Variation in the number of capitate glandular trichomes in wild and cultivated sunflower germplasm and its potential for use in host plant resistance

2014 ◽  
Vol 13 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Jarrad R. Prasifka

The capitate glandular trichomes of wild sunflowers (Helianthus spp.) are considered to be effective defence components that act against some herbivorous insects, but cultivated sunflowers are reportedly deficient in glandular trichomes. To investigate whether glandular trichomes have a role in the protection of cultivated sunflowers against insects, in the present study, Helianthus annuus L. accessions were grown to quantify glandular trichome density in wild and cultivated germplasm types and assess potential anti-insect effects of terpenoids in the glandular trichomes of cultivated sunflowers. Evaluation revealed that capitate glandular trichomes are often abundant in cultivated sunflowers; relative to wild H. annuus, inbred maintainer (HA) lines have similar numbers of glandular trichomes per floret, while commercial hybrids have only ≈ 20% fewer trichomes when compared with wild sunflowers. In the laboratory assay, it was found that glandular trichome extracts increased the mortality rates of sunflower moth, Homoeosoma electellum (Hulst), larvae exposed from the neonatal stage to 9 d. In the surviving larvae, the extracts significantly reduced larval mass and head capsule width. Though there are limitations to the value of glandular trichomes for host plant resistance, the feeding deterrent or toxic effects of sesquiterpene lactones and diterpenes in sunflower glandular trichomes are not limited to sunflower moth larvae, suggesting a potential for resistance to other sunflower insect pests. Additional research is required to understand the inheritance and value of glandular trichomes in commercial sunflower germplasm and how the composition of terpenoids in the glandular trichomes of wild H. annuus may differ from that in cultivated material.

2003 ◽  
Vol 128 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Joseph J. Coombs ◽  
David S Douches ◽  
Wenbin Li ◽  
Edward J. Grafius ◽  
Walter L. Pett

The colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), is the leading insect pest of potato (Solanum tuberosum L.) in northern latitudes. Host plant resistance has the potential use in an integrated pest management program for control of colorado potato beetle. During the 1998 and 1999 seasons, field studies were conducted to compare natural (leptine glycoalkaloids and glandular trichomes), engineered (Bt-cry3A and Bt-cry5 transgenic potato lines), and combined (Bt-cry5+glandular trichomes) plant resistance mechanisms of potato for control of colorado potato beetle. Nine different potato clones representing five different host plant resistance mechanisms were evaluated under natural colorado potato beetle infestation at the Montcalm Research Farm in Entrican, Michigan. The Bt-cry3A transgenic lines, the high leptine line (USDA8380-1), and the high foliar glycoalkaloid line (ND5873-15) were most effective for controlling defoliation by colorado potato beetle adults and larvae. The Bt-cry5 line (SPc5-G2) was not as effective as the Bt-cry3A transgenic lines ('Russet Burbank Newleaf,' RBN15, and YGc3.1). The glandular trichome (NYL235-4) and Bt-cry5+glandular trichome lines proved to be ineffective. Significant rank correlations for the potato lines between the two years were observed for egg masses, second and third instar, and fourth instar seasonal cumulative mean number of individuals per plant, and defoliation. Egg mass and first instar seasonal cumulative mean number of individuals per plant were not strong indicators of host plant resistance in contrast to second and third instars or adults. Based on these results, the Bt-cry3A transgenic lines, the high leptine line, and the high total glycoalkaloid line are effective host plant resistance mechanisms for control of colorado potato beetle.


HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 967-970 ◽  
Author(s):  
D.S. Douches ◽  
T.J. Kisha ◽  
J.J. Coombs ◽  
W. Li ◽  
W.L. Pett ◽  
...  

The Colorado potato beetle, Leptinotarsa decemlineata (Say), is the most serious insect pest of potatoes throughout the eastern and north central United States. Host plant resistance to the Colorado potato beetle has been identified in wild Solanum species and Bt-transgenic potato lines. Detached-leaf bioassays (72 h) were conducted on insecticide-resistant, first instar Colorado potato beetles to study the effectiveness of individual and combined host plant resistance traits in potato. Potato lines tested include non-transgenic cultivars (`Russet Burbank', `Lemhi Russet', and `Spunta'), a line with glandular trichomes (NYL235-4), a line with high foliar leptines (USDA8380-1), and transgenic lines expressing either codon-modified Bt-cry3A or Bt-cry5 (Bt-cry1Ia1). Bt-cry3A transgenic lines, foliar leptine line, and foliar leptine lines with Bt-cry5 had reduced feeding compared to non-transgenic cultivars. Glandular trichome lines and glandular trichome lines with Bt-cry5 did not reduce feeding in this no-choice feeding study. Some Bt-cry5 transgenic lines, using either the constitutive promoters CaMV35s or (ocs)3mas (Gelvin super promoter), were moderately effective in reducing larval feeding. Feeding on Bt-cry5 transgenic lines with the tuber-specific patatin promoter was not significantly different than or greater than feeding on the susceptible cultivars. Mortality of first instars was highest when fed on the Bt-cry3A lines (68% to 70%) and intermediate (38%) on the Bt-cry5 `Spunta' line SPG3 where the gus reporter gene was not included in the gene construct. Host plant resistance from foliar leptines is a candidate mechanism to pyramid with either Bt-cry3A or Bt-cry5 expression in potato foliage against Colorado potato beetle. Without multiple sources of host plant resistance, long-term sustainability is questionable for a highly adaptable insect like the Colorado potato beetle.


1977 ◽  
Vol 64 (6) ◽  
pp. 341-341 ◽  
Author(s):  
A. C. Waiss ◽  
B. G. Chan ◽  
C. A. Elliger ◽  
V. H. Garrett ◽  
E. C. Carlson ◽  
...  

2005 ◽  
Vol 130 (6) ◽  
pp. 857-864 ◽  
Author(s):  
Joseph J. Coombs ◽  
David S. Douches ◽  
Susannah G. Cooper ◽  
Edward J. Grafius ◽  
Walter L. Pett ◽  
...  

Colorado potato beetle (Leptinotarsa decemlineata Say) is the leading insect pest of potato (Solanum tuberosum L.) in northern latitudes. Host plant resistance is an important tool in an integrated pest management program for controlling insect pests. Field studies were conducted to compare natural host plant resistance mechanisms (glandular trichomes and Solanum chacoense Bitter-derived resistance), engineered [Bacillus thuringiensis (Bt) Berliner Bt-cry3A], and combined (glandular trichomes + Bt-cry3A and S. chacoense-derived resistance + Bt-cry3A transgenic potato lines) sources of resistance for control of colorado potato beetle. Six different potato clones representing five different host plant resistance mechanisms were evaluated for 2 years in a field situation under natural colorado potato beetle pressure in Michigan and New York, and in a no-choice field cage study in Michigan. In the field studies, the S. chacoense-derived resistance line, Bt-cry3A transgenic, and combined resistance lines were effective in controlling defoliation by colorado potato beetle adults and larvae. Effectively no feeding was observed in the Bt-cry3A transgenic lines. The glandular trichome line suffered less defoliation than the susceptible control, but had greater defoliation than the Bt-cry3A transgenic lines and the S. chacoense-derived resistance line. In the no-choice cage study, the Bt-cry3A transgenic lines and the combined resistance lines were effective in controlling feeding by colorado potato beetle adults and larvae with no defoliation observed. The S. chacoense-derived resistance line and the glandular trichome line suffered less defoliation than the susceptible control. Based on the results of the field trials and no-choice field cage studies, these host plant resistance mechanisms could be used to develop potato varieties for use in a resistance management program for control of colorado potato beetle.


1988 ◽  
Vol 68 (2) ◽  
pp. 439-447 ◽  
Author(s):  
A. W. LENSSEN ◽  
E. L. SORENSEN ◽  
G. L. POSLER ◽  
L. H. HARBERS

Host-plant resistance in alfalfa (Medicago sativa L.) is insufficient for control of the alfalfa weevil (Hypera postica) or the potato leafhopper (Empoasca fabae), two of the most important insect pests of alfalfa. Some wild Medicago species, which have erect glandular hairs, possess adequate host-plant resistance for control of both pests. We established a field trial (Wymore silty clay loam) in 1985 to determine the effects of erect glandular hairs on forage quality of several perennial Medicago species. Glandular and eglandular (without erect glandular hairs) plant populations were selected from the diploids, M. prostrata Jacq. and M. glandulosa David, and the tetraploids, M. glutinosa Bieb., M. sativa × M. glutinosa, and M. sativa × M. prostrata. Eglandular M. sativa ’Riley’ and M. sativa subsp. caerulea (Less, ex Ledeb.) Schmalh. were included as controls. Foliar diseases and insects were controlled. Leaves and stems were separated for three harvests in 1985 and one in 1986. The presence of erect glandular hairs did not significantly affect concentrations of neutral or acid detergent fibers, hemicellulose, lignin, or cellulose of leaves or stems within the species or hybrids tested. Neutral and acid detergent fibers and cellulose concentrations were generally lower in stems and higher in leaves of diploids than in corresponding parts of the tetraploid alfalfa cultivar Riley.Key words: Alfalfa, Medicago sp., glandular hairs, forage quality


2008 ◽  
Vol 48 (12) ◽  
pp. 1543 ◽  
Author(s):  
H. Gu ◽  
O. R. Edwards ◽  
A. T. Hardy ◽  
G. P. Fitt

An integrated pest management (IPM) approach that relies on an array of tactics is adopted commonly in response to problems with pesticide-based production in many agricultural systems. Host plant resistance is often used as a fundamental component of an IPM system because of the generally compatible, complementary role that pest-resistant crops play with other tactics. Recent research and development in the resistance of legumes and cereals to aphids, sorghum midge resistance, and the resistance of canola varieties to mite and insect pests have shown the prospects of host plant resistance for developing IPM strategies against invertebrate pests in Australian grain crops. Furthermore, continuing advances in biotechnology provide the opportunity of using transgenic plants to enhance host plant resistance in grains.


2013 ◽  
Vol 34 (3) ◽  
pp. 176 ◽  
Author(s):  
R.P. Soundararajan ◽  
N. Chitra ◽  
S. Geetha

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