A systematic study of Fusarium crown rot resistance in hexaploid wheat

Zhi Zheng

    Research output: ThesisDoctoral Thesis

    263 Downloads (Pure)

    Abstract

    Fusarium crown rot (FCR) has become more prevalent in semi-arid regions worldwide. Efficient breeding of resistant cultivars requires quality resources and deep understanding of the genetics of resistance. Most of the QTL identified from previous studies were inconsistent with minor effects. However, one major QTL on 3BL explaining up to 49% of the phenotypic variance was identified. While this QTL deserves more research, other QTL need to be identified.
    For QTL identification and other experiments on FCR resistance, segregating 'pure lines' populations are required to produce reliable and reproducible phenotypic data. However, it usually takes a long time to obtain such materials. In the first part of this project, a procedure which allows eight generations of wheat and nine generations of barely per annum was developed by combining embryo culture with managements of watering regimes, lighting intensity and duration, temperature and quantity of potting mixture. This method could significantly accelerate projects of plant breeding and biological studies.
    Following the developed procedure, three populations of recombinant inbred lines (RILs) were developed and advanced to characterize one of the most FCR resistant commercial varieties EGA Wylie in bread wheat. Four QTL were detected and all of them were derived from the resistant parent EGA Wylie. One of these loci was located on the chromosome arm 5DS and explained up to 31.1% of the phenotypic variance. The second locus was detected on the chromosome arm 2DL and explained up to 20.2% of the phenotypic variance. Significant effects of these two QTL were further validated in other two different genetic backgrounds. Another two QTL were located on the chromosome 4BS. However, neither of these two QTL was significant in a co-factor analysis. The
    Original languageEnglish
    QualificationDoctorate
    Publication statusUnpublished - Jan 2015

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