bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for Spontaneous Inversions in Cultivated Barley1
Authors: Powell Jerrel B. , Nilan R. A.
Published: July 2010

Anaphase I microsporocytes of fifteen barley varieties and their hybrids have been examined cytologically. Approximately 2% of the microsporocytes of hybrids involving OAC 21 had bridges, fragments, or both, as well as other aberrations. The usual occurrence of very small fragments of uniform size accompanied by a bridge suggested the presence of one or possibly two small paracentric inversions in OAC 21. Analyses of other hybrids indicated that at least two other varieties also possessed inversions. These findings tend to support the very limited genetic evidence for inversions in cultivated barley. The difficulty in detecting inversions in barley having localized chiasmata as well as the possible influence of such inversions on recombination are discussed.
A Bulk Method of Producing Hybrid Wheat
Authors: Watson I. A. , McWhirter K. S.
Published: July 2010

The use of a small‐seeded, fertility‐restoring pollinator line, and a normal‐seeded, male‐sterile female parent line for production of hybrid wheat seed by a Bulk Method is suggested. The difference in seed size would enable pure hybrid seed to be graded from bulk harvested seed lots. The feasibility of using the sphaerococcum gene to obtain the required seed size characteristic in pollinator lines is being studied.
Scion Control of Genotypic Differences in Sr and Ca Accumulation in Soybeans Under Field Conditions1
Authors: Kleese R. A.
Published: July 2010

Genotypic differences in Sr and Ca accumulationin soybean seeds grown under field conditions are controlled by the above ground portion of the plant. These results are the same as those found nsing plants grown in the green house in soil to which Sr‐89 and Ca‐45 were applied.
Effect of Cytoplasmic Source on the Performance of Double‐Cross Hybrids in Maize, Zea mays L.1
Authors: Hunter R. B. , Gamble E. E.
Published: July 2010

"Cytoplasmic effects" were identified in 11 different double cross hybrids by studying the following combinations of inbreds in each hybrid: (AXB) (CxD), (BxA) (CXD), (CXD) (AXB), and (DXC) (AXB). Eleven agronomicharacters were studied over two years and two locations. Significant cytoplasmic effects occurred for all characcers. Certain inbreds and inbred combinations were associated more frequently with cytoplasmic effects than others although cytoplasmic effects were not always related to the presence of a particular inbred. Cytoplasmic effects were reasonably consistent from year to year and location to location. The year by cytoplasm and location by cytoplasm interactions were usually smaller than the year by hybrid and location by hybrid interactions. It would appear to be desirable to evaluate cytoplasms so as to bring together the best combinations of cytoplasm and nuclear genetic materials.
Genotype ✕ Management Interactions Among Plants of Orchardgrass (Dactylis glowerata L.)1
Authors: Christie B. R. , Armstrong K. C.
Published: July 2010

Spaced plants of orchardgrass, from different accessions, were subjected to six different managements, involving combinations of two cutting regimes and three levels of nitrogen fertility. Accession means and intraaccession variances for vigor ratings, heading date, bloom date, plant height, percent leaf, and number of leaves per stem were calculated and analyzed. Level of nitrogen had little effect on means or variances nor was there a consistent accession ✕ nitrogen interaction. The accession ✕ cutting regimes interaction appeared to be unimportant.
Heterosis and Inheritance of Quantitative Characters in Interspecific Crosses of Cotton1
Authors: Marani A.
Published: July 2010

Performance of the F1, F2 and backcross generations of nine interspecific crosses, between each of three varieties of Gossypium hirsutum L. (‘Acala 4‐42’, ‘Empire W,’ and ‘Coker 100A’) and each of three varieties of G. barbadense L. (‘Karnak,’ ‘Malaki,’ and ‘Giza 7’), in comparison with the parental varieties, was evaluated in three field trials in 1964 and 1965. Heterosis (F1 performance above mean of parents) was between 52% and 73% for lint yield and was associated with heterosis for boll number, flower number, and percentage of boll retention. Boll weight of F1 hybrids was intermediate and their lint percent and number of seeds per boll were lower than the parental mean. Heterosis was also significant for seed index, lint index and plant height.

F2 deviation (F2 performance below mean of F1 and midparent) and backcross deviations (BC performance below mean of F1 and recurrent parent) were significant for almost all of the characters examined. Lint yield of the F2 was much lower than that of either parent, whereas lint yield of backcrosses was similar to that of the recurrent parents. Heterosis was caused by dominance effects only (no epistasis) for seed index and in one trial for final plant height. Heterosis for yield of seed cotton, yield of lint, boll number, flower number, percentage of boll retention, lint index and plant height at flowering was caused by dominance in the presence of epistasis. Intermediate F1 performance (no heterosis), found for boll weight and for maturity, was caused by the estimates of dominance and additive ✕ additive epistasis parameters being of nearly equal magnitudes. The negative heterosis found for lint percent and number of seeds per boll was caused by the additive ✕ additive epistasis being larger than the dominance effects.
Some Effects of Photoperiod on the Performance of Korean Lespedeza1
Authors: Offutt M. S.
Published: July 2010

The effect of photoperiod on the performance of Korean lespedeza (Lespedeza stipulacea Maxim.) was investigated under field conditions for 5 years at Fayetteville (north) and for 3 years at Hope (south), Ark. varieties and strains differing widely in maturity were planted at each location on four different dates each year beginning in March and continuing at monthly intervals through June. Floral initiation took place in the earliest maturing variety at Fayetteville and in all four varieties at Hope while the natural photoperiods still were increasing in length. Rate of vegetative growth was reduced when seedlings emerged in the spring before day‐lengths were equal to or greater than their critical photoperiod. With one exception, the three earliest maturing varieties produced highest hay yields from the April date of planting at both locations. Conversely, hay yields from the latest maturing variety were highest from the March date of planting at each of the two locations. Seed maturity for all varieties was delayed only one to two days for each month planting was delayed at both locations, but each variety matured earlier at Hope than at Fayetteville for any given date of planting. Seed yields of the three earliest maturing varieties were highest from the June date of planting at Fayetteville and from the May date of planting at Hope, whereas the exact opposite was true for the latest maturing variety.
Ribonucleotide Compositional Changes in Wheat Leaves Caused by Water Stress1
Authors: Stutte Charles A. , Todd Glenn W.
Published: July 2010

Total ribonucleic acid and nucleotide compositions were determined at different levels of water stress on leaves of winter wheat varieties recognized as being resistant or non‐resistant to water stress. Water stress resulted in a reduction of the total ribonucleic acid content with the nonresistant variety showing a greater decrease in ribonucleic acid content per plant than the resistant variety on severe water loss. The (G + C)/(A + U) ratios increased with water stress in both varieties grown under different environmental conditions. Under more severe drought the nonresistant variety gave higher ratios than the more resistant variety. The base composition was also affected by the temperature regime under which the plants were grown, making the interpretation of the effects of water stress alone more difficult.
Chemical Composition of Two Warm‐Season Prairie Grasses in Three Environment1
Authors: Newell L. C.
Published: July 2010

Chemical analyses and yields of forage were used to evaluate domestic collections of two warm‐season prairie grasses for revegetation and forage production and as breeding stock for variety improvement. Ten strains each of switchgrass, Panicum virgatum L., and of the big bluestem complex, Andropogon gerardi Vitman and A. hallii Hack., were compared at three locations. Chemical composition of the forage varied with the source of grass strain and the location of test. Best quality forage, as judged by crude protein, was indicated for the early and midsummer season. In both grasses crude protein was highest from frequent clipping and lowest from once‐harvested mature growth. Average crude fat content was higher in the forage of these grasses from the sites of two sandy soils than from a silty clay loam. Crude fat content was also higher in grass strains originating on sandy soils than in strains originating on fine‐textured soils. Variation among strains suggests opportunities for variety improvement in forage quality as well as yield.
Sources and Inheritance of Resistance to Phytophthora megasperma var. sojae in Soybeans1
Authors: Lam‐Sanchez A. , Probst A. H. , Laviolette F. A. , Schafer J. F. , Athow K. L.
Published: July 2010

Inheritance of resistance to Phytophthora megasperma var. sojae in soybeans was studied in a group of crosses involving nine resistant varieties, originally from fairly diverse geographical areas. Each of eight resistant varieties was crossed to the ninth, ‘Mukden,’ or one of its resistant backcross derivatives (‘Lindarin 63’ or ‘Clark 63’), and seven also were crossed to the susceptible varieties ‘Wabash,’ ‘Lindarin,’ or ‘Clark.’ From inoculation tests performed on F3 progenies of F2 plants of crosses between susceptible x resistant parents, monohybrid segregations were obtained, indicating that the resistance to phytophthora rot of soybeans is conditioned by a single dominant gene in each case. Inoculation tests on F2 populations of crosses between resistant parents gave no segregation, suggesting that all resistant parents have Mukden‐type resistance reported by Bernard et al. (1) and assigned the gene Rps (formerly Ps).
Genetic Variation in Quantitative Characters in Maize Inbred Lines, I. Variation Among and Within Corn Belt Seed Sources of Six Inbreds1
Authors: Higgs R. L. , Russell W. A.
Published: July 2010

The genetic variation among and within strains of long‐time inbred lines of maize was investigated. Six inbred lines and male fertility restorer versions of four of these lines were obtained in 1963 from Corn Belt foundation seed stock organizations and the Iowa Agricuture Experiment Station. Significant variation was found among nonrestorer strains, restorer strains, and strain X strain crosses for nearly all of the eight quantitatively inherited characters studied. The Iowa non‐restorer and restorer strains (maintained by ear‐to‐row method) were significantly less vigorous than the other non‐restorer and restorer strains (maintained by selfing and bulking) for many comparisons. The restorer strain versions excelled over the nonrestorer versions from the same seed source in many comparisons. Vigor of strain X strain crosses was greater than the vigor of their parental strains for 34 of 35 comparisons where differences were significant. Variation within the Iowa WF9 strain was generally less than within the other four WF9 strains, which indicated that the ear‐to‐row procedure was more effective in maintaining a low degree of genetic variability within an inbred line. The time span between the year of release of a particular inbred and the commencement of this study showed little relationship with the variation among strains within the inbreds.
A New Method of Using Interchanges as Chromosome Markers1
Authors: Burnham C. R.
Published: July 2010

A new method of utilizing interchanges as chromosome markers which will require one less than the n number of chromosomes to test the entire genome for linkage is proposed. The underlying principle is that each of the interchanged chromosomes in each stock would be marked by two widely separated breakpoints. Breeding procedures in maize for constructing a series with 2‐chromosome, double interchange stocks are described and illustrated by the results from a cross between two genetically marked T1‐5 interchange stocks. Breeding procedures for a series with 3‐chromosome, triple interchange stocks are described also.

The detection of linkage with any major gene, using either the double or the triple interchange series should be much more efficient than tests using single interchanges. When heterozygous, many of the products of crossing over in the differential segments are deficient and hence not recoverable. Also only part of the recoverable crossovers are recognizable as recombinants.
Genetic Effects for Yield in Single, Three‐way, and Double‐Cross Maize Hybrids1
Authors: Eberhart S. A. , Hallauer Arnel R.
Published: July 2010

Additional investigations were conducted with maize (Zea mays L.) in which significant epistatic effects had been detected. Single, three‐way, and double‐cross hybrids were used in these studies. The small correlations between predicted and observed performance suggest that the genotype X environmental interactions are clearly the most important factor in obtaining reliable predictions. Although epistatic effects were present in the material studied, there was no evidence that the standard singlecross prediction formulas for three‐way and double‐cross hybrids should be abandoned in favor of more complex procedures.
Resistance in Soybeans, Glycine Max L,. Merr., to the Reniform Nematode1
Authors: Rebois R. V. , Johnson Wiley C. , Cairns Eldon J.
Published: July 2010

Of eight soybean cultivars tested ‘Pickett’ and ‘Dyer’, were found to be resistant to the reinform nematode, Rotylenchulus reniformis. In the presence of Pickett and Dyer, the soil counts of renifonni nematodes were significantly reduced from an initial 10,000 larvae to less than 500 per pot over a 2.5‐month period. Cultivars resistant to the root knot, Meloidogyne spp., did not possess resistance to the reniform nematode but those resistant to the soybean cyst nematodes, Heterodera glycines, did. Under the conditions of the test, the seed yields of Pickett increased while those of ‘Hood’ decreased when inoculated with reniform nematodes.
Varietal Differences in Internode Number and Length in Ten Varieties of Alfalfa1
Authors: Sheridan Kevin P. , McKee Guy W.
Published: July 2010

In ten common varieties of alfalfa, Medicago sativa L., grown and measured under comparable conditions, varietal differences in internode number and internode length were statistically significant. This technique could be useful in varietal purity testing, genetic studies, and characterization of alfalfa varieties.
Morphology and Inheritance of Sterile Brachytic Dwarfs in Peanuts, Arachis hypogaea1
Authors: Ashri A.
Published: July 2010

Various morphological manifestations of brachytic dwarfs in peanuts, Anachis hypogaea L., and their inheritance have been studied. It was concluded that two duplicate genes control this trait, although a third locus was indicated in one cross. Apparently modifiers were also involved.

These genes cause marked shortening of the internodes, petioles, flowers and floral organs and other deviations. The plants are male sterile, having no pollen. They are also female sterile, or are unable to support embryo development. The trait demonstrates how undesirable recessive alleles can accumulate in self‐pollinating amphiploid species, containing duplicate loci.
Evaluation of Mechanical Damage to Roots of Commercial Varieties of Corn (Zea mays L.)1
Authors: Fitzgerald Paul J. , Ortman Eldon E. , Branson Terry F.
Published: July 2010

The roots of six commercial varieties of corn, (Zea Mays L.), in 1963 and eight varieties in 1964 and 1965 were mechanically injured to simulate feeding of rootworm larvae. Approximately 0, 25, 50, and 75% of the roots were removed by cutting with a sharpened spade on 1, 2, or 3 dates. Highly significant differences in grain yield and percent lodging resulted from treatments in 1964 and 1965. Differences in percent moisture were significant only in 1964. A highly significant treatment X variety interaction was also present in 1964. The implications of these results in breeding for resistance or tolerance to the corn rootworm are discussed.
Stomatal Conductivities in K‐Deficient Leaves of Maize (Zea mays, L.1
Authors: Peaslee D. E. , Moss D. N.
Published: July 2010

Potassium deficiency, spraying with phenylmercuric acetate, and temporary “wilting” each caused varying degrees of stomatal closure in maize leaves. Concomitant decreases in photosynthesis and stomatal permeability were similar for all treatments. In normal air, viscous transfer of gas through stomata of these leaves was related to diffusive transfer of CO2 in photosynthesis as predicted by theoretb cal and experimental observations of other workers. In CO2‐enriched air, stomatal diffusive resistance of the leaves as calculated from photosynthesis rates, and stomatal viscous resistances as measured by a porometer, tended to be related differently in the case of K‐deficient leaves and previously wilted leaves as compared to the normal leaves. The data suggest these experimental treatments decreased the stomatal apertures and the capacity of the leaves to internally fix CO2. The latter phenomenon may be viewed as an increased internal diffusive resistance, which reacted serially with increased stomatal diffusive resistance and thereby resulted in marked decreases in CO2 assimilation in treated leaves.
Yield and Quality of Early and Late‐Maturing, Near‐Isogenic Populations of Pearl Millet1
Authors: Burton Glenn W. , Gunnells Joel B. , Lowrey R. S.
Published: July 2010

Duplicate early and late near‐isogenic populations of three pearl millet (Pennisetum typhoides (Burm.) Stapf and C. E. Hubb.) hybrids were cut at 2‐, 4‐, 6‐, and 8‐week intervals for 24 weeks to ascertain the effect of maturity on forage yield and quality. Equal quantities of selfed seed from 50 of the earliest F2 plants from each early ✕ late hybrid were mixed to make seed for each early population. Its duplicate was prepared from seed from 50 other early F2 plants. The late near‐isogenic populations were prepared by mixing selfed seed from 50 of the latest‐maturing F2 plants of each cross. Early populations reached anthesis 24 to 25 days earlier than late populations. The similar response of duplicate populations furnished evidence that early and late populations were near‐isogenic except for maturity genes and linkage effects. Late populations outyielded early ones by 9% when cut at 2‐week intervals and 19% when cut at 8‐week intervals. Late populations gave a better seasonal distribution of forage, were easier to manage, were more persistent, were leafier, were higher in protein content, and were more digestible (nylon‐bag technique) than early ones. These results indicate that a millet reaching anthesis in 78 days will make a better forage crop than one maturing in 53 days.
Growth Response of Orchardgrass (Dactylis glomerata L.) to Different Light and Temperature Environments. II. Leaf Age and Photosynthetic Activity1
Authors: Treharne K. J. , Cooper J. P. , Taylor T. H.
Published: July 2010

The variation in rate of apparent photosynthesis (PR) with leaf age in three populations of orchardgrass, grown in two different temperature environments, was investigated using a Warburg manometric technique. Fully expanded leaves maintained a high PR for 15 to 20 days but the rate rapidly declined thereafter. PR (oxygen evolution) per unit leaf area closely paralleled the synthesis and degradation of the chlorophyll pigments; PR per unit chlorophyll changed very little throughout the life of the leaf. These results were confirmed by the pattern of assimilation of C14O2 by leaves of different ages. The Portuguese ecotype had a significantly higher photosynthetic rate at 21 C than the cultivars ‘S.143’ and ‘Boone’ in both growth environments. Plants grown at 21 C day/13 C night temperatures had a significantly higher rate at 21 C than plants grown at 29 day/21 night temperatures, but when measured at 29 C plants grown in the higher temperature regime had a significantly higher rate of PR. The relative pattern of change of PR with leaf age was unaffected by the temperature at which the plants were grown.
Intra‐ and Intervariety Crosses of Medicago sativa L. and Medicago falcata L.1
Authors: Sriwatanapongse Sutat , Wilsie C. P.
Published: July 2010

Interspecific, intervariety, and intravariety crosses in alfalfa were compared for expression of heterosis. In spaced plantings, highest yields were obtained from interspecific crosses, followed by inter‐variety and finally by intravariety crosses. Variability within progenies was increased through hybridization, unrelated parents having the most effect. The importance of genetic diversity in parents as a determinero f heterosis is considered.
Evaluation of Early Generation Testing in Spring Barley1
Authors: Smith E. L. , Lambert J. W.
Published: July 2010

An analysis was made of the combining abilities of bulks in F2 and F3 diallel crosses among 10 barley parents. There were relatively large and significant variances for general combining ability for seed yield, kernel weight, maturity, and plant height. Ratios of general to specific combining ability indicated that most of the genetic variances was associated with general combining ability for these characters. The predictive value with respect to yield and kernel weight of six of the parents and the early‐generation bulks of their crosses was measured by the performance of F5 lines derived from the crosses. The performance of parents themselves, of individual crosses in F2 and F3, as well as in the F2 and F3 parental arrays were all generally reliable as indications of parental prepotency and the potential value of the crosses, although the predictive value of the F2 bulks for seed yield was slightly lower than that of the parents and F3ďs. The performance of F1 topcrosses was of limited value for either yield or kernel weight in evaluating parental prepotency.
Flowering and Fertility of Alfalfa as Influenced by Inbreeding and Stage of Plant Growth1
Authors: Miller M. K. , Schonhorst M. H.
Published: July 2010

Two clones of alfalfa (Medicago sativa L.) and their F1, S1, and S2 progenies were studied in the greenhouse at Tucson, Arizona. Numbers of seeds and pods produced and self‐fertility, measured as seed‐set percentage per self‐pollinated flower, generally decreased with inbreeding. The F1 plants sampled were more self‐fertile than either parent clone. No relationship was found between generations of inbreeding and number of racemes or flowers produced. Self‐fertility of all plants was highest during the first weeks of flowering; however, considerable variation occurred among plants in later weeks. The ratio of cross‐fertility (seed‐set percentage per cross‐pollinated flower) to self‐fertility of the parent clones was 4.1:1.0.

Numbers of seeds and pods produced, and self‐fertillty were highly correlated. Numbers of racemes and flowers produced were also highly correlated, but they were not correlated with self‐fertility, number of pods, or number of seeds produced.
Nitrogen in Plant Parts of Seven Spring Wheat Varieties at Successive Stages of Development1
Authors: McNeal F. H. , Boatwright G. O. , Berg M. A. , Watson C. A.
Published: July 2010

Nitrogen content of leaves and stems, head chaff, and grain was determined for seven spring wheat varieties on five sampling dates at two locations near Bozeman, Montana, in 1966. Nitrogen percentages in the chaff were at about the same levels as the nitrogen percentages in stems and leaves, and each decreased with successive sampling dates at nearly the same rate. Grain nitrogen percentages were similar at the late flowering and milk stages, but showed a significant increase by the dough stage.

The amount of nitrogen translocated from top growth to grain averaged 66.2% under irrigation and 74.8% on dryland. Varietal differences in grain nitrogen percentages could not be attributed to differences in the percentage of total nitrogen that was translocated from top growth to the grain. Nitrogen increases in the total top growth from first to last sampling date were 85.1 kg/ha under irrigation and 20.1 kg/ha on dryland.

Correlation coefficients at the irrigated and dryland locations of —0.88 and —0.93, respectively, for grain nitrogen percentages vs. the grain to straw ratio, and 0.89 and 0.92 for grain nitrogen content vs. total top yield indicate that grain nitrogen percentages are closely associated with top growth. These r values suggest that grain nitrogen percentages decrease as the grain to straw ratio becomes larger.
Influence of Intensity, Quality, and Duration of Light on Nitrogen Reduction and Assimilation in Wheat1
Authors: Harper James E. , Paulsen Gary M.
Published: July 2010

'Pawnee' wheat (Triticutn aestivum L.) seedlings were grown under lighting of low (7,500 lux) or high (15,600 lux) intensities, blue (380‐470 mu) or red (680‐740 mu) qualities, and short (8‐hr) or long (16‐hr) nhotoperiods. A single level of N was supplied in graded ratios of nitrate and ammonium in solution cultures.

In leaf blades, high light intensity had no consistent effect on nitrate reductase (NR) activity, increased soluble protein, and decreased nitrate. Blue light increased NR activity and soluble protein but decreased nitrate as compared with red light. The long photoperiod increased NR activity and decreased nitrate and soluble protein as compared with the short photoperiod. The light treatments had little effect on roots except for an accumulation of nitrate under the short photoperiod. NR activity and nitrate content in leaf blades and roots increased under all light treatments as the nitrate‐to‐ammonium ratio in the nutrient solution increased, and soluble protein content decreased slightly.
Duplicate Linkage of Glandless and Nectariless Genes in Upland Cotton, Gossypium hirsutum L.1
Authors: Holder David G. , Jenkins Johnie N. , Maxwell Fowden G
Published: July 2010

We developed a phenotypic classification system to identify several nectary genotypes in cotton, Gossypium hirsutum L. Duplicate linkage groups were established between the glandless genes, gl2 and gl3, and the nectariless genes, ne1 and ne2. The linkage value for gl2‐ne1 in linkage group V in the A genome was 32.23 ± 1.40% crossover units and the linkage value for glones in linkage group IX in the D genome was 38.27 ± 1.40% crossover units. The establishment of these linkages marks these two chromosomes so that three‐point linkage tests may be conducted to establish the gene order of the duplicate genes for glandless, nectariless, and withering bract.
Sampling Techniques and Early Generation Testing for Alkaloid Selection in Tobacco1
Authors: Chaplin James F.
Published: July 2010

Selection of F2 flue‐cured tobacco (Nicotiana tabacum L.) plants on the basis of seedling analysis for total alkaloids was effective in separating F5 lines into groups with significantly different means. Green‐leaf analyses of field‐grown F6 plants were compared with those from cured leaves. The green‐leaf samples were taken at three stages of maturity; 2 weeks before the plants flowered, when the plants were in full flower, and 2 weeks after they were topped. The total alkaloid analyses from all of the three samplings of the green leaves were highly correlated with those from the cured leaves. The highest correlation was obtained when the percent of total alkaloids were averaged from the three green‐leaf samplings and compared with the weighted average of the cured leaves. High correlations were also obtained when alkaloid percentage from each of the three stalk positions of the cured leaves were compared with the weighted average of all the cured leaves from the plant. For cured‐Ieaf alkaloid analyses, the highest correlation was obtained when the alkaloid percentages from the top stalk positions were compared with those from the weighted average of all stalk positions. Therefore, the total alkaloid percentages of the cured leaves from the top stalk positions should give reliable results for selecting lines with varying levels of total alkaloids.
Occurrence of Two Homozygous Self‐incompatibility Genotypes in I1 Segregates of Red Clover, Trifolium pratense L.1
Authors: Johnson Karl , Taylor N. L. , Kendall W. A.
Published: July 2010

Intercrosses within three I1 families of red clover (Trifolium pratense L.) established that two families possessed both of the gametophytic homozygous S‐allele classes (S1S1 and S2S2) along with the heterozygous class (S1S2). The other family segregated only one homozygous class (S1S1) indicating the possibility of differential growth rates of pollen tubes. Reciprocal backcrosses of 15 I1 progenies to their I0 clones revealed a deficiency of the sum of the two homozygous classes. The inference is that the deficiency may have resulted from heterozygotic advantage or from zygotic lethality. We conclude that the gametophytic type of S‐allele system is common in red clover, but segregation of S‐alleles is influenced by the interaction of alleles with temperature and possibly other environmental factors.
Inheritance of Pigment Color in the Soybean1
Authors: Bhatt G. M. , Torrie J. H.
Published: July 2010

Fourteen soybean crosses, Glycine max (L.) Merr., were used to study the inheritance of pigment color and pattern. Black and brown seed coat and hilum colors were controlled by two gene pairs, Tt and Rr, their expression being modified in certain gene combinations by Oo and W1w1. The distribution or dilution of the pigment color was controlled by the locus (Ktiki). Brown seed coat (TrO) was dominant over reddish brown (Tro) and green seed coat (G) over yellow (g). The I allele for light hilum gave gray hilum with TR and tKW1 genotypes and yellow hilum with Tr, tRw1 and tr genotypes.

Difficulty was experienced in classifying plants for saddle pattern, due to the possible interaction of pigment promoting factors. In three crosses the saddle pattern gene ik was dominant over self black seed, whereas in one cross self black seed appeared to be dominant over ik. Saddle patterns were not observed on seed having brown or buff seed coats. These phenomena may be due to pigment‐promoting factors masking the expression of the gene ik.
Variation in Selfed Progeny of Doubled Haploid Stocks of Nicotiana tabacum L.1
Authors: Legg Paul D. , Collins Glenn B.
Published: July 2010

Six doubled haploid stocks of Nicotiana tabacum L. were evaluated for 10 quantitative characters. Significant differences were found among lines within five of the stocks. The results indicate that genetic changes had occurred in some of the haploid‐derived lines and that the stocks differed in degree of stability.
Snow‐Mold‐Tolerant Winter Wheats1
Authors: Sunderman D. W. , McKay H. C.
Published: July 2010

Fifteen winter wheats (Triticum aestivum L.) have been selected for tolerance to snow mold (Fusarium nivale (Fr.) and Typhula idahoensis Remsburg). Under a severe epiphytotic, the total survival of plants among the selections ranged from 30 to 70%.
Phenotype Selection in Crested Wheatgrass1
Authors: Schaaf H. M.
Published: July 2010

Open‐pollination progenies were used to study the effectiveness of phenotypic selection for seed characteristics in crested wheatgrass of Agropyron desertorum (Fisch. ex Link) Schult. maternal parentage. Source material consisted of 468 plants set out on 0.9‐m centers. The plants were assessed for spike number and seed yield, set, and size over a 2‐yr period (1959 and 1960). Progenies of the plants averaging in the top 10% of each of the four characters (125 “high” selections) and in the bottom 5% in spike number and seed size (19 “low” selections) were grown in rows seeded 0.9 m apart. Of the high selections 94, 26, and 5 were 1‐, 2‐, and 3‐character combinations, respectively.

Seed yield of the progenies, averaged over a 3‐yr period (1962 to 1964), ranged from 147 to 687 kg/ha and seed size from 231 to 318 mg/100 seeds. Approximately 8% of the progenies significantly exceeded (P<.01) the crested wheatgrass variety ‘Nordan’ in both seed yield and size. Despite significant (P<.001) parent‐progeny correlations of .517 for seed yield and .797 for seed size, single‐character selection among spaced plants did not positively identify the most desirable genotypes for either yield or size of seed. Progeny seed yield averaged 416, 472, and 526 kg/ha and seed size 280, 275, and 290 mg/100 seeds for the 1‐, 2‐, and 3‐character combinations, respectively. Spaced‐plant selection for high spike number decreased progeny seed size and for low spike number increased progeny seed size. There were indications that multiple‐character selection of plants not in the top 10% would also have given high‐performing progenies. For screening source populations of crested wheatgrass for seed characteristics, large‐scale testing of open‐pollination progenies is suggested to reduce loss of valuable genotypes.
Relationship of Carbohydrate and Nitrogen Compounds in the Haplocorm to the Growth of Timothy (Phleum Pratense, L.)1
Authors: Sheard R. W.
Published: July 2010

The early spring growth of timothy was found to be negatively associated with the fructose concentration in the tertiary shoot. A positive correlation between spring growth and N fractions was established, the water insoluble N fraction being most closely associated with spring growth. While it is generally accepted that high production following a period of stress requires an adequate carbohydrate source, evidence is presented to show an internal source of nitrogenous material for rapid synthesis of new protoplasm may be of greater importance.
Heterosis and Hemeostasis in Secale montanum Guss. ✕ S. cereale L. Hybrids II. Reproductive Characteristics1
Authors: Pfahler P. L.
Published: July 2010

F1 hybrids between Secale montanum (P.1.253956) the female parent and three varieties (‘Florida Black,’ ‘Gator,’ and ‘Wrens Abruzzi’) of S. cereale were made. F2 populations were produced by interpollination within each F1 population.

Under natural daylength and space‐planted conditions, 40% of the S. montanum plants produced seed in 1965‐66 and 10% in 1966‐67, whereas 100% of the plants in the S. cereale varieties and 70 to 100% of the F1 and F2 plants produced seed. For number of seeds, seed weight, and grain yield, the F1 populations were generally intermediate to the parents with S. montanum the lower parent in all combinations. The F2 populations tended to produce a larger number of seeds than the corresponding F1. Substantial differences resulting from the S. cereale variety involved and year tested were observed. The variability of both the F1 and F2 populations as a result of differences in years and the variation within the F1 populations were greater than the higher parent. However, the S. cereale variety involved was a major factor.

With 16‐hr daylength, the F1 populations were generally below or equal to the mid‐parent in percent stainable pollen with S. montanum the lower parent in all combinations. However, the corresponding F2 populations were higher in percent stainable pollen with two out of three combinations exceeding the S. cereale parent. The pollen diameter of the F1 and F2 populations was generally intermediate to the parents with S. montanum the lower parent in all combinations.
Linkage Tests of Mendelian Male Sterility and Other Genetic Characters in Sugarbeets, Beta vulgaris L.1
Authors: Theurer J.C.
Published: July 2010

Linkage tests involving nine genetic factors in Beta vulgaris L. were conducted in the greenhouse. The genetic male sterile (a1) gene was inherited independently from eight other factors. Linkage between red hypocotyl color (R) and trout leaf (Tr) and lack of association of monogerm (m) and russet root (ru) with the Y‐R‐B linkage group, as noted by other research workers, was confirmed. The dwarf factor (d) and lutescens (lu2) appeared to be independent of the Y‐R‐B group. The ru and lu2 characters are not associated with m. A summary table of linkage groups in sugarbeets and linkage maps for two of these groups are presented.
Inheritance of and Interrelationships among Yield and Several Quality Traits in Common Wheat1
Authors: Baker R. J. , Bendelow V. M. , Kaufmann M. L.
Published: July 2010

The inheritance of and interrelationships among six quality characteristics and yield were studied in 50 random lines of a wheat cross grown in Alberta. The heritabilities of all quality traits were higher than for yield with the exception of dough development time, which was characterized by a very high genotype ✕ year interaction variance. Seven of the 21 possible phenotypic correlations were significantly different from zero. Of these, the correlations between nitrogen content and yield, nitrogen content and starch damage, starch damage and yield, sedimentation value and dough development time, and between dough development time and tolerance index would be detrimental to a breeding program, while the correlations between thousand kernel weight and yield and between sedimentation value and tolerance index would be advantageous. The genotypic correlations agreed closely with the phenotypic correlations.
Characterization of Major Carotenoids in Yellow Maize Lines of Differing Pigment Concentration1
Authors: Grogan C. O. , Blessin C. W.
Published: July 2010

Major carotenoids—polyoxy, zeaxanthin, lutein, cryptoxanthin, zeinoxanthin, and carotenes—were determined in 15 lines, 5 high‐carotenoid exotic strains, and 5 crosses of maize, Zea mays L. In general, zeaxanthin and lutein were major carotenoids. In two flint types, zeaxanthin accounted for 67% of the total carotenoids. However, in certain color separations, cryptoxanthin was the major component. The data indicate that selection for any one of the major carotenoids should be possible. In another phase of the study, seeds from a dark yellow by white segregating population were separated into nine recognizable color classes. Zeaxanthin was the only fraction to increase before the dark lemon separation, although all fractions except polyoxy showed a sudden increase with this separation. Zeinoxanthin was the major carotenoid in the dark temon but ,declined as total carotenoid level increased. Zeaxanthin and lutein were the major carotenoids in all separations darker than light yellow. The data show that it is possible to identify phenotypically high‐carotenoid segregates with considerable accuracy when a suitable background is used.
Classification of Environments to Control Genotype by Environment Interactions with an Application to Cotton1
Authors: Abou‐El‐Fittouh H. A. , Rawlings J. O. , Miller P. A.
Published: July 2010

Cluster analysis as a tool for classifying locations in order to minimize the within‐cluster genotype by location interactions was discussed and applied to the data for lint yield per hectare in upland cotton (Gossypium hirsutum L.) obtained from the Regional Cotton Variety Tests for years 1960–1964. The distance coefficient, which was more efficient as a measure of similarity than the product‐moment correlation coefficient in preliminary analyses, was used to study the zoning of the cotton belt. Some modifications in the currently recognized zones of adaptation for cotton were suggested.
Retardation of the Elaboration of Aflatoxin in Cottonseed by Impermeability of the Seedcoats1
Authors: Mayne R. Y. , Harper G. A. , Franz A. O. , Lee L. S. , Goldblatt L. A.
Published: July 2010

Impermeable cottonseed were compared with permeable seed to determine their value in resisting the elaboration of aflatoxin. Undelintered seed were inoculated with a toxigenic strain of Aspergillus flavus and stored for periods up to 49 days under conditions of moisture and temperature conducive to fungal growth and to production of aflatoxin. When stored for 21 days under these conditions, in all cases except one, “selected‐impermeable” seed of 1964 and 1966 experimental crops developed less than 0.2 mg aflatoxin/kg. Permeable seeds (commercial and experimental) treated under the same conditions for the same time contained from 78 to more than 500 mg aflatoxin/kg. The toxigenic fungus grew on or in fewer of the selected‐impermeable than the permeable seed. However, the available lots of impermeable seed which had been grown in 1965 contained a higher percentage of permeable seed than did the lots from other years because of poor storage. As much as 22 to 200 mg aflatoxin/kg were produced in 21 days even in selected‐impermeable seed obtained from improperly stored lots grown in 1965. Apparently cottonseed stored under different moisture conditions differed in their degree of impermeability and susceptibility to the action of A. flavus. When impermeability was maintained, the seed were protected from significant development of aflatoxin.
Triticale—A Review1
Authors: Briggle L. W.
Published: July 2010

Triticale is a polyploid produced by doubling the chromosome number of the sterile hybrid that results from a cross between wheat, Triticum aestivum L. em Thell. (group aestivum) or T. turgidum L. (group durum) and rye, Secale cereale L.

Hybrids between wheat and rye date back to 1875. The first amphiploid was reported in 1891. Early developed amphiploids involved hexaploid wheat with rye and had 56 somatic chromosomes.

Recently there has been more interest in tetraploid wheat ✕ rye amphiploids which have 42 somatic chromosomes. Much effort has been expended toward development of high‐yielding Triticales as a field crop. Marked progress has been made in yield, kernel quality, meiotic stability, better plant type, and other characteristics. However, presently available Triticales cannot compete successfully with wheat in the U. S. Intensified breeding programs based on increased genetic variability in breeding material show promise for further improvement of Triticales.
Some Effects of Genes, Cytoplasm, and Environment on Male Sterility of Cotton (Gossypium)1
Authors: Meyer Vesta G.
Published: July 2010

Male sterility in Upland cotton (Gossypium hirsutum L.) has been produced by mutant genes, cytoplasm from other species, environmental stress, and chemical treatment. Genetic sterilities vary in expression from complete sterility due to a single dominant gene to partial sterility due to recessive genes. The cytoplasmic‐genetic sterile strains with cytoplasm from either G. anomalum Wawra & Peyr. or G. arboreum L. vary in response to genes, cytoplasm, and the external environment. Daily maximum temperature 15 to 16 days before anthesis affects sterility more than any other aspect of the external environment. A‐lines and B‐lines have been produced for pure‐breeding sterile strains, one set for G. anomalum cytoplasm, the other for G. arboreum cytoplasm. All of the commercial strains of G. barbadense L. tested with these two sterilities produced completely fertile F1 hybrids. The commercial cotton crop is largely self‐pollinated. The most critical problem for production of hybrid cotton appears to be finding some way to get the male‐sterile flowers pollinated.
Comparative Seed and Forage Yield in Crosses of Selected Alfalfa Clones as Compared to Polycross Progeny1
Authors: Melton Bill
Published: July 2010

Nine selected alfalfa (Medicago saliva L.) clones were polycrossed and intercrossed in a diallel series. Forage and seed yield determinations were made. Only one cross significantly exceeded the forage yield of the check variety ‘Zia,’ whereas four significantly exceeded the check variety for seed yield. Most crosses yielded less than the polycross progeny of the parental clones; however, at least one cross within a group of crosses involving a given clone produced an increase in seed or forage yield over their corresponding polycross progenies. Increases were considerably higher for seed than forage yield.
Tillering and Coronal Root Formation in Some Common and Durum Wheat Varieties1
Authors: Pinthus Moshe J.
Published: July 2010

Tillering and the production of coronal roots by the main shoots and individual tillers of early and late common (Triticum aestivum L.) and durum (Triticum durum Desf.) spring wheat varieties were studied under various environmental conditions.

It was found that environmental as well as varietal effects on coronal root formation were mainly due to their effects on tillering.

The results indicate that varietal differences in tillering and subsequent root production were induced by differences in the length of the period from seedling emergence to spike differentiation during which tiller primordia were formed and tillers developed. The highest rate of root formation occurred during the period from spike initiation to heading and therefore the length of this period also affected root production.

Root production of the main shoot and the first one or two tillers terminated at heading time. Under favorable environmental conditions, early varieties were able to produce additional roots after heading, due to the renewed growth of late tillers and the development of new tillers from existing primordia.

Durum wheat exceeded common wheat in the root production capacity of its main shoots. In both species only slight and inconsistent differences in the numbers of tillers and of roots were found among varieties with similar growing periods.
Temperature‐Induced Inhibition of Soybean Hypocotyl Elongation and Seedling Emergence1
Authors: Grabe Don F. , Metzer Robert B.
Published: July 2010

The effect of temperature on hypocotyl elongation and seedling emergence of soybean [Glycine max (L.) Merr] varieties was studied under laboratory and field conditions. Hypocotyl elongation of darkgrown ‘Ford’ seedlings was severely inhibited at 25 C, but was normal at 15, 20, and 30 C. Hypocotyl elongation of ‘Hawkeye’ was normal at all four temepratures. Twenty‐five varieties were classified according to their ability to emerge from 10 cm of sand at 25 C. Distinct varietal differences in emergence ability were evident and appeared to be genetically controlled. Instances of erratic emergence of soybean plantings may be partially explained on the basis of depth of planting, variety, and soil temepratures during the germination period.
Graft Compatibility and Its Influence on Self‐ and Cross‐fertility in Selected Species of Melilotus1
Authors: Ojomo O. A. , Gorz H. J.
Published: July 2010

A high degree of graft compatibility was observed between plants of Melilotus infesta Guss. and four closely related species, M. italica (L.) Lam., M. messanensis (L.) All., M. segetalis (Brot.) Ser., and M. sulcata Desf. Similar self‐fertility values were observed with and without grafting. No hybrid seeds were obtained from approximately 400 pollinations made on grafted plants. Thus, crossfertility also did not improve after grafting. Interspecific incompatibility in Melilotus appears to be due primarily to genetic barriers, but environmental factors also are apparently involved.
Auxin Induction and Repression of Peroxidase Isozymes in Oats (Avena sativa)1
Authors: Stuber C. W. , Levings C. S.
Published: July 2010

Eight isoperoxidases separable by electrophoresis were found in subapical coleoptile sections of oats (Avena sativa L.). Appearance of one isozyme was repressed by auxin applications (IAA or 2,4‐D). A second isozyme was induced by similar treatment. Genetic variability for the hormone inducible isozyme was demonstrated. Hormone level was critical to both isozyme repression and induction.
Comparisons of Three Indexes of Self‐ and Cross‐Compatibility in Alfalfa (Medicago sativa L.)1
Authors: Gray Elmer , Rice J. S. , Wang C. L.
Published: July 2010

Percentages of flowers producing pods, seeds/pod, and seeds/flower were compared as indexes of self‐ and crosscompatibility in alfalfa. The indexes did not differ significantly in power to distinguish differences in self‐ or cross‐compatibility.