalfa1
Authors: Peterson M. A. , Barnes D. K. 
Published: July 2010

Although the roots of alfalfa (Medicago sativa L.) usually form pink nodules capable of fixing atmospheric N2 when inoculated with Rhizobium meliloti Dang., one clone incapable of forming nodules (non‐nod) and five clones which produced ineffective nodules were recently discovered. These unusual nodulation traits are useful for research on root infection, nodule formation, and N2 fixation. The objectives of this study were to determine the inheritance of the non‐nodulating trait and of the ineffective nodulation in each of the five clones, to compare the genetic controls for ineffective nodulation in the five clones, and to determine the genetic relationship between ineffective nodules and non‐nodulation.The non‐nod clone and the five ineffective clones were self pollinated, crossed in a diallel mating design, and crossed to two normal effective nodulating clones. F2 and backcross seed was produced on non‐nod ✕ normal and ineffective ✕ normal crosses. F2 seed was also produced on non‐nod ✕ ineffective crosses and ineffective ✕ ineffective crosses. Progenies were evaluated under nil‐nitrate greenhouse sand culture. Six weeks after planting, non‐nod plants were small, chlorotic, and had no nodules. Plants with ineffective nodules were small, chlorotic, and had white nodules. Plants with effective nodules were vigorous, dark green, and had pink nodules. Four of the five clones had a different basis for inheritance of ineffectiveness. Three were conditioned by a single tetrasomically inherited recessive gene (in1, in2, or in3), the nulliplex genotype in each instance producing ineffective nodules. The fourth was conditioned by two recessive genes (in4 and in5), the nulliplex condition at both loci being required for production of ineffective nodules. The non‐nod trait was conditioned by two tetrasomically inherited recessive genes (nn1, and nn2). The nulliplex condition at both loci resulted in non‐nodulation. The non‐nod trait and the four different types of ineffective nodules appeared to segregate independently of one another.