Heat Unit Accumulation and Days to Anthesis Relationship in Tobacco Genotypes with an Introgressed QTL Affecting Leaf Number. Issue 6 (6th October 2016)

• Record Type: Journal Article
• Authors: Wells, Randy; Eickholt, David P.J.; Lewis, Ramsey; Vann, Matthew C.; Fisher, Loren R.
• Is Part Of: Crop science. Volume 56:Issue 6(2016)
• Page Start: 3228
• Page End: 3236
• Publication Date: 2016-10-06
• Subjects: Crop science -- Periodicals; Cultures -- Périodiques; Cultures de plein champ -- Périodiques; Crop science; Nutzpflanzen; Zeitschrift; Pflanzenbau; Periodicals; 633
• DOI: 10.2135/cropsci2016.04.0278
• Languages: English
• ISSNs: 0011-183X

Abstract

Abstract : Plant breeders and crop managers would benefit from an increased ability to predict the requirements for onset of anthesis in tobacco ( Nicotiana tabacum L.). This study was performed to determine the relationship in the field between heat unit (HU) accumulation and the onset of anthesis in tobacco genotypes varying for the zygosity of an introgressed quantitative trait loci (QTL) designated as Many Leaves ( Ml ) affecting flowering team and leaf number. Three commercially important cultivars or breeding lines (Speight 168, K326, and NCTG‐61), their nearly isogenic homozygous ( MlMl ) and heterozygous ( Mlml ) counterparts, and three BC6F3 null‐segregant ( mlml ) lines, were evaluated at three locations and over 2 yr. Days to anthesis (DTA) and HU accumulation were determined. In each environment, the MlMl, Mlml, and mlml genotypes were found to be grouped according to the zygosity of the Ml trait, with the mlml genotypes flowering first followed by Mlml and MlMl genotypes, respectively. An exception to this trend was Speight 168 MlMl, which consistently fell within the Mlml grouping for DTA. No consistent relationships were observed between HU and DTA, which was highly variable among environments. Integrated HU (area under the HU curve) during the 28 d after transplanting (DAT) was positively associated ( R 2 = 0.98; P = 0.0001) with the range of DTA among all genotypes. Integrated HU was a better indicator of the pattern of HU attainment than merely the amount. Early HU exposure seemed important in determining the range in DTA amongst the genotypes examined.