Browsing by Author "Piperidis, N"

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Developing cytogenetic and molecular tools to improve selection for soil-borne pathogen resistance in wild hybrids : final report 2013/358
(Sugar Research Australia Limited, 2017) Piperidis, N
In Australia, sugarcane has been grown for more than 100 years now as a monoculture without much fallow cropping. Consequently, the heavily cultivated areas had no chance to reduce the levels of soil-borne pathogens. Soil health is a major concern for the Australian sugar industry.
Enhancing the Plant breeding outcomes of sugarcane cytogenetic techniques : SRDC final report BSS339
(2011) Piperidis, N
The first part of this project was to attend the annual Plant and Animal Genome XIX (PAG) conference held in San Diego, USA, from January 14-19, 2011, and to present a paper at the associated International Consortium of Sugarcane Biotechnology (ICSB) workshop. The second part of this project was a study visit to the laboratory of Dr Bernd Friebe at the Wheat Genetic and Genomic Resources Centre (WGGRC) in Kansas.
Exploiting Erianthus diversity to enhance sugarcane cultivars : ASSCT peer-reviewed paper
(ASSCT, 2019) Piperidis, N; Tom, C; Aitken, KS; Atkin, FC; Piperidis, G
Introgression of Erianthus arundinaceus into the SRA sugarcane-breeding program has been a goal for researchers for many years. The Erianthus genome was finally accessible to sugarcane breeders with the identification in 2005 of the first Saccharum/Erianthus fertile hybrids, developed in China. Today, Saccharum/Erianthus BC3 and BC4 clones are available in Australia, and Erianthus-sugarcane hybrids have been characterised by cytogenetics and investigated for their potential resistance against pachymetra root rot, sugarcane smut and nematodes. Some clones have shown potential as new sources of resistance for incorporation into the SRA breeding program. These hybrids were created from Erianthus clones indigenous to China and their reaction to the above diseases is unknown in Australian conditions. In Meringa we also have access to many Erianthus clones of Indonesian origin. Some of these Erianthus clones have previously shown immunity to pachymetra root rot. In the late 1990s, these Indonesian Erianthus clones were used in crossing but no fertile hybrids were ever produced due to an incompatibility between the Saccharum and the Erianthus genomes. We revisited this untapped source of resistance by utilising the fertile Erianthus hybrids derived from China to cross with the Indonesian Erianthus of known resistance to pachymetra root rot. Here we report on the early stage results of introgressing Indonesian Erianthus into the SRA breeding program.
Genomic organisation of sugarcane cultivars revealed by chromosome-specific oligonucleotide probes : ASSCT peer-reviewed paper
(ASSCT, 2021) Piperidis, N; Piperidis, G; D’Hont, A
Sugarcane (Saccharum spp.) is probably the crop with the most complex genome. Modern cultivars (2n=100-120) are derived from interspecific hybridization between the noble cane S. officinarum (2n=80) and the wild cane S. spontaneum (2n=40-128). We investigated the genome organization of important sugarcane cultivars and their parental species using chromosomespecific probes combined with genomic in situ hybridization (GISH). This allowed the genomic and genetic characterisation of Australian sugarcane cultivars and one of the major contributing parental clones, Mandalay. The S. spontaneum clone Mandalay follows the classical organization of S. spontaneum clones with x=8 with a major discrepancy related to an extra six chromosomes compared to the previously reported 2n=96 for Mandalay’s clone. Our previous results reported the rearrangements between the S. officinarum (x=10) and S. spontaneum (x=8) chromosomes, with a most likely scenario of a two-step process leading to x= 9 and then x=8, where each step involved three chromosomes that were rearranged into two. Further polyploidization led to the wide geographical dispersion of S. spontaneum clones with x= 8. In modern cultivars, the 13-20% of the S. spontaneum contribution originated from cytotypes with x=8. Modern cultivars have mainly 12 copies of each of the first four basic chromosomes and a more variable number for those basic chromosomes whose structure differs between the two parental species. These new insights and cytogenetic tools substantially improve our understanding of the extreme level of complexity of modern sugarcane cultivar genomes and could lead to guiding breeding strategies in the development of new improved varieties for the Australian industry.