| impact of combining planting date and chemical control to reduce larval densities of stem-infesting pests of sunflower in the central plains. | the guild of stem-infesting insect pests of sunflower, helianthus annuus l., within the central plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, cylindrocopturus adspersus (leconte) (coleoptera: curculionidae), and dectes texanus texanus leconte (coleoptera: cerambycidae). the incidence of a root boring moth, pelochrista womonana (kearfott) (lepidoptera: tortricidae), also has increased. experiments were conducted in three locations i ... | 2007 | 17849877 |
| natural variation in gene expression between wild and weedy populations of helianthus annuus. | the molecular genetic changes underlying the transformation of wild plants into agricultural weeds are poorly understood. here we use a sunflower cdna microarray to detect variation in gene expression between two wild (non-weedy) helianthus annuus populations from utah and kansas and four weedy h. annuus populations collected from agricultural fields in utah, kansas, indiana, and california. when grown in a common growth chamber environment, populations differed substantially in their gene expre ... | 2008 | 18689879 |
| selective sweeps reveal candidate genes for adaptation to drought and salt tolerance in common sunflower, helianthus annuus. | here we report the results of an analysis of variation at 128 est-based microsatellites in wild helianthus annuus, using populations from the species' typical plains habitat in kansas and colorado, as well as two arid desert and two distinct brackish marsh areas in utah. the test statistics lnrv and lnrh were used to find regions of the genome that were significantly less variable in one population relative to the others and thus are likely to contain genes under selection. a small but detectabl ... | 2007 | 17237516 |
| impact of irrigation on larval density of stem-infesting pests of cultivated sunflower in kansas. | the guild of stem-infesting insect pests of cultivated sunflower, helianthus annuus l., within the central plains is a concern to producers, chiefly due to losses caused by plant lodging from the sunflower stem weevil, cylindrocopturus adspersus (leconte) (coleoptera: curculionidae), and dectes texanus texanus leconte (coleoptera: cerambycidae). the incidence of a root boring moth, pelochrista womonana (kearfott) (lepidoptera: tortricidae), also has increased. experiments were conducted in kansa ... | 2007 | 17972632 |