The pea weevil (Bruchus pisorum L.) is the most significant pest of field pea (Pisum sativum L.) in Australia. The only available means for controlling pea weevil at the present time is with chemical pesticides. The aim of this study was to introgress natural pea weevil resistance, derived from the wild pea species, Pisum fulvum Sibth. & Sm. into cultivated field pea and devise strategies for screening for the resistance with breeding applications. Traditional breeding methods were used to transfer pea weevil resistance from P. fulvum accession ‘ATC113’ to cultivated field pea, cv. ‘Pennant’. Progeny derived from this population were examined for inheritance of pod and seed resistance. Seed resistance in F2 plants segregated in a ratio of 1:37:26 (resistant: mixed response: susceptible), indicating a trigenic mode of inheritance (1:63), with at least three major recessive genes controlling pea weevil resistance. Seed resistance was conserved over consecutive generations (F2 to F5) and was successfully transferred to populations crossed with a second adapted field pea variety‘Helena’. Pod resistance presented as a quantitative trait in the F2 population, but this resistance was not retained in subsequent generations. Amplified fragment length polymorphisms (AFLPs) were sought in the parents and in resistant and susceptible F3 plants. Restricted maximum likelihood (REML) analysis was used to identify 13 AFLP markers with a statistically significant association with pea weevil resistance and 23 with pea weevil susceptibility. Principal coordinate analysis (PCO) showed that the AFLP marker loci formed clusters in the PCO space, which could indicate the three proposed gene locations. Eight AFLP markers were cloned, sequenced and converted to sequence characterised amplified regions (SCAR). Two SCAR markers, SC47359 and SC47435 were polymorphic between the resistant and susceptible parents. Both markers co-segregated with the resistant lines and with 30-36% of susceptible lines. Plants which did not possess either band were highly susceptible. The other PCR products were either monomorphic between the resistant and susceptible parents or produced more than one band product. A range of phenotypic traits was measured in the F2 population derived from the hybridisation between P. fulvum and P. sativum and associations with pea weevil resistance were made. In the F2 population, pea weevil resistance was not correlated with any of the negative traits originating from the wild parent, such as increased basal branching, dark seed coat or small seed size, neither was resistance correlated with flower colour, flowering time or seeds per pod. Pea weevil resistance should therefore be transferable with minimal linkage drag. A convenient morphological marker, such as flower or seed colour was not identified in this study based on these results. Using principal component analysis (PCA) as a visual tool, resistant and semi-resistant plants in the F3 and ‘backcross’ introgression populations were identified with improved trait performance compared with the wild parent
| Identifer | oai:union.ndltd.org:ADTP/221165 |
| Date | January 2005 |
| Creators | Byrne, Oonagh Marie Therese |
| Publisher | University of Western Australia |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Oonagh Marie Therese byrne, http://www.itpo.uwa.edu.au/UWA-Computer-And-Software-Use-Regulations.html |
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