scholarly journals Screening Onion Lines for Resistance to Sclerotium cepivorumBerk. using Field and Onion Scale Assessments

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 469B-469
Author(s):  
M.R. McDonald ◽  
M.H.Y. Hovius ◽  
C. Sirjusingh
Keyword(s):  
Field Trial ◽  
White Rot ◽  
Breeding Lines ◽  
Positive Correlation ◽  
Sclerotium Cepivorum ◽  
Strong Potential ◽  
Wide Range ◽  
Commercial Cultivars ◽  
Direct Seeded

Resistance to Sclerotium cepivorum was investigated over 3 years at field sites with known histories of white rot in the Holland Marsh, Ontario, Canada. Onion lines from three sources (Petoseed, Asgrow Ltd., and Univ. of Wisconsin), including commercial cultivars, were direct-seeded (1995) or hand-transplanted (1994 and 1996) and the bulbs were assessed for white rot incidence at harvest. The incidence of white rot in 1994 was low (0% to 2.6%) and not significantly different among lines and cultivars. In 1995, white rot incidence was moderate at sites 1 and 2 (maximum 21.5% and 24%), but low at site 3 (0% to 6.3%). In 1996, white rot incidence ranged from 0.8% to 41.1% at site 1, but was not observed at sites 2 and 3. The results of the 1995 and 1996 assessment suggested that the breeding lines could be divided into two major groups with high (Univ. of Wisconsin) or low (Asgrow Ltd. and Petoseed) resistance to the fungus. Scale segments of harvested bulbs from the 1995 field trial and 35 commercial cultivars were inoculated with mycelial plugs of two isolates of Sclerotium cepivorum. The resulting lesions were measured. Significant differences in lesion diameters among onion lines (9.1–22.4 mm) and cultivars (10.5–26.75 mm) were found within isolates. There was a significant, high, and positive correlation between diameters of lesions formed by the two isolates on the 23 lines (r2 = 0.76, P = 0.05) and 35 cultivars (r2 = 0.62, P = 0.005). Both techniques demonstrated a wide range of resistance to white rot. This suggests a strong potential for increasing resistance through breeding.

scholarly journals Flavor Precursor [S-alk(en)yl-L-cysteine sulfoxide] Concentration and Composition in Onion Plant Organs and Predictability of Field White Rot Reaction of Onions

2005 ◽  
Vol 130 (2) ◽  
pp. 196-202 ◽  
Author(s):  
Marilyn H.Y. Hovius ◽  
Irwin L. Goldman ◽  
Kirk L. Parkin
Keyword(s):  
High Performance ◽  
Disease Incidence ◽  
Field Trials ◽  
White Rot ◽  
Individual Plant ◽  
Onion Plant ◽  
Plant Organs ◽  
Breeding Lines ◽  
Sclerotium Cepivorum ◽  
Cysteine Sulfoxide

Breeders have found field screening for white rot (Sclerotium cepivorum Berk.) resistance in onion (Allium cepa L.) to be unreliable since consistently moderate to high disease levels that significantly differentiate cultivars do not occur over field sites and years. The objective was to determine if differences in onion white rot resistance levels were associated with differing S-alk(en)yl-l-cysteine sulfoxide (ACSO) levels. A collection of onion breeding lines and hybrids were evaluated in field trials at six sites in 1999-2001. High performance liquid chromatography was used to analyze ACSOs in onion plant organs. Four main cysteine-sulfoxides exist in Allium L. species: methyl (MCSO), 2-propenyl (2-PeCSO), 1-propenyl (1-PeCSO), and propyl (PCSO). 1-PeCSO was predominant in onion leaves, bulbs, and roots. 2-PeCSO was found in trace amounts in onion leaves and roots. There was significantly more 2-PeCSO and total ACSO (roots only) and 1-PeCSO (roots and bulbs) in accessions that were more susceptible to white rot in the field trials. This is the first report of significant differences in ACSO contents among white rot susceptible and resistant onions. A covariance analysis was used to determine if the ACSO levels that significantly distinguished among accessions could predict field onion white rot reaction. 1-PeCSO from both roots and bulbs was the best predictor of field disease incidence in field sites that had low, moderate, and high disease levels. Although the ACSO concentrations were not assessed on an individual plant basis, breeders may be able to screen onions for resistance to S. cepivorum by comparing onion root or bulb 1-PeCSO levels based on the results from this research. White rot incidence in the field should be higher in those plants whose roots and bulbs have the highest levels of 1-PeCSO.

Effect of cultivar on uptake of cadmium by potato tubers

1994 ◽  
Vol 45 (7) ◽  
pp. 1483 ◽  
Author(s):  
MJ McLaughlin ◽  
CMJ Williams ◽  
A McKay ◽  
R Kirkham ◽  
J Gunton ◽  
...  
Keyword(s):  
Dominant Role ◽  
Potato Tubers ◽  
Fresh Weight ◽  
Site Factors ◽  
Cd Accumulation ◽  
Breeding Lines ◽  
Commercial Potato ◽  
Wide Range ◽  
Commercial Cultivars ◽  
Joint Regression Analysis

Cadmium (Cd) accumulation in tubers by commercial potato cultivars was assessed at 12 sites around Australia having differing soil and environmental conditions. At all but two sites there were significant differences in tuber Cd concentrations between cultivars. Some major commercial cultivars had tuber Cd concentrations only half that of others. Advanced breeding lines showed further potential to reduce Cd accumulation. Mean tuber Cd concentrations of the 14 most common cultivars, averaged across all sites, ranged from 30 to 50 8g kg-1 fresh weight (FW), below the maximum permitted concentration (MPC) of 50 8g kg-1 of Cd (FW). However, at some sites certain cultivars exceeded the MPC. A modified joint regression analysis of the data indicated that no cultivars have consistently low or consistently high tuber Cd concentrations across a range of environments. While differences between cultivars were significant, the range in Cd concentrations found between sites was generally greater than the range in Cd concentrations between cultivars at any one site. Thus soil and other site factors (e.g. irrigation water quality, climate, etc.) play a dominant role in controlling Cd accumulation by current commercial cultivars and there is a need to breed new cultivars resistant to Cd accumulation under a wide range of environments.

scholarly journals Evaluation of Onion Lines for Resistance to Onion White Rot and Onion Maggot

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 830G-831
Author(s):  
M.R. McDonald ◽  
T. Lewis ◽  
I. Goldman
Keyword(s):  
Block Design ◽  
Organic Soil ◽  
White Rot ◽  
Onion Maggot ◽  
Sclerotium Cepivorum ◽  
Randomized Complete Block Design ◽  
Commercial Cultivars ◽  
Low Levels ◽  
Field Plots

Onion lines were evaluated for resistance to Allium white rot (Sclerotium cepivorum Berk.) and onion maggot [Delia antigua (Meig.)] in field plots established on organic soil in the Bradford Marsh, Ontario. White rote valuations were conducted on 20 lines in 1992–1994, with follow-up laboratory trials in 1995. Onion maggot screening was conducted on these same lines in 1993 and 1994. Plots were arranged in a randomized complete-block design with four replications per line. Significant differences in susceptibility to white rot were found in 1992 and 1993, while differences in onion maggot resistance were identified in 1993 and 1994. Commercial cultivars Norstar and Fortress had relatively low levels of onion maggot damage and Fortress demonstrated some tolerance to white rot. Other lines with low levels of white rot infection were 1292-91, 1564-91, 124-93, 116-93, and 117-93, from the breeding program at the Univ. of Wisconsin. Line 1292-91 also had low levels of onion maggot damage. The horticultural characteristics of the onion lines will be discussed.

scholarly journals Variation in β-Glucan, Protein and Fat Concentration of Oats Created in Latvia

2018 ◽  
Vol 72 (2) ◽  
pp. 71-74
Author(s):  
Vita Šterna ◽  
Sanita Zute ◽  
Zaiga Vicupe
Keyword(s):  
Dietary Fibre ◽  
Protein Concentration ◽  
Significant Positive Correlation ◽  
Bioactive Components ◽  
Nutrition And Health ◽  
Breeding Lines ◽  
Positive Correlation ◽  
Wide Range ◽  
Oat Breeding

Abstract Consumption of dietary fibre has potential in improving nutrition and health. For further breeding of oats, it is necessary to increase knowledge on variation in the content of fibre and bioactive components in oats. Therefore, the aim of the present investigation was to study the extent of variation in β-glucan concentration of oats grown in Latvia and to evaluate association of β-glucan concentration with protein and fat concentration in newly created oat breeding lines. In 2015 and 2016, concentration of protein, fat, and β-glucan in grain of hulled oat varieties ‘Laima’, ‘Peppi’, and ten breeding lines was determined. The obtained results showed a wide range of fat concentration among varieties, with a range from 5.9 to 8.3%. The concentration of β-glucan ranged from 1.8 to 3.6% depending on the year. The β-glucan concentration had medium close positive correlation with lipid and weak significant positive correlation with protein concentration, which significantly differed among genotypes.

Relationship Between Gas Emissions and Dry Matter Intake in Mature Angus Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 32-33
Author(s):  
Amanda Holder ◽  
Megan A Gross ◽  
Alexi Moehlenpah ◽  
Paul Beck
Keyword(s):  
Dry Matter ◽  
Significant Positive Correlation ◽  
Crossover Design ◽  
Dry Matter Intake ◽  
Data Set ◽  
Gas Emissions ◽  
Positive Correlation ◽  
Wide Range ◽  
Carbon Dioxide Co2 ◽  
Second Period

Abstract The objective of this study was to examine the effects of diet quality on greenhouse gas emissions and dry matter intake (DMI). We used 42 mature, gestating Angus cows (600±69 kg; and BSC 5.3±1.1) with a wide range in DMI EPD (-1.36 to 2.29). Cows were randomly assigned to 2 diet sequences forage-concentrate (FC) or concentrate-forage(CF) determined by the diet they consumed in each period (forage or concentrate). The cows were adapted to the diet and the SmartFeed individual intake units for 14 d followed by 45 d of intake data collection for each period. Body weight was recorded on consecutive weigh days at the beginning and end of each period and then once every two wk for the duration of a period. Cows were exposed to the GreenFeed Emission Monitoring (GEM) system for no less than 9 d during each period. The GEM system was used to measure emissions of carbon dioxide (CO2) and methane (CH4). Only cows with a minimum of 20 total >3-m visits to the GEM were included in the data set. Data were analyzed in a crossover design using GLIMMIX in SASv.9.4. Within the CF sequence there was a significant, positive correlation between TMR DMI and CH4 (r=0.81) and TMR DMI and CO2 (r=0.69), however, gas emissions during the second period on the hay diet were not correlated with hay intake. There was a significant, positive correlation between hay DMI and CO2 (r=0.76) and hay DMI and CH4 (r=0.74) when cows first consumed forage (FC). In comparison to the CF sequence, cows on the FC sequence showed a positive correlation between CO2 and TMR DMI during the second period. There was also a significant positive correlation between hay and TMR DMI when assessed across (r=0.43) or within sequence (FC r=0.41, CF r=0.47).

Transpiration Response to Vapor Pressure Deficit in Field Grown Peanut

2012 ◽  
Vol 39 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Maria Balota ◽  
Steve McGrath ◽  
Thomas G. Isleib ◽  
Shyam Tallury
Keyword(s):  
Vapor Pressure ◽  
Soil Water ◽  
Water Deficit ◽  
Water Conservation ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Genotypic Variation ◽  
Moisture Stress ◽  
Breeding Lines ◽  
Wide Range

Abstract Water deficit, i.e., rainfall amounts and distribution, is the most common abiotic stress that limits peanut production worldwide. Even though extensive research efforts have been made to improve drought tolerance in peanut, performance of genotypes largely depends upon the environment in which they grow. Based on greenhouse experiments, it has been hypothesized that stomata closure under high vapor pressure deficit (VPD) is a mechanism of soil water conservation and it has been shown that genotypic variation for the response of transpiration rate to VPD in peanut exists. The objective of this study was to determine the relationship between stomatal conductance (gs) and VPD for field grown peanut in Virginia-Carolina (VC) rainfed environments. In 2009, thirty virginia-type peanut cultivars and advanced breeding lines were evaluated for gs at several times before and after rain events, including a moisture stress episode. In 2010, eighteen genotypes were evaluated for gs under soil water deficit. In 2009, VPD ranged from 1.3 to 4.2 kPa and in 2010 from 1.78 to 3.57 kPa. Under water deficit, genotype and year showed a significant effect on gs (P  =  0.0001), but the genotype × year interaction did not. During the water deficit episodes while recorded gs values were relatively high, gs was negatively related to VPD (R2  =  0.57, n  =  180 in 2009; R2  =  0.47, n  =  108 in 2010), suggesting that stomata closure is indeed a water conservation mechanism for field grown peanut. However, a wide range of slopes among genotype were observed in both years. Genotypes with significant negative relationships of gs and VPD under water deficit in both years were Florida Fancy, Gregory, N04074FCT, NC-V11, and VA-98R. While Florida Fancy, Gregory, and NC-V11 are known to be high yielding cultivars, VA-98R and line N04074FCT are not. The benefit of stomatal closure during drought episodes in the VC environments is further discussed in this paper.

scholarly journals Potato cultivars vary in susceptibility to blackleg (Erwinia carotovora subsp atroseptica)

2009 ◽  
Vol 62 ◽  
pp. 403-403
Author(s):  
P.J. Wright ◽  
J.A.D. Anderson
Keyword(s):  
New Zealand ◽  
Bacterial Growth ◽  
Field Experiments ◽  
Erwinia Carotovora ◽  
Potato Cultivars ◽  
Plant Food ◽  
Breeding Lines ◽  
Susceptibility To Infection ◽  
Food Research ◽  
Commercial Cultivars

Ten potato cultivars were tested for susceptibility to infection by Erwinia carotovora subsp atroseptica (Eca) the causal agent of blackleg over two maincrop seasons in 200506 and 200607 The pathogen was inoculated into seed tubers using toothpicks charged with undiluted bacterial growth Blackleg incidence was assessed 56 weeks after planting The field experiments clearly confirmed that potato cultivars vary significantly in susceptibility to blackleg Some New Zealand cultivars had a lower susceptibility to blackleg than current commercial cultivars The new Plant Food Research release Summer Delight in particular had an exceptional level of resistance and will be used as a parent in efforts to develop potato cultivars with lower blackleg susceptibility than current local commercial cultivars Routine screening of Plant Food Research breeding lines and cultivars will continue to be carried out over several seasons to confirm results presented here and to determine further blacklegresistant germplasm

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