Agricultural weed syndrome

• Rapid growth
• Efficient use of nutrients
• Seed dormancy
• Effective seed dispersal, often more aggressive shattering
• Vavilovian mimicry including introgression of crop alleles if there are nearby crop relatives
• Herbicide resistance
• Short life cycle
• High fertility

Some of these are the opposite of domestication traits.

Insufficient information is available as to the exact contribution of mutations, particular mutation types, pre-existing genetic diversity, specific genes, and introgression to syndrome acquisition. It is also unknown whether we can discern the genetic signatures of adaptation to different weed management regimes from different times.

In some cases domestication alleles may produce weeds that are weedier than the wild parent they were derived from. For example, California wild radish is weedier and more aggressive than Raphanus raphanistrum, despite being merely a combination of R. raphanistrum and R. raphanistrum's own subspecies R. r. sativus.

Pre-existing allelic variety which suddenly became more adaptive when the cultivated environment appeared likely has contributed to the success of Amaranthus tuberculatus, A. palmeri, Lolium rigidum and Ipomoea purpurea especially their quick development of herbicide resistance.

On the other hand, novel mutations may be the source herbicide resistance in Echinochloa crus-galli and E. oryzicola, whose worldwide combined populations have developed resistance to nine modes of action.

Some weeds are themselves the descendants of crops, while some are unrelated to any cultivated species. The origins of those arising from cultivars are variously better and worse understood: Weedy Helianthus annuus is well understood as wild/cultivar hybrids, weedy Secale cereale and O. sativa as purely feral crops, Beta vulgaris weeds are highly studied although some further analysis is called for, and at the other end of the spectrum lie Sorghum halepense and weedy races of S. bicolor,{{cite web | title=Shattercane | website=Mizzou WeedID // Weed ID Guide // University of Missouri | url=http://weedid.missouri.edu/weedinfo.cfm?weed_id=315 | access-date=2021-07-08}} weedy congeners of cultivated S. bicolor with complicated interbreeding histories that have yet to be untangled. Recently ({{as of|2020|lc=yes}}) teosintes have begun invading Spain and France. DNA testing of Spanish teosinte shows it to be intermediate between Zea mays subsp. mays and Zea mays subsp. mexicana.

{{Unbulleted list citebundle

|{{cite journal | last1=Aguirre-Liguori | first1=Jonás A. | last2=Ramírez-Barahona | first2=Santiago | last3=Gaut | first3=Brandon S. | title=The evolutionary genomics of species’ responses to climate change | journal=Nature Ecology & Evolution | publisher=Nature Portfolio | volume=5 | issue=10 | date=2021-08-09 | issn=2397-334X | doi=10.1038/s41559-021-01526-9 | pages=1350–1360 | s2cid=236968585 | pmid=34373621}}

|{{cite journal | last1=Le Corre | first1=Valérie | last2=Siol | first2=Mathieu | last3=Vigouroux | first3=Yves | last4=Tenaillon | first4=Maud I. | last5=Délye | first5=Christophe | title=Adaptive introgression from maize has facilitated the establishment of teosinte as a noxious weed in Europe | journal=Proceedings of the National Academy of Sciences | publisher=NAS | volume=117 | issue=41 | date=2020-09-28 | issn=0027-8424 | doi=10.1073/pnas.2006633117 | pages=25618–25627 | s2cid=222156184 | pmc=7568241 | pmid=32989136 | id=(VLC ORCID: [http://orcid.org/0000-0001-6515-7795 0000-0001-6515-7795]) (MS ORCID: [http://orcid.org/0000-0003-2743-0986 0000-0003-2743-0986]) (YV ORCID: [http://orcid.org/0000-0002-8361-6040 0000-0002-8361-6040]) (MIT ORCID: [http://orcid.org/0000-0002-0867-3678 0000-0002-0867-3678]) (CD ORCID: [http://orcid.org/0000-0003-3290-3530 0000-0003-3290-3530])}}

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• Antioxidant pigmentation:
• {{visible anchor|Rc}} in Oryza rufipogon and its weedy rice descendants.
• Shattering:
• {{visible anchor|sh4}} in O. rufipogon and its weedy rice descendants, including some new alleles of similar function but entirely new origin.
• Germination temperature:
• Unknown in weedy rice.
• Vavilovian mimicry:
• {{visible anchor|SD1}} alleles conveying shorter stature, slower growth, and earlier flowering, introgressed from O. sativa cultivars into weedy rice. (May or may not be adaptive, not actually confirmed.)
• Herbicide resistance:
• Various genes identical to genetically engineered domesticated O. sativa introgressed into weedy rice.
• Codon deletion in {{visible anchor|PPX2L}} in A. tuberculatus.
• Various alleles of ALS - the acetolactate synthase gene - in a variety of species.
• The same amino acid substitution in all 43 genera {{as of|2012|lc=yes}} which have triazine resistance.

Some of these are the same genes as domestication traits, but with alleles of opposite effect.

Polygonum aviculare, Plantago lanceolata, Spergularia rubra, Senecio vulgaris, Poa annua,{{cite journal | last=Baker | first=Herbert G | title=The Evolution of Weeds | journal=Annual Review of Ecology and Systematics | publisher=Annual Reviews | volume=5 | issue=1 | year=1974 | issn=0066-4162 | doi=10.1146/annurev.es.05.110174.000245 | pages=1–24}} weedy rice, Sorghum weeds including S. halepense and weedy races of S. bicolor, weedy Helianthus annuus.

• Domestication syndrome both in animals and plants

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Category:Domestication

Category:Agriculture

Category:Weeds

Category:Genetics