title: Wheat seedling emergence from deep planting depths and its relationship with coleoptile length.
abstract: Successful stand establishment is prerequisite for optimum crop yields. In some low-precipitation zones, wheat (Triticum aestivum L.) is planted as deep as 200 mm below the soil surface to reach adequate soil moisture for germination. To better understand the relationship of coleoptile length and other seed characteristics with emergence from deep planting (EDP), we evaluated 662 wheat cultivars grown around the world since the beginning of the 20(th) century. Coleoptile length of collection entries ranged from 34 to 114 mm. A specialized field EDP test showed dramatic emergence differences among cultivars ranging from 0-66% by 21 days after planting (DAP). Less than 1% of entries had any seedlings emerged by 7 DAP and 43% on day 8. A wide range of EDP within each coleoptile length class suggests the involvement of genes other than those controlling coleoptile length. Emergence was correlated with coleoptile length, but some lines with short coleoptiles ranked among the top emergers. Coleoptiles longer than 90 mm showed no advantage for EDP and may even have a negative effect. Overall, coleoptile length accounted for only 28% of the variability in emergence among entries; much lower than the 60% or greater reported in previous studies. Seed weight had little correlation with EDP. Results show that EDP is largely controlled by yet poorly understood mechanisms other than coleoptile length.
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, Washington, United States of America.
authors.forename: Amita
authors.initials: A
authors.lastname: Mohan
authors.forename: William F
authors.initials: WF
authors.lastname: Schillinger
authors.forename: Kulvinder S
authors.initials: KS
authors.lastname: Gill
mesh_terms: D018548:Cotyledon; D014908:Triticum / Q000254:growth & development*
references.citation: Plant Physiol. 1990 Jan;92(1):242-5
references.pmid: 16667254
references.citation: Theor Appl Genet. 2007 Jun;115(1):59-66
references.pmid: 17429602
references.citation: Nature. 1999 Jul 15;400(6741):256-61
references.pmid: 10421366
references.citation: Funct Plant Biol. 2004 Jul;31(6):583-589
references.pmid: 32688930
references.citation: Theor Appl Genet. 2009 Jun;119(1):65-74
references.pmid: 19360392
references.citation: Theor Appl Genet. 2007 May;114(7):1173-83
references.pmid: 17294164