Publications by authors named "Jenna M Malone"
Article Synopsis
- Two polyploid grass weeds in Australia, Hordeum glaucum and Bromus diandrus, have developed resistance to glyphosate through the amplification of the EPSPS gene, which is crucial for their survival.
- Research involved analyzing the EPSPS gene's genomic structure using molecular cytogenetic methods, showing that resistant plants have significantly more copies of the gene compared to susceptible ones.
- The findings suggest that unequal crossover during meiosis may be responsible for the gene duplication, contributing to the evolution of glyphosate resistance in these weed species.
Article Synopsis
- - Weeds are valuable for research because they affect agriculture and can quickly adapt to changes caused by human activities.
- - A shortage of genomic data limits the understanding of how weeds rapidly adapt, especially regarding traits like resistance to herbicides and stress tolerance.
- - The International Weed Genomics Consortium aims to create genomic resources that enhance weed control research and support crop breeding by providing insights into adaptation and stress tolerance.
Background: Control of prickly lettuce has become increasingly difficult for lentil growers in southern Australia because of widespread resistance to common herbicides, a lack of alternative herbicide options and the prolific production of highly mobile seed. This study aimed to quantify acetolactate synthase (ALS)-inhibiting herbicide resistance in the Mid North (MN) and Yorke Peninsula (YP) of South Australia, characterize the resistance mutations present and investigate population structure and gene flow in this species.
Results: Resistance was identified in all populations tested, with average survival of 92% to chlorsulfuron and 95% to imazamox + imazapyr.
Article Synopsis
- The study examines herbicide resistance in annual sowthistle, a problematic weed in lentil crops in southern Australia, focusing on the Mid-North and Yorke Peninsula regions.
- ALS-inhibitor resistance is widespread and linked to various mutations in the Proline-197 region of the ALS gene, revealing complex genetic combinations and dispersal patterns across the weed populations.
- The findings highlight the need for new control strategies to combat the increasing herbicide resistance in sowthistle, aiming to minimize seed production and spread to curb resistance development.
Article Synopsis
- - The natural plant hormone indole-3-acetic acid (IAA) is crucial for plant growth, while synthetic auxin herbicides like 2,4-D mimic its effects, leading to strong plant responses.
- - A study on a weed population revealed that 2,4-D resistance is linked to a specific 27-nucleotide deletion in the Aux/IAA2 gene, which affects the binding of auxins and cosegregates with herbicide resistance.
- - The findings suggest that this genetic alteration not only explains how weeds develop resistance to synthetic auxins but also offers a potential method for creating genetically modified crops that are resistant to these herbicides through gene editing.
Background: Hordeum glaucum Steud. is an important grass weed species in South Australia that has evolved resistance to glyphosate. This study investigated the mode of inheritance of glyphosate resistance in this species.
View Article and Find Full Text PDFBackground: Gene amplification has been shown to provide resistance to glyphosate in several weed species, including Hordeum glaucum populations in South Australia. The stability of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene copies in resistant populations in the presence or absence of glyphosate selection has not been determined.
Results: Applying glyphosate to a cloned plant resulted in an increase in resistance and EPSPS copy number in the progeny of that plant compared to the untreated clone.
Background: Glyphosate failed to control two populations of Hordeum glaucum (northern barley grass) along a fence line and around stockyards near Arthurton on the Yorke Peninsula, South Australia after more than a decade of regular use of glyphosate. These were investigated to confirm resistance and to determine resistance mechanisms.
Results: Dose-response experiments confirmed resistance of these populations to glyphosate with resistance levels of 2.
Two mutations Leu498 and Glu425 in the PDS gene were identified as the main cause conferring resistance to diflufenican and picolinafen in two oriental mustard populations P3 and P40. As mutations are suspected to affect fitness, this study was designed to test this hypothesis using the F of two crosses P3.2 (P3♂ × S♀) and P40.
View Article and Find Full Text PDFBackground: An oriental mustard population (P40) was identified as resistant to diflufenican by screening at the field rate. As diflufenican and picolinafen both target phytoene desaturase (PDS), cross-resistance to picolinafen was suspected. The mechanism of resistance and its inheritance to diflufenican and picolinafen were investigated.
View Article and Find Full Text PDFThere have been previous calls for, and efforts focused on, realizing the power and potential of weed genomics for better understanding of weeds. Sustained advances in genome sequencing and assembly technologies now make it possible for individual research groups to generate reference genomes for multiple weed species at reasonable costs. Here, we present the outcomes from several meetings, discussions, and workshops focused on establishing an International Weed Genomics Consortium (IWGC) for a coordinated international effort in weed genomics.
View Article and Find Full Text PDFBackground: An oriental mustard population (P3) collected near Quambatook, Victoria was identified as being resistant to diflufenican by screening with the field rate (200 g a.i. ha ) of the herbicide.
View Article and Find Full Text PDFBackground: Two oriental mustard populations (P2 and P13) collected from Port Broughton, South Australia were identified as resistant to 2,4-D. The level of resistance, mechanism and the mode of inheritance for 2,4-D resistance in these populations were investigated.
Results: Populations P2 and P13 were confirmed to be resistant to 2,4-D at the field rate (600 g a.
Background: Five glyphosate-resistant populations of Chloris truncata originally collected from New South Wales were compared with one susceptible (S) population from South Australia to confirm glyphosate resistance and elucidate possible mechanisms of resistance.
Results: Based on the amounts of glyphosate required to kill 50% of treated plants (LD ), glyphosate resistance (GR) was confirmed in five populations of C. truncata (A536, A528, T27, A534 and A535.
Background: Echinochloa colona is an important summer-growing weed species in cropping regions of northern Australia that has evolved resistance to glyphosate owing to intensive use of this herbicide in summer fallow.
Results: Pot trials conducted at 20 and 30 °C on six E. colona populations showed a significant increase in the level of glyphosate resistance in resistant populations at 30 °C compared with 20 °C.
Background: Glyphosate is the most widely used herbicide in the world and has been intensively used to control B. diandrus, a problematic weed of crops and pastures in southern Australia.
Results: Resistance to glyphosate was identified in two populations of B.
Background: A population of Sisymbrium orientale from South Australia has multiple resistance to auxinic herbicides and inhibitors of acetohydroxyacid synthase (AHAS). Inheritance of resistance to 2,4-D and chlorsulfuron was studied in this population.
Results: Crosses were made between seven resistant individuals as pollen donors to seven susceptible individuals.