scholarly journals Genetic variation for tolerance to defoliation in Cirsium arvense (Californian thistle)

2017 ◽  
Vol 70 ◽  
pp. 324
Author(s):  
M.G. Cripps ◽  
C.A. Dowsett ◽  
S.D. Jackman ◽  
A.D.L. Noble ◽  
G.J. Houliston
Keyword(s):  
Final Height ◽  
Adventitious Shoots ◽  
Shoot Density ◽  
Cirsium Arvense ◽  
Management Implications ◽  
Shoot Height ◽  
Plant Experiment ◽  
The Mean ◽  
Selection For ◽  
Californian Thistle

The pasture weed, Cirsium arvense (Californian thistle), is notorious for its ability to tolerate defoliation by herbivores, mowing, or herbicides, which is facilitated by the growth of adventitious shoots from its extensive clonal underground root system. In an outdoor potted-plant experiment, we examined the tolerance of 36 unique genotypes of C. arvense to defoliation by establishing pairs of clonal replicates that were assigned to a clipped, or unclipped treatment. Three clipping treatments were applied, and the final height, number of shoots, and biomass, were measured to compare the fitness between the clipped and unclipped clones. The majority of genotypes were negatively affected by clipping and showed a reduction in most final fitness measurements. However, some genotypes were equivalent or even greater than their unclipped counterparts indicating a large genetic range for tolerance to defoliation. The mean range in tolerance ratios (clipped/ unclipped) was 0.17 to 1.3 for shoot height, 0.26 to 1.2 for shoot density, and 0.6 to 1.2 for biomass (where a ratio of 1 indicates equivalence to the unclipped state). Since repeated defoliation is recommended for control of this weed, selection for more tolerant genotypes is possible, which may have management implications.

Breeding creeping-rooted lucerne for the subtropics

1967 ◽  
Vol 18 (6) ◽  
pp. 891 ◽  
Author(s):  
LA Edye ◽  
KP Haydock
Keyword(s):  
Survival Rates ◽  
Adventitious Shoots ◽  
Mass Selection ◽  
Genotypic Correlation ◽  
Specific Effects ◽  
The Mean ◽  
Selection For ◽  
Successive Generations ◽  
Seed Yields ◽  
Better Than

A lucerne-breeding programme was undertaken at Lawes, south-eastern Queensland, to transfer the creeping-rooted habit from Heinrichs's Canadian strains to subtropical lucerne varieties. Before intensive selection commenced, the inheritance and association of three characters, summer yield, winter yield, and the number of extra crowns originating as adventitious shoots from roots, were determined in the F2 and F3 generations. The F2 genotypic variances for summer yield, winter yield, and number of extra crowns were predominantly additive and were respectively 81, 53, and 54% of their phenotypic variances. The genotypic correlation coefficient for winter yield and number of extra crowns was negative ( rG = –0.18), consisting of a negative additive correlation rg = –0.55 and a positive non-additive correlation rs = 0.50. In the F3 generation the approximate genotypic correlation for these two characters was small and positive and composed of a nearly zero additive correlation and a high positive non-additive correlation. Simultaneous mass selection for summer yield, winter yield. and creeping-rootedness was undertaken in the F3 generation, and the combining ability variances and covariances for these characters were studied in the F4 generation. All three variables were positively associated in their general and specific effects, and the majority of families did not differ significantly from Hunter River in winter and summer yield. The seed production of ten F4 families was studied and it was found that eight families were significantly lower seed producers than Hunter River, their seed yields ranging from 20 to 47% of the mean for Hunter River. Covariance analysis showed seed yield and number of extra crowns to be negatively associated in the F4 generation. The changes in creeping-rootedness in the successive generations F1 to F5 were 2, 9, 34, 19, and 59% compared with a mean of 4% for Heinrichs's Canadian strains at Lawes. Creeping-rooted individuals survived better than non-creeping-rooted plants of similar genotype and better than Hunter River, particularly in the F4 generation, where the respective survival rates were 75, 27, and 23% 19 months after transplanting in the field

scholarly journals Impact of the biocontrol beetle, Cassida rubiginosa, on the secondary weed target, marsh thistle (Cirsium palustre)

2018 ◽  
Vol 71 ◽  
pp. 66-71 ◽  
Author(s):  
Dilani K. Hettiarachchi ◽  
Michael Cripps ◽  
Sarah Jackman ◽  
Chikako Van Koten ◽  
Jon Sullivan ◽  
...  
Keyword(s):  
Cirsium Arvense ◽  
Experimental Conditions ◽  
Primary Host ◽  
Minimal Impact ◽  
Percent Germination ◽  
Plant Experiment ◽  
Californian Thistle ◽  
Germination Parameters ◽  
Number Of Branches ◽  
Cassida Rubiginosa

The folivorous beetle Cassida rubiginosa was introduced to New Zealand to control the weed, Californian thistle (Cirsium arvense). Although Californian thistle is the primary host, many other thistles are accepted hosts. The objective of this study was to test if the beetle can reduce the fitness of marsh thistle (Cirsium palustre). A potted plant experiment was established with four treatments (0, 50, 100, and 200 larvae/plant). Plant growth (width, height, and number of branches) and reproductive performance (number of flowers, seeds, seed weight and percent germination) parameters were measured. No significant differences were found for any of the measured parameters, except percent germination. Higher larval densities (100 and 200) resulted in approximately 10% less germination compared with lower densities (0 and 50). Under these experimental conditions, C. rubiginosa had minimal impact on the performance of marsh thistle. For the beetle to have an impact, it would likely need to attack smaller, non-bolting rosettes, or be combined with additional stressors that might be encountered in a natural field population.

LA MESURE DE L’INTERFÉRENCE DU CHIENDENT DANS L’ORGE

1982 ◽  
Vol 62 (1) ◽  
pp. 183-188 ◽  
Author(s):  
R. RIOUX
Keyword(s):  
Regression Analysis ◽  
Hordeum Vulgare ◽  
Linear Relationship ◽  
Linear Relation ◽  
Shoot Density ◽  
Yield Variability ◽  
Hordeum Vulgare L ◽  
The Mean ◽  
The Relationship ◽  
Agropyron Repens

Barley (Hordeum vulgare L. ’Champlain’) was grown with quackgrass (Agropyron repens (L.) Beauv.) at various densities for 3 yr. According to the regression analysis, a linear relation is appropriate to describe the relationship between yield of barley and biomass or density of quackgrass. A greater proportion of yield variability was explained by density (64%) than by biomass (40%). Density is then a better criterion than biomass to predict yield lost in barley. The linear relationship between barley yield and the shoot density of quackgrass is estimated by the following equation: yield barley = 345.3–0.5682 dens, quackgrass. An increase of 10 shoots/m2 in the mean density of quackgrass resulted in a mean loss of 6 g/m2 in the yield of barley.

scholarly journals Impact of perennial ryegrass seeding densities on weed emergence growth and development

2000 ◽  
Vol 53 ◽  
pp. 38-43
Author(s):  
S.S. Seefeldt ◽  
M.L. Armstrong
Keyword(s):  
Perennial Ryegrass ◽  
Growth And Development ◽  
Field Experiments ◽  
Cirsium Arvense ◽  
Seeding Density ◽  
Senecio Jacobaea ◽  
Carduus Nutans ◽  
Weed Growth ◽  
Californian Thistle ◽  
Weed Emergence

Research was conducted to determine the effect of perennial ryegrass (Lolium perenne) sowing density on weed growth and development In glasshouse and field experiments perennial ryegrass was sown at rates of 0 5 10 20 40 and 80 kg/ha with 5 kg/ha of white clover (Trifolium repens) With increasing seeding density perennial ryegrass enhanced its competitiveness against all five of the weeds studied viz nodding thistle (Carduus nutans) Californian thistle (Cirsium arvense) Scotch thistle (Cirsium vulgare) ragwort (Senecio jacobaea) and hedge mustard (Sisymbrium officinale) In both trials increases in the perennial ryegrass seeding density did not reduce weed emergence However as perennial ryegrass density increased weed biomass decreased and time to flowering increased

scholarly journals Screening of French Bean (Phaseolus vulgaris L.) Genotypes against Alternaria Leaf Spot Caused by (Alternaria alternata) under Dryland Conditions of Kashmir

2021 ◽  
pp. 25-30
Author(s):  
Sabiya Bashir ◽  
Mohammad Najeeb Mughal ◽  
Zahida Rashid ◽  
Shabeena Majid ◽  
Sabeena Naseer ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Disease Incidence ◽  
French Bean ◽  
Phaseolus Vulgaris L ◽  
Dryland Agriculture ◽  
Disease Reaction ◽  
The Mean ◽  
Selection For ◽  
Resistant Genotypes

Sixty-three genotypes of  french bean was screened against leaf spot (Alternaria  alternata) in sick plots at Research Farm of Dryland Agriculture Research Srinagar, Rangreth during  Kharif  2018 and 2019. The highest mean disease incidence ranged from 0.00 to 85.00 per cent  with  the mean disease intensity ranged from 0.00 to 53.26 per cent .One genotype namely  ‘Local Pulwama’ was highly susceptible in their disease reaction. Among the screened germplasm, ‘Highly Resistant’ genotypes was SKU-R-601, SKUA-R-105, SKU-R-927, DARS-25, DARS-66, DARS-R-615,  while as ‘Susceptible’ genotypes was  DARS-8, DARS-12,  DARS-11, SKUAST-R-155, SKU-R-928, DARS-7, DARS-R-4, Bhaderwah (L),  Local  Kupwara black and Raj Jawala. Local Pulwama was found to be a highly susceptible (HS) genotype.  Twenty nine genotypes namely., DARS-16, DARS-9, DARS-54, DARS-39, VL-125, DARS-63, ENTO-504, SKUAST-204,SKU-R-925, DARS-60, DARS-109, DARS-43, DARS-44, SKU-R-23, DARS-4, DARS-74, SKU-R-105, DARS-40, DARS-23, DARS-18, SKU-R-71, WB-341, SKU-R-605, Uri local, Shopian (L), SKU-R-23, DARS-71, SSGB-729, DARS-R-19 showed resistant reaction to disease. The selection for resistance was based on the reaction of varieties on leaves.

Chemistry, mineralogy and microbiology of termite mound soil eaten by the chimpanzees of the Mahale Mountains, Western Tanzania

1999 ◽  
Vol 15 (5) ◽  
pp. 565-588 ◽  
Author(s):  
William C. Mahaney ◽  
Jessica Zippin ◽  
Michael W. Milner ◽  
Kandiah Sanmugadas ◽  
R. G. V. Hancock ◽  
...  
Keyword(s):  
Sandy Loam ◽  
Termite Mound ◽  
Mahale Mountains ◽  
Mahale Mountains National Park ◽  
The Mean ◽  
Selection For ◽  
Bacteria And Fungi ◽  
And Control ◽  
Very High ◽  
Control Samples

Subsamples of termite mound soil used by chimpanzees for geophagy, and topsoil never ingested by them, from the forest floor in the Mahale Mountains National Park, Tanzania, were analysed to determine the possible stimulus or stimuli for geophagy. The ingested samples have a dominant clay texture equivalent to a claystone, whereas the control samples are predominantly sandy clay loam or sandy loam, which indicates that particle size plays a significant role in soil selection for this behaviour. One potential function of the clays is to bind and adsorb toxins. Although both termite mound and control samples have similar alkaloid-binding capacities, they are in every case very high, with the majority of the samples being above 80%. The clay size material (<2 μm) contains metahalloysite and halloysite, the latter a hydrated aluminosilicate (Al2Si2O4·nH2O), present in the majority of both the termite mound soil and control soil samples.Metahalloysite, one of the principal ingredients found in the pharmaceutical Kaopectate™, is used to treat minor gastric ailments in humans. The soils commonly ingested could also function as antacids, as over half had pH values between 7.2 and 8.6. The mean concentrations of the majority of elements measured were greater in the termite mound soils than in the control soils. The termite mound soils had more filamentous bacteria, whereas the control soils contained greater numbers of unicellular bacteria and fungi.

Fall-Applied Glyphosate for Canada Thistle (Cirsium arvense) Control in Spring Wheat (Triticum aestivum)

1988 ◽  
Vol 2 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Steven J. Carlson ◽  
William W. Donald
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Shoot Density ◽  
Cirsium Arvense ◽  
Fresh Weight ◽  
Canada Thistle ◽  
Hard Red Spring Wheat ◽  
Late Fall ◽  
Fall Application ◽  
Root Buds

Effects of repeated late-fall applications of the isopropylamine salt of glyphosate at 1.7 kg ae/ha plus 0.5% (v/v) surfactant on adventitious root buds, thickened propagative roots (> 1.3 mm diam), and shoot density of Canada thistle were studied in continuous hard red spring wheat over a 4-yr period. Glyphosate suppressed Canada thistle shoot density more quickly and to a greater extent than thickened root fresh weight or root bud number. A single fall application of glyphosate drastically decreased Canada thistle shoot density for 1 yr after treatment. However, shoot density was the same as the untreated control by 2 yr after a single fall treatment. Two consecutive late-fall applications of glyphosate in 2 yr decreased Canada thistle shoot density 94% in the fall 1 yr after the last treatment. Glyphosate reduced Canada thistle thickened root fresh weight 70% in the first fall 1 yr after a single fall treatment. However, 2 yr after a single fall application of glyphosate, root fresh weight equalled the controls. Two consecutive fall applications of glyphosate reduced thickened root fresh weight 77% 1 yr after the second treatment.

scholarly journals Linear Growth and Final Height after Treatment for Cushing’s Disease in Childhood

2000 ◽  
Vol 85 (9) ◽  
pp. 3262-3265
Author(s):  
Marie-Christine Lebrethon ◽  
Ashley B. Grossman ◽  
Farhad Afshar ◽  
P. Nicholas Plowman ◽  
G. Michael Besser ◽  
...  
Keyword(s):  
Cushing’S Disease ◽  
Final Height ◽  
Growth Failure ◽  
Height Velocity ◽  
Cushing's Disease ◽  
Childhood And Adolescence ◽  
Target Height ◽  
Gnrh Analog ◽  
The Mean ◽  
The Difference

Abstract Cushing’s disease is associated with growth failure in childhood and adolescence. Growth and final height were analyzed in 10 patients who were cured or in remission after treatment of Cushing’s disease. Seven males and 3 females, aged 6.8–17.6 yr (bone age, 3.3- 15.4 yr), had transsphenoidal surgery, which was combined with pituitary irradiation (4500 cGy in 25 fractions) in 5 patients. At presentation, 5 patients were prepubertal (males), and 5 were pubertal (2 males and 3 females). The mean height sd score was −2.15 ± 1.26 (range, −0.21 to −4.32) compared with mean target height sd score of −0.43 ± 0.58. Height velocity in 6 patients was subnormal (0.9–3.8 cm/yr). After treatment, short-term height velocity, over a mean interval of 0.57 yr, in 8 patients not receiving human GH (hGH) therapy, was variable (range, 0.8–7.6 cm/yr). GH stimulation tests (insulin tolerance test/glucagon) in 9 subjects showed peak GH levels of 0.5–20.9 mU/L. Eight were treated with hGH (14 IU/m2·wk), combined in 2 girls and 1 boy with a GnRH analog. After 1 yr of hGH, the mean height sd score had increased from −2.45 ± 1.0 at initiation of hGH to −2.07± 1.2 (P = 0.01). GH therapy was continued until final height or latest assessment. The mean final height sd score (n = 6) was −1.24 ± 1.38, and at the latest assessment the mean height sd score (n = 4) was− 1.52 ± 1.33. Combining these 2 groups, the mean height sd score was −1.36 ± 1.29. The difference between final or latest height sd score and target height sd score was 0.93 ± 1.13, i.e. less (P = 0.005) than the difference between height and target height sd score of 1.72 ± 1.26 at presentation. In conclusion, catch-up and favorable long-term growth was seen after treatment for Cushing’s disease. Posttreatment GH deficiency was frequent, and early hGH replacement may have contributed to the encouraging outcome.

Vital statistics for an experimental flock of Merino sheep. III. Factors affecting wool and body characteristics, including the effect of age of ewe and its possible interaction with method of selection

1966 ◽  
Vol 17 (4) ◽  
pp. 557 ◽  
Author(s):  
GH Brown ◽  
HN Turner ◽  
SSY Young ◽  
CHS Dolling
Keyword(s):  
Body Weight ◽  
Fibre Diameter ◽  
Vital Statistics ◽  
Fibre Volume ◽  
Age Changes ◽  
Factors Affecting ◽  
Fibre Number ◽  
The Mean ◽  
Selection For ◽  
Staple Length

Estimates were made of the effects of the following factors on 10 fleece and body characteristics measured on breeding ewes aged 1½ to 10½ years in three mating groups over a period of 15 years: age of ewe, single or twin birth, age of dam, the ewe's own lambing performance, the year in which measurements were made, and the year in which each set of ewes was born. Two groups (S and MS) were under selection for high clean wool weight at 15–16 months, with a ceiling on wrinkle score and fibre diameter, while the third (C) was a random control. Changes with age were present in all characteristics and were similar in the three groups. The finding that selection on wool weight at an early age had no effect on subsequent age changes in any characteristic is of considerable importance. Greasy and clean wool weight reached a maximum at 34 years, then declined by 0.3–0.2 1b per year. Percentage clean yield, fibre diameter, body weight, and wrinkle score had maxima at 5½ to 6½ years. Staple length fell consistently by approximately 0.2 cm per year, while face cover rose consistently but slightly. Crimp number rose, fell, and rose again, while fibre number rose, fell, and remained constant from 4½ years. The chief source of increase in wool weight from l½ to 3½ years was an increase in the total number of fibres. The chief source of the subsequent fall was a decrease in fibre volume, with a minor contribution from a fall in total fibre number after 6½ years. Twin-born ewes cut 0.21 lb (4.2% of the mean) less clean wool per year over their lifetime than single-born ewes, while the progeny of 2-year-old ewes cut 0.32 lb (6.4%) less than the progeny of adults. The main source of lower weight in each case was a lower total fibre number. Pregnancy lowered clean wool weight more than lactation, the separate effects being 0.87 and 0.38 lb respectively (17.4 and 7.7% of the mean) and the combined effect 1.25 1b or 25.1%. Pregnancy lowered total fibre number but lactation had no further effect. Mean clean wool weights over all ages in the C group varied from year to year, the range being from 1.08 lb (21.6%)below the mean to 0.97 lb (19.4%) above. Differences in total fibre number contributed between one-third and two-thirds of the variation. Ewes born in consecutive years in the S and MS groups showed marked upward trends in clean wool weight, fibre number, and staple length, with a marked downward trend in crimp number and a slight upward trend in body weight. These trends demonstrate direct and correlated responses to the strong selection for high clean wool weight at 15–16 months of age, and the associated slight selection against fibre diameter and wrinkle score. The mean annual increases in clean wool weight were 0.15 and 0.11 Ib (3.0 and 2.2%) in the S and MS groups, approximately 40% of the increase arising from increased total fibre number and 40% from increased staple length. The effects of age and lambing performance can be used to predict productivity in flocks of differing age structures. As the casting age rises to 54 years changes in productivity are negligible. With a rise in casting age to 7½ years the average clean wool weight of the flock would fall by 0.14 lb, with a slight decrease in staple length and crimp number. These changes need to be balanced against any increased lambing percentage or decreased annual genetic gain due to increased generation interval. Comparison with other available figures indicates that age changes may vary from one area to another.

The control of adventitious root production in tissue-cultured Douglas-fir

1989 ◽  
Vol 19 (10) ◽  
pp. 1322-1329 ◽  
Author(s):  
G. H. Mohammed ◽  
K. R. Patel ◽  
W. E. Vidaver
Keyword(s):  
Second Generation ◽  
Sucrose Concentration ◽  
Douglas Fir ◽  
Fourth Generation ◽  
Root Production ◽  
Root Number ◽  
Shoot Height ◽  
Cell Divisions ◽  
Rooting Medium ◽  
The Mean

Rooting percentage and root number in tissue-cultured Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were influenced by the rooting substrate, the concentration of sucrose and boron in the rooting medium, shoot height, and shoot generation. Peat–perlite was a better substrate than agar, producing 70% compared with 0% rooted shoots, respectively. On peat–perlite, cell divisions were organized and were associated with tracheid nests, whereas on agar proliferation was unorganized and not restricted to the nests. A sucrose concentration of 4% was optimal for the production of nodular or rooted shoots. At 4% sucrose and 3 mg •L−1 boric acid, 100% of the shoots rooted, and the mean root number was 11. Rooting percentage and root number were significantly higher with shoots that were 3 cm tall than 2 or 1 cm tall shoots. Finally, it was found that shoot responses were more rapid in third and fourth generation shoots than in second generation shoots. At least 80% were rooted or nodular after 4 weeks, compared with only 36% from the second generation.

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