bluuebunny/crossref_metadata_2025 huggingface dataset:
Bulk, Pedigree, and Early Generation Testing Breeding Methods Compared in Soybeans1
Authors: Luedders V. D. , Duclos L. A. , Matson A. L.
Published: July 2010

Soybean (Glycine max (L.) Merr.) lines selected from populations advanced by the pedigree, early generation (F4 and F5) testing, and 2 bulk methods were evaluated in the F6 and F7. Differences in the yield of these lines due to method of generation advance were not significant. However, with selection on 2‐year means and in each individual year, the complete bulk (CB) and early generation testing (EGT) methods retained a few more lines than the maturity bulk (MB) and pedigree (P) methods. Methods of generation advance were highly significant for four character‐population combinations but these appeared to occur at random except for seed quality‐maturity in population 6. This association was not unexpected because seed quality and later maturity are significantly correlated in 14 out of 24 cases. Heritability estimates ranged from 10 to 40% for yield, 29 to 88% for height, and 23 to 72% for lodging.

We suggest that plant breeders discard approximately 75% of their yield‐tested lines each year. This would permit larger populations to be evaluated and should result in the retention of more stable high‐yielding lines.
A Yield‐Related Measure of Earliness for Cotton, Gossypium Hirsutum L.1
Authors: Bilbro J. D. , Quisenberry J. E.
Published: July 2010

We propose a Production Rate Index (PRI) as a means of expressing crop maturity, or earliness for cotton (Gossypium hirsutum L.). The PRI values are judged to be generally more suitable than MMD values for earliness measures because they are yield‐related; they express a production rate (i.e., amount produced per unit time). An example is given that compares the two measures applied to actual data.
Environmental and Cultural Preconditioning Effects on the Water Use Rate of Agrostis palustris Huds., Cultivar Penncross1
Authors: Shearman R. C. , Beard J. B.
Published: July 2010

Preconditioning effects of light intensity, growing temperature, irrigation frequency, cutting height, mowing frequency, and nitrogen nutrition level on water use rate and stomatal density of ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) were investigated. Water use rates were recorded as percent moisture lost during exposure to (1) 33 C, (2) 40% relative humidity, (3) lux light intensity, and (4) a constant airflow of 186 sec−1 in a special wind tunnel apparatus. Stomatal density counts were made at 430X from nitrocellulose replications of the leaf surface.

The preconditioning effects of cutting height, light intensity, and nitrogen nutrition level had the greatest influence on water use rate. Irrigation and mowing frequency were intermediate in their influence. Growing temperature had the least effect among the factors considered.

Stomatal density was influenced most by light intensity, and growing temperature had the next greatest effect. Irrigation frequency had an intermediate effect. Nitrogen nutrition level had the least influence of the factors studied. Water use rate was positively correlated (r = 0.88) to stomatal density in the light intensity study. However, it was negatively correlated (r = −0.98) to stomatal density for the nitrogen nutrition level study. No significant correlations were observed for growing temperature or irrigation frequency.
High Lysine Mutant Gene (hl that Improves Protein Quality and Biological Value of Grain Sorghum1
Authors: Singh Rameshwar , Axtell John D.
Published: July 2010

Seeds from over 9,000 lines in the world sorghum [Sorghum bicolor (L.) Moench] collection were classified for endosperm phenotype to identify floury endosperm lines and evaluate each for potential increases in lysine concentration. Sixty‐two floury endosperm lines were selected and analyzed for protein and lysine composition. Two floury lines of Ethiopian origin, IS 11167 and IS 11758, were exceptionally high in lysine at relatively high levels of protein.

The average whole grain lysine concentration of high lysine lines IS 11167 and IS 11758 was 3.34 and 3.13 (g/100g protein) at 15.7 and 17.2% protein, respectively. Both lines were also high in percent oil. Carbohydrate analyses of whole grain samples of the two high lysine lines were similar to that of normal sorghum grain except for a twofold increase in sucrose concentration.

The high lysine gene altered the amino acid pattern in hl hl hl endosperm tissue relative to normal endosperm checks. The major changes were increased lysine, arginine, aspartic acid, glycine, and tryptophan concentrations and decreased amounts of glutamic acid, proline, alanine, and leucine in the hl hl hl endosperm.

Inheritance studies suggest that the increased lysine concentration of each line is controlled by a single recessive gene, although it is not known whether the genes from both lines are allelic. The high lysine gene(s) present in IS 11167 and IS 11758 from Ethiopia is (are) herein designated as hl. The endosperm of kernels homozygous for the hl gene is partially dented.

The biological value of the high lysine lines was much higher than that of average sorghum lines. In a 28‐day isonitrogenous feeding experiment the weight gain of weanling rats was three times higher on an IS 11758 ration and twice as high on an IS 11167 ration as weight gains on rations prepared from normal sorghum lines. When fed rations without any dilution except the usual 2% vitamin and 4% mineral supplementation, rats gained 94 g on high lysine sorghum (IS 11758) and 28.5 g on our current best nutritional quality sorghum line (IS 2319), versus 91.5 g on opaque‐2 corn (Zea mays L.) and 30.2 g on normal corn in a 28‐day feeding trial. Feed efficiency ratios for this trial were 3.0 for high lysine sorghum, 6.8 for IS 2319, 3.4 for opaque‐2 corn, and 7.4 for normal corn.
Persistence of Several Temperate Grasses Grown with Alfalfa and Harvested Two, Three, or Four Times Annually at Two Stubble Heights1
Authors: Smith Dale , Jacques A. V. A. , Balasko J. A.
Published: July 2010

Six grass species were established in 1968 in rows within a seeding of alfalfa (Medicago sativa L.) at Arlington, Wisconsin. The mixtures were harvested two, three, or four times annually at two stubble heights, 4 and 10 cm, during 1969 and 1970. Alfalfa was eliminated by spraying with a selective herbicide during autumn of 1970. Grasses were then evaluated for stand persistence and dry matter yields during the first growth of 1971.

Orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.), and meadow foxtail (Alopecurus pratensis L.) persisted well with alfalfa under all cutting schedules and stubble heights. Tall rescue (Festuca arundinacea Schreb.) was nearly eliminated by cutting twice at the short stubble height, but persisted well in other treatments. Stands of timothy (Phleum pratense L.) and bromegrass (Bromus inermis Leyss.) were affected most by the cutting practices. Stands of both grasses were reduced more by three than four cuts annually and were significantly lower with both cutting schedules at the short than at tall stubble height; stands were nearly eliminated with three cuts at the short stubble height. With two cuts annually, cutting height had no significant effect on stand persistence, but timothy stands were poor at both stubble heights.

Survival of the grasses as related to stage of development at time of cutting and to tillering pattern is discussed, especially with regard to their persistence with alfalfa under the three‐cutting schedule used widely in the northern Great Lakes States. Of the grasses studied, orchardgrass and reed canarygrass showed wide adaptability to all cutting practices used and were most amenable for use in mixture with alfalfa harvested three times annually.
Grass Seedling Response to Wind and Windblown Sand1
Authors: Fryrear D. W. , Stubbendieck J. , McCully W. G.
Published: July 2010

Rangeland grasses are difficult to establish on sandy soils because blowing sand can kill young seedlings. Four grass species, sideoats grama [Bouteloua curtipendula (Michx.) Torr.], cane bluestem [Bothriochloa barbinodis (Lag.) Herter], green sprangletop [Leptochloa dubia (H.B.K.) Nees], and sand bluestem (Andropogon hallii Hack.) were grown in a greenhouse and subjected to wind and wind with sand in a laboratory wind tunnel. The blowing sand killed the seedlings or retarded their growth, but wind alone had little influence. With increasing age, the young grass plants became more tolerant to wind and sand damage. Plant growth was slowed because the blowing sand ruptured plant cells, dried out the exposed tissue, and exposed the damaged seedlings to diseases and insects.
Genetic and Environmental Variation of Seed Yield, Yield Components, and Seed Protein Quantity and Quality of Cowpea1
Authors: Bliss F. A. , Barker L. N. , Franckowiak J. D. , Hall T. C.
Published: July 2010

Pure line cultivars of cowpea (Vigna unguiculata (L.) Walp.) were grown in the field at Ile‐Ife, Nigeria, and the biotron and greenhouse at Madison, Wis., in both short‐ and long‐day environments to study yield, yield components, percent protein, and amino acid content of the mature seeds. Seeds/pod, 50‐seed wt, and methionine content demonstrated medium to high broad sense heritability and the other traits were medium to low. Genotypic variance components for 50‐seed wt, seeds/pod, percent protein, mg of methionine/g of flour and g of methionine/l00g of protein, and genotype ✕ location components for 50‐seed wt and percent protein were statistically significant and large enough to be of practical importance. Genotypic and phenotypic correlations of yield with 50‐seed wt were high and positive, whereas those for yield with percent protein, yield with methionine content, and 50‐seed wt with tryptophan content were negative and relatively high. ‘Producer,’ which is high in percent protein and yield, is a promising parent in crosses with Nigerian local cultivars
Resistance to the Sorghum Midge in Converted Exotic Sorghum Cultivars1
Authors: Johnson J. W. , Rosenow D. T. , Teetes G. L.
Published: July 2010

Sixty sorghum (Sorghum bicolor (L.) Moench) lines selected from the sorghum conversion program were evaluated for midge (Contarinia sorghicola (Coquillett)) damage. Selections from IS 12612C, IS 12666C, and IS 2508C sustained the least damage (<20%), and several other lines also had significantly less damage than the 60 to 100% damage sustained by U.S. cultivars. The implications are that resistance to midge exists among some converted cultivars from the world sorghum collection.
Evaluation of Crosses Among High and Low Yielding Parents of Spring Wheat (Triticum aestivum L.) and Bulk Prediction of Line Performance1
Authors: Busch R. H. , Janke J. C. , Frohberg R. C.
Published: July 2010

Twenty‐five populations resulting from crosses among four high and four low yielding parents of hard red spring wheat (Triticum aestivum L.) were evaluated in three environments. The F4 bulks, F5 bulks, parents, and 21 randomly selected F2‐derived F5 (1970) and F6 (1971) lines from each cross were used to evaluate the performance of crosses between high yielding parents (high ✕ high), high and low yielding parents (high ✕ low), and low yielding parents (low ✕ low). The bulks were included to determine if average cross performance and high yielding individual lines could be predicted. The high ✕ high, high ✕ low, and low ✕ low crosses averaged 343, 321, and 293 g/plot, respectively. The highest yielding line was from a high ✕ low cross, but the highest frequency of lines which yielded two standard deviation units above the experimental mean was obtained from the high ✕ high crosses. The average cross performance of the lines and average of the highest five lines were correlated with the mean of the F4 and F5 bulks, r =.90 and r = .88, respectively. Selection of crosses with high yielding lines and higher frequency of desirable lines was possible in this group of crosses by yield testing the advanced bulk generations.
Inheritance of Indole Alkaloids in Reed Canarygrass (Phalaris arundinacea L.). I. Heritability Estimates for Alkaloid Concentration1
Authors: Barker R. E. , Hovin A. W.
Published: July 2010

Our objectives were to estimate genotypic and environmental variances and heritability of indole alkaloid concentration in reed canarygrass (Phalaris arundinacea L.) The variance component estimates for genotype ✕ environment and genotype ✕ cutting interactions were significant but small as compared to the estimate for genetic variance among 31 unrelated clones of diverse origin. Genotype ✕ environment ✕ replication in environments interactions were statistically nonsignificant. Thus, variation in alkaloid concentration was largely associated with genotypes.

Heritability studies included 36 clones and their 18 two‐clone crosses grown at 2 locations. Heritability estimates from the second cutting were higher than corresponding estimates from the third cutting. Combining data from two regrowth cuttings in one season reduced the bias introduced as a result of sampling the forage at different growth stages. When based on parents in the 0.17 to 1.37% overall alkaloid concentration range, realized heritability estimates for the combined August and September cuttings ranged from 0.67 to 0.72. All heritability estimates were slightly higher for the high alkaloid concentration range compared to estimates for the low range. Narrow‐sense heritability estimates were nearly as large as the corresponding broad‐sense estimates; thus, total genetic variance was largely additive. Parent‐offspring regression analyses of identical materials confirmed this conclusion. Our results suggest that genetic gain in alkaloid concentration can be realized from selection among individual plants.
Effect of Genetic Sampling Technique on Variation Within Populations Derived by Crossing, Selfing, or Random‐Mating Other Populations1
Authors: Hammond J. J. , Gardner C. O.
Published: July 2010

Methods of sampling to form genetic populations used in the Gardner‐Eberhart model for the diallel cross and related populations vary considerably. Sometimes the same plants are used to form the selfed progeny, the random‐mated progeny, and the crosses in order to save nursery space. The purpose of this research was to use computer simulation to generate genetic populations according to some different sampling methods currently in use and to examine the effect of sampling techniques on means and genetic variation.

Methods of sampling did not affect the means but they did affect the variances. Sampling with replacement (using a plant more than once) increases the within population genetic variation of variety crosses, crosses selfed, and crosses random‐mated. The amount of bias is inversely related to sample size. Adjustment for the bias was possible by utilizing expected number of parental individuals.

Conclusions reached are: 1) plants should be used only once as a male or female, 2) each kind of population should be developed from an independent set of parents, and 3) a balanced composite of seed with equal numbers from each female parent should be used rather than bulk seed. The sample size of parents affects the precision of means estimated for progenies. Twenty to 30 plants are believed to be reasonably adequate to represent a segregating population.
Use of Anther‐Derived Haploids in Nicotiana. I. Isolation of Breeding Lines Differing in Total Alkaloid Content1
Authors: Collins G. B. , Legg Paul D. , Kasperbauer M. J.
Published: July 2010

A large population of haploid Nicotiana tabacum plants was obtained from the F1 hybrid ‘LA Burley 21’ ✕ ‘Burley 21’ using an anther culture technique. LA Burley 21 is homoyzgous recessive (aabb) for total alkaloid content, and Burley 21 is homozygous dominant (AABB). Haploid genotypes for alkaloid content included AB, Ab, aB, and ab, obtained from the diploid F1 hybrid of genotype AaBb. The haploid plants were verified cytologically, and individual haploids were chromosomally doubled by either root or leaf in vitro tissue culture procedures to recover the four homozygous doubled haploid forms. The two parental genotypes (AABB and aabb) and the low‐intermediate (aaBB) and high‐intermediate (AAbb) genotypes were evaluated for stability and compared with conventionally derived alkaloid lines. Haploid plants were extracted from doubled haploid genotypes to obtain additional evidence on stability of anther‐derived haploids. The haploids and their derivatives behave as stable true‐breeding genotypes. The evidence presented supports the hypothesis that two major genes control total alkaloid production in burley tobacco. The feasibility of using the anther‐derived haploid technique for the development of tobacco breeding lines is demonstrated.
Selecting Alfalfa Seedlings to Resist the Potato Leafhopper1
Authors: Sorensen Edgar L. , Horber Ernst
Published: July 2010

We subjected three alfalfa (Medicago sativa L.) synthetics to two cycles of recurrent phenotypic seedling selection for resistance to the potato leafhopper [Empoasca fabae (Harris)] in growth chambers. Resistance, based on seedling survival after infestation, was increased by cyclic selection. Resistance to leafhopper yellowing in the field increased directly with cycles of seedling selection in each synthetic. Spring growth and plant vigor were increased in each synthetic. However, actual forage yield declined in one synthetic, did not change in a second, and increased in a third, indicating the importance of field testing in conjunction with laboratory screening.
Effect of Within‐Pod Competion on the Weight of Selfed Seed in Alfalfa (Medicago Sativa L.)1
Authors: Pedersen M. W.
Published: July 2010

The weight of selfed alfalfa seeds (Medicago sativa L.) in pods containing seeds produced by both self‐ and cross‐pollinations was compared with the weight of selfed seeds in pods containing only self‐pollinated seed. Selfed and crossed seeds were individually weighed, grown to the seedling stage, and classified for hypocotyl color. Recessive white‐flowered plants were used as females, so that crossed seeds could be identified by colored hypocotyls. The difference in weight of the selfed seed with and without crossed‐seed competition was nonsignificant. The difference between the weight of crossed and selfed seed was 7 to 10%.
Reaction of Orchardgrass Cultivars to Purple Leafspot Caused by Stagonospora arenaria1
Authors: Zeiders K. E. , Sherwood R. T. , Berg C. C.
Published: July 2010

Twenty‐eight cultivars of orchardgrass (Dactylis glomerata L.) were screened for their reaction to a single isolate of Stagonospora arenaria Sacc. in two inoculation tests. On a scale of 1 (no disease) to 8 (very severe), the overall disease means of cultivars ranged from 3.97 to 5.90. There were significant differences in disease reaction among cultivar means. There was a highly significant correlation (r = 0.82) for disease means between the two inoculations. Although none of the cultivars were highly resistant to purple leafspot, cultivars varied widely in numbers of individual plants that were judged to be resistant on the basis of their low disease ratings. Plants selected for low ratings were compared with randomly selected plants within each cultivar in a third inoculation. Within each cultivar, the mean rating of the selected group was lower than the random group, thus confirming the resistance of selected plants. The best plants are being intercrossed in an attempt to develop lines of orchardgrass with resistance to purple leafspot.
Herbicide Effects on Corn Lipids1
Authors: Penner Donald , Meggitt William F.
Published: July 2010

The effect of herbicides on corn (Zea mays L.) kernel oil percentage and fatty acid composition was determined for 30 herbicide treatments involving 10 herbicides. None of the preplant‐incorporated, preemergence‐, or postemergence‐applied treatments affected corn kernel oil percentage or fatty acid composition. Adjuvants and herbicide combination also were without effect. Failure to control weeds also did not alter the total oil percentage or the fatty acid composition of the corn kernel.
Genotypic Responses in Sorghum to Drought Stress. I. Response to Soil Moisture Stress1
Authors: Blum A.
Published: July 2010

This study evaluated the variability within cultivated sorghums (Sorghum bicolor (L.) Moench.) in some physiological responses to water stress imposed by limited supply of soil moisture in the field.

In 1971 and 1972, 14 and 12 sorghum genotypes were planted, respectively. Water was supplied exclusively by stored soil moisture. During the growing season, periodic determinations were made of leaf water potential, leaf diffusion resistance, and (1972 only) amount of soil moisture.

The most drought susceptible genotypes was ‘Shallu’ which under increasing soil moisture stress had relatively low leaf water potential, high leaf diffusion resistance, and the lowest total soil moisture extraction. ‘Combine Kafir‐60’ and ‘RS 610’ hybrid had, under stress, comparatively high leaf water potential and low leaf diffusion resistance, and were therefore regarded as “drought avoidant.” ‘Feterita’ had the greatest amount of soil moisture extraction, which was associated with very low leaf water potential, but relatively low leaf diffusion resistance. ‘Durra’ also had low leaf diffusion resistance in spite of reduced leaf water potential.

Genotypes differed significantly by nearly 20% in the amounts of stored soil moisture extracted. Appreciable intergenotypic differences also were revealed in the amount of soil moisture extracted prior to heading as determined by percent of the total at maturity.
Effect of Temperature on the Rate of Soybean Hypocotyl Elongation and Field Emergence1
Authors: Hatfield J. L. , Egli D. B.
Published: July 2010

Rate of hypocotyl elongation of ‘Cutler’ and ‘Lee 68’ soybean (Glycine max (L.) Merr.) cultivars was measured at several temperatures and incorporated into a prediction model for initial soybean growth. The rate of hypocotyl elongation was found to be a function of temperature and the length of the hypocotyl. Hypocotyl elongation was extremely slow at 10 C, and the seed did not germinate at 40 C. The rate of hypocotyl elongation reached a maximum at approximately 30 C and increased with increasing hypocotyl length for both cultivars. Elongation rates of Lee 68 were consistently higher than those of Cutler. Prediction equations were developed from the data and used to predict the hours to 50% emergence as a function of soil temperature and depth of planting. These equations provided a reliable estimate of emergence times for each cultivar when compared with the actual data under a range of soil temperature conditions in the field and in the laboratory. Theoretical results from the equations indicated that the optimum time to plant soybeans so that emergence would occur in the least amount, of time was when the soil temperature was in the range of 25 to 35 C, provided no other factors were limiting emergence.
Morpho‐developmental Factors Related to Winter Survival of Wheat. I. Association of Characteristics of Dark Grown Seedlings and Winter Survival1
Authors: Ashraf M. , Taylor G. Allan
Published: July 2010

We examined the relationship between morpho‐developmental characteristics and winter wheat (Triticum afstivum L.) survival utilizing six diverse cultivars planted at five depths in a darkened controlled environment chamber.

Cultivars and planting depths differed significantly for coleoptile length, emergence rate index (ERI), seedling height, and subcrown internode length. The cultivar ✕ depth interaction was significant only for ERI. ‘Froid,’ ‘Yogo,’ and ‘Crest’ had long coleoptiles, high ERI's, and tall seedlings. MT6928, ‘Cheyenne,’ and ‘Itana’ had short coleoptiles, low ERI's, and short seedlings. Froid and Yogo developed the shallowest crown nodes followed by Itana, MT6928, Cheyenne, and Crest in that order.

A significant correlation was noted between coleoptile length and ERI, but not between coleoptile length and mature plant height. Crest, a short cultivar, possesses long coleoptiles and rapid emergence, and should be a useful germplasm source for developing other short winter wheats with these characteristics.

The significant positive correlation (.86*) of subcrown internode length with field winter survival suggests that long subcrown internode lengths (or shallow crowns) are associated with higher levels of winter survival. The determination of long subcrown internode cultivars should be an effective winter survival selection method in winter wheat breeding programs developing cultivars for environments similar to those of Montana.
Effect of Temperature Treatments on Combining Ability for Seed Set in Alfalfa1
Authors: Dane Fenny , Haaland Ronald , Lentner Marvin , Melton Bill
Published: July 2010

Five selected clones of alfalfa (Medicago sativa L.) were crossed in a diallel fashion under four temperature treatments with and without emasculation. Data for seeds per flower were analyzed to determine combining ability components and the interactions across the different temperature treatments.

General combining ability (GCA) was of more importance in determining seed set than specfic combining ability (SCA) across all temperatures. Differences in reciprocal crosses were significant at all temperatures.

Significant interactions for GCA, SCA, and reciprocal effects across temperatures frequently occurred. This indicated that these components of combining ability for seed set were not stable across environments.

Differences due to temperature or emasculation effects were larger in clones with high self‐ and cross‐compatibility ratings than those with low ratings.
Variation Among Soybean Cultivars in Seed Growth Rate During the Linear Phase of Seed Growth1
Authors: Kaplan S. L. , Koller H. R.
Published: July 2010

This investigation tested the hypothesis that differences can exist among soybean [Glycine max (L.) Merr.] cultivars in the accumulation rate of seed dry matter during the linear phase of seed growth. At West Lafayette, Ind., in 1971, the fruit of ‘Harosoy 63,’ ‘Beeson,’ ‘Calland,’ and ‘Kent’ cultivars was harvested at weekly or more frequent intervals from replicated, 1‐m row lengths. Sampling extended from soon after anthesis until past maturity. Seeds were separated from subsamples of the dried fruit. Growth rate of the seed component during the linear phase of seed growth was estimated by regressing seed weight on days from planting after eliminating nonlinear data. Seed numbers were also determined for three of the harvests.

Contrary to results of an earlier study, seed growth rates differed significantly at the 5% level during the linear growth phase from 7.94 to 9.80 g m−2 day−1. Seed numbers did not differ significantly among the cultivars, indicating that the individual seeds had different mean growth rates among the cultivars.
Estimations of Protein and Oil Concentration in Corn, Soybean, and Oat Seed by Near‐Infrared Light Reflectance1
Authors: Hymowitz T. , Dudley J. W. , Collins F. I. , Brown C. M.
Published: July 2010

Simultaneous estimations of protein and oil concentrations in corn (Zea mays L.), soybean (Glycine max (L.) Merrill), and oat (Arena sativa L.) seed meals, made by a near‐infrared light reflectance instrument coupled to an analog computer (grain analyzer), were compared to protein and oil determinations by Kjeldahl and nuclear magnetic resonance (NMR), respectively. Multiple correlations between Kjeldahl protein and grain analyzer values obtained when calibrating the grain analyzer were .994, .996, and .982 for corn, soybeans, and oats, respectively. Similar correlations between NMR oil determinations and the grain analyzer for corn, soybeans, and oats were .993, .992, and .990, respectively. Correlations between the grain analyzer and Kjeldahl protein and between grain analyzer and NMR oil determinations using independent samples were all greater than .91.

At no time were the meal samples analyzed by the grain analyzer weighed. Since moisture content may influence reflectance values, the moisture content of the samples was maintained within a narrow range.

The grain analyzer is extremely simple to operate, requires a minimum of laboratory space, and is nonpolluting. Approximately 50 samples per hour can be run on the grain analyzer, excluding grinding time.
Tillering, Nonstructural Carbohydrates, and Survival Relationships in Alfalfa1
Authors: Chatterton N. J. , Carlson G. E. , Hart R. H. , Hungerford W. E.
Published: July 2010

We attempted to assess the relationships of nonstructural carbohydrates and tillering with survival and productivity by identifying alfalfa (Medicago sativa L.) clones that were tolerant and others that were intolerant of frequent harvests and then comparing their response patterns. Vegetatively propagated alfalfa was grown in the field and subjected to three cutting frequencies during its second year. In autumn of 1972 when the season of cutting was completed, the plants were classified as having low, intermediate, or high tolerance to frequent cutting on the basis of survival. Plants were harvested and their roots removed from the soil. They were classified as tillering if elongated crown buds were present, and as nontillering if no elongation of crown buds were evident.

Root and crown dry weight and total nonstructural carbohydrates (TNC) content (g/plant) of the fall‐harvested plants decreased from low‐ to high‐cutting tolerance plants, but the reverse was true for TNC concentration. The patterns were the same for both tillering and nontillering plants, but in each classification, the values were 25 to 50% greater for tillering than for nontillering plants. The differences in root and crown dry weight were associated with differences in TNC content.

After the field investigation, the same clones were grown in a greenhouse. Root and crown tissues of greenhouse‐cultured plants classified as frequent (those surviving frequent cutting) attained a high percent TNC soon after cutting. Clones that did not survive the frequent field cuttings (low and intermediate tolerance to frequent cutting) did not increase in crown TNC percentage in the greenhouse until flower development (or tiller initiation) had begun. Survival and production of alfalfa may be improved by selecting genotypes that produce new tillers early in the regrowth cycle.
Effects of Inbreeding by Selfing and Full‐sib Mating In a Maize Population1
Authors: Cornelius P. L. , Dudley J. W.
Published: July 2010

Random noninbred full‐sib families (generation 1) out of diploid Syn. O.P., [composite of 36 open‐pollinated maize (Zea mays L.] varieties were inbred on an ear‐to‐row basis through 7 generations of sib‐mating (SBF2 to SBF8) and 4 generations of selfing (SLF2 to SLF5) evaluate the effects of inbreeding and the correlations between generations. Generations 1, SBF2, SBF3, SBF4, SLF2 and SLF3 of 60 families were studied in 1970 and all 12 generations of 42 families in 1971. Characters studied were grain yield, plant height, ear height, percent moisture at harvest, percent oil, and kernel weight.

All characters except percent moisture showed significant inbreeding depression. Inbreeding depression, when significant, was linearly related to coefficient of inbreeding (F), except for percent oil, which showed significant quadratic effects. The linear rate of inbreeding depression for plant height, ear height, and grain yield was greater under selling than under sib‐mating. Generation SBF4 was significantly higher in grain yield than SLF2 (both with F = 0.5) in 1970. Significant generation ✕ family interactions were found for all characters.

Genetic correlations between generations were lower for characters that showed greater inbreeding depression and were lowest for yield. Correlations of generation 1 means with estimates of regression on level of homozygosity in partially inbred generations were generally negative, but significant only for ear height. Correlations of generation 1 means with predicted means of homozygous lines suggest that selection among noninbred families should result in a response in the desired direction in homozygous lines ultimately to be obtained. For yield, however, these correlations were so low that they indicated that yield of noninbred families is of little value as a predictor either of rate of inbreeding depression or of yield of homozygous lines (as lines) ultimately obtained.
Monogenic Resistance to Verticillium Wilt in Sunflowers1
Authors: Fick G. N. , Zimmer D. E.
Published: July 2010

Sunflower (Helianthus annuus L.) inbred lines ‘HA 89,’ ‘HA 124,’ and ‘P‐21 VRI’ and their Fl hybrids were highly resistant to Verticillium wilt under field conditions. Segregation ratios from testcross and F2 populations indicated the presence of a single dominant gene for resistance in each line. Intercrosses among the resistant lines showed that the same gene conditioned resistance in the three lines.
Control of Reed Canarygrass Seedlings in Culm Propagules of Reed Canarygrass1
Authors: Roslansky D. R. , Marten G. C. , Behrens R.
Published: July 2010

Vegetative increase of homozygous reed canarygrass (Phalaris arundlnacea L.) from individual clones by means of culm node propagules is feasible and desirable, but ripe seed heads accompanying chopped culms often lead to seedling contamination of the stands.

We conducted one trial to establish the extent of contamination from seedlings when culm propagation is used and three trials to determine whether some herbicides can eliminate reed canarygrass seedlings without damage to culm propagule growth.

We confirmed that seedlings contaminate when clones are propagated from culms.

Seven herbicides were evaluated for reed eanarygrass seedling control and for culm propagule tolerance. Chloramben (3‐amino‐2,5‐dichlorobenzoic acid), EPTC (S‐ethyl dipropylthiocarbamate), dinoseb (2‐sec‐butyl‐4,6‐dinitrophenol), trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐ρ‐toluidine), and paraquat (l,l’‐dimethyl‐4,4’‐bipyridinium ion) did not prove satisfactory in meeting the objective. These herbicides either did not eliminate sufficient numbers of seedlngs, or they killed the culm propagules. Propachlor ((2‐chloro‐N‐isopropyl‐acetanilide) applied at 3.36 or 4.48 kg/ha provided considerable seedling control without killing culm propagules. Alachlor [2‐chloro‐2’,6’‐diethyl‐N‐(methoxymethyl)acetanilide], applied at 3.36 kg/ha, was the most effective herbicide for reducing seedling contamination without significantly affecting culm propagule growth.
Higher Fatty Acid Content of Perennial Grasses as Affected by Species and by Nitrogen and Potassium Fertilization1
Authors: Barta A. L.
Published: July 2010

Levels of higher chain fatty acids (HFA) in grass herbage may be an important factor in incidence of hypomagnesaemia. The objectives of this study were to determine HFA content of six cool season grasses3 and to investigate the effect of N and K fertilization on HFA content of grasses.

HFA content was determined for Bromus inermis L., Dactylis glomerata L., Festuca arundinacea Shreb., Poa pratensis L., Phleum pratense L. and Phalaris arundinacea L. The range in mean HFA among species was small 03.0 to 14.8 meq/100 g dry wt.). Only Kentucky bluegrass had significantly lower HFA than the mean of all species. Its mean N concentration was also the lowest.

Mean HFA content increased 25% in orchardgrass and 46% in bromegrass with 112 kg/ha N fertilization. Potassium fertilization up to 403 kg/ha had no effect on HFA content.

High correlations (r ≥.89, significant at the 1% level) were found between HFA and N concentration for the six species and for bromegrass and orchardgrass in the N fertility experiment. Regression coefficients for predicting HFA concentration from herbage N concentration compared closely to the regression coefficient determined on mixed herbages in New Zealand.

Nitrogen source (NO3‐N vs NH4‐N) did not differentially influence HFA content of perennial ryegrass (Lolium perenne L.) grown in nutrient culture when 28 to 56 mg N/liter of solution were used. Low NO3‐N (1.6 mg N/ liter) shoots had a greatly reduced HFA and N concentration. Level of HFA in ryegrass roots was not significantly influenced by either N rate or form, although N in roots varied from 1.35% to over 5%. This contrast between roots and tops implies that the concentration of N per se in a tissue does not always determine HFA accumulation. The data support the hypothesis that the relationship between N and HFA concentration in grasses may be mediated by photosynthesis.
Inheritance of Reaction to Race 4 of Soybean‐cyst Nematode1
Authors: Thomas J. D. , Caviness C. E. , Riggs R. D. , Hartwig E. E.
Published: July 2010

Five soybean (Glycine max L. Merr.) crosses involving parents that differed in reaction to race 4 of soybean‐cyst nematode (SCN) (Heterodera glycines Ichinohe) were studied in F1, F2, and backcross populations. Reaction of the parents to race 4 was: PI 88788, resistant; PI 90763, moderately resistant; ‘Peking,’ susceptible; ‘Mack’ and ‘Hill,’ very susceptible.

Frequency distributions from three crosses involving parents that were resistant, moderately resistant, and susceptible indicated that three alleles at a single locus conditioned reaction to SCN. Resistance possessed by PI 88788 was recessive to PI 90763 and the moderately resistant reaction of PI 90763 was recessive to the suceptible Peking cultivar. Backcross data also appeared to confirm this inheritance pattern. Segregation in the F2 generation gave a good fit for a ratio of three resistant and 61 susceptible plants from two crosses; Hill ✕ PI 90763 and Mack ✕ PI 90763 which involved very susceptible and moderately resistant parents. This ratio indicated one dominant and two recessive genes conditioned resistance in these crosses. Apparently two additional loci with two alleles at each locus, also are necessary for resistance to race 4.
Exclusive Preferential Transmission of an Alien Chromosome in Common Wheat1
Authors: Maan S. S.
Published: July 2010

Aegilops longissima S. & M. and Ae. sharonenis Eig were crossed with Triticum dicoccum Schrank ‘Khapli’ pollen, and F1 hybrids were crossed several times with T. aestivum L. em. Thell. pollen to substitute the T. aestivum nucleus into the cytoplasm of these Aegilops species. Partially male and female‐sterile plants having a monosomic substitution (20″+2′) or a monosomic addition (21″+1′) were obtained from these nuclear‐substitution backcrosses. These plants had normal anther extrusion, abundant pollen, and incomplete scattered seed set on bagged or crossed heads, and the reciprocal cross with euploid T. aestivum as a female gave complete seed set. Euploid, 21” plants were not obtained from crosses in either direction, most offspring having again 20″+2′ or 20″+1′, and having abundant pollen but partial seed set on bagged heads. All the selfed progeny of plants with a monosomic substitution or monosomic addition had a disomic substitution or disomic addition, respectively, and were fertile. Evidently, male and female gametes with one Aegilops chromosome were functional, and those without the Aegilops chromosome did not function.

There was thus an apparent gametocidal action of the sporophyte having an Aegilops chromosome, on the gametes lacking this chromosome. Occasionally malesterile euploid T. aestivum plants with Ae. sharonensis cytoplasm were obtained as a result of rare functional female gametes without the critical Ae. sharonensis chromosome.
Effects of Years, Planting Arrangements, and Methods of Pollination on Combining Ability for Seed Set of Alfalfa1
Authors: Haaland Ron , Dane Fenny , Lentner Marvin , Melton Bill
Published: July 2010

Five selected alfalfa (Medicago sativa L.) clones were crossed in diallel manner to determine the effects of environmental factors on combining ability for seed set. General combining ability (CCA) was more important than specific combining (SCA) or reciprocal effects in determining seed set in these crosses. Significant interactions for CCA occurred with years (age of plants), planting arrangements in seed production and methods of pollination. SCA was significant in 2 of the 3 years, in both planting arrangements and in crosses pollinated by honeybees (Apis mellifera L.) and hand crosses made without emasculation. The only significant interaction involving SCA was with years (age of plants). Reciprocal effects were significant in 2 of the 3 years, in both planting arrangements and in hand crosses made without emasculation. Significant interactions for reciprocal effects occurred with years, crossing arrangements, and in comparing honeybee pollinated crosses with hand crosses produced without emasculation.

Results show that crossing environments can influence estimates of combining ability for seed set. It was also suggested that factors other than incompatibility of clones can influence SCA and reciprocal differences.
Relationship of Hydroxamic Acid Content in Maize and Resistance to Northern Corn Leaf Blight1
Authors: Long B. J. , Dunn G. M. , Routley D. G.
Published: July 2010

A cyclic hydroxamate (2,4‐dihydroxy‐7‐methoxy‐l,4‐benzoxazin‐3‐one; DIMBOA) recently has been implicated in the resistance of maize (Zea mays L.) to fungi and insects. In our study, a set of 13 inbreds was used to determine the relationship of concentrations of DIMBOA and resistance to northern corn leaf blight (Helminthosporium turcicum Pass).

DIMBOA concentration was estimated by the colorimettic procedure of Hamilton in plants 60 to 75 cm in height. Mean concentrations of DIMBOA ranged from 0.06 mg/g to 0.66 mg/g fresh weight. Percent leaf infection on plants at the same height ranged from 7.41 to 19.04%. A significant correlation (r =−0.61) was obtained between these two traits.

DIMBOA concentrations also were determined in root, stem, and whorl tissues from five selected inbreds at various stages of growth. At 13‐cm plant height, samples from the inbreds contained uniformly high amounts of DIMBOA. The earliest acceptable separation of high and low DIMBOA lines was obtained using stem or whorl tissue from seedlings 35 to 40 cm in height. Generally those lines highest in DIMBOA at 35 to 40 cm plant height were correspondingly high in DIMBOA at the silking stage. Similarly, lines low in DIMBOA at 35 to 40‐cm plant height were low in DIMBOA at the silking stage.
Postulation of Genes for Stem Rust Resistance in the Entries of the Fourth International Winter Wheat Performance Nursery1
Authors: McVey D. V. , Roelfs A. P.
Published: July 2010

The presence of genes for resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) in wheat (Triticum aestivum L. em Thell.) was detected in entries of the 4th International Winter Wheat Performance Nursery by use of 18 isolates of rust previously characterized for virulence on 12 genes.

Several varieties appeared to have one or two genes in common3. The test isolates detected no genes for resistance in ‘Blueboy,’ ‘Starke,’ ‘Jyva,’ and Vakka.’ Based on this procedure, Sr 9b, 9e, 10,11, 13, and Tt‐1 were not detected in any of the entries. While some varieties possessed other genes for stem rust resistance than those studied4.
Heterosis and Combining Ability in Exotic Soybean Germplasm1
Authors: Paschal E. H. , Wilcox J. R.
Published: July 2010

The objectives of this study were to determine the magnitude of heterosis for yield, its components, and other agronomic characters and to determine the relative importance of general combining ability (GCA) and specific combining ability (SCA) in spaced plants soybean [Glycine max (L.) Merr.] hybrids with both adapted cultivars and exotic strains as parents.

The experiment, conducted at West Lafayette, Ind. in 1971 and 1972, used a partial diallel mating design with 12 parents. There were three parents from each of the following origins; locally adapted cultivars or strains, Manchurian, Chinese, and Korean. Thirty different F1 combinations were produced and, along with their parents, planted in a randomized, complete block design.

Heterosis for yield was greater than that for any other character with a high‐parent value of 8.0% averaged over both years. Twelve of the 30 hybrids outyielded the midparent. Number of pods/plant was the most heterotic of the yield components. Number of seeds/pod and seed size of the Fl's was with few exceptions, intermediate to parental values, as were maturity, height, lodging, and harvest index. Heterosis for plant weight was similar to that for yield, both in magnitude and in the hybrids expressing it.

Significant GCA effects were found for all characters. SCA effects were significant for seed size, maturity, and height. The years × GCA interaction was significant for yield, number of pods/plant, maturity, lodging score, plant weight, and harvest index. Years × SCA were significant for ntunber of seeds/pod, maturity, lodging, and harvest index.
Compensating Ability of Awns in Soft Red Winter Wheat1
Authors: Patterson F. L. , Ohm H. W.
Published: July 2010

Seven families of soft red winter wheat (Triticum aestivum L.) lines were compared for yield, kernel weight, and test weight. Each family consisted of two lines, nearly isogenic, except for awns vs. awnlets. The families of lines (F3BC6 sibs) were developed by backcrosslng to ‘Vermillion’ and by selection. Treatments consisting of flag leaf removal at anthesis, leaf rust, and leaf rust plus stem rust were imposed on the lines.

Leaf rust, leaf rust plus stem rust, and removal of the flag leaf, each greatly reduced yield, test weight, and kernel weight within a given year and had a much greater effect on these characteristics than did the presence or absence of awns. However, due to the large year × leaf‐removal interaction effect, the leaf‐removal treatment was not statistically significant when analyzed over years

Awnedli nes yielded as well as or higher than their awnleted isolines in each of the experiments. Awns appeared to have a more consistent advantage for kernel weight than for yield but compensated little for removal of the flag leaf or its impaired function by rust as compared with the awnless condition. Awned types showed the greatest advantage under severe rust conditions.
Heritability of Nitrate Reductase and Cyanide Levels in Seedlings of Grain Sorghum Cultivars1
Authors: Eck H. V. , Gilmore E. C. , Ferguson D. B. , Wilson G. C.
Published: July 2010

Seedlings of 41 cultivars of grain sorghum [Sorghum bicolor (L.) Moench] including 30 hybrids and all but two of their parents were grown in a growth chamber; harvested 10, 14, and 18 days after planting; and assayed for hydrolizable cyanide and in vitro and in vivo nitrate reductase activity (NRA). The genotype X age variance component was essentially equal to the genetic variance for each character, which suggest that genotype X environment interactions are major components of the phenotypic variance. Cyanide level was highest in 10‐day‐old plants and dropped sharply in 14‐day‐old plants. Broadsense heritability of hydrolizable cyanide was high (0.89 to 0.95) for all three ages of plants. Narrow‐sense heritability indicated the cyanide content of 10‐day‐old plants could be changed 0.76 units for each unit change in the midparental value, but expected progress decreased markedly for 18‐day‐old plants. Broad‐sense heritability of in vitro NRA was high at all ages, and narrow‐sense heritability was moderate to low. Thus, significant genetic advance could be expected from selection among pure lines and hybrids, but nonadditive genetic variance would reduce progress in hybrids based on selection of their parents to a moderate level. In vivo NRA was only 20% of in vitro activity. Heritabilities, in general, also were lower for in vivo than for in vitro NRA.
Linkage of the Genes SBM and WLO in Peas1
Authors: Gritton E. T. , Hagedorn D. J.
Published: July 2010

Linkage between the Pisum gene sbm (conditioning resistance to the pea seed‐borne mosaic virus) and wlo (conditioning deposition of wax on pea leaflets) was studied in the F2 generation. No crossovers were detected in four crosses, involving 323 plants, but two were found in a fifth cross, involving 398 plants. The combined data from all crosses gave a crossover value of 11.95%, indicating that sbm is in Pisum linkage group VI.