|
" Evaluation of oilseed brassicas for resistance to the turnip aphid, Lipaphis erysimi (Kalt.) "
M. Amjad
D. C. Peters
| Document Type
|
:
|
Latin Dissertation
|
| Language of Document
|
:
|
English
|
| Record Number
|
:
|
1112639
|
| Doc. No
|
:
|
TLpq303953186
|
| Main Entry
|
:
|
D. C. Peters
|
|
|
:
|
M. Amjad
|
| Title & Author
|
:
|
Evaluation of oilseed brassicas for resistance to the turnip aphid, Lipaphis erysimi (Kalt.)\ M. AmjadD. C. Peters
|
| College
|
:
|
Oklahoma State University
|
| Date
|
:
|
1991
|
| student score
|
:
|
1991
|
| Degree
|
:
|
Ph.D.
|
| Page No
|
:
|
129
|
| Abstract
|
:
|
Scope and method of study. The objective of this study was to find some sources of resistance to turnip aphids in the oilseed brassicas. I screened 230 entries in the laboratory and 166 entries in the field at the National Agriculture Research Center, Islamabad, Pakistan. Forty-nine entries were selected on the basis of laboratory as well as field screening and were further tested against Oklahoma turnip aphids at Oklahoma State University. Fecundity, survival rate, days to maturity and intrinsic rate of increase (rm) were studied on the most promising entries. The feeding behavior of turnip aphids was recorded by an electronic feeding monitor on 10 promising entries. Findings and conclusions. In laboratory screening, there were about 57 entries that were not significantly more damaged than a resistant standard (K-841, Eurica sativa) and had a mean damage rating less than 4.0 after 3 weeks of infestation. Cluster analysis combining the 3 weekly damage and growth rating was used to assist in selecting entries for further testing. In field evaluations, there were 62 entries not significantly different from a resistant standard. The mean damage rating for these entries ranged from 1.3 to 4.0. Entries in preflowering stages may have escaped the most intensive infestation. Entries of Eruca sativa appeared generally tolerant in the field screening. In further testing at Oklahoma State University, only 12 entries were selected. Among these 12 entries, 11 entries were B. junea which generally had been damaged in the field at reproduction stage except for UCD-8/11. UCD-310/3 (B. carinata) had low damage ratings in all tests in laboratory as well as in the field. Fecundity of turnip aphids was significantly lower for UCD-310/3 and K-841, whereas survival of nymphs was low on UCD-12/4, UCD-6/13 and K-841. Days to maturity were longer for UCD-310/3, K-841, UCD-6/24 and UCD-12/4. The rm value calculated from all three parameters was lowest on UCD-310/3 and K-841. The increase in aphid numbers in 10 days from an infestation of 10 aphids/plant was also significantly lowest in K-841 and UCD-310/3 compared to Toria-A. In feeding behavior studies, there were not significant differences among entries in behavior such as baseline, probing and non-phloem ingestion, for frequency, mean duration and total duration, but turnip aphids spent significantly more time in phloem ingestion on the susceptible Toria-A, than on the other entries. It is concluded from this study that UCD-310/3 (B. carinata) and K-841 (E. sativa) have the best levels of resistance against turnip aphids.
|
| Subject
|
:
|
Agronomy
|
|
|
:
|
Biological sciences
|
|
|
:
|
Entomology
|
|
|
:
|
Entomology
|
| |