bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Resistance to the Javanese Root‐Knot Nematode in Kenaf1
Authors: Adamson W. C. , Stone E. G. , Minton N. A.
Published: July 2010

Three kenaf (Hibiscus cannabinus L.) breeding lines were compared with the variety ‘Everglades 71’ in a field infested with the root‐knot nematode. Meloidogyne javanica (Treub, 1885) Chitwood, 1949a. All entries had previously shown some resistance to three Meloidogyne species in greenhouse tests.; A single entry, j‐1‐113‐1, showed effective field resistance, as indicated by root‐gall ratings and top growth.
Dimensional Balance Among Yield Components and Maximum Yield in an 8 ✕ 8 Diallel of Barley1
Authors: Grafius J. E. , Okoli Laud B.
Published: July 2010

Dimensional balance between yield components played a key role in determining yield of barley (Hordeum vulgare L. Emend., Lam.). The ratios of Y/X, Z/X, and Y/Z, where X = heads/plant, Y = seeds/head and Z = mg/ kernel, were found to account for 72% of the variation in yield of 28 Ft crosses from an 8 ✕ 8 diallel of barley. Such a high correlation between the shape of the yield parallelepiped as measured by these ratios and yield meant an almost 1:1 correspondence between shape and yield.

As yield increased the relative rate of expenditure of available resources for each component measured by component ratios increased for Z/X, decreased for Y/Z, and remained constant for Y/X.

The highest‐yielding crosses were found to have a high value of X and Y and a low value of Z when compared to the low‐yielding group and to the estimated mathematical optimum. The difference between the calculated optimum shape of the yield parallelepiped and the observed shape at the high yield levels was ascribed to component compensation. Negative correlations between Y and Z and between yield and Z indicated that as yield increased, increased values of Y would be attained at the expense of Z.
Evaluation of Turf, Reproductive, and Disease‐Response Characteristics in Crossed and Selfed Progenies of Kentucky Bluegrass1
Authors: Pepin G. W. , Funk C. R.
Published: July 2010

Kentucky bluegrass (Poa pratensis L.) selections ‘An. heuser,’ ‘Belturf,’ ‘P‐107,’ and ‘P‐72’ were selfed and crossed in several combinations. Resulting F1 hybrids and selfed aberrants were compared with their parents for important turf, reproductive, and disease‐response characteristics. Variable parental ploldy levels and difficulties in determining the origin of aberrant progeny made data interpretation difficult. However, plant height, plant circumference, panicle production, and turf quality appeared quantitative in inheritance, whereas genetic resistance to powdery mildew (Erysiphe graminis D. C.) and Helminthosporium vagans Drechsler appeared incompletely dominant. Because of a high incidence of tri. ploidy (fertilization of unreduced female eggs by reduced male gametes), parental ploidy levels and direction of cross were significant factors in the success of hybridization. Some positive transgressive segregation was noted for every characteristic studied. A high level of apomictic seed formation, as measured by the progeny test, was found in 86% of the Belturf ✕ Anheuser F1 hybrids. Some hybrids appear to have excellent turf quality and disease resistance. Considerable inbreeding depression and variation was observed in S1 aberrants.
Interaction of 2,3,5‐Triiodobenzoic Acid and 2,4‐Dichlorophenoxyacetic Acid on Growth and Yield of Soybeans1
Authors: Johnson R. R. , Anderson I. C.
Published: July 2010

The growth regulators 2,4‐dichlorophenoxyacetic acid (2,4‐D) and 2,3,5‐triiodobenzoic acid (TIBA) were foliarly applied to field‐grown soybeans (Glycine max (L.) Merr.) at various growth stages. Simultaneous application of the chemicals resulted in TIBA enhancement of the action of 2,4‐D. Application of a combined spray caused delayed maturity, greater lodging, distorted leaves, and yield reduction when TIBA was combined with 22.5 g/ha of 2,4‐D. When the 2,4‐D was applied 1 or 2 weeks before applying TIBA, it had little effect on maturity, lodging, and leaf morphology, but it tended to increase seed yield. The feasibility of using 2,4‐D with TIBA to increase yield is limited since the optimum rate of 2,4‐D varies with environment and variety.
Inheritance and Linkage Relationship of Strap Leaf Mutant in Cotton1
Authors: Dilday R. H. , Waddle B. A.
Published: July 2010

A new mutant in Upland cotton (Gossypium hirsutum L.) is described. The inheritance and linkage data show that the mutant expression is controlled by homozygous recessive alleles at a new locus. The mutant was designated “strap leaf” and assigned the gene symbols ss for the homozygous recessive character. Strap leaf is linked to veins‐fused (vf) and Green lint (Lg) by 3.7 and 11.1 crossover units, respectively.
Seed Yield Components in Lentils1
Authors: Muehlbauer F. J.
Published: July 2010

A yield component study of 45 lentil (Lens esculenta Moench) cultivars was conducted to determine the interrelationships between yield and yield components and to develop a selection procedure that would take into account important yield components and give special attention to seed weight. Seed weight was negatively correlated with yield (r = −.30*, df= 43) whereas single‐, double‐, triple‐, and quadruple‐pods/plant, yield/plant, seeds/plant, pods/plant, and seeds/pod were all positively correlated. A yield prediction equation was derived involving yield/plant (x1) and triple pods/plant (x2) and having regression coefficients of 49.6 and 185.6, respectively, with an intercept of 650.2. The three variables included in the equation had a multiple correlation value with yield of .79**. However, with this equation, higher yields would be predicted for the small‐seeded types and therefore would be of little use in programs designed to improve the yield of large‐seeded lentils. Within the 19 large‐seeded lines used in the study, seed number per plant accounted for most of the observed variation in yield (69%). Within the 26 small‐seeded lines, podding habit seemed most important. Since seed/weight was estimated to be highly heritable (95%), it is suggested that recurrent backcrossing be used to transfer high seed weight into the higher‐yielding small‐seeded lines.
Combining Ability in I0 Single Crosses of Red Clover1
Authors: Anderson M. K. , Taylor N. L. , Hill R. R.
Published: July 2010

A diallel cross involving 10 I0 red clover (Trifolium pratense L.) clones was evaluated for survival on two dates, total season yield in 1970, vigor, and days to first bloom on three different dates. General combining ability was the most important and the only significant source of genetic variance for all the characters. The additive genetic variance constituted 81% or more of the total genetic variance for each character. Nonadditive genetic variance may not be important enough to warrant production of hybrid red clover varieties, but other justifications exist. Parents for hybrids could be developed by selection and progeny testing, and little emphasis should be placed on examination of specific combinations among selected parents.
Effect of Pregermination Treatments on Germination and Growth of Cottonseed at Suboptimal Temperatures1
Authors: Cole D. F. , Wheeler J. E.
Published: July 2010

Various pregermination treatments were used to determine their effects on germination of cottonseed (Gossypium barbademe L.) at suboptimum temperatures and to determine whether chilling injury was reduced by these treatments.

‘Pima S‐4’ cottonseed were preconditioned in water and gibbercllic acid (10‐3M) at 10 and 30 C or in adenosine‐ 3′:5′.cyclic monophosphate( cyclic AMP,10‐4M) at 30 C, or were hot‐water‐treated at 70 C for 5 rain. After being preconditioned, seed were chilled for 24 hours at 5 C in water. Seed were germinated over a temperature range of 15.5 to 30 C for 7 days on a thermogradient plate. Germination counts were made daily. The speed and percent of germination were higher for seed preconditioned at 30 C than at 10 C. Hot‐water treatment reduced the sensitivity of seed to gibberellic acid and reduced germination at all temperatures. Chilling injury was reduced by preconditioning in either water, gibberellic acid, or cyclic AMP. Our data suggest that satisfactory cotton stands may be obtained at suboptimum temperatures (below 31 C) by elevating seed moisture and/or treating with a growth regulator prior to planting.
Photosynthetic Depression in Beans After Exposure to Cold for One Night1
Authors: Crookston R. Kent , O'Toole John , Lee Rita , Ozbun J. L. , Wallace D. H.
Published: July 2010

Phaseolus vulgaris L. plants exposed to 5 C for a single night exhibited severe reductions in photosynthesis the following day. However, the response was manifest only if the roots as well as the shoots were cooled. Photosynthetic reductions were accompanied by a parallel drop in transpiration, a rise in stomatal and mesophyll resistance to CO2 uptake, and a decrease in leaf water potential. Activities of ribulose diphosphate carboxylase and malate dehydrogenase were unaffected. Starch retention within chloroplasts of cold‐treated leaves accompanied a drop in photosynthesis, but the presence of starch did not reduce photosynthesis. The data suggest that rather than feedback inhibition, the photosynthetic reduction of potted bean plants following an exposure to cold is due to stomatal resistance brought on by temporary water stress.
Chromosome Manipulations in Alfalfa: Scaling the Cultivated Tetraploid to Seven Ploidy Levels1
Authors: Bingham E. T. , Saunders J. W.
Published: July 2010

The general scheme used in scaling genomic multiples down and up in ploidy is summarized, and a specific case of scaling chromosomes of a single cultivated alfalfa (Medicago sativa L.) clone to seven ploidy levels is reported. Cultivated tetraploids were scaled down to the diploid level by haploidy. Scaling upward was accomplished by sexual polyploidization, colchicine chromosome doubling, and spontaneous doubling in tissue cultures. The resulting ploidy series is diploid, triploid, tetraploid, pentaploid, hexaploid, heptaploid, and octoploid. For the single clone, this is the greatest range in ploidy levels known to have been produced with the chromosomes of a single individual. It demonstrates the plasticity of the autopolyploid genome of alfalfa and its ability to function at extremes of polyploidy. It further demonstrates how gene flow can be accomplished in a polyploid series through interploid crosses and bridge crosses. Such gene flow may prevent autopolyploids from becoming dead ends in evolution and isolated in breeding programs. Data on seed size at 2x, 4x, and 8x levels are also reported.
Computing Hourly Values of Diffuse and Direct Sunlight1
Authors: Williams W. A. , Loomis R. S. , Carter M. B.
Published: July 2010

A computer program was constructed to compute average hourly direct and diffuse components of solar radiation for days of differing degrees of cloudiness. Input data are daily total shortwave radiation, day of the year, and latitude of site. Listing in Fortan IV is available upon request.
Photosynthetic Characteristics of Several C3 and C4 Plant Species Grown Under Different Light Intensities1
Authors: Mahendra Singh , Ogren W. L. , Widholm J. M.
Published: July 2010

In 8 of 10 C3 and C4 species examined, photosynthetic rate and extractable ribulose diphosphate carboxylase activity per unit leaf area increased as light intensity received during growth was increased. These increases were associated with increased specific leaf weight. The rate of photosynthesis per unit leaf dry weight appeared to fall into 4 classes for 8 of the 10 species studied. The classes are in order of increasing photosynthetic efficiency: C3 grasses < C3 dicots < C4 aspartate‐formers < C4 malate‐formers. Orchardgrass (Dactylis glomerata L.) and Panicum copillare L. were exceptions in that growth under differing light regimes did not result in appreciable changes in rate of photosynthesis, light saturation, extracted ribulose diphosphate carboxylase activities, or photosynthesis rate per unit dry weight.
Weight, Oil, and Fatty Acid Composition of Components of Normal, Opaque‐2 and Floury‐2 Maize Kernels1
Authors: Arnold J. M. , Piovarci Albin , Bauman L. F. , Poneleit C. G.
Published: July 2010

Normal and opaque‐2 kernels from segregating maize (Zea mays L.) ears were examined for kernel components, oil content, and fatty acid composition. Normal kernels were higher in kernel and endosperm weight and embryo oil concentration, and lower in embryo weight than opaque‐2 kernels. Compared to normal, the oil from opaque‐2 kernels was slightly but significantly higher in oleic acid and lower in linoleic acid composition. Comparison of normal and floury‐2 kernels from segregating ears showed kernel and endosperm weights of the normal kernels were greater than for floury‐2, and embryo weight was similar. In a comparison of near‐isogenic floury‐2 and normal single‐cross hybrids, the kernel components were heavier in normal, while percent oil was greater for floury‐2 owing largely to a greater proportion of embryo. Percent oil in embryo was less in floury‐2 hybrids.
Interaction of Shrunken‐2 with Five Other Carbohydrate Genes in Corn Endosperm1
Authors: Holder D. G. , Glover D. V. , Shannon J. C.
Published: July 2010

The interactions of the shrunken‐2 (sh2) gene with waxy (wx), amylose‐extender (ae), sugary‐1 (su1), dull (du) and sugary‐2 (su2) on the carbohydrate composition of maize (Zea mays L.) endosperm were determined. The contents of fructose, glucose, sucrose, water‐soluble polysaccharide (WSP), and starch of whole kernel samples 21 and 28 days after pollination were determined. Percent starch and amylose of mature kernels were determined.

The sh2 mutation reduced starch drastically concurrent with a large accumulation of sucrose as previously observed. In homozygous double and triple recessive genotypes, sh2 was epistatic over all other genes for the accumulation of sucrose and reduction of starch. Genotype combinations containing both su1 and sh2 produced the most extreme reduction in starch content, and in all cases sh2 inhibited the large WSP content normally caused by su1. Starch from kernels homozygous for ae alone had 60% amylose. Presence of sh2 in the multiple recessive genotypes inhibited the ae enhancement in percent amylose. With few exceptions those genotypes with wx produced no amylose; those which did were in combination with ae. Genotype combinations containing both wx and sh2, had higher sucrose than normal and the starch, although reduced in quantity, was 100% amylopectin.
Inheritance of Resistance to Anthracnose in Alfalfa1
Authors: Campbell T. A. , Schillinger J. A. , Hanson C. H.
Published: July 2010

Resistance to anthracnose caused by Colletotrichum trifolii Bain in a cross of susceptible ✕ resistant plants in alfalfa (Medicago sativa L.) was conditioned by a completely dominant gene inherited in a tetrasomic manner. The symbol AR was suggested for the dominant allele and ar for the recessive. S1, F1, F2, F3, and backcross progenies were used in the study.
Effects of Temperature and Alfalfa Entry on Seedling Reaction to Stem Nematode1
Authors: Elgin J. H. , Peaden R. N. , Faulkner L. R. , Evans D. W.
Published: July 2010

Because of a need for additional information regarding the effects of temperature on the reactions of alfalfa (Medicago sativa L.) seedlings from diverse sources to stem nematodes (Ditylenchus dipsaci (Kühn) Filipjev), we inoculated germinating seeds of 101 alfalfa varieties and experimental lines (entries) with 25 stem nematodes and grew the seedlings for 24 days at 16, 20, and 25 C. After 24 days the seedlings were rated for cotyledonary. node swelling and stained for counts of numbers of hem. atode adults, larvae, and eggs in plant cotyledons, the cotyledonary node, and the hypocotyl.

Greater cotyledonary‐node swelling was observed at 16 and 20 C than at 25 C. A few entries differed in cotyledonary‐node swelling; however, most of the entries were similar. Greater numbers of larvae and eggs were found at 16 and 20 C than at 25 C. Some entries differed for numbers of adults, larvae, and eggs counted in the seedlings. Greater numbers of larvae and eggs occurred in the hypocotyl than in the cotyledonary node or cotyledons. Number of adults, larvae, and eggs in the seedlings increased, particularly in the cotyledonary node and hypocotyl, as the cotyledonary‐node swelling of the seedlings increased.

Due to our inability to easily separate resistant and susceptible entries on the basis of visual symptoms or nematode population counts, we concluded that the usefulness of an early‐stage seedling evaluation similar to what we used is of questionable value to the breeder.
Influence of Maize Endosperm Mutants on Ground Kernel In Vitro Dry Matter Disappearance1
Authors: Garwood D. L. , Shenk J. S. , Barnes R. F.
Published: July 2010

Ground kernels of the W64A maize (Zea mays L.) inbred and 5 single and 10 double endosperm mutants of maize converted to W64A were evaluated using a twostage in vitro rumen fermentation system with and without urea added to the digestion buffer. In vitro dry matter disappearance (IVDMD) values were not correlated with protein content. Urea addition raised IVDMD values to the same level for most genotypes. Four genotypes were investigated using only first‐stage digestion for 3, 6, 12, 24, and 48 hours. Maximum differences were observed after 12 and 24 hours of digestion. At these times, opaque‐2 was most degraded followed by waxy, normal, and amylose‐extender. The superior rate of opaque‐2 digestion compared to waxy could not be explained by differences in particle sizes nor by known rates of isolated starch granule digestion. We suggest that incubation times used for forage IVDMD studies utilizing the basic procedure of Tilley and Terry be shortened when comparing ground grain samples.
Growth Type and Yield Comparisons of Forage Species After Seed Multiplication in Germany and in the United States. I. Red Clover, Alfalfa, and White Clover1
Authors: Simon Uwe , Kastenbauer A. , Garrison C. S.
Published: July 2010

Seed increases of red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.), and white clover (Trifolium repens L.) from seed composites of German origin, representing 20% early, 60% intermediate, and 20% semilate flowering types, were made at one location in Germany and three locations in the United States. The population composition and forage yields of two consecutive generations of increase were investigated at Weihenstephan, Germany. Growth type means and forage yields of red clover increased in the United States were similar to those from seed increased in Germany. Forage yield differences between alfalfa seed lots increased in the United States and Germany were not significant. However, a tendency towards more upright and later flowering types of plants and slightly reduced winter survival was observed in some of the alfalfa lots multiplied in the United States.

Means for leaf size, plant diameter, plant height, regrowth, and flowering intensity of most of the white clover populations fom seed grown in the United States were somewhat lower than corresponding means for the increases made in Germany, but were similar to the means of the original seed. No clear relationships were noted among generations or among harvest years within generations and population changes.

It is concluded that plant characteristics and forage yield of the red clover, alfalfa, and white clover experimental composites were retained when seed was multiplied for two generations at three locations in the United States.
Response of Soybeans to Amo‐1618 and Photoperiod1
Authors: Wilcox J. R.
Published: July 2010

Segregating populations from two soybean (Glycine max (L.) Merr.) crosses were sprayed with aqueous solutons of 0, 250, 500, 1,000, and 2,000 ppm (4‐hydroxy.5‐isopropyl‐2‐methylphenyl)trimethylammonium chloride 1. lpiperidinecarboxylate, designated Amo‐1618. Treatments were applied at V2 (when the first trifoliolate unrolled) and again at V3 (when the second trifoliolate unrolled) on plants grown under 12, 14, and 16‐hour photoperiods in the greenhouse. A concentration of 250 ppm reduced plant height to an average of 76% of the untreated control under 12‐hour photoperiods, 64% under 14‐hour photoperiods, and 66% under 16‐hour photoperiods. A concentration of 500 ppm, applied only at V2, reduced plant height to 50% of the untreated control under a 12‐hour and 62% under a 14‐hour photoperiod. The same concentration, applied again at V3, resulted in an additional decrease in height. Concentrations of 250 ppm under a 12‐hour or of 500 ppm under a 14‐hour photoperiod, sprayed ou plants at V2 and again at V3, resulted in plants 20 to 30 cm tall compared to untreated plants that were 39 to 56 cm tall. This was a convenient plant size to advance large, segregating populations in the greenhouse with a mnimum of maintenance.
Synthesis of Commercial F1 Hybrids in Cotton. I. Genetic Control of Vegetative and Reproductive Vigor in Gossypium hirsutum L. ✕ G. barbadense L. Crosses1
Authors: Davis Dick D.
Published: July 2010

The hybrid vigor in Gossypium hirsutum L. ✕ G. barbadense L. F1 hybrids is usually associated with late maturity and excessive vegetative growth relative to reproductive development. These undesirable traits tend to limit the range of hybrid adaptability to areas with long growing seasons. Experiments reported herein demonstrate that an early semidwarf G. hirsutum line of Yugoslavian, Kekchi, and Acala (YKA) origin produced highly desirable agronomic types of hybrids in crosses with three G. barbadense lines. These F1 hybrids were shorter‐statured and as early and productive as the bestyielding locally adapted commercial variety, ‘Acala 1517‐70.’ The YKA parent transmitted dominant factors for early, prolific fruiting to its progeny. The tendency for heavy fruiting early in the season apparently reduced the rate of vegetative growth so that hybrids were relatively short‐statured at maturity. The interspecific hybrids required a longer period for boll maturation than did Acala 1517‐70. Because the hybrids had fiber 4 to 6 mm longer than the check, it was reasoned that the longer boll period was associated with fiber length and that further advances in earliness might be gained from crossing very short‐fibered lines of G. barbadense ✕ YKA to produce short‐fibered hybrids. Other properties of the hybrids were discussed, and subsequent steps to be taken in the improvement of interspecific hybrids were outlined.
Rapid Procedure for Isolation of Polyhaploids in Bromegrass1
Authors: Tan Geok Yong , Dunn G.M.
Published: July 2010

Cotyledons of Bromus inertnis Leyss. were fixed and decolorized in Carnoy's solution for 24 hours, immersed in 70% alcohol, and softened in lactic acid at 60 C for 15 min. The whole leaf was then mounted in lactic acid. Mean stomatal lengths of 41.8 and 43.4 µ were obtained for adaxial and abaxial surfaces of cotyledons of tetraploid seedlings compared to 62.3 and 65.1 µ for octoploid seedlings. This simple technique provides a rapid and economical method of screening for polyhaploids in populations of octoploid Bromus inermis.
Derivation of the 6X‐Amphiploid of Hordeum Depressum Rydb. ✕ H. Californicum Covas and Stebbins1
Authors: Schooler A. B.
Published: July 2010

Self‐sterile F1 plants were obtained from crosses between Hordeum depression Rydb. (2n=28) (B256) and H. californicum Covas and Stebbins (2n=14) (PI211038). Fertility was restored after the chromosome number was doubled by treating the F1 seedlings with a 0.05% colchicine solution. Chromosome pairing indicated that H. californicum may have one genome in common with H. depressum.
Pollen Collection, Crossing, and Seed Germination of Hop1
Authors: Haunold Alfred , Zimmermann Charles E.
Published: July 2010

Male sidearms of Humulus lupulus L. were placed overnight in tap water in a culture tube taped to the inside wall of a large, round, open‐ended Plexiglas cylinder for pollen collection. Previously bagged female sidearms were pollinated with a hypodermic syringe. Hop seeds were pretreated 6 to 8 weeks in moist Petri dishes in a refrigerator at 2 to 3 C and subsequently germinated at 15 to 25 C in a germinator. Seedlings were transplanted first to greenhouse pots and after about 8 weeks, they were moved directly to the field. Most plants flowered the same season, and many reached the top of the trellis (5.5 m).
Genetic Variances in a Random‐Intercrossed Population of Burley Tobacco1
Authors: Legg Paul D. , Collins G. B.
Published: July 2010

In a random‐intercrossed population of burley tobacco (Nicotiana tabacum L.), genetic variances were estimated using biparental progenies from noninbred plants, biparental progenies from doubled haploid plants, and selfprogenies from doubled haploid plants. Additive genetic variances were important for days to flower, plant height, leaf length, and number of leaves. Additive ✕ additive genetic variances were indicated for yield and total alkaloids. For leaf width, the significant amounts of genetic variability among the full‐sib families in both the noninbred and inbred parental material could not be resolved into specific functions of genetic variances. Dominance variance appeared to be absent.
Potential Selection System for Mutants with Increased Lysine, Threonine, and Methionine in Cereal Crops1
Authors: Green C. E. , Phillips R. L.
Published: July 2010

Simultaneous addition of lysine and threonine inhibits growth in maize (Zea mays L.) callus cultures and embryo cultures from several cereals. Methionine or homoserine reverses lysine‐threonine inhibition. Isolation of feedback inhibition resistance mutants is proposed for several cereals by selecting callus or seedlings which grow in the presence of lysine‐threonine. Resulting mutants may be overproducers of lysine, threonine, or methionine.
Leaf Surface Effects on In Vitro Digestion and Transpiration in Isogenic Lines of Sorghum and Pearl Millet1
Authors: Hanna Wayne W. , Monson Warren G. , Burton Glenn W.
Published: July 2010

Isogenic lines of bloomless Sorghum bicolor (L.) Moench and normal (hairy) Pennisetum americanum (L.) K. Schum. [formerly P. typhoides (Burm.) Stapf. and C. E. Hubb.] were 31% more digestible according to in vitro dry matter disappearance (IVDMD) tests and lost significantly more water than their bloom‐covered and trichomeless counterparts. The increased IVDMD and water loss are caused by differences in leaf surface characteristics. The increased IVDMD of bloomless sorghum and normal pearl millet may significantly affect animal weight gain and/or milk production through more rapid digestion and increased intake. The bloom‐covered and trichomeless lines are probably more drought‐tolerant because of slower water loss through the leaves.
Meiotic Chromosome Behavior and Pollen Fertility of a Triploid Hop1
Authors: Haunold Alfred
Published: July 2010

In triploid Humulus lupulus L., metaphase I cells had a mean of 3.46 trivalents, 6.47 bivalents, and 6.67 univalents/pollen mother cell. Chromosome distribution at anaphase I was irregular, and 1/3 of the cells had laggards. About half of the quartets had one or two micronuclei, but rarely three. Diploid females pollinated from the triploid male produced less than 1/4 the number of seeds/cone, as the open‐pollinated diploid control, even though most of the pollen grains from the triploid appeared well‐filled. Diploid flowers hand‐pollinated from the triploid male developed into distinctly larger cones than did adjacent nonpollinated flowers on the same plant.
Inheritance of Perloline Content in Annual Ryegrass ✕ Tall Fescue Hybrids1
Authors: Cornelius P. L. , Buckner R. C. , Bush L. P. , Burrus P. B. , Byars J.
Published: July 2010

Progeny of crosses among nine clones derived from hybrids of tall fescue (Festuca arundinacea Schreb.) and annual ryegrass (Loliurn multiflorum Lam.) were studied for perloline content. The data were analyzed by a modified partial diallel analysis. The results suggest that perloline is controlled primarily by a few major genes, with a high degree of dominance for low peroline. However, some genes with smaller effects may exist.
Early Generation Testing and Selection in Soybeans: Association of Yields in F3‐ and F5‐Derived lines1
Authors: Thorne J. C.
Published: July 2010

One hundred F3‐deprived lines were established from each of 31 soybean [Glycine max (L.) Merr.] crosses. From these 3,100 F4 lines, 658 were yield‐tested and simultaneously two F5 lines were established from each F3‐derived line. About 25% (153) of the 658 F3‐derived lines were selected and tested with their respective F5‐derived lines. The correlations of yields of F3 with F5‐derived lines were all positive and were significant in 13 of 16 cases (mean r = 0.581).
Disease Reaction of Wheat with Alien Cytoplasms1
Authors: Washington W. J. , Maan S. S.
Published: July 2010

Alloplasmic lines of Triticum aestivum L. em. Thell. ‘Chris’ and ‘Selkirk’ and T. durum Desf. Sel. 56‐1 were tested to three individual physiologic races of wheat leaf rust (Puccinia recondita Rob. ex. Desm. f. sp. tritici) at the seedling and adult plant stages. Chris was resistant at the adult stage but susceptible at the seedling stage to all three races used. However, alloplasmic Chris lines with the cytoplasm of T. araraticum Jakubz., T. timopheevi Zhuk., T. macha Des. & Men., T. boeoticum Boiss., Aegilops ovata L., or Ae. speltoides Taush. were susceptible or moderately susceptible at the adult stage to one or more of the rust races. Selkirk and alloplasmic Selkirk lines with the cytoplasms of these and several other species were resistant at the seedling and adult plant stage to the three races. T. durum Sel. 56‐1 and alloplasmic durum lines had mesothetic reactions to the three races, and rate of uredial development was slower on alloplasmic durum lines than on the controls. Apparently, certain alien cytoplasms influence the expression of genes for resistance to certain races of wheat leaf rust.
Potassium Absorption by Excised Barley Roots in Relation to Antecedent K, P, N, and Ca Nutrition1
Authors: Ohki K. , Ulrich A.
Published: July 2010

In absorption studies with excised roots, the nutritional status of roots in relation to root growth has been difficult to assess prior to the absorption period. Since the antecedent nutrition greatly influences the subsequent K absorption, it is important to assess the nutritional status of roots undergoing ion absorption. Therefore, this study was initiated to determine the influence of antecedent nutrition of K, P, Ca, NO3‐N, and overall salt status of excised barley (Hordeum vulgare) roots on K absorption.

Assessment of the nutritional status of the plants was made by comparing the analytical results of the excised roots to the corresponding critical nutrient value of 13.5 meq, 4.5 mmol, 2.9 meq, and 2.5 meq kg‐1 fresh wt, for K, P, Ca, and NO3‐N, respectively.

Under severe K deficiency, excised barley roots absorbed less K than comparable roots slightly deficient in K. Losses of K to the absorbing solution occurred from roots with high endogenous K. Excised roots from Pdeficient plants, low in endogenous K, absorbed less K than roots low in endogenous K with adequate P. Nitrogen deficiency alone did not increase the capacity for K absorption. Calcium deficiency suppressed K uptake primarily as a result of high endogenous K in Ca deficient roots. A combination of N deficiency and low endogenous K increased the capacity for K absorption. Low salt plants however, had the largest capacity to absorb K.
Selection in Six Crops of Sugarcane. I. Repeatability of Three Characters
Authors: Miller J. D. , James N. I.
Published: July 2010

Phenotypic correlation coefficients for three characters among 6 crops of sugarcane (Saccharum sp.) showed that repeatability for stalk diameter among plant crops was somewhat higher than that for stalk number and Brix, which were about equal. Repeatability for stalk number and diameter was about equal between plant crops and first ratoon crops, but Brix was more repeatable among ratoon than among plant crops.

Stalk number and Brix in seedling crops and 1.2‐m clonal crops were not significantly correlated with yield in 4.6‐m clonal crops. Stalk diameter in seedling crops and 1.2‐m clonal crops was significantly correlated with yield in 4.6‐m clonal crops and ranged from 0.17 to 0.34 (.01 level of significance). Thus, stalk diameter was a better selection criterion for yield in early stages of selection than was stalk number or Brix.

Since Brix and cane yield were not associated, it should be possible to select high‐yielding clones that also have high Brix.
Seed Production by Ryegrass‐Fescue Hybrid Derivatives in Muslin‐Covered Cages1
Authors: Berg Clyde C. , Hill R. R.
Published: July 2010

Clones of ryegrass‐fescue (Lolium‐Festtica) hybrid‐derivative origin were used to produce syn‐1 generation seed of eight 4‐clone synthetics under muslin‐covered isolation cages. Cages, about 1.5 m wide ✕ 5.2 m long ✕ 15 m high, were constructed over plots containing 16 space‐planted ramets of each of the four clones of each synthetic. The cages were covered with muslin a few days before anthesis.

Very large differences, which could be attributed to cages (or synthetics) and to clones within synthetics, were observed in 1966 and 1968. Some clones produced very little seed. Although differences between years were large, the correlation between seed production in 1966 and 1968 was highly significant (r = 0.478).

The effects of several cage treatments on seed production were evaluated on plots established to one 4‐clone synthetic. The cage treatments were: no fan, fans, and fans plus dehumidifier in 1970; open cage, no fan, and fans in 1971; and open cage, no fan, one fan, and two fans/cage in 1972.

The presence of fans in the cages significantly increased seed yields in 1970, but not in 1971 or 1972. Using a dehumidifier did not increase seed production over that with fans alone. Seed production outside cages was always significantly greater than production in cages, regardless of the cage treatment. Although smaller than variations due to cage treatments and clones, significant clone by cage treatment interactions were observed each year. This interaction suggests that seed produced under different conditions could be genetically different. Seed of experimental ryegrass‐fescue hybrid‐derivative populations can be produced in isolation under muslin‐covered cages. However, more research is needed to determine the effect of cage environments on the genetic composition of the seed produced and on techniques to reduce interactions.
Determining Lock Tenacity in Pima Cotton1
Authors: Young E. F.
Published: July 2010

These investigations were initiated to develop a technique for estimating storm resistance under field conditions in Pima cotton (Gossypium barbadense L.). A 500‐g force gauge was used for field determination of lock tenacity. Lock tenacity was measured for fully open bolls. The pull of the lock was made parallel to the suture opening when the gauge was held horizontally. The most consistent readings were obtained from bolls located in the upper two‐thirds of the open‐boll zone. Storm resistance was overestimated if diseased locks or bolls not fully open were measured.

Field estimates of lock tenacity of several Upland cotton (G. hirsutum L.) cultivars were close to earlier laboratory estimates. Highly significant differences in lock tenacity among Pima cultivars and consistent ranking of cultivars over experiments showed that they differ genetically for lock tenacity. The force gauge effectively measures the trait in a breeding program.
Heritability of Oil Content in Sunflowers1
Authors: Fick G. N.
Published: July 2010

Seed oil content in sunflowers (Helianthus annuus L.) was determined by nuclear magnetic resonance (NMR) for parent, F1, F2, and backcross generations of the cross P‐21 VRl/Menn RR‐18‐1 and for the F2 and F3 generations of the cross cmsPI 343765/HA 119//HA 62‐4‐5/3/T66006‐2.

Broad and narrow‐sense heritability estimates on an individual‐plant basis in the F2 generation of the cross P‐21 VRl/Menn RR‐18‐1 were 0.72 and 0.61, respectively. The ratio of narrow to broad‐sense estimate indicated that genetic effects were largely additive. Heritability in the F2 generation of the second cross, as estimated by the parent‐progeny regression method, was 0.52. Actual gain in F3 from simulated selection for high oil content in the F2 generation was in good agreement with that predicted from the regression estimate. The heritability values were of sufficient magnitude to encourage selection for high oil content on individual plants in early generations.
Photosynthetic‐respiratory Responses of ‘Merion’ Kentucky Bluegrass and ‘Pennlawn’ Red Fescue at Reduced Light Intensities1
Authors: Wilkinson J. F. , Beard J. B. , Krans J. V.
Published: July 2010

The objectives were to characterize the photosynthetic‐respiratory responses of Kentucky bluegrass (Poa pratensis L. ‘Merion’) and red fescue (Festuca rubra L. ‘Pennlawn’) to reduced light intensities. Merion and Pennlawn were grown in separate growth chambers at light intensities of 2.7, 10.8, and 43 klux. Light quality, soil moisture, and soil temperature were standardized among chambers. Infrared CO2 analysis was used to measure assimilation rates, light saturation levels, and light compensation points of both swards and individual plants.

Both species had decreased net photosynthesis (PN) and dark respiration (RD), lower light saturation levels, and decreased light compensation points under reduced light intensity. Swards generally had lower PN and RD rates but higher light saturation levels and light compensation points than individual plants.

Both species responded similarly to reduced light intensity in terms of PN, light saturation levels, and light compensation points. These factors could not be associated with the ability of Pennlawn to provide a more desirable turf than Merion in the shade. RD of individual plants of Pennlawn was reduced at the lowest light intensity, whereas the RD of Merion was not. This response may contribute to the positive CO2 balance of Pennlawn at reduced light intensities and thus to its shade adaptability.
Inheritance of Plant Height in Cotton. I. A Cross Between Lubbock Dwarf and Texas Marker‐1
Authors: Quisenberry J. E.
Published: July 2010

In Upland cotton (Gossypium hirsutum L.), plant height is determined primarily by the number and length of the main stem internodes, but it can be significantly modified by variation in the node on the main stem where fruiting branches are first initiated. F1, F2, and backcross populations from a cross between the inbred lines of Lubbock Dwarf and Texas Marker‐1 provided estimates about the inheritance of plant height, number of main stem nodes, length of main stem and fruiting branch internodes, and node of the first fruiting branch. Phenotypic correlations were computed from the F2 population for all character combinations.

The parental lines differed in plant height, main stem and fruiting branch internode lengths, and the node of the first fruiting branch. The parental lines were not different in the number of main stem nodes; only environmental variation occurred for this character. Each of the other characters were quantitatively inherited with additive genetic effects, without any indication of significant dominance genetic effects. Plant height was shown to be associated with the number of main stem nodes (r = 0.57), main stem internode length (r = 0.88), and node of the first fruiting branch (r = 0.38). A significant association was also found between the number of main stem nodes and node of the first fruiting branch (r = 0.34). The lack of significant association between the main stem internode length and the fruiting branch internode lengths suggested that these characters can be manipulated by traditional breeding techniques independently of each other.
Inheritance of Fiber Properties Among Crosses of Acala and High Plains Cultivars of Upland Cotton1
Authors: Quisenberry J. E.
Published: July 2010

Although High Plains and Acala cultivars of cotton are taxonomically classified as Gossypium hirsutum L., their pedigrees suggest that they have remained largely discrete populations during cultivar development. To evaluate the genetic control associated with certain fiber properties when High Plains and Acala cultivars are hybridized, a factorial mating design was used to cross randomly‐ selected High Plains and Acala lines. The hybrid populations that resulted from those crosses were used to obtain estimates of genetic variances for fiber length, strength, elongation, and fineness.

Additive genetic variance predominated for fiber length, strength, and elongation. Most of the phenotypic variance for fiber fineness was due to the environmental component; however, a statistically significant, nonadditive component was observed. The results suggested that in general, within segregating populations derived by hybridizing High Plains and Acala cultivars, lines can be selected that have desirable combinations of fiber length, strength, and elongation, but that genetic gain for fiber fineness will probably be difficult.
Comparison of Three Selection Procedures for Yield in Soybeans1
Authors: Boerma H. R. , Cooper R. L.
Published: July 2010

Four segregating soybean [Glycine max (L.) Merr.] populations were used to evaluate the effectiveness and efficiency of three selection procedures in isolating highyielding lines; early‐generation yield testing (EGT), pedigree selection (PS), and single‐seed‐descent selection (SSD). Lines were obtained from the PS procedure in the F4 generation and from the EGT and SSD procedures in the F5 generation. These lines were yield‐tested and selected in either the F6 or F7 generation in each procedure. In the F8 generation of each cross the selected lines in each procedure were compared.

The means of all selected lines, the means of the five highest‐yielding lines, and the highest‐yielding line from each population showed no consistent differences in procedures. The lines from the EGT procedure were consistently later in maturity than the lines from the other two procedures. This was attributed to the yield‐testing in unbordered plots in the early generations by the EGT procedure. The SSD procedure emerged as the most efficient procedure, because it required less selection effort than the EGT and PS procedures, allows a rapid advance of the early‐generation segregating populations, and did not use expensive yield‐testing until later generations, when yield‐testing is more efficient.
Frequency of Progenies Resistant to Corn Stunt and Maize Dwarf Mosaic in Maize Populations1
Authors: Scott Gene E. , Rosenkranz Eugen E.
Published: July 2010

S1 progenies from 10 maize (Zea mays L.) populations were evaluated for reaction to maize dwarf mosaic virus following manual inoculation and to the corn stunt agent(s) under conditions of natural infection, respectively. All populations except one had at least some progenies showing some resistance to maize dwarf mosaic (MDM), but there were differences among the populations. ‘Kenya Composite’ and ‘PR‐Mpl’ had the greatest frequency of progenies highly resistant to MDM. Heritability estimates for MDM resistance within the populations tested ranged from 0.21 to 0.85. ‘Corn Belt’ ✕ ‘Brazilian Synthetic No. 1,’ ‘Corn Belt ✕ Mexican Synthetic No. 1,’. and PR‐Mpl had higher numbers of progenies resistant to corn stunt (CS) than the other populations tested. Heritability estimates for CS resistance within the populations tested ranged from 0.03 to 0.59. The greatest expected progress for improvement of CS resistance would be in Kenya Composite. Index selection based on the “total score” for both diseases was an efficient method of selecting parents to be used for population improvement for resistance to both diseases.
Differential Response of Cotton Varieties to Infection by Aspergillus flavus
Authors: Brown C. M. , Ashworth L. J. , McMeans J. L.
Published: July 2010

Ten cultivars of upland‐type cotton (Gossypium hirsutum L.) tested in the Imperial Valley of California were susceptible to infection by Aspergillus flavus. But two cultivars were more severely affected than the others, based upon the amount of aflatoxins occurring in seeds at harvest. Seeds of ‘Paymaster 54‐B’ had about 800 ppb aflatoxins and seeds of ‘Stoneville 3209’ had about 125 ppb aflatoxins while seeds of the other cultivars contained a trace to 6 ppb aflatoxins.
Resistance of Red Clover to the Clover Leaf Weevill1
Authors: Gorz H. J. , Manglitz G. R. , Haskins F. A.
Published: July 2010

Red clover (Trifolium pratense L.) varieties in the third season of growth, that had been exposed to a heavy infestation of larvae of the clover leaf weevil [Hypera punctata (Fabricius)], differed significantly in percentage defoliation, feeding injury score, plant height, and forage production. Based on these four characters, ‘Mammoth,’ ‘Lakeland,’ ‘Dollard,’ and ‘LaSalle’ were highly resistant to larval feeding; ‘Kenland,’ ‘Common,’ and ‘Pennscott’ were highly susceptible. Long term second‐season yield tests including six of these varieties indicated no consistent superiority of any of the varieties in the absence of weevil feeding.
Eragrostis curvula: Influence of Low Temperatures on Starch Accumulation, Amylolytic Activity, and Growth1
Authors: Hilliard Joe H.
Published: July 2010

Four varieties of Eragrostis curvula (Schrad.) Nees (weeping lovegrass) were evaluated for growth at reduced temperatures, amylolytic activity, and diurnal changes in leaf starch content in order to ascertain whether the variety with the most relative growth at reduced temperatures would retain the least amount of leaf starch after a cool night. Growth was measured by dry matter production; amylolytic activity by the ability of a leaf extract to hydrolyze starch; and leaf starch by enzymic hydrolysis of the starch followed by a glucose assay.

It was found that growth at reduced temperature was positively associated with amylolytic activity and negatively associated with leaf starch retention after a cool night. Differences in amylolytic activity were due to the total amount of enzyme activity present and not due to differences in enzymic resistance to cool temperatures. The Q10 for amylolytic activity of all varieties was 2.0. These findings suggest that amylolytic activity and leaf starch measurements might be useful selection criteria in the search for cool temperature resistant tropical grass forages.
Heterosis and Combining Ability in Chili Peppers by Diallel Analysis
Authors: Lippert L. F.
Published: July 2010

Significant heterosis was recorded from hybrids in a nine‐parent diallel of chili peppers (Capsicum annuum L.) for dry fruit wt/plant (27.4%**, significant at the 1% level), fruit length (7.3%**), and percentage mature fruit at harvest (3.0%*, significant at the 5% level). Additive effects (GCA) were more important than nonadditive (SCA) in explaining variability among Fl's for fruit number, dry fruit wt/plant, fruit length and width, and total carotenoids of the fruits.

Performance, predicted in synthetic populations formed from parents selected on the basis of carotenoid concentration, is presented, and breeding procedures applicable to chili pepper improvement are discussed.