bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kernel Growth Rate and Duration in Maize as Affected by Plant Density and Genotype1
Authors: Poneleit C. G. , Egli D. B. 
Published: July 2010

The rate of kernel dry weight accumulation and filling period duration of corn (Zea mays L.) have been suggested as significant factors that influence yield potential. To determine the importance and usefulness of these kernel characteristics, environmental and genetic variations should be investigated. The objectives of this study were to measure the effects of plant density on the kernel growth components and observe the inheritance of these characteristics in the F1 hybrids. Kernel dry weight accumulation rate and effective filling period duration (EFPD) were examined in three corn inbreds and their three F1 hybrids at two plant densities. Kernel dry weight accumulation rate was not affected by plant density; however, EFPD was 2.5 days less at the high plant density. The resultant, smaller kernels along with a reduced number of kernels resulted in a 20% yield reduction per plant at the higher plant density. Yield per plant and per unit area in response to changes in plant density were altered more by kernel number per plant than by kernel size.A significant increase in kernel size contributed to the greater F1 yields although the major advantage of the hybrids was due to more kernels per plant. In two of the three F1 hybrids, the larger kernel size was due solely to longer EFPD's since the rate of dry weight accumulation of one of the parental inbreds was the same as that of the F1's. In the other F2 hybrid, both rate and EFPD were greater in the F1 genotype than for either parental inbred.These data show that EFPD but not the rate of kernel growth is influenced to a limited extent by plant density and both are under genetic control. Thus genetic modification of these kernel growth components should be feasible.
Cytology and Breeding of Hexaploid Alfalfa. I. Stability of Chromosome Number1
Authors: Yen Sheng‐Tian , Murphy R. P. 
Published: July 2010

Two hexaploid amphiploids (2n=6x=48), a naturally occurring hexaploid, and two hexaploid wild species of alfalfa (Medicago spp.) were used in this study. The parents, F1 hybrids, and a portion of their progenies were analyzed cytologically. Variation in somatic chromosome number was detected in most of the populations studied. Chromosome numbers varied from 2n=36 to 2n=51 with a mean of 46.7 ± 2.51 in the F1 population, and from 2n=33 to 2n=51 (except for one with 2n=72) with a mean of 46.1 ± 2.34 in the selfed and crossed progenies derived from euplold F1 plants (2n=48). The percentage of hexaploids was estimated at 64 in the F1 population and 27 in the selfed and crossed progenies of the euploid F1 plants.A wide range in plant vigor among individual plants was observed in the field nurseries about 2 months after transplanting. The overall mean vigor score (I lowest to l0 highest) was 5.9 for the progenies of hexaploid F1 plants and 5.6 for the progemes of aneuploid F1 plants. Both values were significantly lower than the mean vigor of the cultivated check cultivars (2n=‐4x=32). The frequency of plants with vigor of 7 (average of the check cultivars) or higher within the progenies of hexaploid and aneuploid F1 plants was 38 and 28%, respectively. No apparent relationship was detected between vigor and the chromosome number of the plants. In the progenies of hexaploid F1 plants, 33% of the plants with vigor of 7 or higher were hexaploids.
Response of Soybeans to High Temperature During Germination1
Authors: Emerson B. N. , Minor H. C. 
Published: July 2010

The variability among soybean [Glycine max (L.) Merr.] genotypes for tolerance to above optimal temperatures during germination was evaluated. In an initial screening, germination of 289 genotypes in maturity groups VIII, IX, and X was tested at 32 and 38 C. Forty‐eight of these genotypes germinated as well at 38 as at 32 C and were selected for further study.Absolute response of the selected genotypes to temperature in subsequent tests depended on previous history of the seed. Germination of all selected genotypes was significantly reduced at 38 C in tests utilizing seeds stored for 15 to 18 months. Germination of stored seed of 21 genotypes was not significantly affected by temperatures as high as 36 C. When germination of fresh seed harvested at maturity or 3 weeks afterwards was compared at 32 and 38 C, the increase in temperature was found to reduce germination in both harvests, but most markedly among genotypes which were delay‐harvested.Genotypes represented within each source (stored, harvested at maturity, and delay‐harvested) were classified for relative tolerance. A confidence interval drawn about the mean germination at 36 (stored seed) or 38 C (seed harvested at maturity and delay‐harvested seed) was used for dividing the genotypes into three classes: those with above, intermediate, and below average tolerance to high temperature. Four genotypes (PI 259538, PI 346304, PI 374166, and PI 374174) were consistently classified as having above average tolerance to high temperature, while four others (PI 174860, PI 203405, ‘Cherokee’, and ‘Hardee’) were consistently classified as having below average tolerance.Results presented indicate that consistent genotypic differences exist for tolerance to high temperature during germination and that these differences can be most effectively identified among genotypes which have not been subjected to prior stress.
Association Between Grain Filling Rate and Duration and Yield Components in Rice1
Authors: Jones D. B. , Peterson M. L. , Geng S. 
Published: July 2010

The identification of readily measured traits that are associated with higher yields of field crops is important to plant breeders. The objective of this research was to determine if differences in grain filling rate and duration existed in rice (Oryza sativa L.) and if so, were these grain filling parameters correlated with other yield related components of the rice plant.Fifteen genotypes of rice were selected to represent a sample having diverse agronomic characteristics. Samples of panicles of the 15 genotypes were taken at weekly intervals for approximately 6 weeks during the grain filling period. The cubic polynomial model was found to closely fit the dry weight data (r2 ≥ 0.95 for all genotypes). Grain filling rate and duration as well as other grain filling parameters were determined from the model. Correlation between the grain filling parameters with yield components indicated that grain firing rate was more important than duration in this study. Grain filling rate, in turn, was positively and highly significantly correlated with actual panicle weight and 100‐grain weight and negatively correlated with panicles m‐2.
Inheritance of Resistance to Bacterial Wilt in Two Alfalfa Gene Pools: Response to Selection and Quantitative Analysis1
Authors: Viands D. R. , Barnes D. K. , Stucker R. E. , Frosheiser F. I. 
Published: July 2010

Bacterial wilt (BW) caused by Corynebacterium insidiosum (McCull.) H. L. Jens. is a serious disease of alfalfa (Medicago sativa L.). High levels of resistance to BW in alfalfa are available, but the inheritance of resistance is unclear. Objectives were to study the response to selection for resistance to BW and conduct a quantitative genetic analysis of inheritance of resistance to BW in two unrelated alfalfa gene pools. In the study of response to selection, the original gene pool plus six cycles of selection in the MSA gene pool and the original plus eight cycles of selection in the MSB gene pool were evaluated simultaneously. In the genetic study three sets of six‐parent diallels, including reciprocals and selfs, were produced within each gene pool. Two sets of six‐parent Design II's were produced by crossing parents of one gene pool with parents of the other.The results from the selection study suggested different modes of inheritance in the two gene pools. The response to selection in the MSA gene pool was quadratic, with a rapid increase in resistance in early cycles of selection; the response in MSB was linear and less rapid. In the genetic study variation due to reciprocals was nonsignificant in both gene pools and specific combining ability was significant only in MSB. Assuming a fixed model, all variances of genetic effects were greater in MSB than in MSA. General combining ability effects also suggested that inheritance was different in the two gene pools. The different types of inheritance suggested why the two gene pools responded differently in the selection study.
Selection for Winterhardiness in Wheat. I. Identification of Genotypic Variability1
Authors: Fowler D. B. , Gusta L. V. 
Published: July 2010

Cold hardiness is the primary factor restricting the northward expansion of winter wheat (Tritlcum aestivum L. em. Thell.) in the Great Plains area of North America. Several factors, including the absence of a simple, reproducible method of screening, high experimental error associated with field trials, limited genetic variability, and difficulties in combining a high level of cold hardiness with other desirable characteristics have all been responsible for the lack of progress in breeding for this character. To assess the extent of these limitations 61 field trials were grown in Saskatchewan, Canada, from 1972 to 1977. Included in these trials were 43 winter wheat cultivars of diverse origin.The Field Survival Index (FSI), based on a modified procedure for determining relative winter hardiness of cultivars in field trials, was developed. This method of estimating cuitivar winterhardiness potential reduces the experimental error associated with field trials, alleviates the difficulties arising from the absence of partial winteridll for a few cultivars in each trial, and allows for the pooling of results from different trials.A wide ranges in FSI's was observed for the cultivars considered. These ratings suggest that most successful winter wheat cultivars have only marginally greater winterhardiness than the minimum required for the sea in which they are grown. As in the past, cultivars with USSR genotypes in their pedigrees had the highest winter terhardiness potential.
Effects of Intergenotypic Competition on Plant Height, Days to Heading, and Grain Yield of F2 through F5 Bulks of Spring Wheat1
Authors: Busch R. H. , Luizzi D. 
Published: July 2010

The effect of intergenotypic competition in F2 through F5 bulk generations was evaluated in six tall/semidwarf crosses of spring wheat (Triticum aestivum L.). The bulks had been advanced each generation in competitive yield plots at a commercial production seeding rate. Approximately 100 seeds of each generation (F2 to F5) were sampled in each cross, space‐planted, and plant height and days to heading, both found to be monogenic in these crosses, were measured on each plant. The three photoperiod insensitive/sensitive crosses had excess numbers of short plants in the F2 and F3 but two of the three crosses fit monogenic expectations in the and F4 and F5 The sensitive/sensitive crosses fit the expected genetic ratio each generation. A minor shift toward tallness was observed by the F5 when data from the five homogeneous crosses were pooled. Individual insensitive/sensitive crosses fit the expected genetic ratios for days to heading in F5, but when pooled over crosses an excess late‐heading plants was detected.Grain yield of the F2 through F6 of each of the six crosses across generations did not differ significantly. Correlations of the F2 bulk yields with yields of through F6 bulks remained positive with no appreciable decrease. Apparently, changes in bulk populations grown in North Dakota, heterogeneous for plant height and days to heading, were due primarily to genetic segregation, with intergenotypic competition having only minor, but significant, effects. These relatively minor shifts should not inhibit ease of selection for semidwarfism or early heading from competitively grown bulks in North Dakota.
Root Characteristics of Black Beans. II. Morphological Differences Among Genotypes1
Authors: Stofella P. J. , Sandsted R. F. , Zobel R. W. , Hymes W. L. 
Published: July 2010

Total root biomass of two black bean (Phaseolus vulgaris L.) cultivars, ‘Black Turtle Soup’ (BTS) and ‘Strain 39,’ and four black‐seeded lines (70001, 70002, 70003, and 70004) was partitioned into adventitious, basal, and taproot components at several growth stages under both greenhouse and field conditions. Basal root weights were significantly higher for the four lines in the field and for 70001 and 70002 in the greenhouse than for BTS and Strain 39. Genotypes did not differ for adventitious root weights in both environments. Taproot weights were higher for all the lines compared with BTS; and for 70001, 70003, and 70004 compared with Strain 39 in the field. Genotypes did not differ for taproot weights in the greenhouse.Stem, hypocotyl, and taproot diameters were significantly higher for all the lines than for the two cultivars in the field. Hypocotyl and stem diameters of all lines were higher than for the two cultivars, except for stem diameter of 70002 when compared with BTS in the greenhouse. Taproot diameters of 70001, 70002, and 70004 were significantly higher than for Strain 39 under greenhouse conditions. Basal root diameters (sum of individual basal root diameters) of the four lines were significantly higher than for BTS or Strain 39 in both experiments. Genotypes did^ot differ in the number of basal roots under field conditions.In the field, most root parameters increased up to the seed initiation stage, followed by a significant decrease or no further increase at the pod fill stage. Significant stage ✕ genotype interactions occurred for basal root diameter and hypocotyl diameter in the field and for taproot weight, stem, hypocotyl, and basal root diameters in the greenhouse. The erect plant type of the lines may be attributable to larger basal roots.
Inheritance of Several Cold Tolerance Traits in Corn1
Authors: McConnell R. L. , Gardner C. O. 
Published: July 2010

To learn more about early season growth of corn (Zea mays L.), generation means analyses were used to study inheritance of germination at 7.2 C in the laboratory, and emergence, juvenile growth, and yield in the field. Six inbred parents, their 15 F1 hybrids, their 15 F2, and their 30 backcross populations were used in the analyses. The inbreds were classified into warm (W) and cool (C) season groups based upon their reaction to cold and heat stress in previous experiments.For the specific group of parents evaluated, generation means analyses indicated that epistatic gene effects as well as additive and dominance gene effects contributed significantly to the variation observed for germination at 7.2 C in the laboratory and for emergence measured in the field. Seedling vigor or growth after emergence in the field appeared to be conditioned predominantly by additive and dominance gene effects. Although some epistatic gene effects were detected, grain yield in the specific group of parents studied was controlled by additive and dominance gene effects.Contrary to expectations, C ✕ C crosses were no better than W ✕ W or C ✕ W crosses for the cold tolerance traits studied. Percent germination and field emergence data favored W ✕ W crosses, while C ✕ C crosses were slightly better for early season vigor. W ✕ W crosses produced the highest grain yield followed by C ✕ W and C ✕ C crosses.
Inheritance of Seed Protein in Crosses Involving ‘Hand’: A Hard Red Winter Wheat1
Authors: Cowley Craig R. , Wells Darrell G. 
Published: July 2010

‘Hand’ wheat (Triticum aestivum L.) is high in protein, has excellent baking and dough handling properties, and is resistant to leaf rust (Puccinia recondita Rob. ex. Desm. f. sp. tritici) and stem rust (P. graminis f. sp. tritici Eriks. and Henn.). The pedigree of Hand is uncertain. However, it possesses a single gene, SrTt1, for resistance to stem rust as determined by an F2 analysis of crosses with stem rust tester lines. A study was conducted of Hand to determine the inheritance of high seed protein.Crosses were studied of Hand with ‘Centurk’ and an experimental line, TX62A2522‐8‐2, both low in protein, and of Hand with ‘WS1809’, a spring habit cultivar, and an experimental line, NE68513, both high in protein. Single plants of progeny rows of artificially vernalized seedlings of parents, F1, F2, F3 BCF1, and BCF2 were studied in the field. Hand differed from Centurk and TX62A2522‐8‐2 for protein level by one dominant gene for high protein which we have named PrHand. In NE68513*2/Hand, 21% of the BCF2 lines were higher in protein than NE68513 which derived recessive high protein from Atlas 66. Based upon dominance relations and transgressive segregation, we concluded that Hand and NE68513 have unlike genes for high percent seed protein.Transgressive segregation was not detected in the reciprocal backcrosses involving WS1809 and Hand. However, three selected progeny rows from WS1809/2*Hand averaged 2.1 and 0.8 percentage points higher than the means of the respective parents. Although not significantly different, that may suggest a difference in genes or alleles for high protein. Selections higher in protein than Hand were most prevalent in crosses involving only high protein parents, providing additional evidence that different genes were involved.
The Effect of Carbohydrate Concentration on the Respiration Rate of Soybean1
Authors: Coggeshall B. M. , Hodges H. F. 
Published: July 2010

Two experiments were conducted to determine the relationship between respiration rate and carbohydrate concentration in source and sink tissue in soybean (Glycine max (L.) Merrill). Experiment I was conducted during V8/R1, R2, and R4 stages of maturity. Defoliation, 92% shading, and control treatments established a range in sugar and starch concentrations for source leaves and the corresponding above.ground sinks at each stage. This range was primarily due to a reduction in source size by defoliation, or a reduction in photosynthate source by shading, thereby reducing the carbohydrate supply to the sinks. This range was primarily due to a reduction in source size by defoliation, or a reduction in photosynthate source by shading, thereby reducing the carbohydrate supply to the sinks. Respiration was positively correlated with carbohydrate content in V8/R1 and R2 tissues in which growth respiration predominates. However, where maintenance respiration likely predominated (R‐4 leaves and pods) the respiration‐carbohydrate content correlations were poor.Experiment II was conducted during the R5 stage of maturity. Control, 92% shading, defoliation, and depodding treatments resulted in a range in sugar and/or starch concentrations in source leaves and pod tissues. Defoliation and shading reduced the carbohydrate supply from the source to the sink as in Experiment I. The two‐thirds depodding treatment was not severe enough to affect the carbohydrate concentration in the pods. However, starch accumulated in the leaves 7 days after the treatment was initiated. A significant positive relationship was found in the R5 leaves among respiration and sugar or starch concentrations. Conversely, an insignificant relationship was found in pods which contained predominately storage tissue undergoing maintenance respiration.
Relationship of “Bloomless” (bm bm) Sorghum to Greenbug Resistance1
Authors: Peiretti R. A. , Amini Iraj , Weibel D. E. , Starks K. J. , McNew R. W. 
Published: July 2010

Parental, F1 and F2 sorghum [Sorghum bicolor (L.) Moench] populations involving the bloomless trait were studied for their reaction to greenbugs (Schizaphis graminum Rondani). Plants were grown in pots in the greenhouse, classified into bloom or bloomless (presence or absence of white wax on leaf sheath) categories, rated for greenbug damage, and studied for tolerance, anti. biosis, and non preference. The objective of the researchwas to learn more about the nature of the resistance of bloomless sorghum to greenbugs since bloomless may be useful in commercial sorghums.Bloomless was inherited as a simple recessive with complete dominance of bloom. The tolerance to damage of ‘Shalin Grain’ and ‘IS 809’ by greenbugs was inherited independently of the bloomless trait. The bloomless plants did not exhibit greenbug tolerance as did Shallu Grain and IS 809, except where the two traits were combined in an F2 individual plant. Bloomless plants showed only slightly more of an antibiotic effect on greenbugs than the susceptible check and significantly less than the resistance check. In this study, bloomless plants 50 to 70 days old exhibited a significant nonpreference to greenbugs compared to the susceptible check.
Agronomic, Genetic, and Cytologic Evaluation of a Vigorous New Semidwarf Oat1
Authors: Brown P. D. , McKenzie R. I. H. , Mikaelsen K. 
Published: July 2010

A vigorous new semidwarf line of oats (Avena saliva L.), designated as OT 207, was selected from OT 184 following irradiation of seed with 1,150 rads of fast neutrons. Because of the potential of a semidwarf oat, the genetics, cytology, and productivity of this new semidwarf were studied. The stature of OT 207 is controlled by a single dominant gene for which the symbol Dw‐6 has been assigned. Cytological observations showed that OT 207 contains 42 chromosomes and that meiosis and mitosis are normal. OT 207 is 34% shorter than its mother‐line. The height reduction is due to shorter internodes, particularly the peduncle. There is no change in the number of internodes. Lodging resistance and shattering resistance are superior to that of the check cultivars ‘Rodney’ and ‘Hudson.’Yield of this semidwarf relative to the check cultivars has been variable. Usually differences in yield were insignificant or OT 207 yielded significantly less. In 19/75, OT 207 yielded significantly more at a 15 cm than at a 30 cm row spacing, while the yield of Harmon’ was not significantly different at the two spacings. Genotype by row spacing interaction was significant. In 1976, both varieties gave significantly higher yields at a 114 kg/ha seeding rate than at a 57 kg/ha, while neither genotype, row spacing (15 cm vs. 30 cm) or interactions were significant.
Root Volumes of Avena Species1
Authors: Carrigan Lori , Frey K. J. 
Published: July 2010

Volumes of root systems were measured at regular intervals during the growth cycle of one oat cultivar and one (Avena saliva L.) line and four weedy oat (A. sterilis L.) lines. The oat plants were grown hydroponically by using modified Hoagland nutrient solution to provide the nutrient source. The experimental design was a randomized block with three replicates, and a plot consisted of two plants imbedded in a 6.3‐cm cork. Root volume was measured on each plot at weekly intervals by water displacement. When mature, the plants in a plot were harvested, separated into roots, straw, and panicles, and dried. Subsequently, dry weights were taken on the three portionsThe oat lines and cultivars differed significantly in final root volume and weight and in panicle and straw weight. The relationship among genotypes for root volume varied with measurement period. The root volume per plot was quite similar for all genotypes until the 6th week. After 6 weeks the root volumes for five genotypes, CI 9170 and ‘Dal’ (A. saliva) and PI 324774, PI 324776, and PI 324780 (A. sterilis), did not change much (volumes of 2.5 ml/plot for CI 9170 to 6.5 to 8.0 ml/plot for the other four). But the volume of the A. sterilis line, PI 324748, increased from 10.0 ml/plot at week 6 to 28.0 ml/plot at week 16. PI 324748 also had significantly greater root, straw, and panicle weights at harvest.