bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Nutritional Value of Wheat and Triticale As Evaluated by Weanling Mice Bioassay1
Authors: Ulmer R. L. , Mattern P. J. , Johnson V. A. , Kies C.
Published: July 2010

Experimental lines and cultivars of winter wheat (Triticum aestivum L.) and an experimental line of winter triticale (Χ Triticosecale), differing in the protein content of their grain, were subjected to mouse bioassay. Feeding efficiency ratios (FER) were computed from feed consumption and weight gain data from mice, fed diets containing equal amounts of grain of the test cultivars. Protein efficiency ratios (PER) were determined from weight gain and protein consumption data from mice fed diets containing equal amounts of protein from the test cultivars.

Lower percentages of wheat protein in the diets tended to reduce mouse weight gains and increase FER values. Test cultivars with the highest lysine/unit protein produced the highest PER values. The triticale line with high protein and higher lysine/unit protein than the wheat cultivars generally produced higher mouse weight gains and more favorable FER and PER values.
Studies on Male Sterility in Barley Induced by Sodium 1‐(p‐Chlorophenyl) 1,2‐Dihydro‐4,‐6‐Dimethyl‐2‐Oxonicotinate1
Authors: Wang R. C. , Lund Steve
Published: July 2010

Foliar sprays with various rates of an aqueous solution of sodium 1‐(p‐chlorophenyl) 1,2‐dihydro‐4,6‐dimethyl‐2‐ oxonicotinate (RH‐531) were applied to barley (Hordeum vulgate L.) plants at different stages of growth to find the optimum application time and dosage for induction of complete male sterility. Under greenhouse conditions, 1.5 kg/ha a.i. of RH‐531 applied several days before meiosis in pollen mother cells (about six.leaf stage or 20 days before heading) induced complete male sterility. At least 19% female fertility was present on RH‐531. induced male‐sterile ‘Barsoy’ plants, estimated by natural pollination. Female fertility of RH‐531.induced malesterile ‘Larker’ barley was 40% of the control when both were hand pollinated.

Meiosis in pollen mother cells did not appear to be affected by RH‐531. Paraffin sections of anthers from RH‐531‐induced lnale‐sterile barley revealed abnormal persistence of the tapetum. Acetocarmine was inferior to iodine‐potassium iodide (IKI) and Alexander's multiple stain for determining pollen viability in RH‐531‐ treated barley plants. Staining of pollen grains with IKI suggested that pollen sterility induced by RH‐531 was related to an absence of or a decrease in carbohydrates.

Positive correlations were found between percentage seed‐set of bagged spikes and anther length, and between percentage seed‐set of bagged spikes and pollen grain carbohydrate content. It appeared that RH‐531 inhibited anther growth thus leading to either degeneration of microspores or reduction in carbohydrates in pollen grains.
Endosperm Structure of High Lysine Sorghum1
Authors: Sullins R. D. , Rooney L. W. , Rosenow D. T.
Published: July 2010

Scanning electron micrographs showed that high lysine sorghum [Sorghum bicolor (L.) Moench] endosperm contains fewer and smaller protein bodies than normal sorghum endosperm. This Indicates that an alteration in protein synthesis had occurred in the endosperm of higher lysine sorghums. Improved lysine content resulted because these protein bodies contain mainly alcohol soluble proteins, which are very deficient in basic amino acid content. The marked reduction in protein bodies suggests the change in endosperm protein synthesis was significant and that it may be possible to isolate plump kernels with fewer protein bodies and higher lysine content. The potential use of scanning electron microscopy as a nondestructive tool to select sorghums with plump kernels and high lysine content should be explored.
‘Cougar’ Kentucky Bluegrass Seed Production as Affected by Clipping to Stimulate Grazing1
Authors: Evans David W.
Published: July 2010

This study was conducted to determine the seed production responses of ‘Cougar’ Kentucky bluegrass (Poa pratensis L.) to clipping at different times from early fall through late panicle branching at the onset of panicle elevation in the spring. Treatments were repeated for 3 years. The bluegrass was grown in rows, sprinkler irrigated, and fertilized as needed to maintain high levels of N, P, and K.

Some clipping treatments increased seed yields; none decreased yields. Late fall and the onset of panicle development were the two best times for defoliation. Clipping in late fall markedly increased panicle numbers, decreased weight of seed/panicle, and increased seed yield. Clipping at the onset of panicle development in the spring slightly increased panicle numbers and seed yields without materially reducing the weight of seed/panicle.

Two clippings produced significantly more Iorage than most single clippings, but not more than one clipping in late fall, apparently because little vegetative growth occurred between late fall and late panicle branching.

Defoliation in late fall or early spring prior to secondary panicle branching offers the possibility not only of providing forage but of increasing subsequent seed yield through increased panicle production.
Inheritance of Leaflet Size and Specific Leaf Weight in Alfalfa1
Authors: Song S. P. , Walton P. D.
Published: July 2010

The combining abilities for leaflet size and specific leaf weight (SLW) were determined at two different stages of growth in a 7 ✕ 7 diallel cross population of alfalfa (Medicago sativa L.). Both characters were heritable since the general combining ability was larger than either the specific combining ability or the reciprocal effects. Greater genetic variance was observed at an early bud stage than at a late bloom stage. Large differences in SLW were obtained only at an early bud stage. Leaflet size and SLW were not correlated. Genotypes that combined larger leaflet size and higher SLW were identified. Thus both traits would respond to selection in a plant breeding program. The correlation of these characters with forage yield was generally poor.
Maternal Effects in Maize Hybrids Infected with Bipolaris maydis (Nisikado) Shoemaker, Race T1
Authors: Hallauer Arnel R. , Martinson C. A.
Published: July 2010

The entry sums of squares for the diallel analysis of 72 maize (Zea mays L.) hybrids produced reciprocally in normal (Nrf) and T‐ cytoplasm (TRf) inbred lines partitioned into the general (GCA) and specific (SCA) combining ability, maternal, and reciprocal sources of variation. The 144 hybrids were evaluated for 2 years under artificial infection with Bipolaris maydis (Nisikado) Shoemaker (Helminthosporium maydis, Nisikado) race T, inoculum. Data were collected for stand, root and stalk lodging, dropped ears, days to silk, B. maydis race T ratings, yield, and grain moisture. The differences among entries for root lodging and dropped ears were not significant (P > 0.05) and were not included further analyses. Separate diallel analyses were made for the Nrf and TRf hybrids.

Significant maternal mean squares were detected for all traits except stand. There were three instances of significant reciprocal mean squares. Although the maternal mean squares were significant for all traits except stand, the proportion of the entry sum of squares attributable to maternal effects was less than for GCA and SCA. The maternal ✕ year interaction mean square was not significant in any instance. There were 16 instances of significant maternal effects for hybrids produced on Nrf females and 21 for hybrids produced on TRf females. The hybrid Oh43 had the greatest frequency, nine, of significant maternal effects, and B45 the least, one. Most of the significant maternal effects, however, were not large.
Effect of Ethrel on Sterility in Triticale1
Authors: Nelson L. R.
Published: July 2010

Triticale cultivars were treated with Ethrel (2‐chloroethylphosphonic acid) under greenhouse and field conditions to study the potential of Ethrel to induce sterility. The greenhouse study involved three cultivars (‘Tifton Exp. 8641,’ ‘Fas‐gro 203,’ and ‘Fas‐gro 205’) treated at five chemical rates (0, 500, 1,000, 2,000, and 3,000 ppm) and at two growth stages (mid‐boot and early heading). Spikes were bagged to prevent cross‐pollination. Significant differences in the number of seeds/spike were observed for chemical rate and for date of application. The highest degree of sterility was observed in Tifton Exp. 8641 treated in the boot stage at 3,000 ppm where a mean of two seed/spike was present. Complete sterility was not obtained. The higher rates of Ethrel delayed pollination and reduced plant height of all cultivars. Field applications of Ethrel at rates of 0, 500, 1,000, 1,500, and 2,000 ppm in 1972 and 0, 1.12, and 2.24 kg/ha in 1973 caused no apparent sterility. Bagging of spikes significantly reduced the number of seeds/spike.
Tissue Culture of a Tobacco Albino Mutant1
Authors: Schaeffer G. W. , Menser H. A.
Published: July 2010

This report describes the survival and successful in vitro culture of albino tobacco tissues normally lethal during seedling development. The culture of the lethal homozygous tissue requires a complete tissue culture medium supplemented with auxins of the indole‐3‐acetic acid type. In vitro the tissue of the albino phenotype grows as rapidly under low light or in the dark as tissues of the normal green type.
Breeding Potentials of Noncultivated Cottons. I. Some Agronomic and Fiber Properties of Selected Parents and Their F1 Hybrids1
Authors: Wilson F. D. , Wilson R. L.
Published: July 2010

Using a complete diallel set, we analyzed 12 agronomic and fiber characters in five cottons (Gossypium hirsutum L.), and their F1 hybrids. Two of these were adapted cultivars, and the remainder were Texas race stocks. The cultivars were early and productive at Phoenix, whereas the three race stocks varied widely in earliness, lint characteristics, fruit size, growth habit, and other agronomic characters under consideration. Narrow sense heritability estimates for the 12 characters ranged from 0.04 for date of first flower to 1.29 for 2.5% fiber span length. Estimates of general combining ability were significant for number of bolls/plot, peduncle length, and five fiber traits. Thus, selection for these characters should be effective.

Nonadditive variance was significant for nine of the 12 characters measured, and comprised the majority of the genetic variance for three of these nine characters. There were no significant maternal effects. Reciprocal effects were significant for a few character/hybrid combinations. Fifteen of the possible 120 character/hybrid combinations showed specific heterosis. Eleven were positive, three negative, and one that may be neutral in the sense of agronomic fitness. Mean heterosis (F1 vs. midparent) was significant only for date of first flower.
Influence of Cotton Genotypes on Floral Visits of Honey Bees1
Authors: Moffett Joseph O. , Stith Lee S. , Burkhardt Chris C. , Shipman Charles W.
Published: July 2010

Cotton genotypes (Gossypium spp.) were studied for their floral attractiveness to honey bees (Apis mellifera L.) in Pima County, Ariz. The genotypes varied greatly in floral attractiveness, but differences tended to be consistent.

Genotypes containing at least some cytoplasm from species other than G. hirsutum L. were generally more attractive than normal lines developed from G. hirsutum. The most attractive genotypes were three late blooming tetraploids developed from crosses involving G. arboreum L., G. thurberi Todaro, and G. hirsutum. A purple‐flowered hexaploid developed from an ‘Acala 44‐10‐1’ ✕ G. sturtianum Willis cross also ranked high in attractiveness.

None of the genotypes of cytoplasms studied were sufficiently attractive to overcome the mid‐season drop in bee visits that occurs in southern Arizona. Some of the more attractive genotypes may be used in hybridization programs to increase the floral attractiveness of the parental A, B, and R‐lines that will be used to produce hybrid cotton seed.
Leaf Conductance and Leaf Water Status of Sesame Strains in Hot, Dry Climates1
Authors: Hall A. E. , Yermanos D. M.
Published: July 2010

Leaf conductance to water vapor loss was examined as a potential physiological index of yield potential in hot, dry climates. Differences in leaf conductance were observed between some strains of Sesamum indicum L. that were consistent from day to day, in irrigated field environments. Generally, plants with dehiscent capsules had higher leaf conductances and more negative xylem pressure potentials than non‐dehiscent plants. These larger leaf water deficits were probably caused by faster transpiration rates that would result from higher leaf conductances in hot, dry weather.
Use of Triploid Males for Increasing Hop Yields1
Authors: Haunold Alfred
Published: July 2010

Hand pollination of receptive flowers of six diploid cultivars of hop (Humulus lupulus L.) increased cone size by 7 to 24%, regardless of ploidy level of the pollen parent. In 1973, cone weights, which directly affect yield, increased an average of 46% when female flowers had been pollinated from diploid males and 17% upon pollination from triploid males. Bracts plus bracteoles increased an average of 23% over the untreated control from the diploid pollination treatment, and 11% from the triploid pollination treatment. Pollination had the most striking effect on strig length and strig weight, but little effect on number of nodes/strig. Seeds from the triploid pollination treatment averaged less than half the weight of the open‐pollinated control and contained 60 to 83% aborted embryos, whereas seeds from the diploid pollination treatment contained only 18%. Well‐filled seeds were purple, and usually weighed three to four times as much as tan seeds. Seeds resulting from the triploid pollination treatment had about 25% less crude fat than seeds of the control.

Hop yields in seedless production areas probably can be increased significantly without additional production costs (except for harvesting a larger crop) by use of pollen from triploid males to stimulate cone size and weight. Such cones look like seeded cones, but contain only about one‐fourth as many seeds as those pollinated by comparable diploid males. They will probably mature earlier and tend to shatter, as do seeded cones. Replacing diploid by triploid males in presently seeded hop yards will probably decrease yields slightly from lack of seeds. This decrease will probably be offset by the premium received for a seedless crop.
The Crested Wheatgrasses of Iran1
Authors: Dewey D. R. , Asay K. H.
Published: July 2010

More than 200 collections of crested wheatgrass, Agropyron cristatum (L.) Gaertn., from Iran were studied with respect to geographic origin, cytology, morphology, and fertility. In Iran, crested wheatgrasses are found primarily in the Alborz mountain range at latitudes north of 35° and at elevations between 600 and 3,400 m.

Iranian crested wheatgrasses occur at three ploidy levels — 2n=14, 28, and 42. Tetraploids are the most common, and they are found throughout the entire distribution area. Hexaploid populations occur only in the Azerbaijan province in northwestern Iran. Only one diploid collection, from Mt. Sabalan in northwestern Iran, is known. The polyploid races behave cytologically as autoploids. Heterozygous chromosome interchanges are common in the tetraploids, and aneuploidy is uncommon.

Significant variation in maturity, height, texture, rhizome development, fertility, and seed size occurs between and within populations. More than half of the collections are rhizomatous. Breeders may be able to incorporate the rhizmnatous habit into strains for use on sites where stand establishment is difficult or where solid ground cover is important.

All Iranian crested wheatgrass collections are broadspiked types, identified by North American agrostologists as A. cristatum. Although this usage differs from that of some European and Asian authors, a change in nomenclature is not recommended until the biological and taxonomic relations among all crested wheatgrasses are clarified.
Laboratory Technique for Bleaching Pea Seeds1
Authors: Riehle W. G. , Muelbauer F. J.
Published: July 2010

Conditions for bleaching pea (Pisum sativum L.) seeds in the laboratory were studied to find a method of identifying bleach‐resistant selections in the early stages of a breeding program. Among the genotypes used, differential seed bleaching without germination was obtained when 4.2 g pea seed (about 25 seeds) was placed on five sheets of Whatman no. 1 filter paper in 9‐cm petri dishes and moistened with 6 ml water. The petri dishes were then placed in a growth chamber at 23 C with 8.6 klux of continuous light. After 8 days, the seed coats were removed, and the cotyledons were scored on a scale from 0 for no bleaching to 4 for complete bleaching. The technique was highly correlated (r = 0.78**, df = 27) with seed bleaching occurring in the field and should therefore be useful for early generation testing of green, dry‐edible pea selections.
Aflatoxins in Cottonseed as Affected by the Pink Bollworm
Authors: McMeans J. L. , Brown C. M.
Published: July 2010

Pink bollworm [Pectinophora gossypiella (Saunders)] larval exit holes increased infection by Aspergillus flavus Link and aflatoxin accumulation in seed from all zones of the cotton plant (Gossypium hirsutum L.). The average aflatoxin level in seed from the bottom, middle, and top zones of the plant was at least 1,000 times greater in 1970, when the pink bollworm was common, than in 1965 when the insect was absent. In order to determine total aflatoxins in cottonseed from pink bollworm infested areas, it becomes necessary to harvest seed from the entire plant as infection by A. flavus and aflatoxin accumulation are no longer limited to the bottom third of the plant. Control of the pink bollworm will be necessary if the aflatoxin problem is to be minimized.
Effect of Temparature and Dormancy on Germination of Tall Fescue1
Authors: Boyce K. G. , Cole D. F. , Chilcote D. O.
Published: July 2010

The effects of alternation and duration of temperature levels on the germination of dormant and nondormant seed of tall fescue (Festuca arundinacea Schreb ‘Fawn’) were evaluated. Dormancy induction and temperature preconditioning of dormant seed were also studied.

Dormancy was greater in seed matured at 15 C compared to that matured at 26.6 C. The expression of dormancy was also more pronounced at a higher germination temperature (26.6 C).

Temperature preconditioning of dorma nt fescue seed was important in relieving dormancy; germination response was essentially confined to imbibing temperatures of ≥ 15 C. Preconditioning time was important and 48 days at 1 C, 24 or 48 days at 5 C, and 24 days at 10 C gave near maximum germination response.

Germination of dormant and nondormant seed was influenced differentially by level and alternation of temperature and by the amplitude of temperature fluctuation. For nondormant seed, constant temperature at 20 to 25 C was optimum. For dormant seed, alternating temperatures were more favorable, and the optimum regime was 8 hours at 20 to 25 C and 16 hours at 10 to 15 C with the range of response to temperature being more restricted than for nondormant seed. Germination response of dormant seed diminished as the time period at the higher temperature increased.

The germination responses of dormant seed observed in this study indicate that at least two physiological phenomena may be involved. The thennogradient response could be a combination of the effects of temperature on the germination processes, per se, and on the metabolic and/or physical processes involved in dormancy. In nondormant seed, only the rate and extent of germination was affected by the temperature regime.
Inheritance of High Lysine in Maize1
Authors: Choe Bong‐Ho , Zubér M. S. , Krause G. F. , Hilderbrand E. S.
Published: July 2010

Two maize (Zea mays L.) families with high and two with low lysine were selected from the first cycle of Zuber and Helm's recurrent selection experiment in Logan County Composite. Plants from these four families were selfed and crossed to opaque‐2.

The level of lysine from the high and low families was transmitted to the testcross F1's and to both the normal and opaque phenotypes of the F2 populations. The results indicate that two genetic systems are involved in lysine synthesis, one associated with the opaque‐2 gene per se and the second operating independently of opaque‐2. Several of the opaque phenotypes from the F2's involving the high‐lysine parents had more lysine than the opaque‐ 2 parents. The two genetic systems appeared to complement each other in an additive manner.

Although the selection criterion in the recurrent selection for high lysine was only lysine content on a whole kernel basis, the protein level for the'high‐lysine families and their crosses was higher than that for the low‐lysine families. Thus recurrent selection for high lysine resulted in higher levels of protein.
Relationship in Protein Concentration between Whole Oats and Oat Groats1
Authors: Youngs V. L. , Senturia Jerome
Published: July 2010

We tested the feasibility of predicting protein concentration in either whole oats or oat groats if protein in one is known. Kjeldahl protein was determined on the whole oats and in the corresponding oat groats of 18 cultivars, most of which were grown at three U.S. locations over 2 years (105 samples). The regression equation was = 0.81 + 1.27 PO, where = predicted oat groat and PO = whole oat protein concentrations. Correlation between observed whole oat and oat groat protein was 0.98 significant at the 1% level of significance. The 95% confidence interval for predicting individual values of oat groat protein included a range of values falling within ±1.9 percentage points of the regression line, . The regression equation was tested with 12 additional groups of samples (311 samples) grown under less homogeneous experimental conditions. The mean square error of all samples compared to was 0.98. Oat groat kernel weight and groat yield were also determined for all samples. Correlations between these quality characteristics and groat protein concentration were very low.
Top and Root Growth of Irrigated and Nonirrigated Soybeans1
Authors: Mayaki W. C. , Teare I. D. , Stone L. R.
Published: July 2010

Root depth and distribution in the field were correlated with easily measurable above‐ground morphological paranfeters of soybeans (Glycine max L. Merr. ‘Williams’) at specific physiological stages. Previous research on soybean rooting depth and distribution was conducted with pots or field soil containing a barrier limiting full expression of root development. Other studies sampled a limited numberof times in a barrier free soil.

We investigated soybean root depth and distribution under irrigated and nonirrigated conditions in a deep barrier‐free Muir silt loam soll profile. Irrigated plots received a total of 28 cm of water in three furrow applications. We measured plant height and dry weight, root depth, root distribution, and leaf area index each time roots were sampled. Each soil increment sampled (75 cm wide, 7.5 on thick, and in 15 cm increments to the 180 cm depth) was soaked and roots washed free of soil using a 35‐mesh screen. We used neutron moderation and gravimetric sampling to obtain soil water measurements.

Soybean roots reached the 160 cm depth in both irrigated and nonirrigated plots. Root depth increased faster than plant height. At physiological maturity, 67% of the soybeans' root dry matter was in the 0–15 cm layer and 89% in the 0‐90 cm layer of the irrigated soil compared with 51% in the 0‐15 cm layer and 83% in the 0–90 can layer of nonirrigated soil.

A quick estimate of rooting depth after six node stage (V3) in nonirrigated soybeans, based on our work, would be twice the top height. With irrigated soybeans, root depth would be twice top height from V3 until pod development began (R5.5) and 1.4 ✕ top height thereafter. The coefficient of determination (R2) for root depth vs. plant height was 0.994 and 0.987 for irrigated and nonirrigated soybeans, respectively.
Heritability of Soluble Proteins in Alfalfa1
Authors: Gutek L. H. , Goplen B. P. , Howarth R. E.
Published: July 2010

This study was conducted to assess the feasibility of breeding alfalfa cultivars with low soluble protein concentrations as a means of reducing the bloat‐causing potential of alfalfa (Medicago sativa L.). Narrow‐sense heritability estimates were obtained for soluble fraction I, fraction II, and total soluble protein concentrations in alfalfa. Heritability estimates (h2) were based on the parent‐offspring regression method using data from 32 unselected clones and their open‐pollination progenies.

The h2 estimates for the soluble proteins for 1972 and 1973 were as follows: soluble fraction I (19 and 20%), soluble fraction II (19 and 27%), total soluble protein (23 and 31%). These relatively low heritability estimates indicate that it should be possible to lower the soluble protein content of alfalfa by consecutive cycles of recurrent selection procedures involving well‐replicated progeny tests.
Sequential Trait Development and Breeding for High Yields in Safflower1
Authors: Abel G. H. , Driscoll M. F.
Published: July 2010

The development of the sequential traits of seed yield (heads/area, seeds/head, and seed wt) of safflower, Carthamus tinctorius L., and the breeding for high and low yield were studied. The original data for each of the three traits were standardized by two transformations and compared.

Of the sequential traits, genotype had a large effect on seed wt and smaller effects on seeds/head and heads/ area. Location effects were generally highly significant for each trait; dates of planting were less important.

The sequential traits show independence in a correlation analysis. Together the traits account for 97% of the variation in yield, with head numbers and seeds in the head accounting for most of the variation. For each trait separately, seed wt accounts for most of the variation in yield, followed by seeds/head and head numbers. Standardized partial regression coefficients indicate that for selection, one should give more weight to head numbers and seeds/head when all these traits are considered simultaneously and to head numbers when one trait is considered at a time.

In general, head numbers or seeds/head or both traits could be responsible for high yielding lines. Seed wt was generally inflexible in different environments, but heads/ area and seeds/head were more flexible. Line A1186‐1 was among the five highest yielding lines in nearly all locations and for all planting dates, indicating the highest adaptation to the range of environments in the experiments.
Hybrid Wheat seed Production Methods for North Dakota1
Authors: Miller J. F. , Lucken K. A.
Published: July 2010

A North Dakota male fertility restorer, R5 (Triticum zhukovskyi Men. & Er./3* T. aestivum L. em ThelL ‘Justin’), and several male‐sterile wheat lines (T. aestivum with T. timopheevi (Zhuk.) Zhuk. cytoplasm) were planted in a systematic arrangement of alternate drill strips to evaluate hybrid wheat seed production. Approximate ratios of 1:1, 2:1, and 3:1 of male sterile to restorer were tested over several environments from 1972‐1974. Drillstrip widths of the male sterile ranged from 3.1 to 11.0 m. Overall mean yields of hybrid seed were 13.7, 10.0, and 8.4 quintals/ha for the 1:1, 2:1, and 3:1 ratios, respectively. A production unit concept was used to compare the efficiencies of the three different ratios from a commercial perspective. Actual yields of hybrid seed from a production ha were 6.9, 6.7, and 6.3 quintals for the 1:I, 2:1, and 3:I ratios, respectively.

Narrowing the drill.strip width of male‐sterile and restorer parents within the 1:1 or 2:1 ratios from 3.1:3.1 m to 1.5:1.5 m or from 6.1:3.1 m to 3.1:1.5 m did not increase yields of hybrid seed. Therefore, adequate hybrid seed production can be accomplished with machinery (2.1 to 3.7 m/drill section) currently used on North Dakota farms.

The growing degree day technique was used to determine timing of planting dates between a male sterile and its maintainer for proper synchronization of maximum pollination of the male line and optimal floret opening of the female line. In 2 years of study, higher yields were obtained with the projected 44 C growing degree day difference than with 0, 22, or 66 growing degree day differences.

Hybrid seed production yields were highly correlated with restorer yields over several environments indicating that hybrid seed production would be most successful in high yielding production regions. Decreases in hybrid seed yields at low yielding environments were due to environmental factors affecting yield and pollination potential of both parents. The low yields of the restorer, especially in adverse environments, were attributed to its low vigor and poor adaptability. Consequently, successful hybrid seed production is dependent on availability of high yield environments and on stable, high yielding, adapted parents.
Response to Inbreeding in Alfalfa Populations Derived from Single Clones1
Authors: Hill R. R.
Published: July 2010

Spring growth and plant heights at each of three harvest times in each of 2 years were studied in progenies from three clones each in ‘MSA‐W4’ and ‘MSB‐W4’ alfalfa (Medicago sativa L.). The generations from five of the clones were S0, S1, S1‐SYN‐1, S3, and S3‐SYN‐1. One of the clones from MSB‐W4 had the S4‐SYN‐1 generation, but not the S1‐SYN‐1. The data were analyzed by multiple regression on the coefficients of inbreeding, by Gallais's genetic model, and by a newly developed genetic model for autotetraploid populations.

Except for first harvest height in MSB‐W4, additive and digenic genetic effects were responsible for more than half the total genetic variation among and within families. Trigenic or quadrigenic effects for individual families were frequently significant, but significant average trigenic or quadrigenic effects were rare. Deviations from neither genetic model were significant, but better fits were obtained with my model and regression on the coefficients of inbreeding than with Gallais's model.

Large differences due to parental clone were observed in the response to inbreeding—two clones showed almost no response and others were drastically reduced in vigor by the S3 or S3‐SYN‐1 generations. The frequent presence of an inbred generation with greater vigor than a less inbred, previous generation was attributed to unavoidable selection during development of the inbred progenies.
Genetic Variability for Cottonseed Germination at Favorable and Low Temperatures1
Authors: Buxton D. R. , Sprenger P. J.
Published: July 2010

Many plant breeders are concerned with developing cotton (Gossypium hirsutum L. and G. barbadense L.) lines that are adapted for germination and seedling emergence when soil temperatures are low. Seedlings, however, should emerge rapidly over a range of soil temperatures. Little information is available about the association between rapid seedling emergence at favorable and low temperatures. To evaluate this relationship for a broad base of genetic lines, seeds of 18 G. barbadense and 12 G. hirsutum lines of diverse genetic background were germinated in six experiments at 15 and 25 C. Significant differences in germination properties were found among the genotypes and the temperature ✕ genotype interaction was generally significant. Correlation coefficients for germination parameters of the genotypes at the two temperatures were generally positive but small in magnitude. Germination properties of the cotton lines were associated with geographical area where developed. Generally lines developed for low elevations had better germination properties at both 15 and 25 C than did lines developed for high elevations. The results of this study suggest that potential exists for developing cotton lines with improved germination at low temperatures. Because of the poor correlation between germination at low and favorable temperatures, cotton lines should be evaluated under both conditions.
Effect of Increasing Morphological Component Expression on Yield in Corn1
Authors: Kuhn W. E. , Stucker R. E.
Published: July 2010

A backcross‐conversion program was utilized to increase expression of number of ears/plant, ear length, and kernel depth in five corn (Zea mays L.) inbreds. Four versions (normal, deep‐kerneled, long‐eared, and multiple‐eared) of the inbreds were evaluated as lines per se and in single‐crosses in separate experiments at Waseca and Lamberton, Minnesota in 1973. Yield component expression was greater in the converted lines than in their normal counterparts, but direct responses to conversion varied significantly for different inbred backgrounds. Correlated responses for the two unselected morphological components and three agronomic traits occurred in the lines themselves.

Single‐crosses involving converted lines were higher yielding than singlecrosses of normal lines. However, this yield advantage occurred primarily in the lower yielding single‐cross backgrounds (low yielding normal ✕ normal crosses). Single‐crosses involving multiple‐ear and deepkernel lines had the highest and lowest yields, respectively, relative to the normal ✕ normal control.
Leaf‐feeding Resistance to Bollworm and Tobacco Budworm in Three Soybean Plant Introductions1
Authors: Hatchett J. H. , Beland G. L. , Hartwig E. E.
Published: July 2010

Three plant introductions (PI 171451, PI 227687, and PI 229358) of soybean [Glycine max (L.) Merr.] having resistance to the Mexican bean beetle [Epilachna variveslis Mulsant] were evaluated in the laboratory for leaffeeding resistance (antibiosis) to the bollworm [Heliothis zea (Boddie)] and tobacco budworm [H. virescens (Fabricius)]. Five commercial cultivars were used for comparison. Criteria for antibiosis were larval mortality, larval and pupal weights, and duration of larval stage. All three plant introductions were resistant to both species. Among larvae fed on the plant introductions, mortality was greater than among larvae fed on the commercial cultivars, weight gains of larvae were reduced and time to pupation was greater. On the basis of percentage of larval mortality, PI 171451 and PI 229358 were more resistant to the bollworm than to the tobacco budworm; PI 227687 was equally resistant to both species. None of the larvae of either species survived on PI 227687, which suggests that this plant introduction may have a different genetic basis for resistance.
Photosynthetic Efficiency of Alfalfa with Increasing Potassium Nutrition1
Authors: Wolf D. D. , Kimbrough E. L. , Blaser R. E.
Published: July 2010

Potassium concentration in alfalfa (Medicago sativa L.) herbage has been used to indicate sufficient levels to attain maximum dry matter productions. Since photosynthesis is the source of dry matter, the relationships of potassium concentration to CO2 exchange rate (CER) was studied in an attempt to find an optimum level. Several soil K rates were applied to four alfalfa plant populations. CER measurements were made for single leaves and canopies of alfalfa during early vegetative growth. CER increase due to added increments of K could be camouflaged by differential growth rates of canopies and mutual shading of leaves that result from increased fertility. The confounding was avoided by adjusting CER to similar leaf area index values across K rates.

CER increased 22% as the K concentration in prebud herbage increased by 133% (1.62 to 3.77). A herbage K concentration of about 2.0% resulted in 90% of maximum observed CER. K concentration of 2.0% for prebud herbage relates to a concentration of 1.3% for one‐tenth bloom herbage. The CER and K concentrations of individual young and old leaves increased with added soil K increments. High K rates prolonged CER as leaves aged. These data indicate a lower critical K percentage for maximum CER than is reported in literature for maximum yields; thus, other growth processes may be more limiting by low K concentrations than photosynthesis. Plant development, plant part sampled, leafiness, and geographic locality may influence the K sufficiency concentration.
Effect of Nonpollination of First or Second Ears of Nonprolific and Prolific Maize Hybrids1
Authors: Prior C. L. , Russell W. A.
Published: July 2010

Three types of maize (Zea mays L.) single‐cross hybrids were compared for flexibility to transfer grain development between first and second ears when pollination was prevented on one of the ears. The three types, with seven crosses/type, were: nonprolific, prolific, and elite‐prolific. When pollination of the first ear was prevented, grain production of second ears was increased, but yield losses relative to the controls were: nonprolific (85.5%), prolific (39.4%), and elite‐prolific (27.5%). When pollination of the second ear was prevented, yield changes relative to the controls were: nonprolific (+1.4%), prolific (−13.5%), and elite‐prolific (−10.2%). Evidently, flexibility was much greater in the prolifics than the nonprolifics, but considerable variation was observed among hybrids of a type.
Improved Soybean Growth in Urea with pH Buffered by a Carboxy Resin1
Authors: Lahav E. , Harper J. E. , Hageman R. H.
Published: July 2010

An improved nutrient culture technique has been devised for producing vigorous soybean [Glycine max (L.) Merr.] plants with urea as the only source of N. Of the sources of reduced‐N tested, (urea, amides, and ammonium salts of citrate, malate, fumarate, succinate, and sulfate), urea caused the least amount of plant injury. However, seedlings grew less when cultured with urea than with nitrate. The rapid decline of solution pH was likely responsible for the limited plant growth with the reduced N sources. Adjusting the solution pH daily did not alter the injurious effects. Addition of the Ca form of a carbpxy resin (Amberlite IR.C‐50, 50 g/liter) to the urea nutrient medium stabilized the pH and permitted plant growth equivalent to that of nitrate grown seedlings. In the presence of resin, plant growth with urea was superior to that with ammonium salts [e.g., (NH4)2SO4].

Growth of soybeans and wheat (Triticum aestivum L.)was equivalent with urea (in the presence of resin) and nitrate while growth of peas (Pisium sativum) and velvet leaf (Abutilon theophrasti) was less with urea than with nitrate. All species grown on urea contained low amounts of nitrate (about 10% of nitrate grown controls) indicating that some interconversion of urea to nitrate occurs, although no nitrate was detectable in the nutrient solutions. In vivo nitrate reductase activity was low [less than 0.21 /μmoles NO2 (g fresh wt‐hour)−1] with all species while in vitro activity ranged from 68% (soybean) to 11% (peas) of the activity of respective nitrate‐grown controls.
Nonstructural Carbohydrate in the Spring Herbage of Temperate Grasses1
Authors: Jung G. A. , Kocher R. E. , Gross C. F. , Berg C. C. , Bennett O. L.
Published: July 2010

Nonstructural carbohydrates are sources of readily available energy that enhance rumen microbial activity and forage utilization. Experiments were conducted in Pennsylvania and West Virginia to determine the effect of maturity on total nonstructural carbohydrate (TNC) concentrations in spring herbage of eight grass species and determine TNC concentrations in herbage at immature and mature growth stages on a given day. The grasses were fertilized early each spring and summer with 0, 60, 120, or 240 kg N/ha.

Determinations for TNC were made using the Smith takadiastase technique. Mean TNC concentration in the spring herbage of ‘Masshardy’ orchardgrass (Dactylis glomerata L.), ‘Climax’ timothy (Phleum pratense L.), and ‘Sac’ smooth bromegrass (Bromus inermis Leyss.) decreased seven or more percentage units with maturation from vegetative to full bloom stage, but decreased less than four percentage units in ‘Fawn’ tall fescue (Festuca arundinacea Schreb.), ‘Kenblue’ Kentucky bluegrass (Poa pratensis L.), and redtop (Agrostis alba L.). Mean TNC concentration was 50% higher in ‘Pennfine’ perennial ryegrass (Lolinm perenne L.) than in Kenblue Kentucky bluegrass or redtop. Concentration of TNC was inversely related to maximum air and soil temperatures and was affected much more by harvest date than by maturation of the herbage. Concentration of TNC was usually lower in N‐fertilized herbage than in unfertilized controls at early growth stages, but N had little effect on TNC concentration of herbage at full bloom.

Maximum yields of TNC were obtained at the stem elongation stage with ryegrass, at flower‐head emergence with Pennmead orchardgrass and ‘Ky. 31’ tall rescue, and at full bloom with other grasses. N fertilization increased TNC yield of orchardgrass, tall rescue, and reed canarygrass; decreased TNC yield of smooth bromegrass and redtop; and had little effect on TNC yield of ryegrass and timothy.
Tolerance of Soybean Cultivars to Manganese Toxicity1
Authors: Heenan D. P. , Carter O. G.
Published: July 2010

The reasons for differences in tolerance to manganese toxicity among four cultivars of soybeans [Glycine max (L.) Merr.] were studied in solution culture using grafting, chemical analyses, and dry matter yield changes. Yield data and visual symptoms indicated considerable variation between cultivars with ‘Lee’ being the most tolerant and ‘Bragg’ the most sensitive. Leaf crinkle was the most prominent visual symptom of toxicity observed. Chemical analyses revealed little variation between cultivars in uptake of maganese or in distribution of manganese between root and shoot. Grafting of Bragg scions onto Lee rootstocks revealed that genotype of rootstocks had little or no control over tolerance or susceptibility to high (15 ppm) manganese in solution culture.
Influence of Environment on Seed Quality of Four Cotton Cultivars1
Authors: Turner John H. , Ramey H. H. , Worley Smith
Published: July 2010

Oil content, protein content, seed index, and percent immature seed were determined on 136 cottonseed samples (Gossypium hirsutum L.) from the 1973 National Cotton Variety Tests. Samples of four cultivars from two replications at 17 locations were used to study seed quality parameters. Environment influenced the level of oil and seed maturity far more than did the cultivars. A differential response of cultivars across the 17 environments for oil content and seed maturity was explained on the basis of genotypic differences in growth and fruiting patterns and their response to diverse climates. Cultivars had as much influence on protein content as environmental conditions but no interaction was detected. The results indicate that breeders might find it more feasible to screen for protein content than oil content, unless greater diversity for oil content can be found in cotton germplasm.
Genotypic Responses in Sorghum to Drought Stress. III. Free Proline Accumulation and Drought Resistance1
Authors: Blum A. , Ebercon Adelina
Published: July 2010

We explored a possible association between free proline amino acid accumulation in water‐stressed leaves and the drought resistance of various grain sorghum [Sorghum bicolor (L.) Moench] cultivars.

Eight sorghum cultivars were grown in a growth chamber under a drying cycle (to a leaf water potential of −18 to −21 bars) and a subsequent recovery phase. Free proline, free ammonia, dark respiration rate, and recovery rating were recorded, as well as desiccation tolerance of each cultivar when grown in the field.

Free proline accumulation was initiated in leaves of all cultivars as leaf water potential was reduced to −14 to −16 bars. Free ammonia concentration in leaves of all cultivars did not change appreciably during the drying cycle. Upon rewatering, free proline content was reduced and free ammonia concentration was increased, both rather abruptly. Cultivars difered significantly in maximum free proline accumulation and post‐stress free ammonia concentration, dark respiration rate, and recovery rating.

Correlations indicated that desiccation tolerance was not related to any of the attributes measured, or even to recovery rating. Free proline accumulation during water stress was correlated significantly with post‐stress recovery rating, free ammonia concentration, and dark respiration rate.

It is suggested that accumulated free proline in water‐stressed sorghum leaves is related to the ability of a cultivar to recover upon the relief of stress, possibly by way of proline's role as a source of respiratory energy in the recovering plant.
A Homozygous Interspecific F2 Hybrid of Gossypium Barbadense ✕ Gossypium Hirsutum via the Semigametic Haploid Method1
Authors: Barrow J. R. , Chaudhari H. K.
Published: July 2010

The semigametic phenomenon, which allows the production of haploid plants of any specific cotton breeding strain, was used to produce a haploid plant from a male gamete of an interspecific hybrid between Gossypium barbadense L. and Gossypium hirsutum L. The treatment of this haploid plant with colchicine, doubled the chromosome number, giving an immediate early generation pureline hybrid. This study demonstrates the usefulness of the semigametic phenomenon in producing a genetically stable breeding line in two generations from interspecific crosses.
Periods of Chilling Sensitivity in Germinating Pima Cottonseed1
Authors: Buxton D. R. , Sprenger P. J. , Pegelow E. J.
Published: July 2010

Seed germination and seedling development are adversely affected in many crops by less than lethal chilling temperatures. Periods of chilling sensitivity have been identified in Upland cotton (Gossypium hirsutum L.) but little work has been reported in Pima cotton (G. barbadense L.). This study was conducted to evaluate the influence of temperature on the degree and timing of chilling susceptibility in germinating Pima cotton and to determine if genetic variability exists. Seed were germinated at 25 or 35 C for 72 hours with one additional 24‐hour chilling exposure of 5, 7, or 10 C at various times during germination. Two periods of chilling sensitivity were noted. The first occurred at the beginning of germination. The second period showed maximum sensitivity between 28 and 32 hours when seed were germinated at 35 C and between 40 and 56 hours when seed were germinated at 25 C. Chilling at 7 C during both sensitive periods delayed emergence from a soil mix. In addition, final emergence was reduced by 26% when seed were chilled at the beginning of germination. Chilling at 5 C caused much more severe damage than chilling at 7 or 10 C. Some experimental lines showed greater resistance to chilling than the commercial cultivar, ‘Pima S‐4.’ Two genetic lines that responded similarly when chilled at 5 C differed significantly when chilled at 7 and 10 C. This suggests that these higher temperatures may be best for evaluating genetic variation and seed treatments to impact chilling resistance.
Carbohydrate Status of Narrow Row Cotton as Related to Vegetative and Fruit Development1
Authors: Saleem M. B. , Buxton D. R.
Published: July 2010

Narrow row, high population culture is a promising system for cotton (Gossypium hirsutum L.) production; but with improper management the dynamic balance between vegetative and fruit development can be upset, resulting in low lint yields. This study was conducted to investigate the relationship of plant carbohydrate status to vegetative and fruit development. Plant dry weights and total available carbohydrates (TAG) were compared during two seasons in narrow row cotton planted at population densities of 7.4, 14.8, and 22.2 plants/m3. Although large differences occurred in plant size, TAG levels among the three populations were similar during the various sampling dates. TAG had a cyclic pattern with low levels during mid‐season. This depression coincided with a rapid increase in fruiting form weight when lint yields were high and with a rapid increase in vegetative weight when lint yields were low. This excessive vegetative growth can effectively compete with fruiting forms for TAG. In a related experiment, TAG levels along plant axes were lowest near the central part of the plant where developing bolls were located. This shows that the TAG depression can be relatively localized within plants suggesting that photosynthates are not effectively translocated from the top to the central part of the plant. Restructuring of the plant canopy to allow more solar radiation penetration to leaves near developing bolls and/or selecting for more efficient translocation from upper leaves to developing bolls should help increase yields.