Genetics of Growth Habit (Spring vs. Winter) in Tetraploid Wheats: Production and Analysis of Near-Isogenic Lines

Abstract

Variability in tetraploid wheat species for growth habit (spring vs. winter) was studied in the field and, as a result, winter growth habit samples were identified. Backcrossing on the background of Tririmn tlicoccum cv. Black Winter Emmer developed the near-isogenic lines BSlE and BS2E carrying the dominant genes Vrn1 and VvnZ, respectively. The donors of the dominant genes Vrnl and VrnZ were Pugsley's common wheat near-isogenic lines Triple Dirk D and Triple Dirk B, respectively. The results demonstrated that T. clicoccum near-isogenic lines with the dominant Vm genes do not mature significantly later than the near-isogenic lines of common wheat. Wheat as a major food crop will reindin a plant of undiminishing perennial research interest. The genetics of common wheat, Triticum aestivum L. has been studied more than in the other wheat species. More recently, the genetics of these species has stirred interest with reference to genetic erosion of common wheat, especially the genetic control of resistance to pathogens or insects, and adaptation to environments. Growth habit (spring vs. winter) is very important for the adaptation of wheat cultivars to diverse climates. The winter habit of wheat is characterised by delayed ear-emergence in the absence of cold treatment (vernalization). This mechanism prevents the onset of floral development during winter. Spring wheat has a little or no vernalization response. The spring growth habit is dominant to winter growth habit. It has been previously shown that the Vrn genes controlling growth habit in wheat act not only when the plants developmental program switches to spring or winter growth habit, but also when the developmental phases are enfolding, i.e., control of the duration of the life cycle from shooting to ear emergence and, as a consequence, affect earliness and yield (For references, see reviews FLOOD