Cochylis hospes (Lepidoptera: Tortricidae) damage to male lines varies significantly and inbred susceptibility predicts damage to hybrids

2019 ◽  
Vol 151 (6) ◽  
pp. 817-823 ◽  
Author(s):  
Jarrad R. Prasifka
Keyword(s):  
North America ◽  
Predictive Power ◽  
Primary Source ◽  
Field Trials ◽  
Inbred Lines ◽  
Insect Damage ◽  
Seed Damage ◽  
Damage Data ◽  
Cochylis Hospes ◽  
Sunflower Moth

AbstractLarvae of Cochylis hospes (Walsingham) (Lepidoptera: Tortricidae) (banded sunflower moth) are a primary source of insect damage to seeds of cultivated sunflower, Helianthus annuus Linnaeus (Asteraceae), in North America. Field trials were used to evaluate seed damage under natural infestations for panels of publicly released male lines, publicly derived hybrids (females crossed to one common male parent), and commercial hybrids over a total of four years. For trials in 2013–2014 including 17 male lines, seed damage ranged from 3% to 19%. The least damaged male, RHA 266, was statistically similar to one other male, RHA 455. Three commercial hybrids used as checks also received very little seed damage (< 5%). In trials during 2016–2017, hybrids created by pollinating 15 different female lines with RHA 266 showed 4–14% damage. Data from female parents explained about 28% of variation in seed damage for the hybrids. Results confirm cultivated sunflower has greater variation in susceptibility to C. hospes than previously believed, and that seed damage to inbred lines provides some predictive power for hybrids. Though breeding for resistance to C. hospes seems possible, it may be too labour-intensive without relating resistance to more easily measurable traits or genetic markers.

Relative susceptibility of sunflower maintainer lines and resistance sources to natural infestations of the banded sunflower moth (Lepidoptera: Tortricidae)

2016 ◽  
Vol 148 (6) ◽  
pp. 736-741 ◽  
Author(s):  
Jarrad R. Prasifka ◽  
Brent S. Hulke
Keyword(s):  
North America ◽  
Field Trials ◽  
Inbred Lines ◽  
The Other ◽  
Interspecific Crosses ◽  
Relative Susceptibility ◽  
Resistance Sources ◽  
Seed Damage ◽  
Significant Variability ◽  
Sunflower Moth

AbstractThe banded sunflower moth, Cochylis hospes Walsingham (Lepidoptera: Tortricidae), is a significant seed-feeding pest of sunflowers (Helianthus Linnaeus; Asteraceae) in North America. Though some wild Helianthus, interspecific crosses, and H. annuus Linnaeus cultivars (which precede hybrid sunflower breeding) have low susceptibility to banded sunflower moth, no apparent effort has been made to evaluate modern inbred lines as a source of resistance for hybrids. In field trials from 2013 to 2015, inbred maintainer (HA) lines, resistant accessions (PI), and unreleased, partially inbred (F6) lines were evaluated in field trials using natural infestations of banded sunflower moth. Results show greater seed damage to maintainer lines than the other groups, but also significant variability among lines within groups. The best maintainer, HA 207, had ≈75% fewer damaged seed than the most susceptible HA lines. Among the resistant PI and unreleased inbred lines, only one entry had significantly less damage than HA 207. While PI 494859 showed banded moth resistance superior to the best inbred lines, its other agronomic liabilities make breeding with the least susceptible maintainer lines appear more practical. A key unknown for any attempts to breed hybrids resistant to banded sunflower moth is how closely damage is correlated between inbred lines and their hybrids.

scholarly journals Capitate Glandular Trichomes Fail to Provide Significant Resistance to Banded Sunflower Moth (Lepidoptera: Tortricidae)

2020 ◽  
Vol 49 (2) ◽  
pp. 444-448
Author(s):  
Jarrad R Prasifka ◽  
Brent S Hulke
Keyword(s):  
Insect Pest ◽  
Glandular Trichomes ◽  
Field Trials ◽  
Similar Species ◽  
Seed Damage ◽  
Negative Results ◽  
Pheromone Trapping ◽  
Lepidoptera Pyralidae ◽  
Plant Maturity ◽  
Sunflower Moth

Abstract Extracts from capitate glandular trichomes (CGT) of wild and cultivated sunflowers, Helianthus spp., have repellent or toxic effects on sunflower specialists and generalist herbivores less closely associated with sunflower. Though CGT have been primarily examined for their potential to provide partial resistance to the sunflower moth, Homoeosoma electellum Hulst (Lepidoptera: Pyralidae), a floret- and seed-feeding pest, the banded sunflower moth (Cochylis hospes Walsingham [Lepidoptera: Tortricidae]) is a similar species more common in the primary sunflower-producing states of North Dakota and South Dakota. Replicated field trials using partially inbred lines with low or high CGT densities were used to evaluate possible reductions to seed damage by C. hospes larvae in 2016–2017. Results failed to support the idea that CGT are a useful defense against larvae of C. hospes; the putative plant defense of high trichome density corresponded to slightly more, rather than less, insect damage. A test of a secondary explanation, that strength of sunflower hulls could help determine patterns of seed damage among tested lines, produced similarly negative results. Though timing of bloom differed between groups of most- and least-damaged lines, prior research and pheromone-trapping data suggest differences in plant maturity also cannot adequately explain the observed results. While the specific mechanisms remain unclear, significant differences in susceptibility to C. hospes exist for cultivated sunflower and limit losses from this primary insect pest.

Bt-Cry3Aa transgene expression reduces insect damage and improves growth in field-grown hybrid poplar

2014 ◽  
Vol 44 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Amy L. Klocko ◽  
Richard Meilan ◽  
Rosalind R. James ◽  
Venkatesh Viswanath ◽  
Cathleen Ma ◽  
...  
Keyword(s):  
Large Scale ◽  
Populus Deltoides ◽  
Integrated Management ◽  
Populus Trichocarpa ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Field Trials ◽  
Leaf Beetle ◽  
Insect Damage ◽  
Beetle Damage

The stability and value of transgenic pest resistance for promoting tree growth are poorly understood. These data are essential for determining if such trees could be beneficial to commercial growers in the face of substantial regulatory and marketing costs. We investigated growth and insect resistance in hybrid poplar expressing the cry3Aa transgene in two field trials. An initial screening of 502 trees comprising 51 transgenic gene insertion events in four clonal backgrounds (Populus trichocarpa × Populus deltoides, clones 24-305, 50-197, and 198-434; and P. deltoides × Populus nigra, clone OP-367) resulted in transgenic trees with greatly reduced insect damage. A large-scale study of 402 trees from nine insertion events in clone OP-367, conducted over two growing seasons, demonstrated reduced tree damage and significantly increased volume growth (mean 14%). Quantification of Cry3Aa protein indicated high levels of expression, which continued after 14 years of annual or biannual coppice in a clone bank. With integrated management, the cry3Aa gene appears to be a highly effective tool for protecting against leaf beetle damage and improving yields from poplar plantations.

scholarly journals Gene banks for wild and cultivated sunflower genetic resources

OCL ◽  
2020 ◽  
Vol 27 ◽  
pp. 9 ◽  
Author(s):  
Sreten Terzić ◽  
Marie-Claude Boniface ◽  
Laura Marek ◽  
Daniel Alvarez ◽  
Karin Baumann ◽  
...  
Keyword(s):  
North America ◽  
Genetic Resources ◽  
Helianthus Annuus ◽  
Inbred Lines ◽  
Wild Sunflower ◽  
Gene Banks ◽  
Breeding Programmes ◽  
Wild Accessions ◽  
Modern Breeding ◽  
Local Research

Modern breeding of sunflower (Helianthus annuus L.), which started 100 years ago, increased the number and the diversity of cultivated forms. In addition, for more than 50 years, wild sunflower and other Helianthus species have been collected in North America where they all originated. Collections of both cultivated and wild forms are maintained in gene banks in many countries where sunflower is an important crop, with some specificity according to the availability of germplasm and to local research and breeding programmes. Cultivated material includes land races, open pollinated varieties, synthetics and inbred lines. The majority of wild accessions are ecotypes of wild Helianthus annuus, but also 52 other species of Helianthus and a few related genera. The activities of three gene banks, in USA, France and Serbia, are described in detail, supplemented by data from seven other countries. Past and future uses of the genetic resources for environmental adaptation and breeding are discussed in relation to genomic and improved phenotypic knowledge of the cultivated and wild accessions available in the gene banks.

Influence of headbugs (Eurystylus sp.) on sorghum grain mould in the Nigerian savanna

1999 ◽  
Vol 132 (1) ◽  
pp. 71-75 ◽  
Author(s):  
P. S. MARLEY ◽  
A. M. MALGWI
Keyword(s):  
Fusarium Moniliforme ◽  
Field Trials ◽  
Gibberella Fujikuroi ◽  
Curvularia Lunata ◽  
Insect Damage ◽  
Normal Order ◽  
Fungal Flora ◽  
The Common ◽  
Sorghum Grain ◽  
Nigerian Savanna

The interaction between headbugs (Eurystylus sp.) and grain mould (GM) on sorghum was examined in field trials carried out at Samaru, Nigeria in the 1995 and 1996 wet seasons. The results obtained show that in all three sorghum cultivars tested, insect damage increased the number of fungal colonies associated with the grain. This resulted in lower germination, 1000-grain mass and yield in such treatments. Insect damage also altered the relative abundance of the common fungal flora species as, following insect damage, Fusarium moniliforme (≡Gibberella fujikuroi), Phoma sorghina and Curvularia lunata (≡Cochliobolus lunatus) were the most common fungi in decreasing order of frequency as against the normal order of P. sorghina, F. moniliforme followed by C. lunata. These results are the first clear evidence of interactions between headbugs and GM in Nigeria.

Estimates of emerald ash borer (Coleoptera: Buprestidae) larval galleries in branch samples from asymptomatic urban ash trees (Oleaceae)

2015 ◽  
Vol 148 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Jean J. Turgeon ◽  
Jeffrey G. Fidgen ◽  
Krista L. Ryall ◽  
Taylor A. Scarr
Keyword(s):  
Cost Effectiveness ◽  
North America ◽  
Surface Area ◽  
Predictive Power ◽  
Emerald Ash Borer ◽  
Cost Effective ◽  
Agrilus Planipennis ◽  
Significant Source ◽  
Resource Managers ◽  
Ash Trees

AbstractAgrilus planipennis (Coleoptera: Buprestidae), is causing extensive mortality of ash (Fraxinus Linnaeus; Oleaceae) in North America. Once detected in an area, resource managers require methods to obtain estimates that could improve management decisions. We studied the within-crown and within-branch distribution and abundance of A. planipennis feeding galleries by sampling 3-m-long branches from asymptomatic urban ash trees and subdividing each branch into 12 sections of 25 cm each. We found galleries in all 12 sections of some, but not all, branches. Section was a significant source of variation in A. planipennis gallery density/m2 of branch surface area. A comparison of predictive power and efficiency of estimates for samples of increasing length, and for samples of the same length but consisting of different combinations of sections, revealed that those based on the two basal 25-cm sections of a branch from the lower-crown or mid-crown of an asymptomatic tree were less accurate and precise than those based on more sections, but were the most cost effective. Whittling more sections per branch, irrespective of the combinations of branch sections per length, improved predictive power but reduced cost effectiveness. We also observed that crown level was not important, and aspect was only marginally so, when estimating gallery abundance per sampled branch.

scholarly journals The Influence of Atmospheric Blocking on Extreme Winter Minimum Temperatures in North America

2016 ◽  
Vol 29 (12) ◽  
pp. 4361-4381 ◽  
Author(s):  
Kirien Whan ◽  
Francis Zwiers ◽  
Jana Sillmann
Keyword(s):  
United States ◽  
North America ◽  
Extreme Events ◽  
Climate Models ◽  
Primary Source ◽  
The United States ◽  
Climate Projections ◽  
Cold Temperatures ◽  
Climate Conditions ◽  
The Difference

Abstract Regional climate models (RCMs) are the primary source of high-resolution climate projections, and it is of crucial importance to evaluate their ability to simulate extreme events under current climate conditions. Many extreme events are influenced by circulation features that occur outside, or on the edges of, RCM domains. Thus, it is of interest to know whether such dynamically controlled aspects of extremes are well represented by RCMs. This study assesses the relationship between upstream blocking and cold temperature extremes over North America in observations, reanalysis products (ERA-Interim and NARR), and RCMs (CanRCM4, CRCM5, HIRHAM5, and RCA4). Generalized extreme value distributions were fitted to winter minimum temperature (TNn) incorporating blocking frequency (BF) as a covariate, which is shown to have a significant influence on TNn. The magnitude of blocking influence in the RCMs is consistent with observations, but the spatial extent varies. CRCM5 and HIRHAM5 reproduce the pattern of influence best compared to observations. CanRCM4 and RCA4 capture the influence of blocking in British Columbia and the northeastern United States, but the extension of influence that is seen in observations and reanalysis into the southern United States is not evident. The difference in the 20-yr return value (20RV) of TNn between high and low BF in the Pacific Ocean indicates that blocking is associated with a decrease of up to 15°C in the 20RV over the majority of the United States and in western Canada. In northern North America the difference in the 20RV is positive as blocking is associated with warmer extreme cold temperatures. The 20RVs are generally simulated well by the RCMs.

scholarly journals Agronomic and molecular evaluation of maize inbred lines for drought tolerance

2016 ◽  
Vol 14 (4) ◽  
pp. e0711 ◽  
Author(s):  
Sanja Mikić ◽  
Miroslav Zorić ◽  
Dušan Stanisavljević ◽  
Ankica Kondić-Špika ◽  
Ljiljana Brbaklić ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Maize Yield ◽  
Field Trials ◽  
Inbred Lines ◽  
Partial Least Square ◽  
Least Square ◽  
Maize Breeding ◽  
Heterotic Groups ◽  
Maize Inbred Lines

Drought is a severe threat to maize yield stability in Serbia and other temperate Southeast European countries occurring occasionally but with significant yield losses. The development of resilient genotypes that perform well under drought is one of the main focuses of maize breeding programmes. To test the tolerance of newly developed elite maize inbred lines to drought stress, field trials for grain yield performance and anthesis silk interval (ASI) were set in drought stressed environments in 2011 and 2012. Inbred lines performing well under drought, clustered into a group with short ASI and a smaller group with long ASI, were considered as a potential source for tolerance. The former contained inbreds from different heterotic groups and with a proportion of local germplasm. The latter consisted of genotypes with mixed exotic and Lancaster germplasm, which performed better in more drought-affected environments. Three inbreds were selected for their potential drought tolerance, showing an above-average yield and small ASI in all environments. Association analysis indicated significant correlations between ASI and grain yield and three microsatellites (bnlg1525, bnlg238 and umc1025). Eight alleles were selected for their favourable concurrent effect on yield increase and ASI decrease. The proportion of phenotypic variation explained by the markers varied across environments from 5.7% to 22.4% and from 4.6% to 8.1% for ASI and yield, respectively. The alleles with strongest effect on performance of particular genotypes and their interactions in specific environments were identified by the mean of partial least square interactions analysis indicating potential suitability of the makers for tolerant genotype selection.

Sign in / Sign up

Export Citation Format

Share Document