bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heritability of Lowest Pod Height in Soybeans1
Authors: Martin R. J. , Wilcox J. R. 
Published: July 2010

The feasibility of breeding for increased height of the lowest pod and associations between pod height and other agronomic characteristics of soybeans [Glycine max (L.) Merr.] was studied in progenies of high podding determinate strains crossed with normal podding indeterminate varieties. Heritability estimates for lowest pod height in two crosses were slightly greater than those for seed yield and seed size in the F2 generation and considerably higher than values for seed yield in the F3 generation. Heritability estimates for pod height in the third cross, although lower than in the other two crosses, were higher than estimates for seed yield in both the F2 and F3 generations.Correlation coefficients for height of the lowest pod with date of flowering and maturity date indicated that the higher the height of the first pod, the later these plants flowered and matured. The lack of a close association of pod height with seed yield indicated that selections could be made for increased height of the lowest pod without affecting seed yield.
Inheritance of Semidwarfness in Several Wheat Crosses1
Authors: Romero G. E. , Frey K. J. 
Published: July 2010

Inheritance of plant height in wheat Triticum aestivum L.) was studied by using single‐plant measurements from parental, F1 and F2 generations of nine crosses between three “normal‐height” (‘Napo 63,’ ‘Crespo 63,’ and ‘Bonza 63’) and three semidwarf (‘Sonora 64,’ ‘Son‐Sk‐A,’ and ‘Wt‐Nar’) pure lines. All crosses showed partial dominance for tallness over semidwarfness, with degrees of dominance varying from 0.12 to 0.90. Correlation of dominance values estimated in F1 and F2 was 0.83**.Segregations in the F2 generation of the nine crosses showed the semidwarf lines Sonora 64, Son‐SK‐A, and Wt‐Nar differed from the normal‐height cultivars in alleles at one, two, and two loci, respectively. Three loci were involved in height inheritance among the 6 cultivars with alleles at the A‐a and C‐c loci each differentiating approximately 26 cm in plant height, and alleles at the B‐b locus differentiating 13 cm in height. Gene effects between loci were cumulative. The suggested genetic constitutions for the cultivars were: normal‐height parents (106 cm) = AABBCC; Sonora 64 (79 cm) = aaBBCC or AABBcc; Son‐Sk‐A (66 cm) = aabbCC or AAbbcc; and Wt‐Nar (53 cm) = aaBBcc.
Effect of Time and Rate of Application of Two Growth Retardants on Growth, Flowering, and Yield of Upland Cotton1
Authors: Marani A. , Zur M. , Eshel A. , Zimmerman H. , Carmeli R. , Karadavid B. 
Published: July 2010

Six experiments were conducted at four locations in Israel in order to evaluate the effect of two growth retarding chemicals, CCC and CMH, on plants of Upland cotton, Gossypium hirsutum L. When sprayed during the first week of flowering, CCC at 50 and CMH at 480 g a.i./ha retarded the increase in height of cotton plants without adversely affecting lint yield or quality. These treatments caused a small reduction in flower production, but this was not associated with a decrease in yield. In some of the experiments, the increase in plant height following treatment was reduced by as much as 50%. Application of CCC at the rate of 100 g a.i./h at the beginning of flowering significantly reduced lint yield in one experiment. Increasing the rate of CMH to 720 g a.i./ha produced no harmful effects.When CCC or CMH were applied in the middle of the flowering period, they were less effective in reducing plant height. These results indicate that both CCC and CMH may be used to arrest excessive vegetative development of cotton plants, and that the optimum time of application is the beginning of flowering.
Heterosis and Combining Ability Estimates in Indian Mustard, Brassica juncea (L.) Czern. and Coss.1
Authors: Singh Shree P. 
Published: July 2010

Heterosis and combining ability estimates were obtained for eight agronomic characters in Indian mustard, Brassica juncea (L.) Czern. and Coss. Highest heterotic values were found for yield. Six hybrids exceeded the performance of their best parents by an average of 49% over 2 years. Moderately high values were also found in certain crosses for number of primary and secondary branches and raceme length, but estimates, in general, were low for days to flower, plant height, silique length, and seeds per silique.General combining ability (GCA) and specific combining ability (SCA) variances were important for all characters. The former was larger than the latter in all cases except for seeds per silique. Maternal and nonmaternal reciprocal variances were significant for days to flower and yield; only the former was significant for primary branches and silique length, and only the latter was significant for seeds per silique. Interactions for GCA ✕ years were significant for all characters; for SCA ✕ years for days to flower, number of primary and secondary branches, and plant height; and for nonmaternal ✕ years for days to flower and primary branches.
Influence of High Day and Variable Night Temperatures on Nitrate Reductase Activity of Young Corn (Zea mays L.) Plants1
Authors: Alofe C. Oluwole , Schrader L. E. , Smith R. R. 
Published: July 2010

Sixteen corn (Zea mays L.) genotypes (a four‐parent diallel cross) were grown from seed for a month in controlled‐environment rooms in the University of Wisconsin Biotron. A high day (35 C) and three night temperatures (24, 16, and 7 C) were provided to study the influence of high day and variable night temperatures on nitrate reductase (E.C. 1.6.6.1) activity (NRA) in these genotypes. A 15‐hour photoperiod at 35 klux was provided. Plants were grown in vermiculite with nutrient solution.Growth was fastest at a high night temperature of 24 C and slowest at 7 C, but NRA per g fresh wt (gfw) of leaf blades declined more rapidly at the high night temperature of 24 C than at 16 or 7 C and the decline was least rapid at 7 C. NRA per plant changed little at the 24 C night temperature during the first 21 days, but increased markedly thereafter. At 16 C, NRA per plant increased from 11 to 17 days, but decreased thereafter, whereas it increased at 7 C from 13 to 30 days in most genotypes.Significant genotypic differences were observed at all night temperatures and at 9 of 10 samplings. At 24 C, levels of NRA of each reciprocal cross generally were intermediate with respect to levels of NRA in the two parental inbreds. However, in a few cases, one or both reciprocal crosses were higher than the midparent with respect to NRA. At 16 C, additional crosses were higher than the midparent with respect to NRA per gfw and per plant, though a few were intermediate in NRA as compared with their parents. At 7 C, NRA per plant generally was higher in the hybrids than in either parent.Reciprocal effects were statistically significant in only 2 out of 10 samplings. General combining ability (GCA) effects were significant in eight samplings. In all samplings and at all temperature regimes, inbred ‘A632’ was the parent with most positive GCA effects.
Meiosis of Coronilla varia L.1
Authors: Berchtold D. J. , Cleveland R. W. , Risius M. L. 
Published: July 2010

Meiosis in microsporocytes was studied in nine ‘Chemung’ plants, 14 ‘Penngift’ plants, and one S1 plant of crownvetch (Coronilla varia L.). All plants were tetraploid (2n=24), and 41% of the diakinesis cells had one or more multivalents (III's or IV's). Averages of pairing configurations were 0.8 I's, 10.7 II's, 0.1 III's, and 0.4 IV's per cell. Quadrivalents ranged from 0 to 5 per cell, compared to a theoretical maximum of 6. We concluded that C. varia had autotetraploid‐like meiotic chromosome behavior.No differences were found between cultivars in mean frequencies of configurations per cell. However, plants within cultivars differed significantly in their frequencies of I's per cell (0.2 to 1.8), and in their proportions of cells free of I's or III's (33 to 94%). The mean chiasma frequency among all plants was 1.1 chiasmata per biva‐lent‐equivalent (range 1.0 to 1.3).Laggards were present at meiotic anaphases. Chromosome numbers at TI were largely euploid (n = 12). No micronuclei occurred in pollen quartets, thus laggard chromosomes may have been included in TII nuclei. A first generation inbred plant was much more irregular in meiosis than other plants studied.Cytomixis was a sporadic occurrence in microsporocytes of a few collections.
Alfalfa Pollen Production in Relation to Percentage of Hybrid Seed Produced1
Authors: Pedersen M. W. , Barnes D. K. 
Published: July 2010

The relationship between different levels of pollen production and percentage crossing in alfalfa (Medicago sativa L.) was studied in both hand‐crosses in the greenhouse and bee‐pollinations in the field. White flower color was used as a genetic marker to determine the amount of crossing. Pollen production was rated in 4 classes: 1 = no pollen, 2= trace of pollen, 3 = moderate amount of pollen, and 4 = much pollen dehisced when the flower was tripped.Greenhouse studies indicated that the amounts of sibbed and selfed (nonhybrid) seed were affected by the amount of pollen production in the male‐sterile seed parents. Three‐way random crosses among white‐flowered complete male steriles, white‐flowered sibling partial steriles, and unrelated purple‐flowered fertile plants were used to simulate pollination opportunities within a three‐way alfalfa hybrid. The type of seed produced on class 1 plants was 0% self, 2% sib, and 98% hybrid. The amount of self, sib, and hybrid seed produced on class 2, 3, and 4 plants were 3, 5, and 92%; 12, 27, and 61%; and 18, 40, and 42%, respectively.Field studies were also conducted in which 36 crosses, segregating for varying degrees of male sterility, were assigned a pollen‐production index (PPI) by weighting each pollen‐dehiscence class according to its pollination effectiveness. The weighing factors for classes 1, 2, 3, and 4 were 0.0, 0.1, 0.6, and 1.0, respectively. PPI was negatively correlated with percent crossing for 2 years in a field test. The interaction between years and PPI did not significantly affect, crossing. PPI was significantly correlated with seed yield per plant in 1970, but not in 1971. The equation Ŷ = 98 −0.56x, where Ŷ = predicted percent hybrid seed and x = PPI, was arrived at for the prediction of the amount of pollen dehiscence allowable in the male‐sterile component of an alfalfa hybrid. A hybrid with 95% hybrid seed could not have a PPI of more than 5.4. A hybrid with 75% hybrid seed could not have a PPI of more than 41.1.
Tissue Cultures of Maize (Zea mays L.): Initiation, Maintenance, and Organic Growth Factors1
Authors: Green C. E. , Phillips R. L. , Kleese R. A. 
Published: July 2010

Callus from 17 of 23 single crosses and 10 of 17 inbreds of Zea mays L. was isolated from mature embryos grown on Linsmaier and Skoog RM medium with 15 mg 2,4‐dichlorphenoxyacetic acid (2,4‐D) per liter. This callus growth was greatest from the first node of the seedling shoot; occasionally callus growth was observed from the radicle and coleoptile regions. All callus was easily transferred and maintained on media with 2 mg 2,4‐D/liter. Genetic variability for callus growth was observed among both single crosses and inbreds. Callus was initiated from 70% of 23 single crosses tested and from only 40% of the 17 inbreds tested. The most rapidly growing cultures were isolated from Oh51A ✕ Os420 which had a 20‐ to 25‐fold fresh‐weight increase during a 30‐day incubation at 30 C.Cultures maintained on 2,4‐D did not require cytokinins for growth, nor was 2,4‐D effectively replaced by idoleacetic acid or α‐napthaleneacetic acid. Several complex media additives were studied and only 800 mg yeast extract/liter and 200 mg casamino acids/liter individually stimulated significant increases in fresh weight over unsupplemented media. The callus from Oh51A ✕ Os420 has been maintained for 20 months with transfer to fresh media every 30 days (representing 19 subcultures).
Anther‐Derived Haploids in Tobacco: Evaluation of Procedures1
Authors: Kasperbauer M. J. , Collins G. B. 
Published: July 2010

Anther‐derived haploids are potentially useful in plant physiology and breeding programs. Techniques for largescale production of anther‐derived haploids were evaluated. Anthers were excised from immature floral buds that developed on tobacco (Nicotiana tabucum L.) plants in a greenhouse and in widely differing controlled environments. The anthers were cultured in Erlenmeyer flasks and petri dishes in several physical and chemical environments.Haploid plants were successfully cultured from anthers that developed on plants grown under a wide range of light and temperature environments.Numerous haploids were obtained from anthers cultured on different chemically‐defined nutrient formulations with and without auxin and c tokmin. Plantlets emerged earlier from anthers culturedr at 26 than at 21 C. Light was not essential for embryogenesis during anther culture; however, light was needed to prevent etiolation of the plantlets after emergence from the anthers. The simplest successful anther culture environment consisted of a stack of petri dishes under a plastic bag on an office desk.
Gene Effects Responsible for Inbreeding Depression in Autotetraploid Maize1
Authors: Rice J. S. , Dudley J. W. 
Published: July 2010

Inbreeding depression was studied in autotetraploid maize (Zea mays L.). Experimental material included the original population, S2 through S4 generations derived by selling, and the sib 1 through sib 6 generations resulting from full‐sib mating in an open‐pollinated autotetraploid synthetic. The genetic model used was µ1 = µ + 6FβH + (4P0 + P1)γiii + P0γiii + P2γiiii, where µ1 is the mean of an inbred generation; µ is the mean of the noninbred generation; βii, γiii, and δiiii are interaction effects resulting from the presence in a genotype of two, three, and four alleles, respectively, identical by descent; and δiiii is the interaction effect resulting from the presence of two pairs of alleles identical by descent. F is the inbreeding coefficient (probability that two alleles are identical by descent); P0, P1 and P2 are the probabilities of obtaining genotypes with four alleles, three alleles, and two pairs of alleles identical by descent, respectively.Least squares estimates of βii, γiii δiiii, and δiii,showed that for most characters, much of the depression could be accounted for by βii and βiiii,. These results were supported by multiple regression analyses ushig successively more complex models and measuring the sum of squares accounted for by each term in the model. It was concluded that the amount of inbreeding depression per unit of F in early generations of autotetraploids may differ for selfing and full‐sib mating. The significance of the results in terms of expected inbreeding depression in autotetraploid species is discussed.
Vegetative and Reproductive Development of Virginia‐Type Peanut Varieties in Different Stand Densities1
Authors: Cahaner A. , Ashri A. 
Published: July 2010

The yield and reproductive and vegetative development of four Virginia‐type varieties of peanuts (Arachis hypogaea L.) differing in growth habit and plant size were tested under standard, medium, and high densities. The following parameters were studied in biweekly intervals during the season: plant size and dry weight; length of main branches and degree of branching; number and dry weight of pegs and pods at four maturity stages; and final yield and quality of mature pods.Despite the size and growth habit differences between the varieties, there were no significant density ✕ variety interactions.Increased stand density led to increased vegetative growth and more numerous reproductive organs at all maturity stages per unit area, but the yields of mature pods were equal in the three densities. Yield did not increase with density because crowding did not lead to earlier termination of pod setting. The presence of many maturing pods apparently arrested the maturation of a high proportion. Breeding and physiological research should be devoted to the production of varieties which terminate their pod setting early.
Analysis of the Genetic Relationships Between Several Yield Components Maize and Leaf Area at Specific Leaf Positions
Authors: Johnson G. R. 
Published: July 2010

The genetic relationships among leaf area at individual leaf positions, several yield components (row number, kernels per row, and weight per 300 kernels), and yield in a set of maize (Zea mays L.) hybrids were investigated by a series of multiple regression models. The regression models determined, in sequence (1) the leaf positions that were the best linear predictors of the yield components, (2) additive and additive‐plus‐nonadditive genetic effects estimates of leaf area at the leaf positions selected in the first step, (3) estimates of yield components from regression on the additive and additive‐plus‐nonadditive leaf area genetic effects estimates obtained in the second step, and (4) the relationship of yield to the yield components estimated in step 3.Yield was related to additive genetic variance for leaf area in the upper leaves through weight per kernel and to nonadditive variation in the upper and lower leaves via kernels per row. The relationships between yield and nonadditive leaf area effects in the upper leaves appeared to be dependent upon, and subordinate to, the relationship between yield and nonadditive leaf area effects fn the lower leaves. Though two distinct genetic pathways linking leaf area to yield via the yield components were evident, the two paths were not genetically independent but were negatively correlated
Genetic Basis of Culm Height Differences Between Two Forage Sorghum Cultivars1
Authors: Singh Shree P. , Drolsom P. N. , Senturia J. N. 
Published: July 2010

Differences between the two cultivars ‘Rox Orange’ (RO) and ‘Early Sumac’ (ES) of forage sorghum. Sorghum bicolor (L.) Moench, for culm height, internode length, number of nodes, and days to flower were statistically significant. Analysis based upon the convolution approach suggests that these differences were monogenic for all characters except internode length. Our data suggest that both cultivars had similar height genotypes but differed at one of the maturity loci. Presumably the latter was responsible for differences in four characters between the two cultivars.Each of the two cultivars appears to be recessive at two and dominant at two other loci for height, but specific identifications were not possible. The reasons for that are discussed.Additive and dominance effects were exhibited, and overdominance was found for all characters except culm height. Only the dominance effect was shown for the latter.
Population Characteristics of Advanced Generations of an Alfalfa Synthetic Increased from Selfed, Single‐Cross, or Polycross Seed1
Authors: Bula R. J. , May R. G. , Garrison C. S. , Rincker C. M. , Dean J. G. , Elling L. J. 
Published: July 2010

An alfalfa (Medicago sativa L.) synthetic, derived from four clones as selfed, single‐cross, or polycross seed, was increased 1 to 4 generations at four western and two north central U.S. locations. Plant populations of each increase were compared for various characteristics when grown at Lafayette, Ind., the area of adaptation of the clones, to determine what method of breeder seed synthesis would result in minimum deviation of population characteristics among the seed increases from the various locations.Variations in fall regrowth height indicated a gradual population change toward taller plants and loss of winterhardiness with advancing generations of increase, regardless of method used to produce the breeder seed. Height of fall regrowth was greatest for populations derived from selfed seed and similar for populations derived from single‐cross and polycross seed.Percentage of plants with purple flowers increased in the advanced generations, particularly those made at the western locations. Breeder seed derived from polycross seed at the two north central locations had percentages of plants with purple flowers similar to those of the first generation increases of the selfed or singile‐cross seed.From a practical standpoint, these data indicate that seed multiplication of alfalfa synthetic cultivars can be accomplished using either selfed, single‐cross, or polycross seed as breeder seed with equally satisfactory maintenance of cultivar characteristics.
Effect of Tannin on In Vitro Dry Matter and Protein Disappearance in Sorghum Grain1
Authors: Schaffert R. E. , Lechtenberg V. L. , Oswalt D. L. , Axtell J. D. , Pickett R. C. , Rhykerd C. L. 
Published: July 2010

The purpose of this investigation was to determine the effect of tannin and added urea on in vitro dry matter disappearance (IVDMD) and in vitro protein disappearance (IVPD) in sorghum (Sorghum bicolor (L.) Moench) grain. IVDMD of low and high tannin genotypes after 48 hours of fermentation was 72.5 and 46.4% respectively. The addition of urea increased IVDMD to 93.4 and 79.2% for the low and high tannin genotypes. IVPD of low and high tannin genotypes was not affected by urea and averaged 88.2 and 69.6%, respectively. After 96 hours of fermentation the IVDMD of low and high tannin genotypes was 93.8 and 85.8%, respectively, indicating a true difference in digestibiltiy of about 8 percentage units.The major factor limiting the utilization of high tannin sorghum is apparently the availability of protein. Undigestible protein and tannin complex may account for more than half of the difference in IVDMD between low and high tannin genotypes.
Improved Technique for Evaluating Resistance of Corn to Corynebacterium nebraskense1
Authors: Calub A. G. , Schuster M. L. , Compton W. A. , Gardner C. O. 
Published: July 2010

An inoculating instrument consisting of multiple needles imbedded in a cork and foam rubber was effective in evaluating corn (Zea mays L.) plants for reaction to leaf freckles and wilt disease caused by Corynebacterium nebraskense Schuster et al.Inoculum concentrations of about l08 bacterial cells/ml in the foam rubber resulted in infection and excellent differentiation between resistant and susceptible lines in both the greenhouse and field, 5 to 7 days after inoculation. Seedlings were pricked by the instruments, one in each hand, from the base of the whorl to the tip of the leaves.The correlation between ratings obtained with the pin‐prick method in the seedling stage and a syringe injection method at tasseling time was 0.977.