bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant Nutrient and Forage Quality Analysis of a Wild Legume Collected from the Highland Rim Area of Middle Tennessee1
Authors: Gallaher Raymond Noel , Buhr K. L.
Published: July 2010

This is a report about a summer annual wild legume (Amphicarpa bracteata L. Rick. and Staf.) found growing in the Highland Rim area of middle Tennessee. It has been observed to be preferentially grazed by farm animals. It reproduces by underground apetalous reproductive organs, as well as above ground seed pods; this suggests that it may have survival potential under conditions of intense grazing. A comparison of the laboratory chemical analyses of this wild legume, known as “wild pea” or “hog peanut,” with plants of peanut (Arachis hypogaea L. ‘Florunner’), revealed similarities between the wild legume and cultivated peanut. Crude protein values for wild pea exceeded 160 g kg−1 Because of its favorable chemical composition, dual mechanism of reproduction, and vining, competitive growth habit, wild pea should receive additional research to explore its potential as a cultivated forage legume.
Iron‐Deficiency Chlorosis of Soybean Cultivars Injured by Plant Cutoff and Defoliation1
Authors: Fehr W. R. , Froehlich D. M. , Ertl D. S.
Published: July 2010

A preliminary observation indicated that iron‐deficiency cholorosis of soybeans [Glycine max (L.) Merr.] grown on calcareous soil may have been accentuated after hail injury that occurred during vegetative growth. The objective of our experiment was to determine the effect of plant cutoff and defoliation on the chlorosis expressed by new leaf tissue that develops after injury occurs. Ten soybean cultivars that differed in resistance to iron‐deficiency chlorosis were grown on a calcareous soil during 2 years. Plants were treated at the V1 to V5 stages of development by removing the main stem above the cotyledonary node, removing the main stem above the unifoliolate node, or complete defoliation. Chlorosis was increased an average of 0.9 score by plant cutoff above the cotyledons, 0.6 score by cutoff above the unifoliolates, and 0.2 score by defoliation. For each type of injury, the stage of development when the treatment was imposed had a significant effect on the change in chlorosis expressed during one or both years. The differences in response among cultivars and the year ✕ cultivar, treatment ✕ cultivar, and year ✕ treatment ✕ cultivar interactions were significant. The increase in chlorosis from plant injury may cause yield loss in addition to that resulting from the injury per se. Artificial plant injury may be a useful tool in selection for improved genetic resistance to iron‐deficiency chlorosis.
Genotype and Media Effects on Callus Formation and Regeneration in Barley1
Authors: Hanzel J. J. , Miller J. P. , Brinkman M. A. , Fendos E.
Published: July 2010

The success of barley (Hordeum vulgare L.) cell and tissue culture research depends upon reliable callus culture and plant regeneration procedures. The objective of this study was to identify callus‐inducible genotypes, to evaluate media for effectiveness in promoting callus growth, and to identify genotypes capable of regenerating plants. Ninety‐one barley genotypes were evaluated for initiation and maintenance of callus growth. Forty‐five of the genotypes initiated callus, while 46 did not. Callus cultures were maintained by subculturing onto fresh media at monthly intervals. Genotypic variation was noted for longevity and rate of growth of callus cultures. Calli of several genotypes were maintained for more than 2 years. Murashige and Skoog's (MS) media promoted more callus initiation and provided better callus maintenance than media of Blaydes (B), Gamborg et al. (B5), Norstog (N), and Shenk and Hildebrandt (SH). Frequencies of callus initiation were high when either 0.5, 1.0, or 2.0 mg/L of 2,4‐D (2,4‐dichlorophenoxyacetic acid) were added to the media. There were significant genotype ✕ media interactions for callus initiation. Established calli were transferred to differentiation media to promote plant regeneration. Although there were genotypic differences in regeneration, the overall frequency was low (15%). Seventy percent of the regenerated plants were from calli of the cv. Akka and Wisconsin experimental selection X2387‐3.
Inheritance of Reaction to Stem Canker in Soybean1
Authors: Kilen T. C. , Keeling B. L. , Hartwig E. E.
Published: July 2010

There are no known published reports concerning the inheritance of reaction to the disease stem canker [caused by the fungus Diaporthe phaseolorum (Cke. & Ell.) Sacc. var. caulivora Athow & Cald.] in soybean [Glycine max (L.) Merr.]. Because stem canker has become a serious soybean disease in the southern United States, and because a source of resistance has been identified, information on the inheritance of reaction to this disease is needed. The objective of this study was to determine the inheritance of resistance to stem canker found in the soybean ‘Tracy‐ M.’ Crosses were made between Tracy‐M and a very susceptible line, J77‐339. The disease reactions of parental, F1, F2 and F3 populations from that cross to stem canker were studied under field conditions to determine the genetic basis for resistance. All F1 plants were resistant and the F2 generation fit a 15 resistant:1 susceptible ratio (✕2 probability = 0.75 to 0.90). The 199 F, families fit a ratio of 7 resistant:8 segregating:! susceptible (X2 probability = 0.25 to 0.50). These results indicate that stem canker resistance in Tracy‐M is controlled by two major dominant genes.
Yield of a Sugarbeet Hybrid from Parents Selected for a High Taproot to Leaf Weight Ratio1
Authors: Snyder F. W.
Published: July 2010

In earlier studies, sugarbeet (Beta vulgaris L.) seedlings of breeding line were selected for a high taproot:leaf weight ratio (TLWR), where TLWR = taproot fresh weight/leaf blade fresh weight. The population from these polycrossed high‐TLWR plants produced significantly more sucrose per hectare than the unselected and low‐TLWR populations. The objectives of this research were to select high‐TLWR seedlings of a male and a cytoplasmic male‐sterile female, produce the high‐TLWR hybrid, and compare its growth and yield with that of the unselected hybrid. Growth in a controlled environment, at 22 days post‐emergence, indicated that selection for parents with high TLWR resulted in a hybrid having 22, 7, and 30% increases in TLWR, blade fresh weight, and taproot fresh weight, respectively, compared with the unselected hybrid (EL44c3 ✕ EL45)CMS ✕ EL40. The high‐TLWR hybrid yielded significantly more sucrose per hectare than the unselected hybrid in seven of nine Minnesota field tests conducted over 2 years.
Leaf and Root Growth of Water‐Stressed Kentucky Bluegrass Infected by Ustilago striiformis or Urocystis agropyri1
Authors: Nus Jeffery L. , Hodges Clinton F.
Published: July 2010

The relative growth of the shoot vs. roots has proven to be a useful parameter in investigations of drought tolerance. In addition, overall plant growth has been used as a measure of tolerance to water stress. Kentucky bluegrass (Poa pratensis) infected by Ustilago striiformis (Stripe smut) or Urocystis agropyri (Flag smut) exhibits greater mortality than healthy plants during periods of water stress and is suggestive of decreased drought tolerance as a result of infection. The purpose of this study was to compare healthy Kentucky bluegrass ‘Merion’ and plants systemically infected by Ustilago striiformis or Urocystis agropyri for total, leaf and root growth, and for root‐shoot ratios in nutrient solution and in nutrient solution amended with polyethylene glycol to provide increasing levels of osmotically‐induced water stress. Infection by U. striiformis increased total and leaf dry weight, and decreased root weight and root‐shoot ratios of plants grown in nutrient solution. Plants infected by U. agropyri exhibited decreased total, leaf, and root weights, and root‐shoot ratios. Total, leaf, and root weights of healthy, U. striiformis‐and U. agropyri‐infected plants decreased, and root‐shoot ratios increased with decreasing osmotic potentials of nutrient solutions. The increases in total and leaf weights of U. striiformis‐infected plants compared with healthy plants grown in nutrient solution were lost as osmotic potentials decreased. Healthy plants maintained higher root‐shoot ratios than infected plants at all stress levels. The decreases in root‐shoot ratios of infected plants represent a morphological basis for reduced stress tolerance and subsequent increased mortality of infected plants during periods of water stress.
Heritability Estimates for Turfgrass Characteristics in Bermudagrass1
Authors: Wofford D. S. , Baltensperger A. A.
Published: July 2010

No genetic estimates for turfgrass characteristics in bermudagrass, Cynodon dactylon (L.) Pers., are currently available in the literature. Therefore, the objectives of this investigation were to evaluate genetic variation among bermudagrass clones and their polycross progenies and to estimate heritability values for several turfgrass characteristics. Parental clones and polycross progenies were established in a randomized complete block design with four replications in 1981. The parental clones differed (P < 0.01) for all characteristics evaluated during 1981 and 1982. Polycross families differed (P < 0.05) for 13 of the 18 characters evaluated. Broad‐sense heritability estimates for a single year ranged from 0.83 to 0.99. Narrow‐sense heritability estimates based on the polycross family analyses ranged from 0.06 to 0.94. Heritability estimates from the parent‐offspring covariance analyses ranged from 0.00 to 1.22. For a number of characters, additive genetic variation accounted for a significant portion of the total genetic variation. Data over a 2‐year period were combined for leaf length and leaf width. Broad‐sense heritability estimates were moderately high with values of 0.94 and 0.83 for leaf length and leaf width, respectively. Narrow‐sense heritability values for leaf length and leaf width were 0.83 and 0.62 from the progeny analysis and 0.57 and 0.43 based on parent‐offspring covariance, respectively. For characteristics which had moderate‐to‐high narrow‐sense heritability values, breeding methods which involve no progeny testing should be suitable for genetic gain to be realized.
Yield Stability in Segregating Populations of Cowpea1
Authors: Ntare Bonny R. , Aken'Ova Michael
Published: July 2010

The suitability of using regression and genotype grouping methods to evaluate yield stability in segregating populations of cowpea [Vigna unguiculata (L.) Walp] was determined. F3 and F5 lines and bulks were used in the study. Significant genotype ✕ environment interactions were present in both generations. The two methods identified the same lines and bulks as stable, but the genotype grouping method would be most useful when a large number of genotypes are evaluated. The yields of F3 lines and those of related F5 lines were well correlated (r = 0.64**, significant at 0.01 level. The mean yields of F3 bulks and the mean yields of F5 lines and bulks were not significantly correlated. The results showed that selection for adaptability in early generations in cowpea was possible.
Nitrogen Partitioning and Mobilization Patterns in Bean Plants1
Authors: Westermann D. T. , Porter L. K. , O'Deen W. A.
Published: July 2010

The assimilation and distribution of N in the vegetative and reproductive plant parts of edible grain legumes are important processes determining final seed and protein yields. Limited information is available describing these processes for beans (Phaseolus vulgaris L.). The objective of this study was to measure the N partitioning and mobilization patterns in this important grain legume. Two dry bean cultivars, ‘3512’ and ‘3591’, were labeled with either K15NO3 or 15N2 at the late vegetative (V5), early pod development (R2‐R3), and seed filling (R6) developmental stages in the greenhouse. Initial N partitioning was evaluated on plants harvested 48 h after the start of labeling, while the N mobilization patterns were evaluated on the 15NO3‐labeled plants harvested at subsequent developmental stages and at physiological maturity (R9). Both cultivars had similar dry weight and N distribution patterns throughout development, but 3512 had a larger final seed yield while the final seed N concentrations were greater for 3591. These differences developed from R6 to R9 where the dry weight increase in 3591 had a N concentration of 28.1 g kg−1 compared with 9.9 g kg−1 for 3512. The relative proportion of 15N in each plant part was dependent upon the growth stage and 15N source, and was independent of cultivar. Greater proportions were found in the mature leaves and roots of plants labeled with 15NO3, and in the seed and nodules in those plants labeled with 15N2 at all growth stages. Pods and seeds were major sinks from both 15N sources when applied at R2‐R3 and R6, respectively. The seed at R9 contained 64, 73, and 84% of the labeled‐N applied at the V5, R2‐R3, and R6 growth stages, respectively. The seed contained an average of 68% of the total plant N and 53% of the total plant dry weight at R9. These data indicate that the photosynthetic and N2‐fixation activities during seed filling can have a significant influence on the final seed N concentrations and yield.
Photosynthetic Responses of ‘Bragg’ Soybean Leaves Adapted to Different CO2 Environments1
Authors: Valle Raul , Mishoe J. W. , Campbell W. J. , Jones J. W. , Allen L. H.
Published: July 2010

Carbon dioxide exchange rates (CER) were measured during seed fill on leaflets of soybean [Glycine max (L.) Merr. ‘Bragg’] plants grown at 330 and 660 μmol mol−1 CO2 environments in outdoor growth chambers to investigate their photosynthetic response to light. During midday periods at the R5 growth stage, the plants were submitted to short‐term CO2 levels ranging from 90 to 990 μmol mo1−1 to determine differences in leaf photosynthetic response caused by CO2 acclimation. The data were fitted to a rectangular hyperbola of the Michaelis‐Menten form in which the independent variable was radiation or CO2. Light and CO2 compensation points were calculated from the parameters of the model. Light response curves showed that leaflets grown and measured at 660 μmol mol−1 CO2 had higher CER asymptotes, higher apparent Michaelis‐Menten constants for light, higher apparent quantum yield, and lower light compensation points than leaflets adapted to and measured at 330 μmol mol−1 CO2. The CER‐CO2 curve parameters also indicated higher asymptotic ceilings of CER at high CO2 and higher apparent Michaelis‐ Menten constants for CO2 for the higher CO2 adapted leaflets. The CO2 compensation point was significantly lower in leaflets adapted to high CO2 levels than those adapted to ambient CO2, indicating a decrease in photorespiration. It was concluded that, during seed fill, leaflets adapted to high CO2 environments exhibited a capability to utilize CO2 and radiation more efficiently at elevated CO2 and throughout all light levels than leaflets grown at low CO2.
Nodulation of Soybean Plant Introduction Lines with the Fast‐Growing Rhizobial Strain USDA 2051
Authors: Devine T. E.
Published: July 2010

The domesticated soybean, Glycine max (L.) Merr., had been thought until recently to nodulate only with rhizobia of the slow‐growing species R. japonicum. However, in 1982, the soybean cultivar Peking was reported to nodulate effectively and fix N2 with newly isolated fast‐growing rhizobial species (as yet unnamed) from China. In the present study, 285 plant introductions of G. max, from nine Asian countries representing maturity groups 00 to ✕ were tested for nodulation with the fast‐growing Rhizobium sp. strain USDA 205. Five seeds of each soybean line were surface sterilized, planted in vermiculite in growth trays, and inoculated with a broth culture of strain USDA 205. After growth for 5 weeks in the greenhouse, plants were removed from the planting medium and the roots were evaluated visually for nodulation response. Fifty‐six percent of the G. max introductions tested formed normal‐appearing nodules (effective). Effectively nodulated lines occurred in all maturity groups. A higher frequency (more than 80%) of nodulation‐compatible lines was found in the southeast Asian nations of Thailand, Malaysia and Indonesia. G. max introductions nodulated by strain USDA 205 varied in apparent efficiency of fixation, as evidenced by relative differences in both plant growth and green color of foliage when grown in N‐free media.
Phenotypic Recurrent Selection for Multiple‐Parted Flower Heads in Red Clover1
Authors: Taylor N. L. , Cornelius P. L. , Long M. G.
Published: July 2010

The objective of this investigation was to ascertain the variation in and the effectiveness of phenotypic recurrent selection for multiple‐parted heads in red clover (Trifolium pratense L.). Additional objectives were to examine the effect of changes in this character on seed yield and other morphological and physiological characters. Six generations of selection were conducted on an annual basis under field conditions involving 1040 to 2548 plants and selection intensity of 2.0 to 6.8%. The effectiveness of selection was evaluated using spaced plants established from remnants eeds. Number of head parts in largest heads increased linearly from 1 to 7.4 with a regression (b) coefficient of 0.92 head parts/generation. The check cultivar Kenstar from which the original selections were made, had 93% single‐parted heads whereas Generation 6 had only 37% single‐parted heads and 9% of the heads with 5 or more parts. Number of seeds per plant, persistence, and vigor (forage yield) declined over generations, probably due, in part, to inbreeding depression and partly due to other factors. Extreme selections for multiple‐parted heads exhibited weak and lodged, fasciated stems containing many growing points. Recurrent selection was quite effective, but changes associated with increasing multiple‐parted heads were deleterious and mayb e difficult to overcomeS. election is a powerful tool that can generate genotypes not previously seen, and conceivably could reduce the need of plant exploration for desirable genes, at least in cross‐pollinated species.
A New Dominant Gene for Resistance to Whitebacked Planthopper in Rice1
Authors: Fa Wu Chun , Khush Gurdev S.
Published: July 2010

The mode of inheritance and allelic relationships of genes for resistance to whitebacked planthopper, Sogatella furcifera (Hbrvath), in 15 resistant cultivars of rice, Oryza sativa L., were studied. One‐leaf stage seedlings were artificially infested with second‐ and third‐instar whitebacked planthopper nymphs. Reactions of the seedlings were recorded when the susceptible check, ‘Taichung Native 1’, (TN1) was completely killed. The reactions of F1, F2, and F3 progenies from the crosses of test cultivars with TN1 revealed that single dominant genes confer resistance in ‘Boegi Boera’, ‘DD4’, PI 184675‐6, ‘Siam Garden’, ‘Rening’, ‘N'Diang Marie’, ‘Manggar’, ‘Oha’, ‘Gokhue Saier’, ‘Tjempo Tolo’, and ‘Nemai‘. Two independent dominant genes govern resistance in ‘ARC5752’, ‘Chaia Anaser’, ‘Katuyhar Dhan’, and ‘Dhera Dun Basmati’. Tests for allelism revealed that the single dominant genes in Boegi Boera, DD4, PI 184675‐6, Siam Garden, Rening, Oha, Gokhue Saier, Tjempo Tolo, and Nemai, and one of the two independent dominant genes in ARC5752, Chaia Anaser, Katuyhar Dhan, and Dhera Dun Basmati are allelic to Wbph 1, and that the second gene in ARC5752 is allelic to Wbph 2. The second gene in Chaia Anaser, Katuyhar Dhan, and Dhera Dun Basmati was allelic to Wbph 3. The single dominant genes of N'Diang Marie and Manggar segregated independently of Wbph 1, Wbph 2, and Wbph 3. The dominant gene of N'Diang Marie was designated an Wbph 5. The allelic relationships of the dominant gene from Manggar to Wbph 5 are not known.
Agronomic Performance of Soybean Genotypes from Glycine max ✕ Glycine soja Crosses1
Authors: Ertl D. S. , Fehr W. R.
Published: July 2010

Genetic improvement of the cultivated soybean [Glycine max (L.) Merr.] may be possible through hybridization with its wild progenitor, G. soja Sieb. & Zucc. When useful genetic traits are found in the wild species, backcrossing is a method that may be useful for transferring the desired genes from G. soja to G. max. One objective of our study was to determine the number of generations of backcrossing necessary to recover the yield and agronomic performance of the cultivated parent following interspecific hybridization of the two species. A second objective was to determine if the yield potential of the recurrent parent in a backcrossing program could be enhanced by the introgression of G. soja germplasm. Two G. soja accessions were crossed to one of two high‐yielding G. max cultivars, followed by five backcrosses to the respective G. max parent. The F2 plants from the backcross populations were visually examined and selected for absence of vining, lack of hardseededness, shattering resistance, maturity, and seed coat color similar to the G. max parent. Progeny of selected plants from the backcross populations were evaluated for seed yield, maturity, lodging, and height in four environments during 2 years. Significant variation was observed among lines in each backcross generation for the four traits. The mean yield and lodging resistance of the populations improved from the BC1 to the BC4 generation. No line from the BC1 generation performed as well as the recurrent parent for all traits. Three backcrosses to the cultivated parent were necessary to obtain a reasonable number of lines similar to the recurrent parent. The introgression of G. soja germplasm into the two soybean cultivars was not an effective method for increasing their yield potential.
Prolificacy and N Fertilizer Effects on Yield and N Utilization in Maize1
Authors: Anderson E. L. , Kamprath E. J. , Moll R. H.
Published: July 2010

Interest in the N utilization efficiency of different maize [Zea mays L.] hybrids has increased due to N pollution in the environment and the cost of N fertilizer. This two‐year field study on a Typic Plinthic Paleudult compared the responses of prolific and semi‐prolific corn genotypes to N fertilization by measuring yield, harvest index, and N utilization efficiency. Four prolific and four semi‐prolific genotypes were grown with 56, 112, 168, and 224 kg N ha−1. Plants were sampled during grain fill, separated into leaves, stalks, and ears, and analyzed for N concentration. The prolific genotypes maintained a greater N utilization efficiency (grain weight/total plant N) than the semi‐prolific genotypes at all N fertility levels and showed a greater decrease in N utilization efficiency as N fertilization was increased. The prolific genotypes partitioned a larger proportion of plant N to the grain at all N fertility levels, apparently by increasing N remobilization. The semi‐prolific genotypes responded to increased N fertility by increasing the ear number per plant, grain N content and grain yield. As N fertility increased, the semiprolific genotypes increased the proportion of dry matter partitioned to grain, corresponding to increased ear number. These results indicate that the ability of a corn genotype to increase grain yield in response to N fertility was not necessarily indicative of greater N utilization efficiency. Genetic selection for prolificacy under low N fertility may lead to identification of genotypes with more efficient N utilization ability.
Inheritance of Resistance to Stem Rust in the Wheat Cultivar Estanzuela Dakuru1
Authors: Riede C. R. , Williams N. D. , Miller J. D.
Published: July 2010

The inheritance of seedling reaction in the greenhouse to cultures GB121, 111‐SS2, and 72.00 of Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn. was studied in the F2, F3, backcross‐F1, and backcross‐F2 from resistant wheat (Triticum aestivum L.) cv. Estanzuela Dakuru crossed with susceptible ‘Little Club’ (LC) and ‘BH 1146’. The purpose was to determine the number and type of action of genes conditioning resistance. Tests with culture GB121 indicated that E. Dakuru had three genes (SrDG1, SrDG2, and SrDG3) for resistance to this culture. Gene SrDGI was epistatic to SrDG2 and SrDG3, and SrDG2 was epistatic to SrDG3. Tests with culture 111‐SS2 indicated that E. Dakuru had four dominant genes (SrDSI, SrDS2, SrDS3, and SrDS4 for resistance to this culture. Genes SrDSI and SrDS4 were epistatic to genes SrDS2 and SrDS3. Gene SrDS2 was epistatic to gene SrDS3. The segregations in E. Dakaru/BH 1146 indicated that E. Dakuru had one gene for resistance to culture 72.00.
Effect of Maturity and Alfalfa Competition on Expected Selection Response for Smooth Bromegrass Forage Quality Traits1
Authors: Reich J. M. , Casler M. D.
Published: July 2010

Genetic variation for forage quality traits of early headed smooth bromegrass (bromus inermis Leyss.) forage is well documented. There were two objectives of this study. One was to measure genetic variability in the smooth bromegrass experimental synthetic B8HD at seven growth stages of two stand types (pure stands and alfalfa, Medicago sativa L., mixtures) for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid tergent ilgnin (ADL), cellulose, hemicellulose, and insoluble ash. The second objective was to evaluate the effects of growth stage and stand type on heritability esti~aates and expected selection response. Nine polycross families of B8HD were established in solid seeded plots, both with and without an alfalfa overseeding, at Hancock and Lancaster, WI in late August 1981. In 1982 and 1983, smooth bromegrass forage was sampled every seven days for seven weeks, beginning in early May. Differences among the nine B8HD polycross families were more frequently significant in alfalfa mixtures for NDF, ADF, and cellulose, while differences were more frequently significant in pure stands for ADL. Excluding ash, for which no significant differences among families were found, family differences were significant in 23 of 50 growth stage‐stand type combinations during reproductive growth, but in only 2 of 20 during vegetative growth. Expected direct responses to selection at heading for NDF, ADF, ADL, and cellulose were 3.8, 3.2, 0.6, and 2.4 g kg−1 year−1, respectively, in pure stands, and 2.5, 2.2, 0,5, and 1.6 g kg−1 year−1 in mixed stands. Expectedirect responses in pure stands for hemicellulose and ash were 0.4 and 0.1 g kg−1 year−1, respectively. for phenotypic recurrent selection based on uniparental control of pollination, expected selection gains generally were larger for direct selection than for indirect selection at other growth stages. With uniparental control, selection for high forage quality in pure stands would not be expected to identify genotypes with high forage quality in mixed stands. Using near‐infrared reflectance (NIR) analysis for forage quality evaluation and biparental control of pollination to double expected selection gains, selection at vegetative growth stages in pure stands is expected to be morefficient than direct. selection at the target growth stage in alfalfa mixtures. Selection at vegetative growth stages in pure stands using NIR would be expected to increase efficiency 18 and 68% for NDF, and 30 and 88% for ADF, and 92 and 66% for cellulose, as compared to direct selection in alfalfa mixtures.
Genetic Variation for Response to Advancing Maturity of Smooth Bromegrass Forage Quality Traits1
Authors: Reich J. M. , Casler M. D.
Published: July 2010

Genetic variation for quality of early headed forage is well documented, as is the decline in quality with advancing maturity of spring growth forage. The objectives of this research were to i) evaluate nine polycross families of the B8HD smooth bromegrass (Bromus inermis Leyss.) experimental synthetic for differences in response to advancing maturity (RTM) for the forage cell wall fractions neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose, hemicellulose, and insoluble ash on spring growth forage and ii) determine whether differences in RTM among the nine families were consistent across locations, years, and stand types (pure stands vs. alfalfa, Medicago sativa L., mixtures). Nine polycross families of B8HD were established in solid seeded plots, both with and without an alfalfa overseeding, at Hancock and Lancaster, WI in late August 1981. In 1982 and 1983, smooth bromegrass forage was sampled every 7 days for 7 weeks, beginning in early May. Quality of smooth bromegrass forage was reduced significantly in mixtures with alfalfa compared to pure stands. At most growth stages, polycross families in mixed stands averaged 10 to 15 g kg−1 higher in NDF, ADF, and cellulose, as compared to pure stands. Average differences between stand types for ADL and hemicellulose were too small to be of practical value. Polycross families differed significantly in their linear RTM effects for NDF, ADF, ADL, cellulose, and hemicellulose, and in their quadratic RTM effects for NDF, ADF, ADL, and cellulose. Differences among families for RTM involved both changes in rank value at different growth stages and differences in the magnitude of response. For each trait, interactions of families with locations, years, and stand types were nonsignificant for RTM. Improved forage quality of B8HD would be expected as a result of selection for a slow RTM for NDF, ADF, or cellulose. Families selected for a slow RTM in pure stands should also have a slow RTM in mixed stands.
Effect of Temperature on the Expression of Male Sterility in Partially Male‐Sterile Soybean1
Authors: Carlson Dale R. , Williams C. Bruce
Published: July 2010

Previous investigations with msp msp male‐sterile soybean [Glycine max (L.) Merr.] have indicated that temperature affects the expression of sterility. It is not known whether this effect is dependent on the day or night temperature or the diurnal variation between the two. The objective of this study was to determine the effect of decreasing night temperature on the expression of male sterility in the msp msp genotype. Partial malesterile (msp msp) and fertile sibs (Msp_) were grown in growth chambers with the following day/night temperature regimes: 24/24,24/21,24/18, and 24/15 °C. Increased fertility was found to occur concomitant with decreasing night temperatures for the male‐sterile genotype (msp msp). These data indicate an optimum temperature regime for expression of male sterility dependent upon night temperature.
Identification of Promiscuous Nodulating Soybean Efficient in N2 Fixation1
Authors: Pulver E. L. , Kueneman E. A. , Ranga‐Rao V.
Published: July 2010

Many developing countries lack the facilities to produce and distribute high quality rhizobia inoculants for farmers who are interested in planting soybeans [Glycine max (L.) Merr.]. If soybean varieties were available that could nodulate effectively with the ubiquitous, cowpea‐type rhizobia, farmers could successfully grow soybeans without inoculation or fertilizer N. When 400 diverse soybean lines were tested at five sites in Nigeria for the ability to nodulate with indigenous rhizobia, only 10 were highly promiscuous, that is, capable of forming an effective symbiosis at all sites. Some entries were rated as compatible with indigenous rhizobia at one or two sites but failed to nodulate profusely at the other locations. Twenty‐two isolates from nodules collected from profusely nodulated soybean plants and three other isolates prepared from cowpea nodules, were used to inoculate the 10 most compatible selections from the previous trial and two U.S. varieties, ‘Bossier’ and TGm 294. ‘Malayan’, a local Nigerian cultivar, formed an effective symbiosis with 21 of 22 soybean isolates; nodule and shoot weights in each case being greater than or equal to inoculation with Nitragin multistrain inoculant. Other accessions that displayed high degrees of promiscuity were M‐381, TGm 120, TGm 119, Indo 180, and Indo 243. Whereas, Bossier formed an effective symbiosis with only one of the isolates, and TGm 294 was compatible with only 2 of the 22 rhizobia isolates. The promiscuously nodulating soybeans identified in the screening trial were also compatible with at least two of the three cowpea isolates, but Bossier and TGm 294 were compatible with none of them. When the scion of Bossier on ‘Jupiter’ (both of which have high yield potential) was grafted onto the root stocks of ‘Orba’ or Malayan (Promiscuous nodulators) enough N was fixed to meet the requirements of high yielding genotypes. These results indicate that by genetically incorporating promiscuity into varieties with high yield potential one would not necessarily reduce yield potential.
Shoot Developmental Properties Associated with Grain Yield in Winter Wheat1
Authors: Shanahan J. F. , Donnelly K. J. , Smith D. H. , Smika D. E.
Published: July 2010

A large proportion of winter wheat (Triticum aestivum L.) tillers fail to produce grain‐bearing spikes. Should tillers which fail to produce spikes be considered as lost photosynthate? Six selected winter wheat cultivars were grown under two nitrogen (N) fertilizer rates (0 and 70 kg N ha−1) in a 3‐ year (1980–1982) field study on a Rago silt loam soil type (fine, montmorillonitic, Mesic Pachic Argiustolls) to evaluate the relationships among grain yield, shoot emergence, shoot survival, and yield components. Live emerged shoot number per unit area was determined at selected dates throughout the growing season. Final spike number per unit area, grain yield, and yield components were measured at physiological maturity. Grain yield was positively correlated with shoot survival in all three years but was not correlated with maximum live shoot number in any year. Maximum live shoot number was not correlated with kernel number of the spike‐bearing shoots, and shoot survival was positively correlated with kernel number per spike in only 1 year of the study. Therefore, the production of spikeless shoots had little effect on the reproductive development of spike‐bearing shoots. Maximum live shoot number was negatively correlated with shoot survival in 2 of the 3 years of the study. Shoot survival was positively correlated with spike number in all 3 years, and spike number was positively correlated with kernel number per unit area and grain yield in 3 of the 3 years. Thus, shoot survival was more important than the number of shoots initiated in establishing the critical yield components of spike number and kernel number per unit area.
Effect of Temperature on In Vitro Kernel Growth of Flint and Dent Maize Hybrids1
Authors: Major D. J. , Schaalje G. B.
Published: July 2010

Most maize (Zea mays L.) hybrids grown in short‐season areas are flint‐dent endosperm types. The so‐called flint hybrids are believed by some to have faster growth rates than dent hybrids at low temperatures. This study was conducted to determine the feasibility of using the in vitro kernel growth technique to investigate the effects of temperature on growth of northern flint and dent maize hybrids. Kernels of three hybrids in one experiment and five hybrids and three inbreds in a second experiment were cultured in vitro on a defined medium at 15, 20, 25, or 30°C. The kernels were removed after 2 to 7 weeks in culture and dry weights were determined. The dent endosperm hybrid ‘King KI108’ had the highest rate of kernel growth at all temperatures, whereas the European flint‐dent hybrid ‘Limagrain LG1’ had the slowest rate of growth. The Canadian flint‐dent hybrid ‘Pioneer 3995’ had an intermediate rate of growth. In one experiment, the differences were more pronounced at low temperatures than at high temperatures. Kernels of inbreds were difficult to culture in vitro, and the growth rates of their kernels were never greater than those of the F1 progenies. The comparison of flint and dent hybrids suggested that a more extensive study of the major groups of maize would result in detection of differences in growth rates of kernels at different temperatures.
Inheritance of Bruchid Resistance in Cowpea1
Authors: Adjadi O. , Singh B. B. , Singh S. R.
Published: July 2010

This study was undertaken to elucidate the nature of inheritance of resistance to bruchids [Callosobruchus maculatus. (F.)] in cowpea [Vigna unguiculata (L.) Walp.]. The parental F1, F2, and backcross populations involving three resistant and two susceptible parents were bioassayed in the laboratory for bruchid reaction on an individual plant basis. The reaction of F1 seeds was similar to that of seeds from the maternal parent, indicating that the genotype of the maternal plant controls bruchid infestation. The F2 seeds derived from F1 plants represented the true hybrid population and the mean adult emergence was similar to that of the susceptible parents, indicating complete dominance of susceptibility. No reciprocal differences were observed. The F2 plants derived from the six crosses segregated into a ratio of 15 susceptible:l resistant, indicating digenic inheritance. These results were further supported by the backcross data. The Fl plants from the backcross involving the resistant parent segregated into a 3 susceptible:l resistant ratio, whereas those involving the susceptible parent were uniformly susceptible. These data indicate that resistance to bruchids in cowpea is controlled by two recessive genes for which symbols rcml and rcm2 are being proposed.
Effects of Visible Recessive Alleles on Vigor Characteristics in a Maize Hybrid1
Authors: Dollinger E. J.
Published: July 2010

Present knowledge of the control of heterosis and various vigor characteristics on a single gene or locus basis is inadequate. Information on this subject was obtained by producing a number of mutant recessive alleles in a maize (Zea mays L.) inbred line and selecting 31 for study. It was obvious from observation that most of the recessive alleles exhibit numerous pleiotropic effects affecting various vigor characteristics in the homozygous background of the inbred. Five of the recessive alleles were selected for this study to ascertain if pleiotropic vigor effects may also be expressed in the heterozygous background of a hybrid. Each allele produced an array of pleiotropic effects, either positive or negative, affecting various vigor characteristics in the hybrid. Considering pleiotropic effects in the context of single gene differences, the effects on individual vigor characteristics range from small to large. One allele increased the grain yield by three percent. The genetic nature of the pleiotropic effects is not clear at this time; however, it is proposed that pleiotropic effects associated with recessive alleles provide a genetic basis for heterosis.
Evaluation of Peanut Genotypes for Resistance to Water Stress In Situ1
Authors: Erickson P. I. , Ketring D. L.
Published: July 2010

Observations indicate that Spanish‐type peanuts (Arachis hypogaea L.) are more tolerant of dehydration than Virginia types under severe water stress. However, physiological reasons for differences in tolerance to water deficits among peanut genotypes have not been established. The objective of this study was to evaluate peanut genotypes for their response and relative resistance to severe water deficits. A Spanish type (‘Comet’), Virginia type (‘Florunner’), and a Spanish ✕ Virginia selection (OK‐FH15) were grown in situ under irrigated (IRR) and rainfed (RF) conditions. Leaf water potential (ψw), osmotic potential (ψπ), turgor potential (ψp), relative water content (RWC) and its apoplastic water fraction (Aw) were determined weekly between 1300 and 1500 h, and diurnally on selected days. Yields were determined at 149 days after planting (DAP). Ratios (RF/IRR) genotype ψw, ψπ, and RWC showed significant differences among genotypes between 50 and 63 DAP, a critical period of peanut growth and development. The ψw and RWC ratios were maximum for all genotypes at 63 and 70 DAP, respectively. The maximum ψπ ratio occurred on 56 DAP for Comet (1.25), 63 DAP for OK‐FH15 (1.32), and 70 DAP for Florunner (1.18). Regression analysis of 1/ψw vs. RWC showed a biphasic cubic polynomial function best fit the data for all genotypes. The data indicated that as RWC declined, Comet ψw tended to decrease more rapidly than either OK‐FH15 or Florunner. Conservative estimates of ψπ, changes between 95 and 55%R WC were highest for Comet, lowest for Florunner, and OK‐FH15 was intermediate. Aw was calculated for each genotype and plotted against ψp to determine its contribution to hydration maintenance. At high ψp, maximum Aw, was 7.1, 12.1, and 25.2%f or Florunner, OK‐FH15, and Comet, respectively. Florunner Aw, decreased to zero at 0.16 MPa ψp, and the Aw of OK‐FH15 decreased with ψp to the origin. Comet had much greater Aw at low ψp and was the only genotype with appreciable Aw at zero ψp. These results indicate that Aw varies in peanuts and may be genotype specific. Comet showed significantly higher yield, grade, and dollar value than either Florunner or OK‐FH15 under rainfed conditions. The lower ψw, greater change in ψπ, and higher Aw and yield of RF Comet suggests greater resistance to dehydration when high soil moisture deficits and evaporative demand conditions occur.
An Evaluation of Estimators of Location for Maize Yield Comparisons1
Authors: Openshaw S. J.
Published: July 2010

The arithmetic mean's performance as an estimator is well regarded under optimal circumstances, but has received criticism as being nonrobust under less than ideal conditions. This study evaluated how well eight estimators of location performed in comparing maize (Zea mays L.) hybrid yield performance at early stages of testing. Data from five hybrids grown together in 123 tests were taken from commercial yield trials in 1981 and 1982. Eight statistics based on five trials were used to estimate four orthogonal comparisons of hybrid yields and were evaluated for their ability to predict mean differences based upon 118 other trials. The arithmetic mean, the 10% trimmed mean, and a rank‐order weighted mean were the best estimators in the study. The 20% trimmed mean, an adaptive estimator, Huber P15, and a squared deviation weighted mean performed almost as well as the three best statistics. The median was the worst estimator. This study supports the use of the mean, compared with the other seven estimators investigated, for comparing maize hybrid yields at early stages of testing.
Further Studies on the Electrophoretic Patterns of the Multiple Forms of Amylase in Soybean Seeds1
Authors: Norby Shong Wan , Rinne Robert W.
Published: July 2010

Recent work from our laboratory as well as work from other laboratories indicate a greater number of amylase bands (isozymes) in soybean seeds than preViously reported. Our objectives in this study were to determine the amylase patterns in all the soybean cultivars screened and to establish the contribution of α and β amylase to the total amylase activity. Therefore, soybean seed samples from 268 cultivars obtained from the Northern Soybean Germplasm Collection, Urbana, Illinois, were screened for α‐ and β‐amylase by acrylamide gel electrophoresis. Ten amylase isozymelectrophoretic variant patterns were found. Variant pattern II contained 75% while variant pattern I contained 14% of the cultivars screened. The remaining variant patterns contained 4% or less of the total cultivars screened. The number of amylase bands ranged from a minimum of 11 to a maximum of 18. A βamylase inhibition study showed that of the amylase bands detected, a‐amylase accounted for three to six of the bands present. Two of the cultivars screened, Chestnut and Altona, which have been reported earlier as lacking or having low amylase activity were shown to have 18 and 14 amylase bands respectively. The electrophoretic separation was achieved by the incorporation of 3g L−1 soluble starch into the gel, followed by gel slab formation and electrophoretic separation at 4°C.
Effects of Planting Date on Two Soybean Cultivars: Seasonal Dry Matter Accumulation and Seed Yield1
Authors: Anderson L. R. , Vasilas B. L.
Published: July 2010

Delayed planting consistently reduced grain yields of soybean [Glycine max (L.) Merr.] in central Illinois. A field study was conducted during two growing seasons at Urbana, IL, to determine the influence of planting date on grain yield, yield components and dry matter partitioning of ‘Williams 79’ and ‘Corsoy 79’ soybeans in order to gain a better understanding of their yield physiology. Soybeans were planted in mid‐May and mid‐June in 1982 and 1983 on a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll). Tissue samples, including abscised material, were collected at R1, R5, and R7 stages and separated into individual plant parts for analysis. Grain yields of Corsoy 79 were consistently higher than those of Williams 79 under less than favorable growing conditions, i.e. with delayed planting and water stress conditions experienced in 1983. Delayed planting decreased grain yields primarily by decreasing the number of seed. Williams 79 had a higher rate of vegetative abscission and generally a lower harvest index than Corsoy 79, indicating perhaps a greater efficiency of dry matter use in the latter. Delayed planting increased the rate of dry matter accumulation between VE and R1 but decreased rates of vegetative production from R1 to R5. Net vegetative dry matter production during seedfill was influenced by the year, cultivar, and planting date indicating differences in total dry matter production and remobilization to the developing seed. Planting date affected the stem:leaflet:petiole ratio at R5 and R7.
Development of Hard Winter Wheat after Anthesis as Affected by Nitrogen Nutrition1
Authors: Morris Craig F. , Paulsen Gary M.
Published: July 2010

Post‐anthesis nitrogen nutrition should be an important determinant of wheat (Triticum aestivum L.) grain yield because remobilization of vegetative N for grain filling is associated with decreasing photosynthetic activity of leaves. Experimental evidence is contradictory, however. Research was conducted to reconcile different findings on the importance of N nutrition of wheat during grain development and to understand the inverse grain yield/N concentration relationship. Five winter wheat genotypes were grown in sand with nutrient solution in a glasshouse. Two N regimes were imposed at the early boot stage (Feekes scale 9) by continuing the complete nutrient solution by leaching nutrients and supplying solution devoid of N until plants were mature. Plants were harvested 10, 20, or 40 days after anthesis and analyzed for grain and vegetative yields, yield components, and grain and vegetative N concentrations. High N nutrition increased mean biological dry matter yield and grain yield 20 and 40 days after anthesis. Grain yield was significantly correlated with number of spikes per plant, kernels per plant, kernels per spike, and kernel weight. Fertile spikes per plant were affected most by N nutrition, but grain growth rates per plant and per kernel also occasionally increased. Grain N concentration remained nearly constant under low N nutrition, but increased between the first and last samplings under high N nutrition. Vegetative N content wits also nearly constant under high N nutrition, but decreased under low N nutrition as grain filling progressed. We concluded Ihat ample levels of N during late developmental stages are necessary for maximum yields of high‐protein grain.