Mahima Krishnan

Mahima Krishnan

School of Agriculture, Food and Wine

Faculty of Sciences, Engineering and Technology

Eligible to supervise Masters and PhD - email supervisor to discuss availability.

Mahima is a postdoctoral fellow with the Weed Science Research Group at The University of Adelaide. She completed her PhD in the study of salt tolerance in various cereal crops. As a postdoctoral fellow, she has focused her efforts in understanding the mechanisms that drive herbicide resistance in various weeds. Her research has included studying resistance to glyphosate (Group 9), ACC'ase inhibitors (Group 1), ALS inhibitors (Group 2), paraquat (Group 22) and tri-allate (Group 15) in various weed species. Her current research focus is on understanding the evolutionary dynamics of summer weed resistance to pre-emergent herbicides mesotrione (Group 27), S-metolachlor (Group 15), saflufenacil+trifludimoxazin (Group 14) and genetic characterisation of 2,4-D (Group 4) herbicide resistance in common sow thistle, wild radish, Indian hedge mustard, winged slender thistle, capeweed and wild turnip.

Brome grass in a field of wheat

Weeds are an important yield determinant of agriculture and, in Australia, cause annual losses in the vicinity of $5 billion AUD. Herbicides account for most, if not all, of a farmer’s chemical control budget in cropping systems and are therefore a critical tool for broadacre farming. Such strong dependence on herbicides has inevitably given rise to herbicide resistance in various weed species. Understanding how these instances of resistance arise and the mechanisms by which they cause resistance is key for the identification of alternative weed management strategies. My research looks into the mechanisms which give rise to herbicide resistance in weeds and how the resistance can be mitigated.

Year Topic
2015-2018 Mechanisms, evolution and inheritance of herbicide resistance
2018-2020 Understanding resistance to 2,4-D in common sowthistle and opportunities for improving 2,4-D activity on resistant populations
2020-2025 Target-site resistance to 2,4-D or other group I/4 herbicides in winter and summer weed species
2020-2025 Assessment of phenotypic variation in glyphosate resistant populations of feathertop Rhodes grass and awnless barnyard grass in response to the K herbicide S-metolachlor (Group K/15) and saflufenacil + trifludimoxazin (Group G/14)
2025-2030 Dynamics of weed adaptation to management strategies, including the evolution and inheritance of herbicide resistance
2025-2030 Molecular, Biochemical and genetic mechanisms of novel herbicide resistance
2025-2030 Mitigating the impact and development of herbicide resistance

Email me directly if you are interested in pursuing Honours, Masters by research or a PhD project in herbicide resistance and/or weed management. 

More information

  • Appointments
    Date Position Institution name
    2015 - ongoing Postdoctoral Fellow The University of Adelaide

  • Language Competencies
    Language Competency
    English Can read, write, speak, understand spoken and peer review
    Hindi Can speak and understand spoken
    Kannada Can speak and understand spoken
    Malayalam Can speak and understand spoken
    Tamil Can read, write, speak, understand spoken and peer review

  • Education
    Date Institution name Country Title
    The University of Adelaide Australia B.Sc. Molecular Biology
    Charles Darwin University Australia B.Sc. Honours
    The University of Adelaide Australia PhD

  • Journals
    Year Citation
    2025 Krishnan, M., Petrovic, T., Schwerdt, J. G., Merriam, A. B., Hereward, J. P., & Preston, C. (2025). A novel mutation in SoIAA20 confers cross-resistance to 2,4-Dichlorophenoxyacetic acid and other auxinic herbicides in Sonchus oleraceus. Pest Management Science, 81(1), 141-148.
    DOI Scopus6 Europe PMC4
    2025 Qi, Y., Krishnan, M., Tucker, M., & Preston, C. (2025). A point mutation in <scp><i>IAA34</i></scp> confers resistance to the auxin herbicide 2,4‐D in <scp><i>Sisymbrium orientale</i></scp>. Pest Management Science, 81(7), 3523-3531.
    DOI Scopus2 Europe PMC1
    2025 Qi, Y., Krishnan, M., Tucker, M., Boutsalis, P., & Preston, C. (2025). An 18 base pair in-frame deletion in the degron tail of IAA2 provides resistance to 2,4-D and dicamba in Brassica tournefortii. Pesticide Biochemistry and Physiology, 213, 6 pages.
    DOI
    2025 Qi, Y., Krishnan, M., Tucker, M., Boutsalis, P., & Preston, C. (2025). A deletion upstream of the degron of AcIAA27 leads to auxinic herbicide resistance in Arctotheca calendula. Pest Management Science, 8 pages.
    DOI
    2019 Nguyen, H., Malone, J., Krishnan, M., Boutsalis, P., & Preston, C. (2019). Inheritance of glyphosate resistance in Echinochloa colona from Australia. Journal of Research in Weed Science, 2(4), 310-331.
    DOI
    2018 Dang, H., Malone, J., Boutsalis, P., Krishnan, M., Gill, G., & Preston, C. (2018). Reduced translocation in 2,4-D-resistant oriental mustard populations (Sisymbrium orientale L.) from Australia. Pest management science, 74(6), 1524-1532.
    DOI Scopus30 WoS20 Europe PMC16
    2017 Ngo, T. D., Krishnan, M., Boutsalis, P., Gill, G., & Preston, C. (2017). Target-site mutations conferring resistance to glyphosate in feathertop Rhodes grass (Chloris virgata) populations in Australia. Pest Management Science, 74(5), 1094-1100.
    DOI Scopus46 WoS38 Europe PMC21
    2014 Byrt, C., Xu, B., Krishnan, M., Lightfoot, D., Athman, A., Jacobs, A., . . . Gilliham, M. (2014). The Na⁺ transporter, TaHKT1;5-D, limits shoot Na⁺ accumulation in bread wheat. The Plant Journal, 80(3), 516-526.
    DOI Scopus190 WoS140 Europe PMC104
    2007 Alvarez, B., Krishnan, M., & Gibb, K. (2007). Analysis of intragenomic variation of the rDNA internal transcribed spacers (ITS) in Halichondrida (Porifera: Demospongiae). Journal of the Marine Biological Association of the United Kingdom, 87(6), 1599-1605.
    DOI Scopus15

  • Book Chapters
    Year Citation
    - Korres, N. E., Burgos, N. R., & Duke, S. O. (n.d.). Weed Control. In N. E. Korres, N. R. Burgos, & S. O. Duke (Eds.). CRC Press.
    DOI

  • Conference Papers
    Year Citation
    2018 Preston, C., Brunton, D., Merriam, A., Dang, H., Ngo, T., Boutsalis, P., . . . Gill, G. (2018). Herbicide and weed management - latest research. In GRC Updates Papers. Australia.

  • Conference Items
    Year Citation
    2018 Krishnan, M., Petrovic, T., Valappan, G., Merriam, A., & Preston, C. (2018). Understanding the mechanism of 2,4-D resistance in Sonchus oleraceus (Common sowthistle). Poster session presented at the meeting of Weed Biosecurity - Protecting Our Future. Sydney.
    2016 Krishnan, M., Nguyen, T. H., Malone, J., Morran, S., Boutsalis, P., & Preston, C. (2016). Mechanisms and inheritance of glyphosate resistance in Echinochloa colona from Australia. Poster session presented at the meeting of Weed Science Society of America’s Annual Meeting.
    2016 Krishnan, M., Boutsalis, P., & Preston, C. (2016). Understanding the mechanisms of triallate resistance in annual ryegrass. Poster session presented at the meeting of 20th Australasian Weeds Conference.
    2015 Krishnan, M., & Preston, C. (2015). New developments in herbicide resistance in Australia. Poster session presented at the meeting of The 3rd Australian Agrichemical Resistance Meeting.
Year Project Team Amount Grant Role
2015-2020 Protecting your crop: Mechanisms, evolution and inheritance of resistance C Preston, J Malone, M Krishnan, F Dolman $1,498,727 GRDC- Cat 1 Partner investigator
2020-2025 Australian Herbicide Resistance Initiative- Phase 6 M Krishnan, C Preston $720,827 GRDC- Cat 1 Chief investigator
2024 Is the 2,4-D resistance caused by a novel mutation in IAA34 in Sisymbrium orientale a result of reduced herbicide translocation in resistant biotypes? M Krishnan $4,800 Charlick Endowment Fund- internal Chief investigator
2025-2030 UOA Weed Management Initiative C Preston, G Gill, J Malone, M Krishnan N Aggarwal $6,700,000 GRDC- Cat 1 Chief investigator

Bachelor of Agricultural Sciences and the Bachelor of Viticulture and Oenology

Courses:

  • Foundations in Plants Science II
  • Plant Health III
  • Research Skills for Applied Biology II

  • Committee Memberships
    Date Role Committee Institution Country
    2024 - ongoing Representative Gender, Equity, Diversity and Inclusivity University of Adelaide Australia

  • Memberships
    Date Role Membership Country
    2022 - ongoing Member WMSSA Australia
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