bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of DNBP on the Accumulation of 14C‐Sucrose and the Transport of 14C‐Assimilates in Corn1
Authors: Pitombeira Joao B. , Housley T. L. , Ohlrogge A. J. , Counce Paul A.
Published: July 2010

Subtoxic rates of DNBP (2‐sec‐butyl‐4, 6‐dinitrophenol) sprayed on corn (Zea mays L.) have been reported to stimulate dry matter accumulation in the grain in some situations. The purpose of this work was to evaluate the short‐term effect of the application of DNBP on the accumulation of sucrose and the translocation of 14C‐assimilates.

Premerge 3 (Dow Chemical Company) as a source of DNBP was sprayed on the 4‐ to 5‐week old leaves of green‐house‐grown corn, 16 to 24 hours prior to leaf disc sampling or 14CO2 labeling. Leaf discs were also floated on DNBP and DNP prior to 14C‐sucrose accumulation studies.

The accumulation of 14C from a 10 mM 14C‐sucrose solution in discs from untreated leaves was significantly greater than that of discs from leaves sprayed with DNBP or floated on 14C‐sucrose containing 0.7 mM DNBP or DNP. Efflux of 14C from the treated leaf discs indicated a pool of 14C easily leached from the discs. 14C retained was five times greater in untreated leaf discs.

The transport of 14C‐assimilates in DNBP treated and untreated leaves suggested an inhibition of long distant transport with 18.7% of the assimilated 14C transported in 30 min in treated leaves and 29.5% of the assimilated 14C translocated in untreated leaf discs. A significantly greater percentage of 14C was recovered in the sink of untreated plants than was found in the sink of DNBP sprayed plants.

These experiments support the hypothesis that DNBP acts as an inhibitor of 14C‐sucrose accumulation and the movement of 14C‐assimilates from the source leaf in corn.
A Gene for Early Maturity and Photoperiod Insensitivity in Pearl Millet1
Authors: Burton Glenn W.
Published: July 2010

The e1 gene was isolated by repeated backcrossing from a weak, spindly, very early maturing seedling discovered by R. F. Moore in a field of ‘Katharine’ pearl millet, Pennisetum americanum (L.) Leeke, growing in Queensland, Australia. Inbreds T23DBE and T756, carrying e1e1 developed by backcrossing the e1 gene into T23DB and T28, flowered in 45 to 55 days regardless of season planted, whereas T23DB and T28 (like most pearl millets) flowered in 75 to 85 days if planted in May and 55 to 65 days if planted in August. Thus the e1e1 gene imparts photoperiod insensitivity and makes most millets carrying it mature 10 to 40 days earlier. The e1 gene and a rapid backcrossing program make it possible to quickly create very early photoperiod‐insensitive forms of any superior pearl millet cultivar or hybrid.
Host Preferences and Reproduction of Four Cereal Aphids on 20 Triticale Cultivars1
Authors: Kieckhefer R. W. , Thysell J. R.
Published: July 2010

The ability of cereal aphids to survive and reproduce on triticale (X Triticolsecale Wittmack) may be important in predicting yield losses caused by these aphids and the plant viruses they can vector. Since little specific information about aphid adaptation to triticale has been published, we have investigated the host relationships of four cereal aphid species and 20 triticale strains. Preferences and reproduction of Schizaphis graminum (Rondani), Macrosiphum avenae (F.), Rhopalosiphum padi (L.), and R. maidis (Fitch) were tested in environmental chambers on seedlings and mature stages of 20 strains of triticale. M. avenae reproduced equally well (P>0.05) on all strains in both growth stages but S. graminum reproduced more on seedling than on mature plants R. padi failed to reproduce on mature triticale and R. maidis was poorly adapted to both growth stages. There was no immunity among the strains, however, in some tests the strains could be ranked in groups (P<0.05) based on declining aphid responses. We concluded that S. graminum, M. avenae, and R. padi have the potential for causing significant yield losses in triticale, especially because of reproduction on seedling plants.
Nitrogen Fixation of Alfalfa in the Seeding Year1
Authors: Heichel G. H. , Barnes D. K. , Vance C. P.
Published: July 2010

Alfalfa (Medicago sativa L.) obtains N from the soil and from the atmosphere by symbiotic nitrogen (N2) fixation. It is necessary to identify the contribution from each N source to evaluate N2‐fixation of different alfalfa germplasms. Field experiments were undertaken using 15N as a tracer of N metabolism to determine the N2‐fixation of two alfalfa populations in the seeding year. Additional objectives were to investigate the effects of establishment method, stage of plant development, and non‐uniform distribution of isotope in the plant on assessment of N,‐fixation capability.

During the seeding year the two populations averaged about 43% of their N needs from symbiosis and fixed an average of 148 kg/ha of N during the growing season. The isotope‐dilution and A‐value methods gave similar assessments of performance over four harvest intervals. Nitrogen fixation measured by isotope dilution was least (8 to 20 kg/ha) in the first and fourth harvest intervals when 25 to 30% of the N needs were met by symbiosis; it was greatest (47 to 87 kg/ha) during the second and third harvest intervals, when the populations derived more than 60% of their N from symbiosis.

The proportion of N derived from symbiosis for whole plants of seeded and transplanted materials differed significantly (P<0.05) among harvests, but the average over all harvests was not different for plants established by the two methods. A significant (P<0.05) interaction of sample type (herbage vs. whole plant) with harvest in transplants showed that equilibration of isotope in initially unlabeled seedlings occurred slowly early in the growing season.

In contrast to glasshouse evaluations of nitrogenase activity, significant (p<0.05) differences in rates of N2‐fixation per plant were observed between the two populations at several harvests and over the growing season. However, a 14% difference in average plant stand precluded differences between populations in N2 fixation on a land area basis. The rates of N2 fixation of field grown plants mirrored growth rates, which varied with the changing field environment and especially with onset of fall dormancy. The use of stable N isotopes can be a powerful technique in assessing progress in breeding alfalfa for increased N2‐fixation capability.
Effect of Flowering Date on Accumulation of Dry Matter and Protein in Soybean Seeds1
Authors: Gbikpi Pascal J. , Crookston R. Kent
Published: July 2010

The objectives of this study were to determine the effect of time of flowering on the rate of dry matter and protein accumulation in soybean [Glycine max (L.) Merrill] seeds, and to evaluate the relationship between these accumulation rates and the duration of the lag, linear filling, and plateau phases of soybean seed growth.

Field studies were conducted on a well‐drained Waukegan silt loam (Typic Hapludoll) at St. Paul, Minn. In 1978 the cvs. ‘McCall’ (Maturity Group 00) and ‘Hodgson 78’ (Group I) were used. In 1979, ‘Altona’ (Group 00) and ‘Steele’ (Group I) were added. On 1 day during both the early and late stages of flowering, 250 flowers were tagged on several plants of each cultivar. During pod filling, pods from these tagged flowers were harvested at weekly intervals for determination of seed dry matter and protein accumulation rates, as well as the duration of the lag, linear filling, and plateau phases of seed growth.

We concluded that meaningful relationships between soybean seed growth rate, duration of seed growth phases, and seed size do not exist. However, late maturing seeds of all cultivars consistently had faster (+ 32%) rates of dry matter accumulation, and even faster (+ 42%) rates of protein accumulation in both years of the study. Possible explanations of these fast accumulation rates are discussed.
Inheritance of Male Sterility in Flax Involving Nuclear‐Cytoplasmic Interaction, Including Methods of Testing for Cytoplasmic Restoration1
Authors: Burnham Charles R. , Phillips Ronald L. , Albertsen Marc C.
Published: July 2010

An interaction between cytoplasm and nuclear genes affecting the inheritance of male sterility in flax (Linum usitatissimum L.) was reported first by workers in England in the 1920s in crosses between procumbent and tall plants and later by a worker in Poland using Linum floccosum. Previously unpublished data are reported on a similar case involving a large‐seeded flax from Crete. The interaction was discovered in all cases by noting that crosses using procumbent, L. floccosum, and Crete as female parents with most other stocks as male parents had fertile and male‐sterile plants in F2; whereas the reciprocal crosses had only fertile plants.

For certain crosses using Crete as the female parent, the F2 segregation ratios were for a single gene difference. Other crosses may have involved two genes complementary either for restoration of pollen fertility in F1 or for incomplete restoration. Either of two hypotheses will explain the difference in behavior between reciprocal crosses. One hypothesis is that procumbent, L. floccosum, and Crete have a dominant fertility allele, Ms, and a non‐restorer [N] cytoplasm. Most other stocks have the recessive male‐sterile, ms ms, nuclear genotype but a cytoplasm [c R] that restores fertility. The cross of male steriles [N] ms ms with maintainer [c R] ms ms stocks would produce all male‐sterile progeny. Crossing these male steriles with Ms Ms would produce hybrid seed.

The second hypothesis that may explain the difference in behavior between reciprocal crosses assumes that procumbent, L. floccosum, and Crete have cytoplasmic male sterility [cms] together with a nuclear gene for restoration of pollen fertility (Rf). Most other flax stocks would have a normal non‐male‐sterile cytoplasm [N] and the non‐restorer gene, rf. Male‐sterile plants would be [cms] rf rf and maintainer stocks would be [N] rf rf.

Tests using genetic male sterility to identify lines with cytoplasmic restoration of fertility are discussed, together with methods of distinguishing the possible nuclear genotypes.

For any species in which most stocks have the nonrestorer [N] type of cytoplasm and the restorer type [c R] is rare, an advantage of this system for producing hybrid seed is the ability to produce large quantities of seed that will give only male‐sterile plants yet not transmit a unique cytoplasm to the hybrid seed offered to farmers. Development and maintenance of the parental stocks can be accomplished by conventional breeding techniques.
Effect of Atrazine Carryover on Malting Quality of Barley1
Authors: Brinkman M. A. , Langer D. K. , Harvey R. G. , Burger W. C.
Published: July 2010

This study was a continuation of an earlier study which showed that spring barley (Hordeum vulgare L. and H. distichum L.) produced higher grain and straw yields in soil containing atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) carryover than spring oats (Avena sativa L.). and spring wheat (Triticum aestivum L.). The objective of this study was to evaluate the effect of atrazine carryover on malting quality of barley.

In 1976 and 1977, six barley genotypes were grown to maturity in soil containing atrazine carryover, and the seed was analyzed for malting quality. Atrazine treatments (0, 1.12, 2.24, 3.36, and 4.48 kg of active ingredient/ha) had been applied postemergence to corn (Zea mays L.) 1 year prior to growing the barleys.

Light atrazine carryover had a minor effect on malting quality, but heavy carryover reduced quality considerably. Heavy atrazine carryover reduced kernel weight, kernel plumpness, kernel color, malt extract, and wort color, and increased barley and wort protein percentages, diastatic power, and alpha amylase activity. With the possible exception of the increases in the two enzyme systems, all of these changes detracted from malting quality.

Although genotype × atrazine level interactions were significant for several quality parameters, only one interaction had special importance. In both years, the genotype ‘Morex’ maintained a high malt extract despite increasing atrazine carryover.
Corn Yields as Related to Legumes and Inorganic Nitrogen1
Authors: Fleming A. A. , Giddens J. E. , Beaty E. R.
Published: July 2010

High corn (Zea mays L.) yields require heavy N applications. Sources of inorganic N fertilizer have become less dependable and prices more expensive. A 3‐year study was initiated to evaluate the use of winter legumes and inorganic N as sources of N for corn production under modern culture. The experiment included three whole‐plot clover treatments (arrowleaf, Trifolium vesiculosum Savi; crimson, Trifolium incarnatum L; and fallow) and five inorganic split‐plot treatments ranging from 0 to 180 kg/ha N.

Significant whole‐plot × split‐plot interactions occurred in 1975 for both grain yield and dry stover. Corn following clover produced 318% more grain than corn following fallow in 1975. When no N was applied, corn yield on fallow averaged 25 q/ha and increased 272% and 364% when grown following arrowleaf and crimson, respectively. The 180 kg/ha N did not increase corn yields significantly when compared with 90 kg/ha N with or without clover. Differences in stover yields between the 90 and 180 kg/ha N were not significant in any of the whole‐plot treatments in any year.

Crimson clover produced in a 2‐year average about 1600 kg/ha more dry‐weight forage than arrowleaf. Total forage N at time of turning averaged 163 and 131 kg/ha, respectively, for crimson and arrowleaf. Differences in forage yield and in N content of the clovers were attributed to differences in maturity at time of turning.

Growing a winter legume to replace all or part of the N may become a viable alternative in double‐cropping systems for corn production and conserving soll in the southern U.S. and in developing countries.
Inheritance of Crown Rust Resistance in Tall Fescue1
Authors: Wofford D. S. , Watson C. E.
Published: July 2010

Crown rust caused by Puccinia coronataCordn. is a major disease of tall fescue (Festuca arundinacea Schreb.) in the southern United States. The objectives of this study were to examine the inheritance of crown rust resistance in tall fescue and to determine if it is possible to select for crown rust resistance using a greenhouse seedling technique.

In the first experiment a six parent diallel cross was evaluated for crown rust resistance. General (GCA) and specific combining ability (SCA) were both significant sources of variation for rust resistance. Significant SCA effects indicated that there was some nonadditive gene action for rust resistance among these six parents. In most cases, resistant ✕ resistant crosses had high levels of resistance, susceptible ✕ susceptible crosses had no resistance, and resistant ✕ susceptible crosses had intermediate levels of resistance.

In the second experiment, eight cultivars of tall fescue were subjected to a single cycle of mass selection for crown rust resistance. All eight cultivars were found to have some resistance to crown rust with the Mediterranean cultivars having the highest levels of resistance. There was a wide range of variation in the realized heritabilities (0.07 to 0.52) for crown rust resistance in these cultivars. Cultivars of related origin exhibited similar heritabilities and it appeared that different populations had different gene systems controlling crown rust resistance. It appears that mass selection is an efiicient means of improving the level of rust resistance in some cultivars.
Screening the Genus Glycine Subgenus Glycine for the 120,000 Dalton Seed Lectin1
Authors: Pueppke S. G. , Hymowitz T.
Published: July 2010

To complete our screening of the genus Glycine for the presence of the 120,000 dalton seed lectin (SBL), 56 lines encompassing six previously unexamined species of the subgenus Glycine were examined. None of the 56 lines tested by the conventional Ouchterlony double diffusion method contained SBL or immunologically crossreactive materials. All lines were devoid of hemagglutinating activity.
Effects of Natural Selection in Segregating Soybean Populations Exposed to Phytophthora Rot or Soybean Cyst Nematodes1
Authors: Hartwig E. E. , Kilen T. C. , Young L. D. , Edwards C. J.
Published: July 2010

A study was conducted to determine the effects of natural selection in soybean [Glycine max (L.) Merr.] populations segregating for reaction to phytophthora rot (caused by Phytophthora megasperma Drechs. var. sojae Hildeb.) and soybean cyst nematode (SCN) (Heterodera glycines Ichinohe). Plantings of an F2 population of ‘Forrest’ ✕ ‘Tracy’ and 10 backcross F3 families of Forrest (2) ✕ Tracy were made at Stoneville, MS, where phytophthora rot caused injury to susceptible genotypes and at Ames Plantation in west Tennessee where SCN race 3 was present. The parent cultivar, Forrest, is resistant to SCN race 3 and moderately resistant to phytophthora rot, and Tracy is susceptible to SCN and resistant to phytophthora rot, races 1 through 9. The populations were advanced in bulk at each location for four generations.

Natural selection was not effective in increasing the percentage of plants having major genes for resistance to phytophthora rot in Stoneville plantings where susceptible cultivars show injury from the disease. The failure of natural selection to be effective was attributed to the presence of field resistant plants in the segregating population which competed effectively with plants having major genes for resistance.

Segregating populations grown on SCN infested soil showed a distinct increase in percentage of resistant plants as compared with populations grown on non‐infested soil. On the basis of three recessive genes and 1 dominant gene being necessary for resistance to SCN race 3, 5.5% of the population would be expected to be resistant after the F5 generation. The population of Forrest ✕ Tracy grown on non‐infested soil had 5% resistant plants after the F5 generation, while the population advanced on SCN race 3 infested soil had 40% resistant plants. Backcross families of Forrest (2) ✕ Tracy also had a distinctly higher percentage of SCN resistant plants when grown on infested soil than when grown on non‐infested soil.
Adaptation of Iron‐Efficient and ‐Inefficient Lovegrass Strains to Calcareous Soils1
Authors: Voigt P. W. , Dewald C. L. , Matocha J. E. , Foy C. D.
Published: July 2010

Iron chlorosis can occur in Eragrostis curvula (Schrad.) Nees when cultivars like ‘Morpa,’ ‘Ermelo,’ or common are grown on calcareous soils. As a result, forage yields are greatly reduced and stands are lost in as little as 1 or 2 years. Our objectives were to determine if lovegrass strains found to be iron efficient as seedlings in greenhouse studies were better adapted than inefficient strains to calcareous soils in the field and if genetic differences in iron efficiency were of sufficient importance to consider improving iron efficiency as a worthwhile breeding objective.

Iron‐efficient and iron‐inefficient strains were grown on a calcareous soll at Beeville, Tex., and a slightly acid soil (control treatment), a calcareous soil, and the same calcareous soil with all plants follar sprayed with ferrous sulfate at Woodward, Okla. Selections rated as iron inefficient in the greenhouse when grown on calcareous soils in the field were, on the average, more chlorotic, lower in forage production, and less persistent than iron‐efficlent strains grown on the same soils or inefficient strains grown on a noncalcareous soil. However, performance of the strains was not always consistent when grown on different calcareous soils. This was true for both iron‐efficient and iron‐inefficient strains. In tests conducted on calcareous soils, the vigor of iron‐efficient selections was dramatically better than that of iron‐inefficient strains, suggesting that this characteristic could be of economic benefit and should be considered in selecting new weeping lovegrass cultivars intended for use in areas where calcareous soils occur.
Adaptation of Soybean Cultivars to Low‐Yield Environments1
Authors: Walker A. K. , Cooper R. L.
Published: July 2010

The objective of this research was to determine whether any recently released Maturity Group II soybean [Glycine max (L.) Merr.] cultivars were well adapted to low‐yield environments. A regression analysis was conducted on data from the Uniform Group II Northern States Tests in 1978 and 1979. Maturity, height, lodging, and yield data for each of 10 cultivars were regressed onto the environmental mean yield.

Only one cv., ‘Amcor,’ had a regression coefficient for yield which was significantly less than one. It also had the highest mean yield. Thus, Amcor was more adapted to low‐yield environments than the other cultivars. Amcor's adaptation to low‐yield environments may be attributed to its greater plant height.
Detection of Identification Errors in Germplasm Collections1
Authors: Porter W. M. , Smith D. H.
Published: July 2010

A germplasm collection contains seed of many accessions. During nursery increases of accessions, seeds may be mistakenly planted in a row identified as a different accession. When such mistakes are not detected, the value of the collection declines in proportion to the number of wrongly, ldentified accessions it contains. This paper develops methods for calculating estimates of the degree of influence of several factors in detecting identification errors in nurseries; it tests those estimates with data from over 4,000 wheat (Triticum sp.) accessions.

For a given descriptor, the probability of detection of an identification error increases as the number of descriptor states increases and as the frequencies of the different states approach equality. When more than one descriptor is used, efficiency of error detection is greatest when the different states of the descriptors are independently distributed. The frequency of error detection was greater in randomized nurseries than in nurseries planted in order of accession numbers.
Leaf Anatomy and Stomatal Characteristics of Four Tall Fescue Selections Differing in Forage Yield1
Authors: Cohen C. J. , Chilcote D. O. , Frakes R. V.
Published: July 2010

Leaf anatomy and stomatal characteristics of four tall fescue (Festuca arundinacea Schreb.) selections differing in forage yield were examined to determine if selection differences in these characteristics existed that might be important to yield differences. Selections were grown in a greenhouse. Transverse sections of leaf blades that were within 4 days of full expansion and for which CO2‐exchange rate (CER) measurements had been made in a concurrent study were used in the anatomical study. Leaf impressions of fullyexpanded leaves of comparable tiller position of the same genotypes were used to study stomatal characteristics.

In all selections, mesophyll cell area was the major fraction and comprised 40 to 44% of total cross‐sectlonal area, while large air spaces comprised 20 to 27 % of the area. Bulliform cells contributed more than 50% of the adaxial epidermal tissue area. The presence of prominent adaxial leaf ridges, lignified vascular bundle fibers, and lignified fiber caps was also noted. While adaxial stomatal frequency was more than 3.5 times greater than abaxial stomatal frequency, adaxial stomatal size (guard cell length) was only about 10% smaller than abaxial stomatal size.

The lowest yielding selection in field trials, TFM 16, had approximately 22, 16, and 25% greater fractions of cross‐sectional area consisting of fiber cap tissue, epidermal cell layers, and bulliform cell area within the adaxial epidermis, respectively, compared with other selections. Selection TFM 16 also had 9% smaller abaxial stomata, 44% lower abaxial stomatal frequency, but 10% greater adaxial stomatal frequency, on average.

No difference among selections was found for percent cross‐sectional areas of vascular bundle, phloem, metaxylem, and mesophyll tissues or in number of ridges, ridge height, leaf thickness, or metaxylem and mesophyll cell diameters. Mesophyll cell diameter did not appear to be related to CER. while significant differences among selections of CER were found, diameters of mesophyll cells of the same leaves were similar.
Genotype‐Environment Interaction Study of Lock Tenacity in Upland Cotton1
Authors: McCall Lloyd L. , Verhalen Laval M. , McNew Ronald W.
Published: July 2010

Sixteen upland cotton (Gossypium hirsutum L.) cultivars were grown in replicated experiments under irrigation and on dryland at each of two Oklahoma locations over a 3‐year period. The storm resistance trait, measured as “lock tenacity”, was studied in genotype ✕ environment interaction analyses over years for all four experiments, for the two irrigated tests, and for the two dryland tests to estimate those interactions and to consider their implications relative to the cotton breeding and cultivar evaluation programs within the state.

A number of genotype ✕ environment interaction mean squares for lock tenacity were significant for both observed and log‐transformed data; however, the magnitudes of the interaction variance components were relatively small compared to their respective cultivar components and were concluded to be of minimal importance in the determination of the trait. Classifications into major bolltype categories and selections for the trait in one environment should be relatively stable in other environments. However, because the range of values observed was greater under irrigation than on dryland and because the separation of boll types was more distinct, more effective selections for the trait are probably made under irrigation.
Effect of Upper‐Profile Soil Water Potential on Numbers of Cysts of Heterodera glycines on Soybeans1
Authors: Heatherly Larry G. , Young L. D. , Epps J. M. , Hartwig E. E.
Published: July 2010

Upper‐profile (0 to 15 cm) soil water potential (SWP) was maintained at four levels in a greenhouse study to determine the effect of these soil moisture regimes on cyst formation by Heterodera glycines (Ichinohe) on soybeans [Glycine max (L.) Merr.]. Number of cysts increased significantly above initial levels in the wet (−0. 1 to −0.2 bar SWP) and optimum (−0.3 to −0.4 bar SWP) soll moisture treatments. The optimum soil moisture treatment had the highest number of cysts at termination. Root weight in the 0 to 15‐cm zone was highest in the wet treatment and lowest in the dry treatment (−0.6 to −0.7 bar). Number of cysts in the 15 to 45‐cm depth zone of all treatments (equally wet at −0.25 to −0.35 bars) increased significantly above initial levels and reached a level essentially equal to the number of cysts in the 0 to 15‐cm zone of the optimum soil moisture treatment. No difference in root mass or number of cysts was measured in the deeper zone. Shoot weight and height were not significantly different among treatments, but a decrease in leaf area index with increasing dryness of the upper soil zone indicated moisture stress. The similar shoot weights among treatments indicated that the cyst levels in the wet and the optimally wet treatments may have reduced plant development, since the wetter soil should have increased shoot growth.
Tillering Differences after Close Clipping in Russian Wildrye and Tall Fescue1
Authors: Laude H. M. , Fox R. E.
Published: July 2010

Tillering after clipping plants at heights of 0.5, 2.5, and 5.0 cm, or leaving them uncut was compared in ‘Fawn’ tall fescue (Festuca arundinacea Schreb.) and ‘Vinall’ Russian wildrye (Elymus junceus Fisch.). The plants were vegetative when cut and depending on age had produced an average of 3.6 to 9.1 shoots. With progressively lower clipping heights tillering was stimulated in the Russian wildrye and depressed in tall rescue. Forty‐eight hours after clipping Russian wildrye at 0.5 cm, more than 70% of the plants had increased in number of elongating shoots, while less than 30% of uncut plants had done so. This rapid acceleration of tillering after clipping at 0.5 cm did not occur following clipping at 2.5 cm. These differences were considered in relation to numbers of macroscopic axillary buds visible after leaf sheaths were carefully stripped from the stems. The number of tiller buds and young shoots concealed by leaf sheaths was three times greater in Russian wildrye than in tall rescue, and this may be associated with the rapid tillering response noted. No explanation is known for the difference in response to cutting heights of 0.5 and 2.5 cm.
Growth of Spring Wheat Kernels as Influenced by Reduced Kernel Number per Spike and Defoliation1
Authors: Simmons Steve R. , Crookston R. Kent , Kurle James E.
Published: July 2010

Field studies with the spring wheat (Triticum aestivum L.) cultivars ‘Era’ and ‘OlaF’ were conducted to assess the effects of reductions in kernel number per spike and defoliation of individual culms on kernel growth characteristics. The importance of stage of kernel growth at which treatments were applied was also examined by treating both at anthesis and anthesis + 14 days, the later date being after the beginning of the kernels linear dry matter accumulation period.

The effects of the treatments on final weight per kernel depended on the time of treatment and on the relative weights of kernels from the untreated (control) culms. Reduction in kernel number per spike increased final kernel weight, particularly when control weights were low, whereas defoliation always reduced final weight. Treatment at anthesis usually had a larger effect.

Growth rates of kernels during the linear dry matter accumulation period were enhanced by kernel removal and depressed by defoliation. Within each genotype, growth rates were highly correlated with final kernel weight. This association, however, differed between years because of variation in length of the grain filling period. No consistent effect of the treatments on grain filling duration was found.

The response to early kernel number reduction, as well as the response in additional experiments to spikelet “trimming” suggested that upper limits, or potentials, for both final weight and growth rate were approached. These potential kernel weights and growth rates appeared to depend on genotype, kernel position in a spikelet, and possibly environment.
Inheritance Studies of Bract Size in Cotton1
Authors: Bowman D. T. , Jones J. E.
Published: July 2010

Bracts in Upland cotton, Gossypium hirsutum L., have been implicated in byssinosis, a lung disorder associated with textile mill workers. Before initiating a breeding program with the objective of reducing bract trash in machine‐harvested seedcotton, inheritance studies were performed on the trait bract size or bract surface area.

In the first study, heritability was calculated from regression of 83 F3 plot means on F2 plant values from a cross involving a small bract parent and a nectariless normal bract breeding llne. Correlation coefficients were calculated to determine herltability in standard units. Highly significant regression and correlation coefficients of 0.69 and 0.75, respectively, were computed for heritability estimates.

In the second study a seven parent diallel was used and analyzed by the procedures outlined by Jinks and Hayman. The experiment included the seven parents, their 21 F1's, and their 21 F2's and was performed at two locations for 2 years.

Partial failure of the assumptions of no epistatis, no multiple allelism, and independent gene distribution was observed in the three general tests. Epistasis and multiple allelism were tested and considered negligible. Discrepancies were noted between populations for estimates of frequency of alleles and dominance gene effects. Partial dominance was expressed at most loci where dominant alleles governed bract surface area. Narrow‐sense heritability estimates indicated that bract size heritability was primarily additive although dominance gene effects contributed significantly. Parents were identified with bract size and levels of dominance suitable for cultivar breeding programs.
Generation Mean Analyses of Various Allelochemics in Cottons1
Authors: White W. H. , Jenkins J. N. , Parrott W. L. , McCarty J. C. , Collum D. H. , Hedin P. A.
Published: July 2010

Several secondary plant metabolites are alleged to confer resistance of cotton, Gossypium hirsutum L., to various insects and mites. At the present time, only the inheritance of the sesquiterpenoid gossypol has been elucidated. This research was conducted to determine inheritance of several inferred/hypothesised allelochemics from cotton, in particular those alleged to confer resistance to the tobacco budworm, Heliothis virescens (F.).

Generation mean analysis (GMA) was used as the genetic design. The following GMA's were evaluated: ‘DES‐24’ × ‘SATU‐65’, DES‐24 × ‘BJA‐592’, and DES‐24 × MOHG. The six populations (P1, P2, F1, F2, BCP1, and BCP2) comprising a GMA were planted as a randomized complete block with four rcplicatlons. Analyses of young cotton leaves for condensed tannins, catechln, total phenols, E1.1, aniline reacting terpenes, and phloroglucinol reactive compounds were obtained at intervals during the growing season. Analysis of variance was conducted on seasonal means.

The inheritance of gossypol, as measured by the CHEA extract of the phloroglucinol test, was predominately additive. Gossypol, as detected by the aniline reacting terpene test, was shown to be inherited by predominately dominant gene action. The genetic analysis indicates that the CHEA and aniline reacting terpene tests are measuring gene products which are inherited in different manners. The four tests used for the determination of condensed tannins also appeared to be measuring somewhat diverse genetic products. This was apparent because E1.1 and fresh disc assay tannins, but not tannin and catechin tannins, showed significant variation among populations in the DES‐24 × SATU‐65. E1.1 and catechin tannins, but not the tannin and fresh disc assay tannins, showed significant variation among populations in the DES‐24 × BJA‐592 cross. When condensed tannins as measured by any of these tests were genetically analyzed in a cross, inheritance was highly additive.

The high degree of additive gene action for condensed tannins, a flavonoid‐anthocyanin mixture, gossypol by the CHEA test, and total phenolics indicate that it should be possible to fix and select for increased levels of these compounds.
Inheritance of Basmati and Dimpled Seed in Sorghum1
Authors: Murty D. S. , Nicodemus K. David , House L. R.
Published: July 2010

Studies on F1, F2, F3, and backcross generations of three crosses and their reciprocals in sorghum, Sorghum bicolor (L.) Moench, showed that the inheritance of basmati (scented plant) and dimpled seed characters is controlled by two independent recessive genes. The plump seed character exhibited xenia.
Progress in Selecting for Resistance to Stemphylium botryosum (Cool‐Temperature Biotype) in Alfalfa1
Authors: Gilchrist D. G. , Teuber L. R. , Martensen A. N. , Cowling W. A.
Published: July 2010

Plants from seven alfalfa, Medicago sativa L., cultivars were inoculated with the cool‐temperature biotype of Stemphylium botryosum Wallr. in a controlled environment chamber to identify plants resistant to Stemphylium leafspot. Seedlings were inoculated at the 6 to 8‐leaf stage, maintained at 18 to 20 C under constant mist for a 48‐hour infection period and scored for disease seven days after inoculation. Resistant plants were intercrossed to form a single population which was subjected to two cycles of phenotypic recurrent selection. Progress after two cycles of selection was evaluated in a greenhouse modified to provide conditions similar to the smaller controlled environment chamber. Relative disease reaction of six test cultivars in the two infection environments was the same (r[4] = 0.978). A proportional bulk population, constructed in proportion to each cultivar's contribution to the first selection cycle, was evaluated as an internal standard to measure progress during selection. Disease resistance increased in each selection cycle compared to the standard proportional bulk population with 10, 59, and 89% resistant plants in the proportional bulk, cycle‐1, and cycle‐2 populations, respectively.
Nitrates in Petioles of Three Cottons1
Authors: Jenkins Johnie N. , Nichols Jim R. , McCarty J. C. , Parrott W. L.
Published: July 2010

Three cotton strains, Gossypium hirsutum L., were grown with two N levels, 56 (soil applied) and 86 kg N/ha (56 kg/ha soil applied plus 30 kg/ha foliar applied). Foliar applications were based on results from petiole nitrate monitoring. The primary objective was to determine if petiole nitrates and phosphorus levels were affected by cotton strains. We chose three cottons which we knew were different in leaf area and rate of fruiting.

Significant differences among ‘Stoneville 213,’ Stoneville 817 frego, and Stoneville 7A nectariless, okra leaf were found for levels of petiole nitrates and P when monitored for 11 weeks during the growing season. No significant differences in levels of petiole nitrates or P were found between two levels of N. There was a significant cotton strain by week interaction for petiole nitrates but not P.

Petiole nitrates ranged from 310 to 16,000 ppm during the sea‐son. There was a significant increase in lint yields at the second harvest in foliar‐fed plots and an increase of 47 kg lint/ha in total yield. However, total llnt yields were not significantly different between the two levels of N or among the three strains. Yields ranged from 981 to 1,010 kg lint/ha for the three strains. Strains did not respond differently to the two N levels. Follar feeding did not affect boll size or lint percent. These data illustrate some of the inherent difficulties associated with the use of petiole nitrate monitoring as a useful tool for assessing N application.
Cultivar Response to Wheat Strawworm1
Authors: Martin T. J. , Harvey T. L.
Published: July 2010

A survey of six Ellis county Kansas wheat (Triticum aestiuum L. em. Thell.) fields in 1979 indicated that 53% of culms were infested with larvae of the second generation wheat strawworm, Harmolita grandis (Riley) form grandis. Early maturing cultivars tended to escape infestation in cultivar yield trials at Hays, Kans. in 1979. However, ‘Centurk’, ‘Centurk 78’, ‘Rocky’, and ‘Parker’ cultivars had lower infestations than others of the same maturity class, indicating possible cultivar resistance. Yield losses of 6 to 10 % were recorded for ‘Sage’ wheat culms infested with form grandis in 1979 and 1980. These losses, combined with the more serious damage reported for the spring form minuta, indicate this pest should be monitored more accurately, since moderate wheat strawworm damage may go unnoticed or credited to other insects.
Selection for Fiber and Protein Concentration in a Diverse Alfalfa Population1
Authors: Sumberg J. E. , Murphy R. P. , Lowe C. C.
Published: July 2010

A diverse alfalfa population derived from crosses within and among the species Medicago sativa L., M. falcata L., and M. caerulea Less. was evaluated for variation in acid‐detergent fiber (ADF) and crude protein (CP) concentration. A sequential selection scheme based on first and second harvest ADF, CP, and yield was developed to identify vigorous plants with differing levels of the nutritional characteristics. An analysis of two five‐parent diallel sets indicated that variation in ADF and CP concentration among crosses was accounted for primarily by general combining ability. Four experimental synthetics were grown in small plots and evaluated for yield and nutritional quality. The low fiber and high protein synthetics averaged 5.7% (1.9 units) lower in ADF, and 7.2% (1.5 units) higher in CP than the cultivars Vernal and Honeoye
Nitrogen Metabolism and Yellowberry of Two Bread Wheat Cultivars1
Authors: Henson James F. , Waines J. Giles
Published: July 2010

Lath house experiments were conducted to study the relationship between the timing of N deprivation, subsequent N metabolism and yellowberry expression of two spring bread wheat (Triticum aestivum L. ‘Chinese Spring’ and ‘Anza’) cultivars. Wheat plants were grown in pots containing sand and were supplied with 350 ml Hoagland's solution containing 15.0 mM nitrate every 4 days. Plants were initially deprived of N (nitrate) at the jointing, boot, and flowering growth stages. Nitrogen deprivation at each growth stage increased percent yellowberry and decreased percent grain N. Percent yellowberry was inversely and curvillnearly related to percent grain N. The N metabolism traits which controlled percent yellowberry and percent grain N were percent above‐ground plant N, percentage of N in reduced form, and harvest index for dry weight and for N.
Cultivar ✕ Herbicide Interaction in Sugarbeet1
Authors: Smith G. A. , Schweizer E. E.
Published: July 2010

Eight commercial sugarbeet (Beta vulgaris L.) cultivars consisting of both diploid 2N = 2X = 18 and triploid 2N = 3X = 27 hybrids were studied for 2 years for their response to three herbicide regimes. The specific registered sugarbeet herbicides consisted of preplanting applications of 1) cycloate (S‐ethyl‐N‐ethylthiocyclohexanecarbamate) (3.4 kg/ha), 2) ethofumesate [(± >2‐ethoxy‐2,3‐dihydro‐3,3‐dimethyl‐ 5‐benzofuranyl methanesulfonate] (2.2 kg/ha), and 3) a mixture of ethofumesate (2.2 kg/ha) + diclofop |2‐{4‐{2,4‐dichlorophenoxy) phenoxy] propanoic acidsj (1.7 kg/ha), each followed by a post‐emergence mixture of desmedipham [ethyl m‐hydroxycarbanilate carbanilate (ester)] and phenmedipham (methyl m‐hydroxycarbanilate m‐methylcarbanilate) both applied at 0.6 kg/ha. A fourth treatment regime was that of no herbicide application. The six characters examined were 45‐day plant dry weight, harvest root weight, foliar suppression, stand count, sucrose, and purity. Differential herbicide and cultivar response was evidenced by significant year ✕ herbicide, year ✕ cultivar, and herbicide ✕ cultivar interactions for several of the six characters analyzed. Although a significant second order interaction was detected for foliar suppression, none of the yield components (root weight, sucrose, purity) exhibited significant second order interactions. Certain cultivars were suppressed significantly less than others at 45 days and recovered the most by harvest time. Under favorable soil moisture and temperature conditions, the eight commercial cultivars showed reductions in total 45‐day plant weight of 39 to 55% of their nontreated equivalent controls. In both years, early season suppression was mostly, but not entirely, overcome by harvest. Reductions averaged about 5%.
Effects of Planting Depth on Vegetative Characteristics of Three Forage Grasses at 14 Days Post Emergence1
Authors: Tischler C. R. , Voigt P. W.
Published: July 2010

Deep planting has often been advocated as a method of improving seedling establishment of plants in semi‐arid regions. However, because deep planting could theoretically reduce seedling vigor, the potential for greater moisture availability could be offset by slower growth. In the case of forage grasses, a slower rate of growth could result in slower development of the adventitious root system. The present study was undertaken to investigate effects of depth of planting on performance of seedlings of kleingrass (Panicum coloratum L.), weeping lovegrass (Eragrostis curvula Schrad. Nees), and wilman lovegrass (Eragrostis superba Peyr.). Seed were planted at 2, 4, 6, and (kleingrass only) 8 cm and grown at 21/29°C in plastic cones the growth chamber. Plants were excavated and evaluated at 14 days post emergence. Subcoleoptile internode (SI) length was used to indicate actual planting depth and to determine the relation of depth of planting to other plant characteristics. With increasing SI length, days to emergence increased while shoot weight, root weight, and number of leaves decreased for all species. Length of longest adventitious root, mean adventitious root length, total adventitious root length, and number of adventitious roots decreased with increasing SI length for kleingrass and wilman lovegrass, but the adventitious root development of weeping lovegrass was not significantly affected by SI length. Primary root length decreased with increasing SI length for all species. However, primary root depth (primary root length + SI length) increased with increasing SI length in kleingrass, decreased with increasing SI length in weeping, and did not change with increasing SI length in wilman lovegrass. These results indicate that the response of primary root depth to SI length (or depth of planting) varies from species to species. Although wilman lovegrass displayed the most vigorous growth at shallow planting depths, Kleingrass had a higher fresh weight at harvest, at a planting depth of 6 cm. Hence, performance of a species (in terms of fresh weight) at one depth of planting can be a poor indicator of performance at other planting depths. In general, increasing planting depth tends to have a negative influence on post‐emergence performance of the three grass species investigated. Deep planting should be correlated with controlled water availability and plant survival to draw any concrete conclusions. Early growth may only be of temporary significance.
Associations Between Bracts and Several Agronomic Traits in Cotton1
Authors: Bowman D. T. , Jones J. E.
Published: July 2010

Cotton (Gossypium hirsutum L.) bracts, as part of the trash in machine‐harvested seed cotton, have been implicated in the brown lung disease, byssinosis, in mill workers. As part of two separate investigations into the genetic nature of bract surface area (cm2 of bract area), genotypic and phenotypic correlations were calculated to determine linkages or associations with several agronomic traits. These field studies were conducted at Alexandria and Baton Rouge, La. on typic udifluvents and aquic fragiudaif soils, respectively. Significant positive associations in both studies between bract surface area and boll weight suggested little progress would be made in reducing the bract relative to the boll if only the bract surface area was considered. A better measure of heritable changes in bract surface area relative to boll weight may be the ratio of bract surface area/lint weight per boll. A low ratio of bract surface area/lint weight per boll would denote a low bract trash potential and may denote a low byssinosis potential. The ratio bract surface area/lint weight per boll appeared to be positively associated (genotypically) with 50% span length, and negatively associated with fiber micronaire and lint percent. These associations would suggest that parents with high lint percent and parents with small bracts should be selected. The potential problem with fiber length and micronaire should be considered in breeding cottons for low bract trash potential.
Stability Parameters of Soybean Cultivars in Maturity Groups VI, VII, and VIII1
Authors: Weaver D. B. , Thurlow D. L. , Patterson R. M.
Published: July 2010

Environmental stability parameters were estimated for adapted soybean [Glycine max (L.) Merr.] cultivars for two 3‐year periods 28 environments in central and southern Alabama. Objectives were to measure and compare relative stabilities of the cultivars and to compare the effect of the different periods and productivity levels on the stability parameter estimates. In Exp. 1 (1976–1978) nine adapted cultivars (Maturity Groups VI, VII, and VIII) and one unadapted cultivar (Maturity Group V) were analyzed.In Exp 2 (1979–1981) 12 adapted cultivars and one Maturity Group V cultivar were analyzed. Seven cultivars were common to both experiments. ‘Forrest,’ the Maturity Group V cultivar, had the lowest or nearly the lowest seed yield and highest deviations from regression in both experiments. In Exp.1, all cultivars except ‘Coker 338’ had significant deviations from regression, and ‘Coker 136’, ‘Ransom’, and ‘Hutton’ had significant regression coefficients. In Exp. 2, ‘Bragg’, Ransom and ‘Coker 488’ had nonsignificant deviations from regression, and ‘Centennial’, ‘Coker 237’, and Hutton had significant regression coefficients. Joint regression analyses of both experiments revealed that a major part of the genotype ✕ environment interaction could be accounted for by differences between the fitted regression lines. Differing levels of productivity of the two experimental periods had little effect on stability parameter estimates.