bluuebunny/crossref_metadata_2025 huggingface dataset:
Germination of Cotton (Gossypium hirsutum L.) Pollen on an Artificial Medium1
Authors: Taylor Richard M.
Published: July 2010

Gossypium hirsutum L. pollen was germinated by dusting it on a 3.5% agar medium containing sucrose, manganous sulfate, calcium nitrate, and boric acid. The medium was autoclaved for 5 min at 15 pounds per square inch and then poured into petri dishes to a depth of 5 to 7 mm. After cooling, the agar plates were stored in a refrigerator for 24 hours before use. Pollen was dusted onto the medium and the plates were placed in a germination chamber at 30 C and a relative humidity approaching 100%. To date, germinations have been low, ranging from 10 to 64% with an average of 30%. Advantages of this technique over the Broncker's method are: (i) more rapid germination (2 to 3 hours); (ii) more normal‐appearing tube cytoplasm, and (iii) much longer tubes.
Two Methods of Tannin Analysis for Sorghum Bicolor (L.)Moenchgrain1
Authors: Maxson E. D. , Rooney L. W.
Published: July 2010

Urea extraction followed by reaction with ferric ammonium sulfate (FAS) and a modified vanillin‐hydrochloric acid (MV.HC1) technique are two promising methods for analysis of polyphenolic compounds (tannins) sorghum [Sorghum bicolor (L.) Moench] grain. Both procedures are presented. Tannic acid values (FAS) ranged from 0.20 to 0.76 mg/100 mg and catechin equivalents (MV‐HC1) ranged from 0.21 to 3.11 rag/100 mg. The MV‐HCl method is rapid, but has a significant cultivar ✕ day interaction. The FAS method is slower; but does not exhibit the interaction.
Relationship between Grain Yield and Environmental Variability in Oats (Avena sp.)1
Authors: Pfahler P. L.
Published: July 2010

The yield of 94 populations consisting of 89 homozygous and homogeneous lines and five recommended varieties was tested for 6 years at Gainesville, Fla. The r values between the yield of the 94 populations and their variability in yield over the 6 years were as follows: 1964 = −.24*; 1965 = −.79**; 1966 = .03; 1967 = −.39**; 1968 = −.47**; 1969 = −.37**; and six year mean = −.60**. Selection for high yield generally resulted in selecting populations with low environmental variability.
Genetic Variation of Four Anatomical Traits and Their Association with Stalk Quality Traits in Maize (Zea mays L.)1
Authors: Chang Hui‐shong , Loesch P. J.
Published: July 2010

Stalk quality traits, including crushing strength and rind thickness, were evaluated in 1967 and 1968. In addition, four anatomical traits of the stalk were evaluated in 1967 for 66 inter se crosses among 12 inbred lines of maize (Zea mays L.). The nature of the genetic variation of (i) area of the stalk cross‐section, (ii) area of rind, (iii) of pith, and (iv) the number of vascular bundles in the pith were determined by means of diallel analysis. Significant differences among the 66 F1 hybrids were obtained in each trait. General combining ability (gca) mean squares were significant in each instance, whereas specific combining ability (sca) mean squares were small and not statistically significant. Low genotypic correlation coefficients among three of the four characters studied and traits known to be diagnostic of stalk strength indicated that stalk cross‐section, pith area, and bundle number in the pith would have linfited merit in a selection program. Genotypic correlation coefficients of rind area with diagnostic stalk quality traits were higher, but rind area determinations would be prohibitively expensive and time consuming. The number of vascular bundles in the pith was a poor indicator of stalk strength. We concluded that rind attributes were better indicators of stalk strength than were traits associated with the pith of maize stalks.
Natural Sterility Maintainer and Fertility Restorer Mutants in Tift 23A1 Cytoplasmic Male‐sterile Pearl Millet, Pennisetum typhoides, (Burm.) Stapf & Hubb1
Authors: Burton Glenn W.
Published: July 2010

Fertile sectors discovered in heads of cytoplasmic malesterile ‘Tift 23A1’ pearl millet, Pennisetum typhoides (Burm.) Stapf and C. E. Hubb., were shown to result from the occurrence of a dominant fertility restorer mutation or from apparent mutation of the sterile (A1) to normal (N) cytoplasm. Several male sterile plants with one or more completely fertile heads and five plants with all heads fertile (the latter heterozygous for the restorer gene) could also have arisen by mutations occurring earlier in their embryonic development. The environmental “breakdown” observed in one plant produced pollen that maintained the sterility of Tift 23A1 just as pollen of ‘Tift 23B.’ The occurrence of fertility restorer mutants in Tift 23A1 snggests that mutant genes for fertility restoration may be found in large populations of cytoplasmic male sterile plants of other species.
Gene Action in Oh45 and Oh45B Crosses of Zea mays L.1
Authors: Findley W. R. , Dollinger E. J. , Eberhart S. A.
Published: July 2010

Experiments were conducted to study types of gene action contributing to yield increases obtained by substitution of inbred Oh45B for inbred Oh45 in the pedigree of certain double‐cross corn (Zea mays L.) hybrids. Estimates of mean, additive, dominance, additive ✕ additive, additive ✕ dominance, and dominance ✕ dominance gene effects, and deviations due to linkage and/or higher orders of epistasis were obtained. Generations P1, P2, F1, F2, F3, B1, B2, BS1, and BS2 were grown for inbred lines WF9, Oh51A, Oh26, and Hy each crossed with Oh45 and Oh45B. Grain yield, kernel weight, ear length, and ear diameter were studied.

Crosses involving Oh45 showed an average yield heterosis of 95%; whereas, the heterosis for Oh45B crosses was 136%. Differences in average yield of the Oh45 and Oh45B families were due primarily to dominance effects. The addition of digenic epistatic effects did not improve the predictive ability of the model even though epistatic effects were statistically significant. Most of the variation among generation means was accounted for by the mean, the additive effect, and the dominance effect for all attributes studied. Deviations from the digenic model were non‐significant, except for grain weight in one family and for ear diameter in two families.
Yield Response of Six Cultivars of Upland Cotton, Gossypium hirsutum L., in Two Cultural Regimes1
Authors: Ramey H. H.
Published: July 2010

Six cotton (Gossypium hirsutum L.) cultivars grown in yield trials from 1935 through 1938 were again evaluated in 1967 and 1968. Yields in the latter period were 61% greater than those in the earlier period, but two varieties responded more favorably than did the other four. A yield model, lint yield = bolls/m2 ✕ seeds/boll ✕ lint/seed, was used to assess the response of the cultivars to changes in cultural inputs. The two varieties that responded more favorably to improved production practices produced more bolls/m2 relative to the other four. The other two components did not change appreciably. It was concluded that the ability to produce more bolls/m2 under increased input levels must have been a factor in selection of germ plasm.
Inheritance of Dry Matter Digestibility in Bermudagrass, Cynodon dactylon (L.) Pers.1
Authors: Burton Glenn W. , Monson Warren G.
Published: July 2010

Heritabilities were estimated for dry matter digestibilities (DMD) of forage samples. The samples were collected from 5 to 11 harvests, of 148 germudagrass (Cynodon dactylon (L.) Pers.) selections and F1 hybrids evaluated in three clipping tests from 1962 to 1969. DMD was measured by the nylon bag or in vitro techniques. Heritabilities for a seasonal average of two to four clippings ranged from .27 to .69 indicating that the DMD of bermudagrass can be increased by breeding. F2 hybrids between ‘Coastal’ bermuda and high or low DMD parents had average DMDs similar to the mean DMDs of the two parents. F2 hybrids between ‘Midland’ bermuda and ‘Kenya 61’ had average DMD values 1.8 to 2.8 percentage points lower than the parental average. In most hybrid populations, the best F1 was nearly equal if not superior to its best parent in DMD. The two‐year average IVDMDs of 5‐week‐old second‐harvest forage samples taken from a world collection of over 500 bermudagrasses ranged from 40 to 69%. DMD in bermudagrass appears to be conditioned by a number of genes that exhibit little if any dominance. Additional index words:
Amino Acid Percentages in the Groat‐Protein of Oat Lines from an Interspecific Cross1
Authors: Campbell A. R. , Frey K. J.
Published: July 2010

Samples of groat protein from 15 F2‐derived oat lines from an interspecific cross (Avena sativa L. ✕ Avena sterilis L.) were analyzed for amino acid composition. In general, these lines had higher percentages of the essential amino acids arginine, histidine, leucine, lysine and phenylalanine and lower threonine than those reported by other investigators. Groat protein of two lines contained over 8.0% lysine, an essential amino acid often deficient in cereal proteins.
Mechanical Scarification of Cicer Milkvetch (Astragalus Cicer L.) Seed1
Authors: Townsend C. E. , McGinnies W. J.
Published: July 2010

Seed of Astragalus cicer L. was subjected to 30 scarification treatments. The treatments were: the number of times passed through the scarifier (1 through 5); air pressures (2.8, 4.2, and 5.6 kg/cm2); and abrasives (fine and coarse). Seed coat permeability, as measured by percentage germination, was significantly influenced by number of times scarified and air pressure but not by abrasive. However, all factors influenced the percentage of damaged seeds. The most satisfactory treatment was to pass the seeds through the scarifier five times at the 2.8 kg/cm2 pressure with the fine abrasive. This treatment reduced the percentage hard seed from 54% to 1% without damaging seeds.
Carbon Dioxide Exchange in Water‐stressed Sorghum1
Authors: Shearman Linda L. , Eastin J. D. , Sullivan C. Y. , Kinbacher E. J.
Published: July 2010

Carbon dioxide exchange was monitored in potted RS 610 sorghum [Sorghum bicolor (L.) Moench] in a growth chamber as it dried out from a freshly watered condition to severe water stress. Carbon dioxide uptake in the light decreased to near the compensation point at water potentials near ∓25 atmospheres. Leaf resistance to gaseous exchange was high at this point. Evolution of CO2 in the light occurred as stress became greater. Dark evolution of CO2 was higher at water potentials near ∓20 atmospheres than in either the more severely stressed or non‐stressed condition. The activity of phosphoenolpyruvic carboxylase remained comparatively high as water stress increased.
Simulation of Growth and Yield in Cotton: III. Environmental Control of Morphogenesis1
Authors: Hesketh J. D. , Baker D. N. , Duncan W. G.
Published: July 2010

Time intervals between the appearance of leaves, floral buds and flowers at successive main stem and fruiting branch nodes of the cotton plant (Gossypium hirsutum L.) were studied in eight temperature regimes at the Southeastern Environmental Plant Laboratories. The time interval between such events on the main stem or the first node of the fruiting branch, as affected by temperature, would seem to provide (with some qualifications) a simple physiological time‐base for modeling plant development. Our observations agreed fairly well with a physiological time concept attributed to Zaitzev in 1927.
Responses of Spring Wheats to Vernalization and Photoperiod1
Authors: Levy Jose , Peterson Maurice L.
Published: July 2010

Spring wheat (Triticum aestivum L. em. Thell.) cultivars from various sources and different maturity classes were analyzed for responses to vernalization and photoperiod. Response measurements were days to heading, number of leaves on the main culm, and number of tillers at time of heading. Seven of 13 spring cultivars responded to vernalization as measured by reduced leaf number at heading, although differences were small. All 13 spring cultivars, plus a semi‐winter and a winter cultivar, headed sooner if vernalized, although the reductions (2 or 3 days) in some of them can probably attributed to slow development during vernalization. Tiller number at heading was reduced in cultivars responding to vernalization. Response to vernalization of spring types appeared unrelated to earliness of maturity under field conditions. All cultivars tested headed earlier with increasing photoperiods in a series of treatments from 9 to 17 hours. Early maturing cultivars responded least to lengthened photoperiods, and late‐maturing cultivars responded most. A highly significant interaction was obtained between the vernalization and photoperiod responses in one cultivar showing small responses to these individual treatments. However, photoperiod alone rather than vernalization appeared to be the primary factor controlling maturity in spring wheats.
Oil Content and Groat Weight of Entries in the World Oat Collection1
Authors: Brown C. M. , Craddock J. C.
Published: July 2010

Wide‐line nuclear magnetic resonance (NMR) was used to determine the oil content from primary groats of more than 4,000 entries of the world oat (Avena sp.) collection. Weight per groat, based on the mean weight of the same primary groats used for oil determinations, was also determined.

Oil content varied from 3.1 to 11.6%, with a mean oil content of 7.0%. Ninety percent of the entries ranged from 5 to 9%, but five entries contained more than 11%, while 25 contained less than 4% oil. Groat weight of entries ranged from less than 10 mg to 41.2 mg, with a mean weight for all entries of 26.2 mg. Most of the observations (85%) ranged from 20 to 32 mg per groat.

A positive correlation coefficient of .ll between oil content and groat weight was obtained. While this was statistically significant, based on more than 4,000 d.f., it was considered too small to have practical importance in oat breeding.
Estimates of the Percentage of Self‐ and Cross‐Pollination in Sainfoin (Onobrychis viciaefozia Scop.)1
Authors: Knipe W. J. , Carleton A. E.
Published: July 2010

Percent cross‐pollination in sainfoin (Onobrychis viciaefolia Scop.) was estimated under three planting arrangements by using flower color and growth characteristics as genetic markers. The amount of cross‐pollination was dependent upon the planting arrangement. A substantial amount of crossing occurred when one row of a maternal multicut line was seeded between two rows of a sinplecut pollen parent. More than 90% of progeny produced by three white‐flowered maternal clones surrounded by rows of pink‐flowered pollen parents resulted from crosspollination. Eight to 28% cross‐pollination occurred between white‐flowered maternal clones and pink‐flowered male clones in two clone crosses under isolation with honey bees as pollinators.
Isogenic Analysis of the Effects of the Awn on Productivity of Barley1
Authors: Schaller C. W. , Qualset C. O. , Rutger J. N.
Published: July 2010

The performance of four isogenic lines of ‘Atlas’ barley (Hordeum vulgare L.) ‐ ‘Full‐,’ ‘Half‐,’ ‘Quarterawned,’ and ‘Awnless’ ‐ was measured at 22 locations in western U.S. and Canada, and in a date‐of‐planting experiment at Davis, Calif. The relative mean yields over all environments were 110.1, 112.6, 105.1, and 100.0 for Full‐, Half‐, Quarter‐awned and Awnless, respectively. Although Half‐awned had the highest mean yield over all locations, a differential trend in genotype performance at high and low yield levels was evident. Half‐awned was most productive at low yield levels and was superior to Awnless and Quarter‐awned throughout the range of productivity. Full‐awned was the highest‐yielding in good environments, but lower than Half‐awned and comparable with Quarter‐awned in low‐yielding environments. Isogenic line‐environment interactions were not strongly associated with years or locations, but were generated by conditions specific to each test site and were related, in part, to the productivity level of the site.

The differential performance of Full‐awned in the low and high‐yielding environments was independent of kernel weight. Competition for substrate at the time of awn development and initiation and development of additional florets and tillers was suggested as a possible cause for the failure of Full‐awned to attain maximum yield expression in low‐yielding environments.

The linear regression coefficient of kernel weight on awn length, b = 0.69 mg kernel−lcm−l, obtained in the date of planting study, agreed very closely to the value (0.64) reported previously. The contribution of the awns to grain yield was estimated as 35.6 kg ha−1cm,−l. In addition to the effect on kernel weight, the awns provided considerable protection to the developing kernels from infection by foliar pathogens.
Safflower Introduction Resistant to Verticillium Wilt1
Authors: Urie A.L. , Knowles P.F.
Published: July 2010

Safflower (Carthamns tinctorius L.) plant introductions were tested for resistance to Verticillium wilt (Verticillium albo‐atrum Reinke and Berth.) in a Verticilliuminfested field near Visalia, California. Of the many introductions tested, 48 were highly resistant to the disease. Small quantities of seed from each resistant introduction are available upon request.
Stomate Density and Size as Related to Ozone‐Induced Weather Fleck in Tobacco1
Authors: Dean C. E.
Published: July 2010

A study was conducted to investigate the relationship between stomate density and size on reaction of tobacco (Nicotiana tabacum L.) to elevated concentrations of ozone. The resistant varieties ‘Florida 20’ and ‘C‐80’ averaged 25.4 stomates per mm2 on the adaxial leaf surface, while the susceptible varieties ‘2612‐2,’ ‘2612‐3,’ and ‘Bel W‐3’ averaged 37.4. This decrease in stomate density by one‐third in resistant varieties is thought to be associated with resistance by reducing the amount of ozone‐rich air which can enter the leaf. No relationship was found between stomatal size and plant reaction to ozone.
Estimates of Dry Matter Digestibility Differences in Grain of Some Sorghum bicolor (L.) Moench Varieties1
Authors: Miller F. R. , Lowrey R. S. , Monson W. G. , Burton G. W. , Cruzado H. J.
Published: July 2010

Grain of several varieties from the World Collection of Sorghum, Sorghum bicolor (L.) Moench, was analyzed for dry matter digestibility using the nylon‐bag method (NBDMD). Selected lines, parents, and hybrid combinations were analyzed using the NBDMD and in vitro dry matter digestibility (IVDMD) methods.

All exotic sorghums selected for a high proportion of floury endosperm were more digestible than US varieties used as controls. White‐colored grains with more than 70% floury endosperm produced highest NBDMD values. Brown or purple grains containing high proportions of floury endosperm did not produce as high NBDMD values as white grains, but did produce higher NBDMD values than nonbrown grains of US varieties. Varieties with high NBDMD values as ground kernels were not always more digestible as whole kernels. NBDMD values of whole and ground nonbrown grain from hybrids was similar to the more digestible parent in the cross. Brownseeded hybrids tended to be intermediate between both parents when evaluated as ground grain. Whole kernel digestion showed nonbrown‐seeded hybrids to be intermediate between both parents in digestibility, but brownseeded hybrids were generally significantly lower in digestibility than the lowest parent.

The modified Tilley‐Terry 2‐stage IVDMD method gave higher dry matter digestibility values than the 1‐stage IVDMD (rumen fluid alone) or NBDMD methods. NBDMD and IVDMD values for whole grain were highly correlated (r = .98). The 1‐stage and 2‐stage IVDMD percentages were significantly correlated for ground grain but IVDMD and NBDMD values for ground grain were not. Both the NBDMD and IVDMD methods gave significant correlations for whole vs. ground grain.
Differential Growth of Corn (Zea mays L.) Hybrids Seeded at Cold Root Zone Temperatures1
Authors: Cal J. P. , Obendorf R. L.
Published: July 2010

Field observations, which indicated differential growth among corn (Zea mays L.) hybrids after early seeding but not after later seeding, led to a study of the growth of four hybrids in three different root zone temperature regimes. Initial root zone temperatures of 12, 16, and 20 C, respectively, were subsequently raised by 2, 1, and 0 C with each 2 weeks of growth following the initial 3 weeks after seeding. Hybrid ‘Cornell M‐3’ was most sensitive to cold root zone temperatures; the hybrids ‘Michigan 250,’ ‘Cornell M‐4,’ and ‘Pennsylvania 290’ followed in decreasing order of sensitivity. Percent survival and leaf number were similar for all hybrids, but dry matter accumulation differed among hybrids at the lower temperature regimes. Compared to the other hybrids, Cornell M‐3 accumulated less dry weight of roots, blades, sheaths, and stems and less blade area and stem height after 11 weeks of growth in the 12‐C root temperature regime. Differential growth among hybrids was less apparent when grown at 20 C.
Associations Between Chromosomal Knobs of Zea mays L. and Agronomic Performance1
Authors: Moll R. H. , Hanson W. D. , Levings C. S. , Ohta Yasuo
Published: July 2010

Four polymorphic chromosome knobs in the open‐ pollinated variety of Zea mays L., ‘Jarvis,’ were found to be associated with effects related to plant vigor. Random inbred lines of the variety were categorized for knob constitution at each of the four knob sites. Inbreds of similar knob constitution were intermated to produce subpopulations with known knob constitution. The subpopulations were evaluated for four quantitative traits in replicated trials. Heteromorphic knob constitution was associated with greater ear height and plant height at four knob sites, and with higher yield of grain at three of the knob sites.
Cyanogenesis in Green Tissues of Cotton Plants1
Authors: Radin J. W.
Published: July 2010

A cyanogenic compound was present in extracts of nearly all tissues of cotton plants (Gossypium hirsutum L.), with the greatest amounts present in photosynthetic tissues. Measured as HCN evolved from aerated aqueous homogenates, amounts in leaves varied from 27 to 92 μg/g (fresh wt basis). No significant correlation was found with leaf age. Unlike other green tissues, carpel walls contained little cyanide. Cyanogenesis in cotyledons depended upon light. Turnover of the cyanogenic compound was also accelerated in light, with more than 50% of the pool of cyanogenic compound being metabolized each day.
Sexual Reproduction in Panicum maximum Jacq.1
Authors: Smith Rex L.
Published: July 2010

Completely sexual plants of Panicum maximum Jacq., formerly believed to be an apomictic species, were isolated. Progenies of 742 plants were screened for within‐progeny variability to locate these sexual plants. Off‐type and typical selections were tested, with segregating progenies being over 20 times more frequent in the off‐type group. This indicates the importance of testing off‐type plants when searching for sexual plants in an apomictic species. Segregating families also segregated for apomixis and sexuality, with sexuality being predominant. Morphological and biochemical (esterase and peroxidase) withinprogeny variability was sufficient to be explained only by sexual recombination. Final proof of sexuality was the transfer of isoenzymes from the pollen parent in hybrid progeny.
Variation in Sensitivity to Photoperiod Among Early Maturing Soybean Strains1
Authors: Criswell J. G. , Hume D. J.
Published: July 2010

Two experiments were conducted to identify soybean [Glycine max (L.) Merrill] strains that were nonsensitive to photoperiod for possible use as parental lines in a breeding program. Twelve soybean varieties were subjected to photoperiods of 12, 16, 20 and 24 hours in growth cabinets. The number of days from planting until first flower was increased by long photoperiods in all but 1 of 12 varieties. Early maturing varieties were less sensitive to photoperiod than were later varieties. for this reason, 111 soybean strains from Maturity Group 00 were grown in a controlled‐environment room at photoperiods of 12, 22, 23 and 24 hours. In approximately 70% of these strains the length of time from planting to flowering was unaffected by photoperiod.
Inheritance of the Golden Tip Trait in Alfalfa1
Authors: Elgin J. H.
Published: July 2010

A golden tip trait in alfalfa (Medicago sativa L.) was identified and described. Young leaves at stem tips are yellow in color with lower leaves a normal green, giving the appearance of a golden tip to the growing stems. Golden tip trait was determined to be controlled by a single recessive gene (gt) inherited in a tetrasomic manner.
Effects of Plant Maturity on Oil Composition of Several Spearmint Species Grown in Indiana and Michigan1
Authors: Murray Merritt J. , Faas William , Marble Phillip
Published: July 2010

In 1970, herbage samples of 2nd‐year meadow mint of the native spearmint cultivar (Mentha spicata), the Scotch spearmint cultivar (M. cardiaca), and the wild mint M. crispa were harvested on May 16, June 3, June 17, July 1, and thereafter insofar as possible every 10 days until Nov. 3. Assay data for 10 principal constituents accounting for at least 85% of the oil showed that overmature and senescent herbage had more dihydrocarvone than did mature herbage, and that M. crispa had more than both cultivars at all times. Replicated tests in 1971 showed that flower oil of both cultivars had more carvone and less dihydrocarvone than either the whole herbage or the top half of the herbage.

The thesis is advanced that all inter‐regional, intra‐regional, and ontogenetic differences in oil composition must result from either a direct effect of environment on the amount or efficiency of a specific gene‐controlled enzyme for a specific conversion or an indirect effect resulting from environmentally induced changes in plant growth influencing the proportion of young leaves to mature leaves, time of maturity, and extent of flower production. No direct effects are known. Ontogenetic differences in oil composition between juvenile, mature, and overmature plants are believed to depend upon the relative proportions of leaves of various ages and of flowers in the herbage. Ontogenetic trends will not be found unless specific inherited chemical syntheses occur at a slow rate, giving a product increase that is proportional to time and perhaps temperature, or unless there are inherited differences between leaves and flowers. All differences in stand, amount of fertilizer, cultural conditions, frequency of irrigation, weather, or climatic conditions that increase the proportion of young leaves will improve oil quality, whereas the suggestion is made that the poorer oil quality obtained from harvesting overmature herbage or herbage prematurely aged by crop mistreatment is due not only to the increased dihydrocarvone, but also to a higher alcohol/ester content.
Heterosis in Inbred Source Crosses of Maize (Zea mays L.)1
Authors: Grogan C. O. , Francis C. A.
Published: July 2010

This study was designed to determine the variability within maize (Zea mays L.) lines maintained at different stations in the northern maize‐growing areas of the U. S., with particular attention to heterotic expression in withinline crosses. There was significant variation in the various characteristics studied in most of the lines, although certain characteristics such as kernel row number and ear diameter showed considerable stability.

The information should be of particular interest to seed producers and certification agencies where variation within lines could have serious consequences or could be used to an advantage in production of related‐line single crosses.
Stomatal Resistance, Net Photosynthesis, and Transpiration in PMA‐Treated Sorghum: A Field Study1
Authors: Sij J. W. , Kanemasu E. T. , Teare I. D.
Published: July 2010

Diffusion porometry and a field‐chamber system were employed to study the effects of single applications of 90 to 720 µM phenylmercuric acetate (PMA) on stomatal resistance, photosynthesis, and transpiration in fieldgrown sorghum [Sorghum bicolor (L.) Moench]. To maintain increased stomatal resistance up to 20 days it was necessary to apply at least 360 µM PMA. Preliminary data showed that in short‐term studies of 3 to 4 days post‐treatment, photosynthesis was reduced (at least temporarily) more than was transpiration by PMA concentrations that produced prolonged effects on stomata. Diffusion porometry and field chambers can be used to test other antitranspirants applied to field‐grown crops.
Day‐Neutrality in Soybeans1
Authors: Polson D. E.
Published: July 2010

The north‐south range of adaptation of soybean [Glycine max (L.) Merr.] varieties is limited because of the photopcriod requirements for anthesis. If daylengthneutral strains could be identified and used in soybean breeding programs, the range of adaptability of soybean varieties might be considerably increased. The U. S. world collection of soybeans of maturity groups 00 and 0 (about 400 strains) was screened for dayneutrality by growing the plants at various photoperiods in the greenhouse. Strains that flowered in the greenhouse in about the same number of days under photopcriods ranging from 12 to 22 hours were identified. Several strains thus identified were also day‐neutral with respect to flowering in a field experiment in which various photoperiods were established. Under the field conditions, however, some of the day‐neutral strains were delayed in maturity mote than others by the long photoperiods.
Varietal Differences in Growth Potential, Adenylate Energy Level, and Energy Charge of Wheat1
Authors: Ching T. M. , Kronstad W. E.
Published: July 2010

Dynamic synthesis and utilization of adenosine triphosphate in embryos and seedlings of a fast‐growing wheat (Triticum aestivum L.) variety, ‘Yamhill,’ resulted in a higher overall energy level and energy charge than that of slower‐growing ‘Hyslop’ seedlings. The varietal difference in growth potential of seedlings appears to be related to energy metabolism and capacity of synthesis.
Stability Indexes for Isolines of Oats (Avena sativa L.)1
Authors: Frey K. J.
Published: July 2010

An early group and a midseason group of oat (Avena sativa L.) isolines developed via backcrossing were yield tested in 15 environments with a range of productivity indexes from 25.5 to 42.2 q/ha. Isolines within a group were compared for mean grain yields and the stability indexes: regression coefficient (b) and deviations‐from‐regression (s2d).

The isolines in a group were quite homogeneous for appearance, plant height, heading date, and seed traits. For grain yield, however, three isolines in the early group and four in the midseason group produced grain yields significantly deviant from the respective recurrent parents. Two were negative and five were positive. The regression value for neither recurrent parent was significantly different from 1.0, but four early and five midseason isolines had b values significantly different from unity. Occasionally, if one isoline of a pair (i.e., one early and one midseason) with crown‐rust resistance from the same donor cultivar had a b value less than unity, the other one had a b value greater than unity.
Stomatal Density and Distribution in Agrostis as Influenced by Species, Cultivar, and Leaf Blade Surface and Position1
Authors: Shearman R. C. , Beard J. B.
Published: July 2010

Stomatal density and distribution were determined among species of Agrostis grown under the same environmental and cultural conditions. The species studied were A. canina L., A. palustria Huds., and A. tenuis Sibth. The Stomatal density varied significantly among the three species and among the five cultivars of A. palustris. Density and distribution of stomata also varied with the leaf blade surface and position. The adaxial leaf surface of ‘Penncross’ creeping bentgrass had approximately three times the Stomatal density of the abaxial surface. Stomata were distributed in parallel rows on the adaxial leaf blade surface and were scattered throughout the abaxial surface. Stomatal density was greatest on the youngest leaves.
Genetic Variation in Yield and Quality of Oat Forage1
Authors: Stuthman D. D. , Marten G. C.
Published: July 2010

We evaluated 30 cultivars of oats (Avena sativa L.) for forage quality and yield at heading and 10 days later in 1968. Quality traits measured included in vitro digestible dry matter (IVDDM), cell wall constituents (CWC), acid detergent fiber (ADF), acid detergent lignin (ADL), and crude protein (CP) concentration. Eleven of the cultivars were tested for 2 additional years.

All three fiber components (CWC, ADF, and ADL) were positively correlated with each other and all were negatively correlated with IVDDM. Of the three, however, ADL was most closely associated with digestibility. Yield and quality were negatively correlated at heading, but independent 2 weeks later. Forage yield and grain yield were not associated. Forage yield was correlated with plant height and heading date.

Cultivars differed in oat forage quality within a given environment; differences, however, generally were not repeatable over years. In contrast, cultivar variation for forage yield was consistent over years and sufficient for effective selection. Therefore, we recommend primary emphasis on forage yield in the developmnt of superior forage oat cultivars. However, one should examine forage quality before making final selections.
Free Amino Acid Content of the Anthers of Male‐Sterile and Fertile Lines of Grain Sorghum, Sorghum bicolor (L.) Moench1
Authors: Kern J. J. , Atkins R. E.
Published: July 2010

Anthers of cytoplasmic‐genic, male‐sterile lines of Combine Kafir 60 and Martin grain sorghums (Sorghum bicolor L. Moench) were analyzed for free amino acid content at two stages of microsporogenesis, and those of their counterpart fertile B‐lines and recovered restorer lines were examined at three stages. Total amino acid contents were similar for the sterile and the fertile lines at the tetrad stage, but at the free‐microspore stage, total amino acid contents were higher in the fertile lines. In three of the four comparisons among stages in the fertile lines the greatest accumulation of total amino acids occurred between the microspore and the pollen stages.

Proline, tyrosine, and asparagine showed noteworthy differences in concentration between fertile (B‐ and Rlines) and male‐sterile (A) lines. As microsporogenesis proceeded, proline content rose sharply in the fertile lines but did not increase in the steriles. Tyrosine content increased in both the sterile and fertile lines, but the accumulation with advancing stages was more rapid in the fertile lines. In greenhouse plants asparagine content increased in the steriles, but decreased in the fertile lines, as microsporogenesis progressed. This trend was not manifested in field‐grown plants. Significant differences between stages and between fertile and sterile lines also were noted for other amino acids, particularly leucine, but the differences seemed either less pronounced or more inconsistent.
Selectivity of Bromacil on Kentucky Bluegrass and Orchardgrass1
Authors: Shriver J. W. , Bingham S. W.
Published: July 2010

In field studies photosynthesis was reduced by 5‐bromo‐3‐sec‐butyl‐6‐methyluracil (bromacil) to greater extent in orchardgrass (Daetylis glomerata L.) than in Kentucky bluegrass (Poa pratensis L.). Foliage carbohydrates were depressed initially in bluegrass followed by recovery in 2 weeks to 1 1/2 months after bromacil application. Orchardgrass, however, did not exhibit the same degree of recovery. Application of 0.56 kg/ha bromacil each summer and fall for 2 years gave the best control of orchardgrass. During the 2nd year increased foliage crude protein was observed in treated bluegrass. Bluegrass foliage yields were equal to or greater than the controls. Orchardgrass yields were drastically reduced by bromacil. Effective seedling orchardgrass control was obtained with minimal bluegrass injury at 0.14 to 0.28 kg/ha of bromacil. Bromacil‐treated soil was effectively fall‐seeded with bluegrass approximately 8 weeks after a 0.56‐kg/ha application. Rooting of bluegrass sod was not inhibited.
Breeding Behavior for Crosses of Crambe abyssinica and a Plant Introduction Designated C. hispanica1
Authors: Meier V. D. , Lessman K. J.
Published: July 2010

Plant selections from PI 247310 (C. abyssinica) and PI 279346 (C. hispanica) were paired randomly and crossed reciprocally. The average seed set from these crosses was about 77% with no reciprocal differences detected. Chromosome counts were made on pollen mother cells from each species and the F1 progeny. The average count was 41 bivalents at diakinesis for each species and the F1 plants; the number could not be counted accurately in every cell, however, because of difficulties in obtaining good smears, the tendency of bivalents to cluster, and small chromosome size. The actual chromosome number is probably 90 (45 bivalents) as previously reported for C. abyssinica. No cells were observed with 60 chromosomes (30 bivalents), which is the number reported for C. hispanica. Data and observations suggest that PI 247310 and PI 279346 should be classified into one species.

A normal diploid simple Mendelian ratio was observed for pubescence. The gene controlling pubescence, designated p, segregated 3 glabrous seedlings:1 pubescent seedling, indicating single‐gene control of this character. A total of 6,229 seedlings were observed. Seedlings that were thought to be heterozygous had several hairs at the edges and tips of the older leaves. Nevertheless, these seedlings, indicating partial dominance, were classified as glabrous.

Estimates of natural outcrossing were obtained. Crambe appears to be mainly self‐pollinated with an average of 4 to 7% outcrossing among adjacent rows 96 cm apart. Estimates from individual plants ranged as high as 28%. Results indicate that crambe belongs to the often cross‐pollinated group of plants. The estimates are conservative, since crosses to the dominant parent are not detected in the first generation.
Effects of Growing Temperature on Chemical‐Physical Properties of Kenaf Fibers1
Authors: Crouse Barry W.
Published: July 2010

Several cultivars of kenaf (Hibiscus cannabinus L.) were grown under five different thermal regimes in the Duke University phytotron, simulating a wide latitudinal distribution in the U.S. Kenaf stems were analyzed for carbohydrates by the gas‐liquid chromatograph.y trimethylsilyl method. Xylose, the major pentose species found in kenaf stems, was found to increase linearly with increasing environmental temperature over the range studied. Single kenaf bast fibers, from plants grown under the two temperature extremes, were tensile tested. A positive correlation was found between percent xylose of unfractionated stem sections and individual bast fiber axial tensile strength. Bast fibers from the warmest environment were strongest in axial tensile strength when expressed on a per unit area basis. It is suggested from this study that kenaf pulps from southerly locations may exhibit some superiority in strength characteristic over kenaf pulps produced from a crop grown at a northerly location.
Heritability of Rachis Node Number of Avena sativa L.1
Authors: Finkner Verne C. , Poneleit Charles G. , Davis D. L.
Published: July 2010

A pure‐line oat (Avena sativa L.) cultivar with a high rachis‐node number was crossed with three low rachisnode number cultivars to establish the existence of genetic variability for rachis‐node number and to determine its heritability. The high‐rachis‐node parent, CI 4897, had more than eight rachis nodes, while the other parents each had less than seven rachis nodes. Broad‐sense heritability calculated from the mean of F3 progenies was greater than that calculated from individual F3 plant data. Although rachis‐node number is subject to environmental effects, the relatively large heritability obtained from F3 means indicates that selection based on F3 means should be effective for increasing rachis‐node number. Transgressive segregation for higher node number was not observed. Owing to the morphology of the oat panicle, an increase in node number results in a large increase in spikelet sites.
Glands, Gossypol Content, and Tobacco Budworm Development in Seedlings and Floral Parts of Cotton
Authors: Wilson F. D. , Shaver T. N.
Published: July 2010

Larvae of tobacco budworm, Heliothis virescens (F.), were placed on seedlings and fed on detached fresh flower buds (squares) of cotton, Gossypium hirsutum L. Cotton entries included four parents, carrying all truebreeding combinations of the duplicate gland‐determining alleles Gl2, gl2, Gl3rat, and gl3, and all 12 F1 hybrids, including reciprocals. Data were obtained on larval preference for seedlings; weight of larvae fed on fresh squares; gland density in seedlings; stigmas; and bolls; and gossypol content of cotyledons, seedling leaves, and squares. Gland density and gossypol content were highly correlated with the number of gland‐determining alleles present and with each other. Both were highly negatively correlated with larval seedling preference and larval weight. Gl2, the “A” subgenome allele, was more expressive in seedlings, while Gl3rat, the “D” subgenome allele, transferred from G. raimondii Ulbr., was more expressive in stigmagland density and square‐gossypol content. In fact, the number of stigma glands was as high, and larval weights were as low, in the monomeric gl2gl2Gl3ratGl3rat as in the dimeric Gl2Gl2Gl3ratGl3rat, thus suggesting the predictive value of stigma‐gland counts in these cottons, and the possible practical value of the monomeric as a breeding stock. Diallel analyses showed that most of the genetic variance in gland density, gossypol content, and larval response was additive. Dominance was virtually absent. Epistasis varied considerably, but contributed substantially to the total genetic variance of gland density in seedlings, stigmas, and bolls. Reciprocal and maternal effects were generally small and nonsignificant.
Use of Dye‐Binding for Alfalfa Protein Analysis1
Authors: Gengenbach B. G. , Miller D. A.
Published: July 2010

A modified dye‐binding (MDB) method of protein analysis was adapted for fast analysis of alfalfa (Medicago sativa L.) herbage samples. Results from the MDB method and the micro‐Kjeldahl (Kj) method of protein analysis were highly correlated (r=0.96); the relationship was linear over the range of protein values expected of alfalfa herbage. The MDB method was satisfactory for detecting high‐ or low‐protein alfalfa samples and for predicting the corresponding micro‐Kj protein values from the equation, Kj = 2.90 + 0.389 (MDB). The coefficient of variation for MDB was less than 2%; MDB was equally, or more, precise than micro‐Kj.
Procedure for Estimating Ratio of Live to Dead Root Dry Matter in Root Core Samples1
Authors: Knievel Daniel P.
Published: July 2010

assessed using triphenyltetrazolium chloride (TTC) reduction techniques in an effort to establish a relatively simple method of determining the amount of living tissue in soil core samples from the field. Formazan (reduced TTC) was extracted with 95% ethanol and measured colorimetrically. Relationship between TTC reduction per gram roots and dry weight ratios of living to dead root tissue, established by simple correlation and regression analysis, was used to determine live and dead root dry weights of unknown root samples. TTC reduction per gram live root dry weight declined with plant age and, although not measured directly, probably varied with species. The procedure would accommodate large sample numbers if parts were automated.
Effects of Seed Size on Seedling Performance in Soybeans: II. Seedling Growth and Photosynthesis and Field Performance1
Authors: Burris J. S. , Edje O. T. , Wahab A. H.
Published: July 2010

Emergence percentage, photosynthesis, and growth in the laboratory, and field performance were compared in four seed sizes of four varieties of soybeans [Glycine max (L.) Merrill]. The three largest seed fractions exhibited superior emergence percentages and greater cotyledonary and unifoliolate leaf area in the laboratory. However, the smallest seed size exhibited higher photosynthetic rates. The three largest seed sizes showed greater overall emergence percentage, leaf area, and height in the field. Further, the three largest sizes yielded significantly more than did the small size when grown at uniform populations. Although the yields were significantly different, neither the percentage size distribution of the harvested seeds nor the seed quality was affected by the size of the seeds used to plant that plot.
Yield Stability in Doubled Haploids of American Pima Cotton1
Authors: Feaster Carl V. , Turcotte E. L.
Published: July 2010

We compared the yield performances of three American Pima cotton cultivars (Gossypium barbadense L.), a doubled haploid from each of the three cultivars, and a composite of the three doubled haploids. The relative yields and yield stabilities of the three doubled haploids were similar to the relative yields and yield stabilities of the cultivars from which the doubled haploids were derived. The probable increased homozygosity and homogeneity of the doubled haploids did not influence yield stability. The greatest yield stability was obtained from a composite of the doubled haploids.
Temperature Effects on Hypocotyl Elongation of Soybeans1
Authors: Gilman D. F. , Fehr W. R. , Burris J. S.
Published: July 2010

Effects of temperature on hypocotyl elongation of soybean [Glycine max (L.) Merr.] cultivars were studied in unlighted growth chambers. We evaluated the relationship between length of exposure to 25 C and amount of inhibition of hypocotyl elongation. Seeds of four cultivars were germinated in sand and in paper towels at each of three temperatures (20, 25, and 30 C), then transferred at daily intervals to a different temperature for the remainder of an 11‐day growth period. Initial → final temperature sequences used were 20 → 25 C, 30 → 25 C, 25 → 20 C, and 25 → 30 C. Hypocotyl lengths of ‘Hawkeye’ seedlings (a long hypocotyl cultivar) were similar in the four temperature regimes. Hypocotyl lengths of ‘Clark,’ ‘Ford,’ and ‘Amsoy’ seedlings (short hypocotyl cultivars) decreased with increased length of exposure to 25 C.

The length of exposure to 25 C needed for classification of cultivars was evaluated. Seedlings of Clark, Ford, Amsoy, and Hawkeye were grown at constant temperatures of 20, 25, and 30 C and measured daily up to 10 days after planting. Hypocotyl growth rates of all cultivars were comparable at 20 and 30 C. At 25 C, Hawkeye grew at a faster rate than the other cultivars beginning 3 days after planting, and differences among cultivars increased with days after planting. Differences among cultivars were most fully expressed 10 days after planting.

Inhibition of hypocotyl elongation was studied at constant temperatures between 20 and 32 C, at 1‐C increments. Inhibition of short hypocotyl cultivars occurred at all temperatures between 21 and 28 C, with maximum inhibition at 25 C.

Our results indicate that the amount of inhibition of hypocotyl elongation is influenced by length of exposure to inhibiting temperatures between 21 and 28 C. This range of inhibiting temperatures permits the use of ordinary laboratory facilities for large‐scale testing of soybean genotypes in a breeding program.