ï§ This study was undertaken to transfer resistance against Acanthoscelides obtectus
into South African dry bean cultivars; to select breeding lines with increased
resistance against A. obtectus through bioassay with adult insects of the species;
to develop a recombinant inbred line population, which could be used in future
research for near infrared spectroscopy or any other technique; to test the yield
ability, resistance against A. obtectus, seed size and colour of the developed
breeding lines (progeny) and comparing it to that of the susceptible commercial
parents and arcelin donor parent in the breeding scheme and to identify backcross
progeny lines equal or better in all characteristics than the commercial parents.
ï§ Crosses were made between six commercial and semi-commercial South African
dry bean cultivars (recurrent parents) and the SMARC4-PN1 breeding line
(arcelin donor parent). Parental characteristics were recovered in a backcross
breeding programme. Bioassays were conducted with adult A. obtectus insects to
identify resistant backcross progeny lines. The most resistant backcross progeny
lines were selected for evaluation in a yield trial, and bioassay, against the
commercial parents. A population of 95 F6 RI lines was developed from which
the 10 most resistant and 10 most susceptible (as determined through a bioassay
with adult insects of the species A. obtectus) were selected.
ï§ A replicated yield trial was conducted and one RI line (BRUX1100-2) was shown
to have significantly higher yield ability than the commercial parents. A replicated
bruchid emergence test was conducted where one RI line (BRUX1100-2) was
shown to have significantly higher bruchid resistance than the arcelin donor parent. The seed size evaluation showed that ten backcross progeny lines had
significantly smaller seed size than the commercial parents and seven backcross
progeny lines had seed colour that could be compared to that of the commercial
parents.
ï§ The combination of all the important parental traits along with good bruchid
resistance was not attained in any single backcross progeny line with only two
backcrosses. Another one or possibly two cycles of backcrossing would be
necessary for the further recovery all of these characteristics.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-10172011-155037 |
| Date | 17 October 2011 |
| Creators | Beneke, Casper Johannes |
| Contributors | Dr JA Jarvie, Prof S vdM Louw, Prof MT Labuschagne |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-10172011-155037/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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