bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inheritance of Reaction of Sorghum bicolor (L.) Moench to Toxin Produced by Periconia circinata (Mang.) Sacc.1
Authors: Schertz K. F. , Tai Y. P. 
Published: July 2010

The inheritance was determined for the reaction of Sorghum bicolor (L.) Moench to the toxin produced by the saprophyte, Periconia circinata (Mang.) Sacc. (1) A precise laboratory screening technique was developed whereby seedlings were subjected to the toxin devoid of the P. circinata organism. (2) The inheritance of the host‐pathogen reaction among established cultivars was confirmed to be controlled at a single locus. Susceptible seedlings (PcPc) died quickly, resistant seedlings (pcpc) grew normally, and heterozygotes (Pcpc) showed an intermediate response. (3) The mutation frequency from susceptibility to resistance (Pc→pc) was one per 7,876 gametes among 55,137 seedlings of ‘Colby,’ a susceptible cultivar.Mutations at the controlling locus are sufficiently frequent to be of significance in a breeding program and the disease response is precise enough for critical genetic analyses.
Phenotypic Recurrent Selection for Seedling Vigor in Side‐oats Grama, Bouteloua curtipendula (Michx.) Torr.1
Authors: Voigt P. W. , Brown H. W. 
Published: July 2010

We evaluated three cycles of phenotypic recurrent selection for seedling vigor in Bouteloua curtipendula (Michx.) Torr. Seeds from each of the three cycles, from the base material, and from a drilled increase block of the base material were included in all trials. Bulk seed harvests in 1963 were used to drill field trials in 1964, 1965, and 1966. Bulk harvests in 1964 were used for additional trials in 1965 and 1966.Relative to the base material the third cycle established more (35%) and taller (24%) seedlings over the five trials. Number and height of seedlings were closely correlated, r = .80. However, a path coefficient analysis indicated that in one trial seedling height was much more important than seedling number in determining first‐year forage yields. Differences in stand usually had little effect on forage yield. However, any increase in ability to produce a stand is desirable because it reduces the possibility of stand failure.Seed from the Syn‐1 of the base material produced results intermediate between the base material and the advanced cycles. This apparent natural selection emphasizes the importance of seeded as opposed to transplanted plots.
Oviposition Preference by the Sorghum Shoot Fly (Atherigona varia soccata) in Progenies of Susceptible ✕ Resistant Sorghum Crosses1
Authors: Blum A. 
Published: July 2010

Eight crosses were made between two shoot fly (Atherigona varia soccata)‐susceptible and four resistant sorghum (Sorghum sp.) lines. Parental lines and F2 were planted on three dates, corresponding to three distinct levels of shoot fly infestations. F1 was planted only on the third date (highest infestation). The maximum number of deposited eggs was recorded for each plant in each entry and date.It was found that the size of the shoot fly population had a most pronounced effect on both absolute and relative rates of oviposition in various sorghum genotypes. Data on the F2 indicated that resistance (nonpreference) was partially dominant when evaluated under low shoot fly population. When evaluated under high population, susceptibility (preference) appeared be dominant. It was indicated that selection of nonpreferred genotypes should be established under extreme infestation as measured by. an average of at least 13‐15 deposited eggs per plant in susceptible lines.
Specific and Non‐specific Index Selection in Soybeans, Glycine max L. (Merrill)1
Authors: Byth D. E. , Caldwell B. E. , Weber C. R. 
Published: July 2010

General, average, and specific index selection were evaluated for yield advance in two populations over three environments. In all environments, predicted genetic advance was greatest for the specific index from each population, but specific indices were generally less efficient for actual yield advance over environments than were yield truncation and the general index. Relationships among traits were reasonably comparable for closely related crosses, and for early generation and later generation material from these crosses. Average relationships among traits for non‐related soybean populations had utility in selection of specific breeding populations of Midwest soybeans.The use of high performance environments resulted in maximum predictions of genetic advance, but actual yield advance evaluated over environments was essentially equal for all environments tested. Actual advance evaluated over environments may be the only accurate criterion for comparison of selection procedures in the presence of substantial genotype ✕ environmental interactions.
Photosynthetic Efficiencies and Photorespiration in Calvin Cycle and C4‐Dicarboxylic Acid Plants1
Authors: Bull T. A. 
Published: July 2010

SummaryThe efficiency of photosynthetic utilization of light in Calvin cycle plants was lower than that found in plants with the C4‐dicarboxylic acid path of CO2 fixation when measured in air. Inhibition of photorespiration by O2 depletion indicated that potential photosynthetic efficiencies of both groups were similar. The ability of C4 plants to utilize higher light intensities than Calvin cycle plants was associated with a greater affinity for CO2 at the carboxylation site.Photorespiration was detected in a leaf attached to an 18 month old sugarcane plant. The leaf was significantly less efficient than similar leaves from a young plant and displayed a greater resistance to CO2 transport. An explanation is advanced in terms of end‐product feedback from assimilate stored in the stalk.
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.
Hybrids Between Tetraploid and Hexaploid Crested Wheatgrasses1
Authors: Dewey Douglas R. 
Published: July 2010

SummaryDoubled‐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.
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, respectivelySemidecumbent 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.
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.
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.
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.
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.
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.
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

SummaryOrchardgrass 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

SummarySelections 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.