bluuebunny/crossref_metadata_2025 huggingface dataset:
Transfer of a Smoothleaf Allele from Gossypium Barbadense L. to Gossypium Hirsutum L.1
Authors: Lee Joshua A.
Published: July 2010

Five generations of backcrossing of the Gossypium barbadense L. line, ‘AS‐2 Sea Island,’ to the upland G. hirsutum L. stock, ‘Station Glandless,’ attended by selection for leaf and stem smoothness, produced a truebreeding upland population homozygous for a smoothleaf allele at the sm1 locus.
Differential Response to Hail Damage among Pima Cotton Strains1
Authors: Kittock D. L. , Feaster C. V. , Turcotte E. L.
Published: July 2010

Large differences in vegetative regrowth among nine cultivars were noted in an American Pima cotton (Gossypium barbadense L.) regional test after severe hail damage on 22 July 1974. These differences were correlated negatively with the lint yield of the same cultivars in a nearby, undamaged, Pima cotton regional test. Correlations of number of new leaves and dry weight of new leaves 5 weeks after hail with lint yield on the undamaged test were −0.84 and −0.91, respectively. Theories on transport and utilization of photosynthate in cotton were used to explain differences in recovery among cultivars.
Space‐planted and Mass‐seeded Progeny Tests for Seed Yield and Seed Size in Tetraploid Crested Wheatgrass1
Authors: Schaaf H. M.
Published: July 2010

Twenty‐four tetraploid crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] genotypes were evaluated as clones (parents), open‐pollination (OP) progenies, and topcross (TC) progenies. Parents and OP's were grown in replicated spaced plantings and assessed for spikes/plant, seeds/spike, seed yield, and seed size (mg/100 seeds). Mass‐seeded OP's and TC's were evaluated for seed yield and seed size in replicated singlerow plots.

Although space‐planted and mass‐seeded progenies provided similar evaluations of seed‐yidd potential, method of culture caused sizable shifts in the expression of seed size. When seeking simultaneous improvement of both characters, selecting parents on the basis of spaced‐progeny performance appeared to retain some undersirable genotypes, the effects of which could decrease the efficiency of recurrent selection. The heritability of all four characters was lower for the spaced progenies than for the seeded progenies. In addition, space‐planting altered the relationship of seed size to spikes/plant, seeds/spike, and seed yield.

Correlations of 0.83 and 0.85 (P < 0.001) for seed yield and seed size, respectively, demonstrate close similarity of OP and TC performance in mass‐seeded tests.
Interrelationships of Seedling Vigor Criteria of Wheat Under Different Field Situations and Soil Water Potentials1
Authors: Gul Azam , Allan R. E.
Published: July 2010

The relationships among emergence rate index (ERI), total stand (TS), culm length, coleoptile length, seedling height, root weight, and kernel weight of 93 wheat (Triticum aestivum L. em Thell.) lines and four check cultivars were studied at four different water potentials (—2.2, —6.0, —10.2, and —14.4 bars) in the laboratory and in three eastern Washington field situations (Lind shallow‐sown, Lind deep‐sown, and Pullman).

The ERI values of the three field tests correlated with one another but they gave small or nonsignificant r values with ERI's from the four laboratory water potential levels. The marked differences in planting depth and water potential level between the field and laboratory could explain the lack of relationship.

Coleoptile length, seedling height, and culm length correlated positively with field ERI. In the laboratory, however, ERI at only —2‐2 bars correlated significantly with coleoptile length and seedling height. Kernel weight inconsistently correlated with ERI and gave significant positive r values with field ERI on two occasions but had a significant negative r value with ERI of one laboratory water potential level. In the laboratory, the association between ERI and TS, ERI and root weight, and TS and root weight became progressively closer as the water potential decreased and verified other work that showed fast‐rooting lines emerge better than slow ones under low soil‐water potential.

As with ERI, significant correlations were found between both TS and coleoptile length and TS and seedling height in field studies. These seedling traits (field) were independent of the TS values obtained at the four water potentials (laboratory). Kernel weight gave low or nonsignificant r values with field and laboratory TS values. Comparisons of both ERI and TS values in field tests and at low water potentials (laboratory) suggest that different genetic systems regulate the growth potential of these wheat lines under these contrasting environments.

The optimum advance from selection should be achieved by testing wheat lines for seedling vigor (ERI, TS) under diverse field situations and at low soil water potentials (—10.2, —14.4 bars).
Changes in Nonstructural Carbohydrate Fractions of Developing Spring Wheat Kernels1
Authors: Escalada J. A. , Moss Dale N.
Published: July 2010

Nonstructural carbohydrate fractions were studied at four stages of kernel development of wheat (Triticum aestivum L. em. Thell.) to quantify the amounts present and differentiate sucrose from the glucofructan (GF) fractions. We accomplished this by using different ethanol concentrations to extract different oligosaccharide fractions followed by hydrolysis with acid or incubation with takadiastase enzyme. Concentrations of ethanol from 100 to 60% yielded steadily increasing perc.entages of nonstructural carbohydrates, indicating a series of GF of increasing chain length. Glucose to fructose ratios of 1:14 were found in GF extracted with 60% ethanol from the residue of the 70% ethanol extraction.

Carbohydrate content/kernel gave a clearer picture of nonstructural carbohydrate changes with maturation of the grain than did concentration. The glucose, fructose, and glucofructan contents reached maxima before the phase of rapid starch synthesis, but then decreased as the kernels matured. Sucrose content, however remained high during the rapid phase of starch accumulation before decreasing at Kernel maturity.
Temperature Requirements for Growth of Grass‐clump Dwarf Wheats and the Inheritance of the Trait1
Authors: McVetty P. B. E. , Canvin David T. , Hood C. H.
Published: July 2010

Grass clump dwarf wheat plants (Triticum aestivum L. em Thell.) are characterized by their reduced stature, increased tiller number, and frequent lack of reproductive growth. Three types of grass‐clump dwarf wheat plants occur in the progeny of crosses of normal wheat cultivars. Temperature has been shown to have a dramatic effect on the growth of the most severe dwarf but its effect has not been investigated with the less severe dwarf types. On the other hand, the inheritance of the trait has been most studied with the less severe dwarf types. In this study the temperature requirement for normal growth of the three types of grass‐clump dwarfs and the inheritance of the trait was determined.

Crosses of several common wheat cultivars were made and the F1's were grown in controlled environmental growth cabinets under conditions of continuous 16,146 to 18,299 lux incandescent/fluorescent illumination and constant temperature regimes of 11, 16, 21, and 26 C.

In general, type 1 dwarfs grew normally at temperatures of 26 C or higher, type 2 dwarfs grew normally at 21 C or higher, and type 3 dwarfs grew normally at 16 C or higher. At temperatures below these values, the characteristic grass‐clump dwarf morphology was displayed in plants possessing a dwarfing genotype.

Conventional genetic analysis of F2 populations and F3 lines showed that a three complementary dominant gene system adequately explained and predicted the origin of grass‐clump dwarfs in inter‐class wheat crosses.
Organic Acid Composition of Tall Fescue Leaves from Diverse Genotypes1
Authors: Boland R. L. , Garner G. B. , Asay K. H. , Nelson C. J.
Published: July 2010

Organic acids are important plant metabolites and have been associated with palatability and forage quality. Gas‐liquid chromatography was used to quantify nine organic acids in leaves of 22 genetically diverse tall fescue (Festuca arundinacea, Schreb.) genotypes grown in a greenhouse. Significant differences (p < 0.01) were found among genotypes in concentration of malic, citric, x‐ketoglutaric, succinic, malonic, quinic, shikimic, and total of the nine acids. Malic acid was most abundant in 19 genotypes and averaged 9.3 mg/g dry wt, followed by citric, succinic, quinic, and shikimic acids with 4.4, 3.6, 3.5, and 2.6 mg/g dry wt, respectively. Concentrations of fumaric and aconitic were usually less than 0.1 mg/g dry wt. A genotype selected from ‘Ky 31’' had 19.3, 6.6, and 38.8 mg/g dry wt of malic, citric, and total of the nine acids, respectively. In contrast, a genotype from Algeria had 3.5, 1.2, and 15.1 mg/g dry wt for the same fractions.

Malic acid concentrations were positively correlated (p < 0.01) with quinic, shikimic, and citric acid levels. Succinic acid was positively correlated with a‐ketoglutaric acid, and shikimic acid was positively correlated with quinic acid. The genetic variability observed indicates organic acid content of tall fescue leaves could be altered through breeding.
Effect of Water Stress on 14CO2 Fixation and Translocation in Wheat during Grain Filling1
Authors: Johnson R. R. , Moss Dale N.
Published: July 2010

Field canopies of two semi‐dwarf wheat (Triticum aestivum L.) genotypes were subjected to water stress that caused visible wilting during the grain filling stage to determine the distribution of photosynthesis within the canopies and the pattern of translocation of labeled assimilates following 14CO2 uptake. The stress treatment caused a 14% reduction in kernel weight and a 20% reduction in grain yield compared to control plants.

Plants in the control and stress plots were exposed to 14CO2 at 12, 16, and 23 days after heading. During this time, the severity of stress increased on the stress plots. Under water stress, the site of photosynthesis tended to shift away from leaf lamina to the upper leaf sheaths, upper portions of the stem, and the spike.

Within 24 hours after labeling, the majority of the 14C had been transloeated from leaves and sheaths; in stressed plants 46% of the 14C (averaged over genotypes and dates of exposure) was found in the grain compared to 35% in control plants. Of the total 14C recovered from shoots at maturity, 83% was found in the grain of stressed plants and 69% in control plants. The lower percentage of 14C in grain of control plants at maturity was due to accumulation of 14C in stem segments, primarily in the form of structural carbohydrates.

As the lower leaves became senescent, the relative contribution of spikes, upper sheaths, and stems to total photosynthesis increased. The percentage of the present in the grain at 24 hours and at maturity was greatest when 14CO2 was fixed later in the grain filling period.
Selection for Early Flowering in Corn: Seven Late Synthetics
Authors: Troyer A. F. , Brown W. L.
Published: July 2010

Seven corn (Zea mays L.) synthetics adapted to southern Iowa were grown in southern Minnesota at high plant density, and the earliest 5% to flower were sibmated for five generations. The original populations and the five selected cycles were then compared in performance trials at three plant densities over 2 years. Selection effect per cycle averaged: 1.1 q/ha yield increase, 2.2 ears/100 p.lants increase (1‐year data), 1.6 percentage points grain moisture decrease, 2.8% stalk breakage increase, 6.1 cm plant height decrease, 4.1 cm ear height decrease, 1.7 days less to flower, and 0.4 days less silk delay.

We observed a cycle‐by‐density interaction wherein advanced cycles exhibited prolificacy at a low density after selection against barrenness at high densities. The decrease in silk delay and increase in ears per plant indicate that selection for early flowering during stress is effective in adapting materials to high plant densities.

Flowering date is highly heritable and responds readily to selection. Selection for early flowering is an effective way to adapt late corns to an earlier area. It provides more genetic divergence than the pedigree method or other breeding schemes that use early germplasm as donor of maturity genes.

Strong correlated responses to selection for early flowering were found for lower kernel moisture, lower plant and ear height, and higher stalk breakage.

Earlier flowering increased yields among late flowering corns and decreased yields among early ones. Earlier flowering increased yields in a short, cool season and decreased yields in a long, warm season. These phenomena can be explained by the contrasting relationships of flowering date with plant size and length of grain filling period: earlier flowering increases yield when longer grain filling period is critical and decreases yield when larger plant size is more important.
Genetic Association between Yield and Fiber Strength in Upland Cotton1
Authors: Scholl R. L. , Miller P. A.
Published: July 2010

Genetic variances anl correlations were measured on the segregating progeny of a cross between two upland cotton (Gossypium hirsutum L.) cultivars. One cultivar (‘TH‐149‐8‐5’) had high lint yield and high fiber strength, whereas the other parental cultivar (‘Lankart 57’) had low lint yield and low fiber strength. Previous studies of genetic correlations between lint yield and fiber strength in upland cotton have shown that there is a negative association between these two traits. However, in the previous studies, high yield and high fiber strength were introduced from opposite parents in the cross. The present study was undertaken to determine if alteration of this relationship between parental means would change the observed genetic association in the progeny population. Eighty‐nine progeny families, generated by selling individual F2 plants, were evaluated in two replicates in each of three environments for lint yield, several yield components, and fiber quality indices. Population means were generally intermediate to the parental means, and significant genetic variance was found for each trait. Genotypic correlations generally agreed in both sign and magnitude with past estimates. The genotypic correlations between lint yield and the fiber quality traits were generally negative. Both 2.5% span length and fiber strength (T1) were negatively correlated with yield (both −0.36). Significance of the correlations and the expected gain from selection were discussed.
Ontogenetic Changes in Respiration and Photosynthesis in a Uniculm Barley1
Authors: Winzeler H. , Hunt L. A. , Mahon J. D.
Published: July 2010

Respiratory (R) and photosynthetic (P) rates, together with root and shoot dry weights (W) and leaf areas were measured at intervals throughout the ontogeny of a uniculm barley (Hordeum vulgate L.) grown at three temperatures (15, 20, 28 C). Increasing shoot photosynthesis per unit area of leaf lamina as the plants aged was probably related to the increasing contribution by non‐laminar tissue. Absolute values appeared to be higher than those reported in other cultivars. The rates of both shoot and root respiration on a dry weight basis decreased throughout the life cycle with a more rapid decline in the early stages and with a more rapid decline in the shoots than in the roots. The R/P ratio decreased from an initially high value to a minimum and increased again as the plants matured. The period during which minimum ratios were obtained depended on the temperature. The relationship between R/W and P/W appeared curvilinear with a greater slope in the early growth stages. The results emphasize that care should be taken in the choice of coefficient's for application in a two parameter respiration model.
Use of Progenitor Species Germplasm for the Improvement of a Cultivated Allotetraploid1
Authors: Wernsman E. A. , Matzinger D. F. , Mann T. J.
Published: July 2010

The suitability of progenitor species germplasm as a source of genetic variation for the improvement of quantitatively inherited genetic traits in a cultivated allotetraploid species was investigated. Tobacco, Nicotiana tabacum L. cv. SC 58 was doubled with colchicine to the octoploid state and crossed with the diploid progenitor species N. sylvestris Speg. and Comes. The partially fertile pentaploid hybrid was selfed, or backcrossed one generation to SC 58, to increase fertility. Two cycles of a recurrent selection scheme using SC 58 as a tester parent were then followed to concentrate desirable germplasm from N. sylvestris in the species‐derived synthetic populations.

The two synthetic populations (Syn I and Syn II), 58, S1 families, and testcrosses to SC 58 of plants in Syn I which were used to produce Syn II were evaluated in three environments for 11 agronomic and chemical constituents. Significant differences were detected among genetic entries for all characters measured except percent nornicotine in cured leaf, indicating that germplasm from the diploid species, N. sylvestris, had been introgressed into the N. sylvestris genome of tobacco. The potential value of this genetic variation is demonstrated by the fact that Syn I and Syn II yielded 7.7 and 12.9%, respectively, more cured leaf than SC 58. Thus, the breeding technique may be useful in broadening the genetic base for the improve. merit of quantitatively inherited characters in this cultivated species.
Factors Affecting Haploid Plant Production from in vitro Anther Cultures of Nicotiana Species1
Authors: Tomes D. T. , Collins G. B.
Published: July 2010

Twenty seven Nicotiana species were evaluated for their response to the in vitro culture of immature anthers on chemically defined media. Several variables were examined for their effect on haploid plant production from anther culture: stage of microspore development, anther culture medium, pretreatment of anthers prior to placing on culture medium, and stage in the flowering cycle when floral buds were collected. Thirteen Nicotiana species produced plants from anther culture. N. glutinosa L., N. knightiana Goods., N. paniculata L., N. rustica Schrank, N. sylvestris Speg. and Ccmes, and N. tabacum L. produced primarily haploid plants from anther culture. Diploid plants were obtained from the anther cultures of N. bonariensis Lehm., N. longiflora Cav., N. langsdorfii Wein., N. nudicaulis Wat., N. plumbaginifolia Viv., and N. stocktonii Brand. Plants of undetermined ploidy level were obtained from N alat Link and Otto anther cultures. Anthers cultured at the binucleate microspore stage produced plants more frequently, and more plants were produced per anther from these cultures than from anthers cultured at other microspore stages. Anthers from floral buds collected from plants in flower for an extended period did not produce as many plants as anthers from floral buds collected from plants in earlier stages of flowering. Low temperature anther pretreatment increased the number of plants produced from such anthers under certain conditions, but did not extend the number of species in which haploid plants were formed. The effect of culture medium varied with the species, length of flowering time when anthers were collected for culture, and pretreatment conditions.
Interrelationships Among Gland Density, Gossypol Content, and Lint and Seed Characters in Cotton1
Authors: Wilson F. D. , Lee J. A.
Published: July 2010

We crossed a heavily glanded, agronomically inferior strain of cotton, (Gossypium hirsutum L.), to a normally glanded, agronomically acceptable strain. The former has a high percentage of gossypol (2.63%) in flower buds (squares) whereas the latter has a much lower percentage (0.95%). In the F2, none of the five visual methods selection for high gossypol content that we used were particularly efficient, but some were significantly correlated with gossypol content. Probably the most useful one in this population was a rating of the number and size of glands on the calyx lobes. Stigma glands/mm identified as many plants with a high gossypol content, but was not as practical because glands had to be counted. Boll glands/cm2 was uncorrelated with gossypol content. The two other visual methods that we used, distribution of glands on the style, and rugose, heavily glanded bolls, were impractical in this population because too many F2 plants were saved. Even though gossypol content was significantly negatively correlated with boll size and lint percentage, correlations were low and should not constitute formidable barriers to improvement.
Hill Plots for Preliminary Yield Evaluation of Doubled Haploids in a Barley Breeding Program1
Authors: Walsh E. J. , Park S. J. , Reinbergs E.
Published: July 2010

Fourteen dolbled haploids and six commercial cultivars of barley (Hordeum vulgare L.) were grown at two locations in Ontario, Canada, in 1972 and 1973. The materials were planted in row and hill plots and were studied for grain yield, heading date, and plant height. The hill plots were seeded by three planting methods (jab planter, stove pipe, and hand hoe seeding) with three seeding rates (15, 25, and 35 seeds per hill) for each method. The combined analysis over locations and years showed that neither genotype ✕ planting method nor genotype ✕ seeding rate interactions were significant, indicating that genotypic responses in grain yield to different planting methods or seeding rates were similar. The coefficients of variation were relatively higher in the hill plots as compared to row plots but this was compensated for by the larger genotypic differences in the hill plots. Genetic variance among lines and heritability for grain yield were generally higher in hill plots. For both years, the genotypic correlation between row and hill plots, as well as the selection efficiency in hill plots. remained high, suggesting that selection of lines for conventional row planting through the hill plot technique would be efficient. Ten replications were found to be appropriate for testing barley in hill‐plot tests in Ontario.
Development of Cotton Fruit. III. Amino Acid Accumulation in Protein and Nonprotein Nitrogen Fractions of Cottonseed1
Authors: Elmore C. D. , Leffler H. R.
Published: July 2010

This study was conducted to determine the metabolic events occurring during cottonseed development as revealed by N and amino acid compositions of both the whole seed and the free amino acid pool. Flowers on field grown cotton (Gossypium hirsutum L.) plants were tagged the day of anthesis, and bolls were sampled at intervals between 10 days after bloom and maturity. Developing seed were analyzed for both total N and nonprotein N (NPN). While total N was accumulated by the seed throughout development, NPN increased until 21 days after anthesis and then declined. At boll opening, only about 1% of the total N was in the NPN fraction.

Amino acid compositions of the seed and the NPN fraction were also determined. In juvenile seed tissue, over 50% of the NPN was accounted for by asparagine. Other amino acids prominent in this free amino acid pool of young cottonseed were, in descending order, glutamine, aspartic acid, glutamic acid, and arginine. At maturity, asparagine and glutamic acid each accounted for about 15% of the NPN. Gamma‐amino butyric acid and ethanolamine were also observed in the NPN fraction. Significant shifts in total amino acid distribution were seen to occur during the fourth week of seed development. The amino acid profile of cottonseed after the fifth week of development closely approximated that of mature seed.
New Genes for Resistance to the Green Leafhopper in Rice1
Authors: Siwi Bernard H. , Khush Gurdev S.
Published: July 2010

The inheritance of resistance to the green leafhopper (Nephotettix virescens Distant) was studied in 13 cultivars of rice (Oryza sativa L.). Seedlings at the one‐leaf stage were artificially infested in the greenhouse with second‐ and third‐instar nymphs of the green leafhopper. Seedling reaction was recorded one week after infestation. A single dominant gene that is allelic to the dominant gene Glh 1 originally identified in ‘Pankhari 203’, conveys resistance to green leafhopper in ‘Jhingasail’. The rice cultivars ‘Godalki’, ‘Lien‐tsan 50’, and ‘Palasithari 601’, each possess a single dominant gene for resistance, located at the Glh 2 locus, originally identified in ‘ASD 7’. The resistance in ‘Betong’, ‘DNJ 97’, and ‘H 5’ is conditioned by single dominant genes that are allelic to Glh 3 originally found in ‘IR8’. Single dominant genes that are independent of Glh 1, Glh 2, and Glh 3 convey resistance to the green leafhopper in ‘ASD 8 (Thuyamalli)’, ‘ARC 6602’, ‘DM 77’, ‘DS 1’, and ‘Khama 49/8’. A single recessive gene that is independent of Glh 1, Glh 2, and Glh 3 conveys resistance to the green leafhopper in ‘Ptb 8 (Chuvannari Thavalakkannan)’. This recessive gene is designated glh 4. The single dominant gene conditioning resistance in ASD 8 is designated Glh 5. We do not know the allelic relationships to glh 4 and Glh 5 of the dominant genes that convey resistance to the green leafhopper in ARC 6602, DM 77, DS 1, and Khama 49/8.
Variation Among Winter‐type Selections of Safflower1
Authors: Ghanavati N. A. , Knowles P. F.
Published: July 2010

Plants with a long‐rosette period were identified in one of the local populations of safflower (Carthamus tinctorius L.) from northwestern Iran. Fifty‐one lines developed from these plants showed considerable variation in winter hardiness, seed yield, oil content, oil yield per hectare, number of heads per plant, and 1,000‐seed weight. The superior winterhardiness of rosette (winter) types over non‐rosette (spring) types should permit fall seeding of safflower in areas where winter temperatures go as low as −15 C.
Relationship of Hydroxamic Acid Content in Corn and Resistance to the Corn Leaf Aphid1
Authors: Long B. J. , Dunn G. M. , Bowman J. S. , Routley D. G.
Published: July 2010

The cyclic hydroxamate, 2,4‐dihydroxy.7‐methoxy‐l,4‐benzoxazin‐ 3‐one (DIMBOA), has been implicated in the resistance of corn (Zea mays L.) to fungi and insects. In our study, bioassay and field experiments tested the relationship between hydroxamate concentration and resistance to corn leaf aphid (Rhopalosiphum maidis (Fitch)).

In the bioassay, various concentrattons of DIMBOA were added to an artificial diet fed to corn leaf aphids. DIMBOA concentrations of 0.1, 0.25, and 0.5 mg/g diet caused 5.1, 12.8, and 20.8% mortality, respectively. In field trials, 12 inbred lines were evaluated for corn leaf aphid resistance under natural infestation. Aphid infestation was evaluated at mid‐silking stage with a visual rating scale and index system. Cyclic hydroxamate concentration in a separate set of the same lines was estimated by a rapid procedure based upon the colorimetric reaction of hydroxamates with ferric chloride. Aphid infestation values ranged from 119 to 366. Hydroxamate concentration ranged from 0.08 to 1.48 mg/g fresh weight. A highly significant correlation (r = 0.72) was obtained between aphid infestation and hydroxamate concentration.

Eighteen hybrids derived from crosses among 12 inbred lines were also evaluated for corn leaf aphid resistance in the field. Aphid infestation values from high ✕ high, intermediate ✕ intermediate, and low ✕ low DIMBOA lines were generally low, intermediate, and high, respectively. Hybrids derived from crossing high ✕ low, high ✕ intermediate, and intermediate ✕ low DIMBOA lines produced infestation values between the parental extremes.
Origin and Composition of a Texture Layer on Seeds of Mungbean1
Authors: Watt Earl E. , Poehlman J. M. , Cumbie Billy G.
Published: July 2010

The surface of mungbean seeds with a dull luster was observed to have a thick covering of cell‐like ridges and crosswalls which is designated the texture layer. Similar, but much less pronounced ridges were observed on seeds with a shiny luster. The thick texture layer of dull seeds could be removed by scraping and with a sodium hydroxide solution. In dull green seeds the texture layer was translucid, the green color originating from a shiny green seed testa underneath which was visible through the texture layer. In dull brown and brownish‐black seeds the texture layer contained a brown pigment which masked the green or green‐black mottled color of the shiny seed testa underneath. We suggest that the texture layer originates from the inner pod membrane Which contracts, becomes fractionated as it dries, and partly adheres to the seed surface. Therefore the texture layer is a reticulated deposit and not an outgrowth from the seed testa. Only thin remnants of the pod membrane maybe observed on shiny seeds, the amount depending on the depth at which the fracture of the membrane occurs. Chemical analyses support these observations. Tests of the texture layer for presence of waxes and pectins were negative. A test for carbohydrates was positive with quantity of carbohydrates in the texture layer from dull seeds three to four times that in the texture layer from shiny seeds. The component monosaccharides included glucose, xylose, arabinose, and galactose, supporting histological observations that the texture layer is made up of remnant cell walls.
A Second Major Gene Locus in Corn for Chlorotic‐Lesion Resistance to Helminthosporium turicum1
Authors: Hooker A. L.
Published: July 2010

Gene Ht2 that conditions a form of chlorotic‐lesion resistance to Helminthosporium turcicum Pass, was identified in the Australian dent corn (Zea mays L.) inbred NN14. Inbred NN14 also carries a second gene at the Ht locus. The two genes are not linked. Gene Ht2 conditions a lower level of resistance than does Ht but the two genes interact together to condition a higher level of resistance than either gene alone.
Role of Multiple Awns in Determining Barley Yields1
Authors: Rasmusson D. C. , Crookston R. K.
Published: July 2010

We developed barley (Hordeum vulgare L.) lines differing in number of awns to learn if yield would be increased by the presence of additional awn tissue. Experimental procedures included field experiments conducted over several years, and structural characterization of awn tissue by light and scanning electron microscopy.

In “multiple awn” lines the glumes are the size of lemmas and have an awn at their apex. These lines therefore contain three awns per spikelet, compared to one awn per spikelet in normal awned lines. Glume awns are structurally similar to normal awns and possess stomata which appear to be functional. The multiple awn lines had 46% more awn tissue by weight, and 76% more by length, than ‘Dickson’. The large glumes supporting the extra awns had six and‐a‐half times the surface area of normal glumes.

The multiple awn lines produced lower grain yields than normal awn lines. Yields ranged from 50 to 88% of Dickson. At least three factors appeared to be involved in the yield decrease; the multiple awn lines were less robust, they had an average of 15 fewer kernels/head, and their kernels were 10% lighter (indicating the absence of component compensation). The reduced plant size suggests that the multiple awn gene affects overall plant growth. We postulate competition for substrate during floral initiation and development to explain the marked reduction in kernel number. The reduced kernel weight presumably means that the extra awns and large glumes had a net negative effect on photosynthate deposition in the kernel.
Sorghum Root Morphogenesis and Growth. I. Effect of Maturity Genes1
Authors: Blum A. , Arkin G. F. , Jordan W. R.
Published: July 2010

Root development of two sorghum [Sorghum bicolor (L.) Moench.] maturity isogenic lines (early – 60 SM and late – 100 M) was closely studied in plants growing up to 38 days after emergence (DAE) in hydroponics. Each adventitious (crown) root was tagged upon appearance and periodically measured for length. Root diameters, root volume, leaf area, and transpiration were also measured periodically. Seminal roots and mesocotyls were removed on some plants at 10 DAE, in order to simulate the effect of some common fungal or insect damage in the field.

The onset of initiation of adventitious roots occurred at 4 and 6 DAE in the early and late genotypes, respectively. Root initiation rates cycled with time, within a range of 0 to 1.5 roots‐plant‐l−day−1. Cycling of root initiation rates appeared to correspond with the formation of concentric whorls of these roots in the crown. Total number of adventitious roots at 38 DAE was 17 and 23 in the late and early genotypes, respectively. In the early genotypes, growth rate of adventitious roots that were initiated at an early stage was the same as for roots initiated later, being about 3 cm day−1 In the late genotype, growth rate of later initiated roots was slower than that of roots initiated earlier. Although the early genotype had a greater total adventitious root length per plant than the late one, the latter had a greater root volume than the former, due to greater number and growth of lateral branches.

Removal of the seminal root and mesocotyl increased the number and growth of lateral branches of existing adventitious roots and subsequently increased root volume in the early genotype. Similar effects were not observed in the late genotype.
Nodulation of Soybeans Grown Hydroponically on Urea1
Authors: Vigue J. T. , Harper J. E. , Hageman R. H. , Peters D. B.
Published: July 2010

Soybeans [Glycine max (L.) Merr.] were grown hydroponically to determine the effects of urea‐ and nitrate‐N sources on nodulation. Urea allowed effective nodule development and function, as evidenced by nodule mass, acetylene reduction, and difference between the total Kjeldahl N gain per plant and urea uptake measurements. Plants grown in solutions with as high as 18 mM urea‐N produced nodules capable of N2 fixation (C2H2 reduction assay) while NO3 concentrations low as 2 mM inhibited nodulation. The amount of N fixed by nodules of plants grown on urea varied from 27 to 71% of total plant N, depending on urea concentrations of the nutrient solutions.

Urea uptake by the plants was slower than NO3 uptake, regardless of urea concentration supplied. Therefore, internal concentrations of N or N‐components in the plant were likely lower with urea than with NO3 nutrition which may have partially accounted for the degree and effectiveness of nodulation. Growth on urea is a convenient hydroponic method of producing healthy, vigorous, nodulated soybeans that are capable of N2 fixation.
Simultaneous Screening of Soybeans Against Three Races of Phytophthora Megasperma Var. Sojae1
Authors: Kilen T. C. , Keeling B. L.
Published: July 2010

Soybean [Glycine max (L.) Merr.] genotypes, differing in response to three physiologic races of Phytophthora megasperma Drechs. var. sojae Hildeb, were inoculated with each individual race and with a mixture of the three races in a hydroponic system. No antagonistic effect among races was found. Any genotype showing susceptibility to one or more races when tested individually was also found to be susceptible when tested with the mixture of three races. The results indicate that the technique would simplify screening for multiple race resistance to phytophthora rot.
Path Coefficient Analysis of Sugarbeet Purity Components1
Authors: Smith G. A. , Martin S. S. , Ash K. A.
Published: July 2010

An analysis of the association of 10 chemical and agronomic characters with purity in three sugarbeet (Beta vuigaris L.) genotypes was used to develop models to identify the components having the greatest effect on purity.

Potassium, betaine, and Na followed by NO3‐N, amino N, and sucrose were the most important variables in the 12 best models developed to explain purity. R2 values (percentage of ascribed variation in purity) for these 12 best models ranged from 89.5 to 94.7%. Soluble nonsucrose constitutents increased in quantity from high plant population density to low density, but this linear change did not greatly affect models constructed to account for juice purity either at regular or low N fertility.
Recognition of Translocations and Alien Chromosome Transfers in Wheat by the Giemsa C‐banding Technique1
Authors: Gill Bikram S. , Kimber Gordon
Published: July 2010

The identification of the wheat chromosome arms involved in four translocation situations has been made through Giemsa staining. One translocation is between wheat (Triticum aestivum L. em. Thell.) chromosomes 4A and 6B, one between rye (Secale cereale L.) chromosome 1R and wheat chromosome 1D and two different translocations between chromosome 6cu of T. umbellulatum (Zhuk.) Bowden and 6B of wheat.
Protein Quality of Triticale. I. Early Generation Selection for Protein Efficiency Indices1
Authors: Knoblauch C. J. , Elliott F. C.
Published: July 2010

The feasibility of selection for protein efficiency indices (PEI = grams body weight gain per protein consumed) in the early generations of a breeding program was studied with selected winter triticale (✕ Triticosecale Wittmack) lines. Weanling vole (Microtus pennsylvanicus) bioassays of seed from F3 plants along with several F4 plant selections from each F3 indicated that selection for protein efficiency indices was practical as early as the F3 generation.

The evacuation period used to simulate beginning caecal weight reduced PEI values appreciably; however, only minor changes in ranking were found. Caecal accumulation had little effect other than increasing cereal protein efficiency indices without negating the nutritional comparisons among the early generation triticale lines tested.
Protein Quality of Triticale. II. Prediction of Protein Efficiency Indices Through Chemical Analyses1
Authors: Knoblauch C. J. , Elliott F. C. , Penner D.
Published: July 2010

Several chemical determinations of triticale (✕ Triticosecale Wittmack) meals have shown promise of predicting protein efficiency indices (PEI = g body weight gain per g protein consumed) as determined by Microtus bioassay. The percent water‐soluble protein (pH 4.9), total trypsin units inhibited (total TUI, adjusted for percent water‐soluble protein), and extracted dye‐binding capacity (DBC completed after removal of water‐soluble proteins) showed the highest correlations with PEI. A group of 42 F4 winter triticale plants representing seven F4 plants from each of two high F3 PEI plants, two average F3 PEI plants and two low F3 PEI plants, were analyzed. The correlations with PEI were −0.45, −0.53, and 0.66 (P<0.01) for percent water‐soluble protein, total TUI, and extracted DBC, respectively. The multiple correlation coefficient utilizing total TUI and extracted DBC was 0.74**.

A group of 20 F3 plants selected for high and low PEI values gave even more predictable responses. Their correlations with PEI were −0.71, −0.79, and 0.66 for percent water‐soluble protein, total TUI, and extracted DBC, respectively. The multiple correlation coefficient for the regression of extracted DBC and total TUI on PEI was 0.86**, indicating that 75% of the variation in PEI was accounted for by the two independent variables.
Floral Induction and Initiation in Kentucky Bluegrass Cultivars1
Authors: Canode C. L. , Perkins Merlin
Published: July 2010

This research was designed to study induction and floral initiation of 11 cultivars of Kentucky bluegrass (Poa pratensis L.). Spring‐seeded plants were in the vegetative condition when exposed in autumn to inductive environment (cool temperatures and short photoperiods). Floral initiation was determined by 1) biweekly dissection of tillers and by 2) biweekly transfer to warm temperature and long photoperiod to force panicle production.

Dissection of tillers showed no transition to floral development from early November, 1974, to 4 Jan., 1975. Transition to floral primordia was. apparent for ‘Merion’ and ‘Newport’ on 27 January, six cultivars on 10 February, and all 11 cultivars on 25 February. ‘Cougar’, ‘Fylking’, and ‘Glade’ require a longer induction period than the other cultivars before floral initiation.

Transfer of plant material from field inductive conditions to warm temperature and long photoperiod in a greenhouse indicated that induction had not occurred before 18 November. Panicles were produced by ‘Arista’, ‘Baron’, ‘Garfield’, and Newport when transferred on 2 December and by an additional four cultivars when transferred on 16 December. Glade and Fylking did not produce panicles until the transfer was made on 27 January, again indicating the longer induction period necessary for these cultivars. Induction and floral initiation, as measured by panicle production, increased in linear association (r = 0.98**) with duration of time plants were left under inductive conditions.

Either method of study, tiller dissection or transfer to artificial environment, has advantages and disadvantages. This research indicates that the two methods are complementary and valuable to understanding induction and development of floral primordia when used concurrently.
Photosynthesis, Stomatal Resistance, and Enzyme Activities in Relation to Yield of Field‐grown Dry Bean Varieties1
Authors: Peet M. M. , Bravo A. , Wallace D. H. , Ozbun J. L.
Published: July 2010

Photosynthetic rates, stomatal resistances and the activities of three enzymes; ribulose bisphosphate carboxylase (RuBPCase), malate dehydrogenase (MDH), glycolate oxidase (GAO) were determined for nine fieldgrown dry bean (Phaseolus vulgaris L.) varieties. Measurements were made during several developmental stages; vegetative growth, flowering, early pod set, and late pod set. All data were compared to biological and seed yields using seasonal averages as well as using data from each developmental stage separately.

Photosynthetic rates and RuBPCase activities were highest at early pod set, which was the only developmental stage where they were significantly correlated with biological yields. Also at pod set MDH activities were significantly correlated with both seed yield and harvest index, and GAO activity was correlated with biological yield. GAO activity was highest at flowering. The amount of the increase in photosynthesis from flowering to pod set of each variety was correlated positively with its final seed yield.

While photosynthetic rates at pod set were positively correlated with both biological and seed yield in eight of the varieties, in one variety high seed yields were associated with very low photosynthetic rates. This variety, however, also had an exceptionally high harvest index and high MDH and GAO activities. Thus high seed yields are not necessarily associated with high photosynthetic rates but may result from a more efficient utilization of photosynthate.
Termination of Late Season Cotton Fruiting with Plant Growth Regulators1
Authors: Kittock D. L. , Arle H. Fred
Published: July 2010

Chemical termination of cotton (Gossypium spp.) fruiting is a new proposed insect control technique. Development of effective fruiting termination treatments is the objective of this research. Treatments were applied to field plots (11 to 20 m long) between 15 August and 10 September. We found two types of plant‐growth‐regulator response: 1) fast acting and non‐persistent; and 2) slow acting and persistent. Mixutres of the two types produced the most effective chemical termination treatments. Two effective growth regulators of each type were identified. The slow acting, persistent growth regulators were chlormequat or CCC, [(2‐chloroethyl)trimethylammonium chloride], and chlorflurenol, (methyl 2‐chloro‐9‐hydroxyfluorene‐9‐carboxylate). The fast acting growth regulators were 2,4‐D. [(2,4‐dichlorophenoxy) acetic acid], and TD 1123, (3,4.dichloroisothiazole 5‐carboxylic acid). 2,4‐D was applied at 37 g/ha when used alone, and usually at 28 g/ha in mixture with other plant growth regulators. The most effective rates for chlormequat and chloroflurenol were 560 g/ha in mixture and about twice that rate when applied alone. TD 1123 was applied in mixture at 1121 g/ha. Mixtures of 2,4‐D with either of the two persistent growth regulators produced more effective chemical termination than 2,4‐D applied alone. These three treatments have been tested extensively and found effective. They are suitable for use by entomologists for large scale testing of chemical termination for insect control. In limited testing, TD 1123 appeared to be superior to 2,4‐D when used in mixture with the persistent plant growth regulators.
Sunflower Moth Damage and Inheritance of the Phytomelanin Layer in Sunflower Achenes1
Authors: Johnson A. L. , Beard B. H.
Published: July 2010

Inheritance of the phytomelanin layer in sunflower (Helianthus annuus L.) achenes was studied in association with resistance to the sunflower moth (Homoeosoma electellum Hulst.). The F2 and F3 populations of four crosses between resistant lines with the layer and a susceptible line without were evaluated for presence of the layer and moth‐damaged seeds.

Segregation ratios for the layer indicated a single locus with a dominant allele determining its presence and recessive alleles determining its absence. There was no indication of differences due to modifying egnes. We suggest Pml pml as symbols for these alleles.

Seed damage was determined from natural and artificial (hand) infestations. Each method has advantages and disadvantages, but with either method there was less larval damage in seeds with the layer than in seeds without.

In laboratory tests older larvae were able to penetrate nearly mature seeds, even those with the phytomelanin layer; but the damage was greater on seeds without the layer. Younger larvae could penetrate immature seeds (1 to 3 days after pollination) but penetration appeared to become more difficult as the seeds developed. Seeds with the phytomelanin layer were not penetrated by young larvae 13 to 15 days after pollination.
Water Relations and Growth of Soybeans in Drying Soil1
Authors: Heatherly Larry G. , Russell W. J. , Hinckley T. M.
Published: July 2010

Soybean plants (Glycine max (L.) Merrill ‘Hill’) were grown in moist soil in ll4‐1iter containers for 63 days in the greenhouse, and then subjected to a 9‐day drying cycle to evaluate water relations and growth in a drying soil. On day 1 of the drying cycle, measurement of xylem pressure potential (P), leaf diffusive resistance (RL), area, soil water potential (SWP), and root dry weight was initiated. Measurements were made at 0500 to 0630, 1000 to 1200, and 1400 to 1600 hours (CDT) on days 1, 3, 5, 7, and 9. The earliest time period was before sunrise. Atmospheric demand was calculated for each sample period.

Xylem pressure potential at each time period of each day decreased linearly with, and was significantly related to (R2 = 0.97, 0.92, and 0.93, respectively) decreasing base (presunrise) SWP of the drying soil for the duration of the experiment. The data indicated the possibility of estimating P of plants growing in a drying soil from base values of SWP. Extremes in atmospheric demand, as well as SWP, influenced levels of P of plants growing in wet soil. The largest decline in P occurred between the presunrise and 1000 to 1200 hour time periods of each day in both soil environments. Presunrise wilting of plants growing in the drying soil occurred at day 7, when the corresponding base (presunrise) P was about —18 bars. No establishment of a water potential gradient between upper‐ and mid‐canopy leaves occurred in either soil environment. Decline in leaf enlargement corresponded to a base P of about —4.5 bars, and cessation of enlargement occurred when base P was between —10 and —12.9 bars.

As SWP and P declined, RL increased. Vapor pressure deficit (VPD) was the most significant single determinant of RL (R2 = 0.56) at the 1400 to 1600 hour time period; however, the interaction between VPD and P influenced RL more than either variable singly at this time period (R2 = 0.67). The interactions between VPD and base and between VPD and base SWP both influenced RL above the level of single variable effect at both the 1000 to 1200 and 1400 to 1600 hour time periods.