Not surprisingly, de novo mutations are quite rare in the real world – but even rare things can happen if the population is large enough. When it comes to the evolution of herbicide resistance, there are two biological pathways. The first is simply natural selection where a small number of the population can withstand a particular stress (e.g. herbicide), they set seed and eventually their progeny are the majority, and they generally thrive. Resistant alleles may prolificate at the site of selection (i.e. due to frequent and regular use of a particular herbicide at that site) or they might be…
Tag Archives | mechanisms
We all put things in boxes inside our head to help us organise our brain. A few of the important boxes I have inside my head – fishing spots, great moments in sport, top five meals of all time, jokes, song lyrics, useless trivia, movie quotes, WA town license plates, and of course the nothing box (the place every man retreats to when he has five minutes of peace and quiet!). Ok, it’s not an over-achieving brain but it gets me by. However, sometimes something new will come along and it won’t fit into your existing boxes. It might need…
The first resistance to HPPD herbicides in wild radish has now been discovered by AHRI researchers led by PhD candidate Huan Lu. Wild radish is just the third weed in the world to evolve resistance to this group of herbicides. The wild radish in this research was resistant to several other groups of herbicides which may have led to metabolic resistance to HPPD.
Merv Hughes was not a fit-looking cricketer. Merv was a notorious consumer of food and alcohol, and it showed! Despite this, he was a successful professional sportsman. Mitchell Johnson, on the other hand, was the epitome of a fit, healthy fast bowler. But who had the better bowling average? You guessed it, big swervin’ Mervin!! 28.38 compared to Johnson’s 28.4. Ok, we’re splitting hairs here, but you get the picture, how fit you look is only part of the story. If you grew 2,4-D resistant radish in pots on its own, and compared that to the good old susceptible radish…
Wine casks, plastic banknotes, WiFi, the refrigerator, lawnmower and the humble ute (pickup truck) are all Australian, world-first inventions. Which of these makes the biggest difference in your life? As long as it’s not the wine cask you’re doing just fine! We now have a world first in herbicide resistance. research by visiting Chinese researcher to AHRI, Dr Pan Lang under the watchful eye of Qin Yu, concluded that they were looking at the world’s first case of metabolism-based resistance to glyphosate. The culprit? Click through to find out!
This AHRI Insight is a follow-up on an earlier article ‘Crops are doin’ it for themselves’ to where we investigated the complex interactions of competitive crops and their weed suppression powers. While that paper focused on cereals, in this one we will consider the mechanisms at play in canola, a crop from the mustard family, long known for its allelopathic ability and yet the exact mechanisms are still shrouded in mystery.
Huan Lu’s been investigating a population of wild radish that has the infamous Ser-264-gly mutation. This is the target-site mutation that is behind TT canola and makes wild radish highly resistant to PSII-inhibiting herbicides like atrazine and, to a lesser extent, metribuzin. But, he wondered if there was more to this resistance than first meets the eye. Does focusing on the strong 264 mutation mean that we could fail to identify other important resistance mechanisms?
We answer a few poignant questions in this insight, including: ‘Can crops do more of the heavy lifting when it comes to weed control than modern farming methods have allowed them?’ or ‘Have we tried so hard to protect crops from weeds that we have forgotten that they have innate mechanisms to ‘stand on their own two feet’ and ‘do it for themselves’?’ A series of important studies into the practical implications of harnessing the crop’s ability to defend itself against weeds are starting to produce important results, leading to improvements in farming practice and the development of new cultivars.
Roberto recently completed a project with GRDC investment where he sampled ryegrass from 17 paddocks across eight farms in Western Australia to see if there are benefits of proactively testing for herbicide resistance. Across these tests, he found ryegrass that was resistant to Clethodim (Select) or Butroxydim (Factor) but no ryegrass that was resistant to the mix of the two. The same went for the pre-emergent herbicides as well, no resistance to mixes.
We once thought that the genetics of eye colour was simple. Both parents have blue eyes, therefore, all of their children will have blue eyes. Easy peasy! Then science progressed and we realised that it isn’t actually that simple because several genes are involved. The genetics of herbicide resistance was simple. One parent is resistant to a herbicide, therefore, all of the offspring will be resistant because the gene is dominant or semi-dominant. This is true for almost all cases of herbicide resistance and was easy to understand. Until now. Click to read more about PhD student Jinyi Chen’s research.