65
Witbasterpakketviroptimaleopbrengste
engoeie risikobestuur.
Konvensionele,stronkboorder-weerstandbiedende,
glifosaat-toleranteenstapelgeenbasters.
®Geregistreerde handelsmerke vanPANNARBPK, © 2014PANNARBPK
2014/MAIZE/A/01A
Wêreldklas-
navorsingvir ’n
vooruit-
strewende
boerdery.
GLOBALE TEGNOLOGIE
PLAASLIKE PRESTASIE
Saam boer ons
vir die toekoms
™
MUTATION
MARKER
SENSITIVE
HETEROZYGOUS
RESISTANT
HOMOZYGOUS
RESISTANT
TOTALSAMPLES
TESTED
ALS122
63
0
0
63
ALS197
20
4
39
63
ALS205
51
12
0
63
ALS574
56
7
0
63
ALS653
60
1
2
63
Total
250
24
41
315
costs will also be finalised this year. Care should be taken to make
sure that the bulked samples are taken frommultiple plants over the
entireproblematic field, so as toobtain a true resistanceprofileof that
field. Seedlings must be kept moist and preferably couriered (at the
producers cost) as soon as possible, to insure that fresh leaf material
arrives inBethlehem.
Please indicate the GPS co-ordinates where the sample was taken as
well as field/farm names. Seeds must be stored in brown paper bags
to prevent microbial contamination. GPS co-ordinates and field/farm
namesmust againbe indicated.
Note: An adequate number of seeds/seedlingsmust be submitted for
the screening process to be conducted successfully. It is important
to resample ryegrass seed at the indicated GPS co-ordinates when
seed have matured, in order to screen the seed with the glasshouse
procedure to determine the possible presence of other resistance
mechanisms.
Please courier samples to:
HestiaNienaber/Scott Sydenham
ARC-Small Grain Institute
BlydskapRoad, S191
Bethlehem
9700
Summary
From data obtained from the screening, it is evident that target site
resistance toALS inhibitor herbicides is common. Themost frequently
observed target site mutation was for ALSmarker 197 in all samples
tested.
This confers a broad cross-resistance in varying levels to all ALS
herbicides. However, by knowing which mutations are occurring in a
specificweedpopulation,a trueresistanceprofilecanbeestablished for
target site resistant biotypes, allowing formore informedmanagement
choices. Themethod of molecular screening can thus be included as
another tool in resistancemanagement.
For further information regarding this topic or how to
sample your weeds, please contact Hestia Nienaber
at 058 307 3420 or email:
or
TABLE 1: PRESENCEOFALS TARGETSITEMUTATIONS 122, 197, 205,
574AND 653 INALL SAMPLES TESTED.
Figure 1: Agarose gel photo of ALSMarker 197 (red – homozygous resistant,
yellow – heterozygous resistant andblue – homozygous sensitivewild type).
