bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of Kentucky Bluegrass Strains to Feeding by the Sod Webworm1
Authors: Buckner R. C. , Pass B. C. , Burrus P. B. , Todd J. R.
Published: July 2010

A Kentucky‐grown common lot of Kentucky bluegrass (Poa pratensis L.) was more resistant to sod webworm (Crambus spp.) injury than cultivar and common lots frcm Demnark and Holland. Certain selected strains had either consistently greater resistance or greater susceptibility to injury than Kentucky‐grown common, indicating that sources of resistance exist that may be used in developing cultivars with resistance to sod webworm injury.

Feeding trials, total sugar, and silica content of the foliage failed to reveal the nature of resistance to sod webworm. Resistant strains had heavier weights of rhizomes during May than suspectible strains. This indicated the possibility of a relationship between stored food reserves prior to the stress period and resistance to sod webworm injury during the summer.
Fatty Acid Composition of Oil from Normal and High‐Amylose Backcross Strains of Corn (Zea mays L.)1
Authors: Jellum M. D. , Helm J. L. , Fergason V. L. , Zuber M. S.
Published: July 2010

Gas‐liquid chromatography was used to determine the fatty acid composition of oil extracted from the germ and endosperm fractions of the corn kernel. Four normal dent inbred lines and high‐amylose strains derived with one to four generations of backcrossing to the normal recurrent parents were studied. Significant differences in palmitic, stearic, oleic, linoleic, and linolenic acids were found among inbred lines and generations of backcrossing. Oil composition of the germ for three of the four inbreds tended to regress toward the oil composition of the recurrent parent with increasing number of generations of backcrossing. For all backcross strains and normal inbreds, the oil from the endosperm was higher in palmitic, stearic, and linolenic acids and lower in linoleic acid when compared with the germ oil. No consistent relationship between endosperm and germ oil was shown for oleic acid. The endosperm oil of the high‐amylose strains was higher in palmitic and stearic acids and lower in linoleic acid than the endosperm oil of the normal recurrent parents. Composition of the endosperm oil from high‐amylose strains did not regress toward the recurrent parent values with increasing number of generations of backcrossing.
Comparative Morphology of Haploids from Cultivated Alfalfa, Medicago sativa L.1
Authors: Bingham E. T. , Binek A.
Published: July 2010

Eight haploids (2n=2x=16) of cultivated alfalfa Medicago sativa L. (2n=4x=32) isolated after 4x−2x crosses were compared morphologically with each other and with the four tetraploids from which they were derived. Haploids in general had smaller leaves and flowers, distinctive leaflet shape, lacked normal leaflet serrations, and had fewer stomatal chloroplasts than their tetraploid parents. The most definitive morphological characteristic was the lack of normal serrations. All haploids could be propagated by shoot cuttings. Seven of the haploids expressed abnormal morphological, anatomical, or physiological characteristics. Deleterious genes revealed in the haploid state and use of morphology in screening for haploids were discussed.
Hybrids Between Tetraploid and Hexaploid Crested Wheatgrasses1
Authors: Dewey Douglas R.
Published: July 2010

Doubled‐diploid Agropyron cristatum (L.) Gaertn., 2n=28, and tetraploid A. desertorum (Fisch. ex Link) Schult., 2n=28, hybridized with hexaploid A. cristatum, 2n=42. Meiosis in the parent plants was typical of that in autoploids. Pentavalent associations, up to five per cell, in the 35‐chromosome hybrids indicated close homologies between parental genomes. Occasional higher multivalent associations and bridge‐fragment formations at anaphase I indicated some structural heterozygosity.

All crested wheatgrasses—whether diploid, tetraploid, or hexaploid—apparently contain one basic genome that has undergone some structural rearrangements. It is recommended that crested wheatgrasses be regarded as one species with taxonomic differentiation at the subspecies and varietal levels.

The pentaploid hybrids were surprisingly fertile and ranged from 0.54 to 4.32 seeds per spikelet under open pollination. Some hybrids were considerably more vigorous than either parent and may have value in a breeding program. Interploidy hybridization is recommended to crested wheatgrass breeders.
Pericarp Thickness of Dent Corn Inbred Lines1
Authors: Helm J. L. , Zuber M. S.
Published: July 2010

The thickness of excised pericarp strips was determined on 33 corn (Zea mays L.) inbred lines grown near Columbia, Missouri, during the period 1964 to 1967. The pericarps ranged 62 to 160 µ in thickness. The distribution was uniform without evidence of clustering. The rankings of the inbreds were very uniform across years. Thus, when grown under the same basic cultural conditions and production practices, the pericarp thicknesses of the 33 inbred lines in this sample were influenced little by seasonal environments.
Cytotaxonomic Relationships and the Role of Apomixis in Speciation in Buffelgrass and Birdwoodgrass1
Authors: Read J. C. , Bashaw E. C.
Published: July 2010

A sexual buffelgrass clone (Cenchrus ciliaris L. = Pennisetum ciliate (L.) Link.), heterozygous for method of reproduction, was crossed with apomictic birdwoodgrass (C. setigerus Vahl.) to determine the relationship of these species. The F1 population contained both sexual and obligate apomictic plants representing a rather complete intergradation between the parents. High fertility of the hybrids and homology of their chromosomes showed that the parents are closely related and undoubtedly belong to the same genus. Some of the hybrids were so different from either parent that populations from them might easily be mistaken for new species. With selfing, average fertility of apomictic hybrids was nearly three times that of sexual hybrids. The diversity of hybrids resulting from brief contact between sexual and apomictic plants and the superior fertility of the obligate apomicts illustrate the dynamic evolutionary potential of apomixis.
Intraspecific Hybridization in Dallisgrass, Paspalum dilatatum Poir.1
Authors: Bennett Hugh W. , Burson Byron L. , Bashaw E. C.
Published: July 2010

Rare intraspecific Paspalum dilatatum Poir, hybrids (2n=45) were produced by using a yellow‐anthered sexual biotype (2n=40) as the female and a common apomictic biotype (2n=50) as the male. All F1 hybrids were sexual In meiosis, the chromosomes formed 20 bivalents and 5 univalents, which indicates that the biotypes are closely related. The yellow‐anthered biotype may be one of the common biotypes' ancestors. Because the univalents were lost during meiosis in the F1 and F2; all F3, F4, and F5 plants had 40 chromosomes which formed 20 bivalents during meiosis. All progeny were sexual.

Semidecumbent habit of growth served as the basis for a selection program regardless of additional selection for any other plant characteristic. Selection for improved seed fertility was practiced among semi‐decumbent segregates. Seed set increased progressively from 40, 70, to 80% for the F2, F3, and F4 generations, respectively

Semidecumbent F6 lines exceeding 90% seed set indicate the effectiveness of intraspecific hybridization as a breeding procedure for the improvement of apomictic types.
Pollen Fertility Restoration by Three Spring Wheats (Triticum aestivum L.) of the Male Sterility Induced by T. timopheevi Cytoplasm1
Authors: Joppa L. R. , McNeal F. H.
Published: July 2010

Fifty introductions of spring wheat, Triticum aestivum L., from throughout the world were crossed as males to a line of spring wheat containing the cytoplasm of T. timopheevi and the nucleus of ‘Selkirk.’ Three of the introductions (PI 167841, PI 277013, and PI 277016) contained genes for pollen fertility restoration.

F1 plants from crosses of two male sterile varieties containing T. timopheevi cytoplasm with PI 277013 and PI 277016 were almost completely fertile under our conditions. These two introductions from Spain provide an additional source of a gene, or genes, with pollen fertility restoration capabilities.
A Search for High Net Photosynthetic Rate among Soybean Genotypes1
Authors: Cannell R. Q. , Brun W. A. , Moss D. N.
Published: July 2010

Two thousand four hundred and fifty‐eight genotypes of soybean (Glycine max (L.) Merr.) were screened for survival at a low carbon dioxide concentration near the CO2 compensation point of Zea mays L. Survival in such an atmosphere requires a low CO2 compensation point and indicates a high maximum net photosynthetic rate. None survived. The CO2 compensation points of 44 soybean genotypes, chosen from among those which died first and last in the screening procedure, were not significantly different from each other with the exception of one which was slightly higher. The CO2 compensation points of 6 other Glycine species were similar to that of Glycine max (L.) Merr.
Organ Specificity and Genotypic Differences in Isoperoxidases of Soybeans1
Authors: Brim Charles A. , Usanis S. A. , Tester C. F.
Published: July 2010

Starch gel electrophoresis was used to examine the heterogeneity of peroxidases in various organs of the germinating seed of soybeans. Isoperoxidase banding patterns were compared in four varieties. Each of the organs examined had a characteristic banding pattern. Differences in banding pattern were greater from organ to organ within varieties than differences between varieties, however, genotypic differences were detected for one cationic and four anionic bands.
Winter Hardiness and Changes in Soluble Protein Fractions of Bermudagrass1
Authors: Davis D.L. , Gilbert W.B.
Published: July 2010

Regrowth data taken following a freezing test indicated that two bermudagrass (Cynodon sp.) cultivars gradually increased in winter hardiness during the autumn and early winter months. Maximum resistance, which represented a change of approximately 6.0 C, was reached during January and February. A decrease in hardiness was observed as the grass initiated new growth in the early spring.

Polyacrylanfide gel electrophoresis was used to characterize the changes in soluble protein fractions in the overwintering parts. When plants were exposed to a hardening environment for more than 15 days, two of the bands present in nonhardened material decreased in density and were more widely separated. Other protein changes during overwintering included the appearance of four cempact and well defined bands near the origin. These changes may reflect alterations in the metabolic systems that are related to the hardening process. Comparable data were obtained in field and growth chamber studies.
Nitrogen Nutrition and Photosynthesis in Sugar Beet (Beta vulgaris L.)1
Authors: Nevins D. J. , Loomis R. S.
Published: July 2010

Nitrogen deficiency was evaluated as an ecological factor affecting CO2 assimilation in sugar beet (Beta vulgaris L.) leaves. Nitrogen deficiency reduced the chlorophyll concentration and photochemical capacity of the older leaves but not of young and recently mature leaves. The maximum rate of photosynthesis was reduced in leaves of all ages. This was correlated with a smaller leaf protein content and with an increase in CO2 diffusion resistances. Although the rate of photosynthesis was reduced as much as 40% when plants were grown for 14 days without nitrogen, the effects were reversible, and activity could be restored to the normal rate within 4 days by adding nitrate nitrogen to the deficient nutrient solution.
Glucosinolate Content of Rapeseed (Brassica napus L. and B. campestris L.) Meal as Influenced by Pod Position on the Plant1
Authors: Kondra Z. P. , Downey R. K.
Published: July 2010

Three major glucosinolates “gluconapin,” “glucobrassicanapin,” and “progoitrin” were quantitatively determined in rapeseed meal for three pod positions on plants of the varieties ‘Nugget’ (Brassica napus L.) and ‘Echo’ (B. campestris L.) grown in three environments. Significant position effects were found for all three glucosinolates in Nugget, but only for gluconapin in Echo when position effects were averaged for three environments. However, within environments the pod position effects did not always follow these patterns. Single pod samples should be restricted to the same position on each plant to reduce the random variation in glucosinolate content. The effect of environment on the glucosinolate content of seed from plants grown under three environments was significant. Comparisons of glucosinolate values for plants grown at different times or locations should be avoided.
Differential Effects of P, K, and Ca Salts on Leaf Composition, Yield and Seed Size of Soybean Lines1
Authors: de Mooy C. J. , Pesek John
Published: July 2010

Significant responses and differential responses in yield, seed size, and leaf composition were found among soybean lines (Glycine max (L.) Merrill) grown in pots in the open. Varietal differences in grain yield response were mainly caused by P and P ✕ Ca interaction factors. Seed size was also differentially affected by K. The N, P, K, Ca, and Mg contents of the leaves at all stages of development were strongly influenced by fertilization. The average range of P and K contents for the varieties, caused by fertilization, narrowed towards the end of flowering. Differential effects in foliar P and N content developed gradually during the season. Average critical percentages of P, K, and Ca at the end of flowering for yield of grain at maturity were 0.45, 2.15, and 1.51, respectively.

Further screening and verification of the results in the field are required to isolate desirable characteristics for soybean breeding programs from different soybean lines.
Effects of Potassium Nutrition on Protein and Total Free Amino Acids in Zea mays1
Authors: Hsiao Theodore C. , Hageman R. H. , Tyner E. H.
Published: July 2010

Corn (Zea mays L.) seedlings were grown in nutrient solutions that ranged in K content from none to sufficient. In comparison with K‐sufficient plants, the shoots of K‐deficient plants exhibited up to 40% increase in protein concentration while the amount of protein per shoot was much reduced. The concentration of free amino acids was increased by about threefold in extreme deficiency, but was hardly affected by moderate deficiency although growth in the latter case was still much retarded.

During the development of K deficiency, the ratio of free amino acids to protein in leaves of two different ages did not increase until growth was retarded; similarly the amount of protein per leaf in the maturing leaf was not affected until growth was substantially reduced. When K was added to deficient plants, to permit their recovery, the ratio of free amino acids to protein in the shoot did not decrease for many hours after K was detected in adequate amounts in the shoots. The ratio decreased only after the added K had induced an increase in growth. This suggests that there was no acceleration of polymerization of amino acids resulting directly from the added K.

The specific activities of aldolase and triosephosphate dehydrogenase were some 30% lower in deficient than in sufficient shoots. The level of nitrate reductase in the tissue, however, appeared to be related to the supply of nitrate and not to the K level.

These data do not support the contention of K level in deficient plants being low enough to directly limit the polylnerization of amino acids and of a reduced rate of protein synthesis being the primary factor limiting growth of K‐deficient plants.
Genetic Nature of the Concentration of 2,4‐dihydroxy‐7‐methoxy 2H‐l,4‐benzoxazin‐ 3(4H)‐one and Resistance to the European Corn Borer in a Diallel Set of Eleven Maize Inbreds1
Authors: Klun Jerome A. , Guthrie W. D. , Hallauer Arnel R. , Russell W. A.
Published: July 2010

A diallel set of 11 inbreds of maize, Zea mays L., was used to study the concentration of 2,4‐dihydroxy‐7‐methoxy‐ 2H‐l,4‐benzoxazin‐3 (4H)‐one (DIMBOA) in the whorl tissue and the resistance to leaf feeding by firstbrood European corn borers, Ostrinia nubilalis (Hubner). The correlation between concentration of the chemical in the plant tissues and level of resistance to leaf feeding by the first‐brood borer was highly significant statistically for the inbreds (r = −0.89**) and the single crosses (r = −0.74**). Also, effects due to general and specific combining ability were highly significant for both traits, but general combining ability accounted for 84% of the variation in the resistance ratings and for 91% of the variation due to concentration of DIMBOA. These results provide further evidence that DIMBOA is a chemical factor in the resistance of maize to the European corn borer and that an objective chemical analysis for DIMBOA in the whorl portion of the maize plant can serve as an indicator of resistance to leaf feeding by the first‐brood European corn borer and possibly eliminate the visual resistance ratings.
Natural Cross‐Fertilization in Veronia anthelmintica (L.) Willd1
Authors: Berry C. D. , Lessman K. J. , White G. A.
Published: July 2010

Vernonia anthelmintica (L.) Willd. was found to be self‐fertile but partially cross‐pollinated in contrast to the reported self‐sterility of species of Vernonia occurring naturally along the southeastern Coastal Plain of the United States. The vernonia flower has characteristics which should promote self‐pollination. A recessive white‐flower character was used to test for cross‐pollination. No crossing occurred when white‐flowered plants were grown with the normal violet‐flowered plants in the greenhouse. When the two types were grown together in the field, however, at least 13% crossing was indicated by the presence of violet‐flowered plants among the progenies of the white‐flowered maternal parents. Pollen for natural crossing is thought to be insect borne.
Perloline Inhibition of in vitro Ruminal Cellulose Digestion1
Authors: Bush L. P. , Streeter C. , Buckner R. C.
Published: July 2010

Perloline, an alkaloid isolated from Festuca arundinacea, inhibited in vitro cellulose digestion by microorganisms of rumen fluid. Digestion of purified cellulose was more sensitive to perloline than was the digestion of cellulose in leaf tissue of F. arundinacea. Poor performance of cattle grazing F. arundinacea may be related to the effect of perloline on the digestion of cellulose by rumen microorganisms.
Estimation of Genetic Variances Using Inbred Relatives1
Authors: Stuber C. W.
Published: July 2010

A procedure for estimation of additive, dominance, and additive by additive genetic variances using two types of covariances among inbred relatives is outlined. Inbred relatives are generated by bulk selfing each of the F1 (non‐inbred) progenies in mating designs such as Design I and II. With appropriate linear functions of covariances among inbred relatives, genetic variances defined for the non‐inbred reference population are estimated with no restrictions on gene frequencies or number of alleles per locus. Although the use of inbred relatives is applicable for both cross‐ and self‐pollinated species, the utility of inbred relatives should be greater for self‐pollinators. Use of covariances among inbred relatives is illustrated with a set of data from a maize study.
Effect of Genotype and Tannin on Dry Matter Digestibility in Sericea Lespedeza1
Authors: Donnelly E. D. , Anthony W. B.
Published: July 2010

Dry matter digestibility (DDM) was determined the in vivo nylon bag technique on two cuttings of low‐ and high‐tannin sericea plants (Lespedeza cuneata [Dumont] G. Don). Low‐tannin sericea was higher in DDM than normal or high‐tannin sericea. Differences in DDM were indicated among low‐ and high‐tannin genotypes. Low‐tannin plants increased in tannin content relatively little from the first to the second cutting compared to high‐tannin plants. The second cutting of low‐ and high‐tannin plants averaged as high in DDM as the first cutting. Tannin and DDM were negatively correlated only when low‐ and high‐tannin plants were combined except for the second cutting of low‐tannin plants. Data indicate a tannin threshold in sericea which is critical in relation to DDM.
Yuma Glandless, an Allelomorph of Glandless‐one in Cotton, Gossypium birsutum L.1
Authors: McMichael Scott C.
Published: July 2010

Yuma glandless, gl1y, forms a multiple allelomorphic series with Gl1 and gl1. Yuma glandless is recessive to Gl1 but dominant to gl1. Normal cotton plants have glands of two distinct sizes. Yuma glandless gene eliminates the smaller glands.
A Possible Source of Cytoplasmic Male Sterility in Intermediate Wheat‐Grass, Agropyron Intermedium (Host) Beauv.1
Authors: Schulz‐Schaeffer Jurgen
Published: July 2010

Amphidiploid Triticum durum Desf. × Agropyron intermedium (Host) Beauv. and T. durum × A. trichophorum (Link) Richt. hybrids were backcrossed twice to A. intermedium and A. trichophorum. A pronounced increase in male sterility was observed in the series from the amphidiploid (AD) to the first and second substitution backcross generations (SB1 and SB2). Male sterility estimates averaged 53.4% in the AD, 83.6% in the SB1 and 96.8% in the SB2. Approximately 69% of all SB2 plants were 99 to 100% male sterile.
Leaf and Panicle Size of Sorghum Parents and Hybrids1
Authors: Quinby J. R.
Published: July 2010

Sorghum (Sorghum bicolor L. Moench) parents and hybrids were measured for leaf blade width and length and their panicles were weighed. Each entry was observed for time of floral initiation and time of flowering. Hybrids had smaller leaf blade areas at maturity than female parents and differences in leaf blade area appeared not to be important differences between parents and hybrids. Panicles of hybrids were heavier than those of parents and were produced in less time. The important difference between parents and hybrids appeared to be a difference in growth rate in favor of hybrids that began in the embryo and finally resulted in larger panicles in hybrids.
Outcrossing in the Ryegrass (Lolium spp.) as Determined by Fluorescence Tests1
Authors: Copeland L. O. , Hardin E. E.
Published: July 2010

Studies were conducted to determine the amount and distance of outcrossing between fluorescent and nonfluorescent strains of ryegrass. Both experimental spaced‐plant conditions and grower seed fields were investigated.

There was substantially less crossing among plants grown in seed fields than in plots of spaced plants. Beyond 6 m from the border, outcrossing became negligible between all cultivars tested. Beyond 12 m from the border there was no evidence of crossing.
Cytology and Crossing Behavior of Triploid Alfalfa1
Authors: Binek A. , Bingham E. T.
Published: July 2010

Cytology and crossing behavior of triploid alfalfa (2n=3x=24) were studied in 15 plants from 2x‐4x and 4x‐2x crosses involving Medicago sativa and M. falcata. Chromosome associations in PMCs averaged 2 to 3 trivalents, 5 to 6 bivalents, and 3 to 4 univalcnts. Triploids were effectively male sterile although pollen grains were about 32% germinable in sucrose solution. Seed set was higher in 3x‐4x crosses than in 3x‐2x crosses. 3x‐2x progeny ranged from 16 to 32 chromosomes. Among 61 progeny examined there were 40 with 16 chromosomes, seven trisomics, nine double trisomics, three plants with 30 chromosomes, and two plants with 32. 3x‐4x progeny ranged from 28 to 40 chromosomes. Among 229 progeny, there were 78 (34%) with 32 chromosomes, 109 (4870) aneuploids with fewer than 32 chromosomes, and 35 (15%) aneuploids with greater than 32. About 3% of the functional female gametes were unreduced and gave rise to tetraploids from 3x‐2x crosses and pentaploids from 3x‐4x crosses. Use of triploids in cytogenetic research and in germplasm transfer was discussed.
Embryonic Leaf Number in Sorghum1
Authors: Clark L. E.
Published: July 2010

The number of embryonic leaves in mature embryos of Sorghum was determined for 11 cultivars of Sorghum bicolor (L.) Moench.s, weet sudangrass(S. sudanense(Piper) Stapf.), johnsongrass (S. halepense (L.) eers.), shattercane (a group of weedy‐type sorghums constituting a hybrid swarm). A minimumof 10 embryos of each entry was examined. All cultivars of S. bicolor and shattercane had four embryonic leaves. Johnsongrass and sweet sudangrass had only three embryonic leaves except one embryo of sweet sudangrass had four leaves. To determine the embryonic leaf number in Sorghum it is beneficial to examine both longitudinal and transverse serial sections of the embryos. The data reported establish the constancy of embryonic leaf number among seeds within a cultivar and among cultivars within a species.
Effect of Temperature on Self‐fertility and In Vitro Pollen Growth Characteristics of Selected Alfalfa Clones1
Authors: Straley Charles , Melton Bill
Published: July 2010

Eight alfalfa clones, Medicago sativa L., were evaluated for self‐fertility and pollen growth characteristics under four temperature regimes (16, 21, 27, and 32 C). Highly significant differences were found among clones and among temperatures. Highly significant clone ✕ temperature interactions were found for self‐fertility, in vitro pollen germination, and in vitro pollen tube elongation. Pollen germination and tube elongation were not correlated with self‐fertility with one exception, self‐fertility and pollen germination at 16 C.
Relationship Between Crown Moisture Content and Killing Temperature for Three Wheat and Three Barley Cultivars1
Authors: Metcalf E. L. , Cress C. E. , Olein C. R. , Everson E. H.
Published: July 2010

A quantitative investigation of the relationship between freeze‐damaged plant crowns and the percent moisture of the crowns was conducted. ‘Wong,’ ‘Hudson,’ and ‘Dicktoo’ barleys (Hordeum vulgare L.) and ‘Genesee,’ ‘Illinois 59‐884’ (CI 14023), and ‘Redcoat’ wheats (Triticum aestivum L.) were the cultivars studied. Artificial freezing tests, over a temperature range of —18 to —7 C and over a range of adjusted plant crown moisture percentages of 55 to 75%, were used. Crown damage was assessed as a root regrowth rating on an arbitrary scale of 0 to 9. Equations were obtained for each cultivar relating root regrowth to crown moisture and killing temperature. Predicted root regrowth was plotted against crown moisture and killing temperature as curves representing several levels of survival. The close relationship which exists between moisture content and freezing injury at specific temperatures was clearly demonstrated. Dicktoo barley and Illinois 59‐884 wheat were the cultivars most resistant to freeze‐damage. Macroscopic pictures of freeze‐damaged plant crowns are included.
A Reduced‐Hull Seed Character of Safflower1
Authors: Urie A. L. , Zimmer D. E.
Published: July 2010

We found an achene (seed) characteristic, reduced‐hull, in progeny of a cross between normal‐hull safflower (Curthamus tinctorius L. var. ‘Ute’) and a purple‐striped line. The reduced‐hull character results from a reduction of the outer sclerenchyma layers of the pericarp. Experimental reduced‐hull lines possess 27 to 33% hull, 41 to 44% oil, and they significantly out‐yield ‘US‐10,’ a standard check variety.
Responses of Some Kentucky Bluegrasses to High Temperature and Nitrogen Fertility1
Authors: Watschke T.L. , Schmidt R. E. , Blaser R. E.
Published: July 2010

Five Kentucky bluegrasses (Poa pratensis L.) were grown at three temperature regimes: 18 C light and 10 C dark; 27 C light and 18 C dark; 35 C light and 20 C dark; and two N rates (15 and 150 ppm N) in solution culture. High temperature increased respiration rates; consequently, plants with high carbohydrates best supported growth at high temperatures. Bluegrasses originating in warm regions appeared more tolerant of high temperatures because of higher carbohydrate levels, lower NO3‐N absorption, and lower foliar NO3‐N than those from cooler regions. Preconditioning at cool temperatures enhanced tolerance of all grasses to high temperatures. Management of grasses can also influence tolerance to high temperatures; however, genetic adaptation is of most importance for survival at high temperatures.
Agronomic Properties Associated with the Glandless Alleles in Two Varieties of Upland Cotton1
Authors: Hosfield George L. , Lee J. A. , Rawlings J. O.
Published: July 2010

Experiments conducted at the North Carolina Agricultural Experiment Station showed that, after five generations of backcrossing, glandless strains of upland cotton (Gossypium hirsutum L.) yielded from 5 to 10% less fiber than their glandular recurrent parents. Replicated trials involving normal (dimeric), semi‐glandless (monomeric), and glandless lines were performed over a period of 3 years at three locations to test the hypothesis that reductions in performance were associated with the glandless alleles. Two varieties were used, and there were four genotypes. In the ‘Coker 100‐A’ varietal background most of the loss in productivity was associated with the g12 allele, whereas the gl2 allele was largely neutral in its effects. Several characters other than fiber yield were affected in some way by the presence of gl2. In the ‘Empire’ background both gl2 and gl3 were associated with yield reduction, and gl2 affected a few other characters. In both varieties gl2 had much more drastic effects than gl3 and affected more characters. Although the experiments were not designed to distinguish between linkage and pleiotropic effects, the pattern of the effects suggested that linked factors were the major cause of the loss in performance.
Factors Influencing Water Absorption by Seeds of the Crested Wheatgrass Complex1
Authors: Keller Wesley , Bleak Alvin T.
Published: July 2010

Seeds of crested wheatgrass Agropyron desertorum (Fisch. ex Link) Schult., Fairway wheatgrass A. cristatum (L.) Gaertn., and their hybrid were subjected to preplanting wetting treatments for various durations and rate of water absorption was determined. Within the temperature range 4.5 to 27.8 C absorption appeared directly proportional to temperature. Absorption was very rapid at the beginning, decreasing with time. In 12 hr seeds absorbed about half the total water absorbed in 90 hr. Percent increase in seed weight gave a linear relation with log of time. Rate of absorption differed significantly with different strains and seed lots. Breeder seed produced in different years on a single field of ‘Nordan’ crested wheatgrass yielded significantly different regressions, only partially explained by age, size of seed, or precipitation the year the seeds were produced. Variations in quality or quantity of water used or method of treatment did not yield consistent differences in rate of absorption.
Identification of Photoperiod Insensitive Strains of Maize (Zea mays L.). II. Field Tests in the Tropics with Artificial Lights1
Authors: Francis C. A. , Sarria V. D. , Harpstead D. D. , Cassalett D. C.
Published: July 2010

Maize genotypes adapted to tropical regions were tested in the field for sensitivity to a change in photoperiod. Near the equator, with naturally equal light‐dark periods, materials were evaluated by a technique which extended day length and created an intensity gradient with artificial light. Some genotypes, including one temperate‐zone hybrid, were relatively insensitive to day length or intensity differences. Most genotypes showed a delay in floral differentiation, when grown in extended days with light intensities above one or two critical levels (5 and 1 to 2 fc, or 54 and 11 to 22 lux). The technique permits evaluation of numerous strains in the field, and has possible applications during the winter in higher latitudes.
Variety‐Specific Variants of Oxidative Enzymes from Soybean Seed1
Authors: Larsen Arnold L. , Benson William C.
Published: July 2010

Three distinct electrophoretic patterns in acrylamide gel zymograms are associated with specific soybean varieties. The patterns represent at least two different enzymes, including peroxidase, hut collectively are called “INT–oxidases.” The enzymes, extracted from dry soybean seeds, inhibit the reduction of colorless iodonitrotetrazolium‐violet (INT) into the red INT‐formazan and thus appear as clear bands on a red background.
Genetic Control of Ovule Number in Peas (Pisum sativum L.)1
Authors: Krarup H. Aage , Davis David W.
Published: July 2010

A complete, six‐parent diallel cross plus F2's and backcrosses was used to study the inheritance of basic ovule number in Pisum sativum L. Ovule number was found to be controlled by a simple additive genetic system. Dominance effects were of no relative importance. There was some slight indication of partial dominance for low over high ovule number. Heritability was estimated as 0.38; no reciprocal effects were found.
Recovery from Shoot Fly Attack in a Sorghum Diallel1
Authors: Starks K. J. , Eberhart S. A. , Doggett H.
Published: July 2010

A diallel test of crosses between sorghum (Sorghum bicolor (L.) Moench) varieties having high, intermediate, and low levels of “recovery resistance” (tolerance) to the sorghum shoot fly, Atherlgona varia Meigen, showed that the inheritance of this character is complex. Additive gene action contributed most to the variation among entries in percentage of recovered plants, but specific and epistatic effects were also significant. The average heterosis was 11% for the single cross mean over the mean of the parents, and the correlation between yield and percentage recovered plants was very high. Cultivars ‘Namatare’ and ‘Serena’ proved valuable in the short‐term breeding work, and populations (including derivatives of these cultivars) are being established for the longer term recurrent selection program. They should be effective in view of the largely additive genetic variance in recovery resistance.
Inheritance and Linkage of A Virescens and A Chlorina in Beta vulgaris L.1
Authors: Stander J. R. , Theurer J. C.
Published: July 2010

Inheritance and linkage relationships were studied for a chlorina and a virescens in sugarbeets, Beta vulgaris L. The virescens differed from the types previously reported as to the color of the affected leaves and the time required to develop normal pigmentation. It was conditioned by a simple recessive gene designated vi4. Chlorina from irradiated SLC 03 seed was the same as ch2 chlorina. Its inheritance as a simple recessive was confirmed. Linkage data showed independent inheritance for vi4 with factors for yellow pigmentation (Y), red pigmentation (R), annual growth habit (B), Mendelian sterility (a1), and ch2. The ch2 gene showed independence with R, a1, and vi4.
Herbicide Effects on Soybean [Glycine max (L.) Merrill] Seed Lipids1
Authors: Penner Donald , Meggitt William F.
Published: July 2010

Herbicide effects on soybean [Glycine max (L.) Merrill] seed oil content and fatty acid composition as related to yield and injury were determined for 27 herbicide treatments involving 13 herbicides on the soybean cultivars, ‘Chippewa’ and ‘Harosoy.’ Although the two cultivars differed in fatty acid composition and yield, there were no significant differences in their response to herbicide treatments. None of the treatments significantly altered the percentage oil content in the seed. However, small but significant changes in fatty acid composition, yield, and injury were observed. Increases in the percent stearic acid content were correlated with decreases in the percent linoleic acid content. Considering all treatments, there was no general correlation of changes in fatty acid composition with yield or injury.
Inheritance of Resistance to Stripe Rust and its Association with Brown Glume Color in Tritieum aestivum L., ‘P.I. 178383’1
Authors: Metzger R. J. , Silbaugh B. A.
Published: July 2010

F2, F3, and backcross generations, representing crosses of ‘P.I. 178383’ (resistant) ✕ ‘Orin’ and ‘Elgin’ (susceptible) were observed in the field for their response to stripe rust and for glume color segregation. A major gene for stripe rust resistance was found to be associated with the gene that regulates brown glume color in P.I. 178383. The two loci are separated by approximately two crossover units. Stripe rust resistance governed by the major gene was not associated with awnedness and spike density.
Approach Crossing of Rice (Oryza spp.)1
Authors: Erickson John R.
Published: July 2010

The use of the approach method of cross‐pollinating rice has given an overall average of 57% hybrid seed set. The amount of time needed to make crosses, and the amount of parental material grown for making crosses has been reduced substantially. This has allowed many more hybridizations to be made with available facilities.
Vegetative Bud Activity in Blue Panicgrass1
Authors: Spiers J. M. , Holt E. C.
Published: July 2010

Bud activity (number of elongated buds) and length of shoot growth from buds were determined in rhizome, crown, and stem tissues of blue panicgrass (Panicum antidotale Retz). Three plants were selected semimonthly from a uniformly fertilized plot. From each of these plants, four samples of viable stem, crown, and rhizome buds were sampled at random. Bud activity was determined by an in vitro method, utilizing a non‐nutritive agar solution. Bud activity appeared to be cyclic in nature, occurring initially in rhizome and crown areas followed by stem bud activity after the plant reached maturity, and then activity moved from the stem back to the rhizome and crown areas later in the season. Shoot growth from rhizome buds increased linearly throughout the season. Stem and bud shoot growth followed a cubic curve in relation with time, reaching a peak in late May, declining in vigor until September, and then increasing at the end of the growing season.
Effect of Environment During Seed Production on Seedling Vigor of Two Alfalfa Varieties1
Authors: Walter L. E. , Jensen E. H.
Published: July 2010

Effect of two air temperatures (hot = 16 to 32C, x̄ = 24C; cool = 6 to 21C, x̄ = 13C) and three soil moisture regimes (wet = 1/6 to 1/3 bar tension, moderate = 1/3 to 1 bar tension, dry = 1 to 10 bars tension) on ‘Moapa’ and ‘Ranger’ alfalfa (Medicago saliva L.) seed production and seedling vigor was studied under controlled environmental conditions. Moapa produced more and heavier seed and had a lower percentage of hard seed than Ranger. When seeds were scarified and grown for 22 days under similar conditions, regardless of seed density, Moapa seedlings emerged faster and were larger than Ranger, but Ranger seedlings developed leaves faster than Moapa.

Seeds produced under cool temperatures were heavier and had a higher percentage of hard seed than those produced under hot temperatures. Seed produced under cool temperatures produced larger seedlings of Ranger, but temperature during seed production had little effect on vigor of subsequent Moapa seedlings.

Seedling vigor of Ranger seed produced under cool conditions increased with decreasing soil moisture. Soil moisture had little effect on vigor of Moapa seedlings produced under hot or cool temperatures. Seedling vigor was increased with heavier seed density.

Air temperature and soil moisture regimes during seed production not only affected seed yield, size, and germination but also influenced vigor of subsequent seedlings.
Effects of Nitrogen on Heading and on Other Components of Bromegrass Seed Yield in the Subarctic1
Authors: Klebesadel L. J.
Published: July 2010

Five rates of nitrogen, from 0 to 270 kg/ha (0 to 240 Ib/A), were topdressed in spring on a 3‐year‐old stand of ‘Polar’ bromegrass (predominantly Bromus inermis Leyss. × B. pumpellianus Scribn.) in subarctic, southcentral Alaska, and compared during the same and the tollowing year for influence on factors that affect seed yield. In the year of application, spikelets per panicle and weight of seed per panicle increased with increasing rates of N. Different rates of N did not influence panicles per unit area or seeds per spikelet in the year of application. Although differences were not statistically significant, seed yields in the year of different N applications displayed a pattern suggestive of N influence but only as engendered through intra‐panicle yield components.

In the following year, when all plots received N in spring at 100 kg/ha (90 Ib/A), the various levels of N applied the previous year affected markedly both panicles per unit area and seed yields per hectare but did not influence seed weight per panicle. These results indicate that for subarctic areas late summer N application should promote higher bromegrass seed yields the following year than application in spring of the year of harvest.

The number of panicles per 1.4 m2 was approximately equivalent to the seed yield in kilograms/hectare (panicles/l.5 yd2 = seed yield in pounds/acre) in both years when spring N application during the same year was 90 kg/ha (80 Ib/A) or more. At lower rates of N, this formula over‐estimated seed yields because of lowered seed yield per panicle.
Variation in Indolealkylamine Content of Individual Phalaris aquatica L. Plants1
Authors: Rendig V. V. , Welch R. M. , McComb E. A.
Published: July 2010

Plants of Phalaris aqtiatica L. (syn. P. tuberosa L.) ‘Stenoptera’ grown from seed have widely varying differences in their concentrations of N,N‐dimethyltryptamine and N,N‐diniethyl‐5‐methoxytryptamine. Although some variation was anticipated, the magnitude of the differences was beyond expectation and in sharp contrast to the indolealkylamine content of plants propagated vegetatively. It is suggested that the variation noted may have important ecological implications with reference to Phalaris toxicity.
Two Cycles of Directional Selection for Improved Nutritive Value of Alfalfa1
Authors: Shenk John S. , Elliott Fred C.
Published: July 2010

A 6‐hour in vitro dry matter disappearance (6H‐DMD) procedure was used to evaluate individual progeny of ‘Vernal’ (Medicago sativa L. and Medicago falcata L.) and ‘DuPuits’ (Medicago sativa L.) clones selected for high or low 6H‐DMD values. Progeny derived from clones with high 6H‐DMD values had consistently higher 6H‐DMD values than progeny from low clones. Additional clones of ‘Culver’ MSA‐C4, MSB‐C4, Medicago glutinosa M.B., and Vernal were screened for high or low 6H‐DMD values over two harvests. Selected clones from Vernal and DuPuits progeny and from the five unselected populations were recombined for a second cycle of directional selection.

Correlations between yield and 6H‐DMD were negative or near zero. Cell wall analysis of clones selected for a second cycle of improvement indicated a significant positive relationship between total cell wall constituents (NDF) and 6H‐DMD values of the forage.

Second cycle clones had significant general and specific combining abilities for yield as well as leaf and NDF content. Progeny from clones with high 6H‐DMD values were higher in leaf content but lower in NDF content than progeny from clones with low 6H‐DMD values. Comparisons of selected two‐clone combinations in the first and second cycles indicated second cycle selection was effective in separating progeny means.
Methods of Asexual Propagation and Minimum Maintenance of Live Cotton Plants1
Authors: Weaver J. B. , Athanas R. P.
Published: July 2010

The effects of different rooting inedia, hormone treatments, and rooting techniques in cotton (Gossypium hirsutum L.) were investigated. Cuttings from cotton plants rooted readily in several different rooting media under intermittent mist with or without rooting hormones.

A plastic bag technique is described which permits rooted cuttings to remain alive for at least one year without any care except to avoid excessive heat or cold.
Development of B‐Lines for Two Cytoplasmically Controlled Male Sterilities of Cotton1
Authors: Meyer Vesta G.
Published: July 2010

One form of male sterility in cotton, Gossypium hirsutum L., depends upon the interaction of nuclear and cytoplasmic factors. Maintenance of such lines is difficult, but is facilitated by using B‐lines as male parents. Blines have the same nuclear factors as cytoplasmicallp male‐sterile lines, but lack the “male‐sterile” cytoplasm. Test crosses of such B‐lines with homozygous male sterile stocks with “pollen‐sterile” cytoplasm gave progenies with pollen sterility equal to, or greater than, those obtained from self pollination of the cytoplasmically male sterile cottons in question.
Reproduction and Cytology of Trifolium uniflorum1
Authors: Gibson Pryce B. , Chen Chi‐Chang
Published: July 2010

Among the 36 T. uniflorum plants studied, 30 plants were highly self‐incompatible, two were highly self‐compatible, and tour were intermediate. The average number of ovules per pod was 7.9 and the average number of seeds per pod following cross‐pollination of emasculated florets was 3.2. Tripping was not necessary for seed production on a self‐compatible plant.

Somatic cells of T. uniflorum contained 28 submetacentric and four subtelocentric chromosomes. The subtelocentric chromosomes possessed satellites. The chromosomes formed almost exclusively quadrivalents and bivalents at metaphase I. The high frequency of quadrivalents (4.46 per microsporocyte) suggests an autotetraploid origin.
Carbohydrate Metabolism in Orchardgrass (Dactylis glomerata L.)1
Authors: Burris J. S. , Carson E. W.
Published: July 2010

Orchardgrass was grown on complete nutrient solution with the nitrogen as nitrate. Plants were grown in controlled environment chambers for 4, 7, and 11 weeks. Release of labeled CO2 from specifically labeled glucose was used to measure the pentose monophosphate shunt and Embden Meyerhoff Parnas (EMP) pathway activities in shoot basal material.

Total respiratory activity decreased with age. The activity attributed to the pentose shunt followed a similar trend showing a complete absence at 11 weeks of growth. However, the EMP activity shifted less predictably, although decreasing with age; a larger proportion of the total respiration was gradually being assumed by the EMP system. Thus, this system is used less for generating reductive energy in the cell while its substrate is also used for carbohydrate storage in the tissue.
Inheritance of Reaction to Flag Smut in Wheat (Triticum aestivum)1
Authors: Helm James Henry , Allan R. E.
Published: July 2010

Selections and cultivars of wheat (Triticum aestivum L.) ‘P.I. 178383,’ ‘P.I. 94349,’ ‘Burt’ (C.I. 12696), ‘Suwon 92’ (C.I. 12666), and ‘Omar’ (C.I 13072) were tested for reaction to flag smut, Urocystis tritici Koern.

P.I. 178383 and P.I. 94349 each have single recessive genes for resistance to flag smut. The genes appear to be different and to have no association with plant height, head type, awnedness, or kernel color. Burt also possesses a single recessive gene that is different from the P.I. 94349 gene for resistance to the pathogen. Omar demonstrated a low level of resistanc to flag smut. Susceptibility of Suwon 92 behaves as a completely dominant characteristic.
Nitrate Reductase Activity in Relation to Heat Stress in Barley Seedlings1
Authors: Onwueme Innocent C. , Laude Horton M. , Huffaker Ray C.
Published: July 2010

Nitrate reductase activity was assayed in barley seedlings (Hordeum vulgare L.) exposed to supra‐optimal but sub‐lethal air temperatures of 41 to 43C for 16 to 24 hours. The activity of this enzyme decreased progressively during stress. Reduced activity was not attributed to production of inhibitors during stress or to water deficiency induced by the heat. Pre‐stress application of cycloheximide resulted in less inactivation of nitrate reductase during stress.

Subsequent to stress, nitrate reductase activity increased gradually, equaling the control in 24 hours, then increasing further to exceed the control. Cycloheximide applied after stress prevented this post‐stress increase. Heat hardening did not alter the level of heat stability of nitrate reductase. Heat stress retarded growth alike in plants of average or low nitrate reductase content. Heat stresses which produced marked inactivation in nitrate reductase had little influence on the activity of several other cytoplasmic and chloroplastic enzymes.