Comparison And Application Of Root Traits Of Common Wheat (Triticum Aestivum L.) And Its Relatives

To explore and clarify the root traits of relatives of common wheat better than that of common wheat for resources improving common wheat, the study was carried out with strong-gluten, medium-gluten and weak-gluten wheat (Triticum aestivum L.) cultivars and 9 relatives of common wheat with different genotypes in the Scientific & Educational Park of Henan Agricultural University in 2007~2009, to compare root traits of common wheat with its relatives. Root samples for measurement of morphologicalï¹ quantitative traits and physiologicalï¹ biochemical traits were investigated and analysed in all growing stages, and the characteristics of protein expression in roots were also explored and studied preliminarily. The main conclusions were as follows:(1) The differences of root development of common wheat and its relatives were made clear. Dry root weight per plant, root volume per plant and root-shoot ratio of relatives of common wheat were all larger than those of common wheat cultivars, and root vigor of relatives of common wheat were also stronger than that of common wheat, soluble sugar content and total nitrogen content in roots of relatives of common wheat were higher than those of common wheat as well. It could be suggested that it be of significance to exploit advantages in rooting ability and root vigor of relatives of common wheat over common wheat cultivars.(2) Clustering analysis on root traits of relatives of common wheat was carried out. Different relatives of common wheat were classified for different categories. Ae. Speltoides was the type with developed nodal roots, high nitrogen content in roots and strong root vigor. T. wittmack was the type with large root weight and volume and high sugar content in roots. T. boeoticum was the type with moderate nodal roots, root weight and volume. T. tauschii was the type with moderate nodal roots, root vigor, soluble sugar content and total nitrogen content in roots. Se. cereale was the type of moderate root vigor. It provided basis for improving common wheat by utilizing of some root traits of relatives of common wheat better than that of common wheat alternatively that different relatives of common wheat had the superiority in different aspects.(3) The correlation analysis on root traits of common wheat and its relatives with grain yield traits were carried out. The positive correlation of nodal roots and root weight per plant, root-shoot ratio and total nitrogen content in roots at different growing stages with ears per plant was significant and extremely significant. The negative correlation of total nitrogen content in roots at different growing stages with kernels per ear was significant and extremely significant. The negative correlation of nodal roots per plant and total nitrogen content in roots at different growing stages with grain weight per ear was significant. The negative correlation of dry root weight per plant, root-shoot ratio and root vigor at different growing stages with 1000-grain weight was extremely significant and significant. Root development had some influences on yield formation. Root traits that were beneficial for formation of ears per plant were unfavourable to formation of kernels per ear and grain weight per ear, and vice versa. Terefore, ideal root structure played an important part in gain formation of wheat.(4) The correlation analysis on root traits of common wheat and its relatives with grain quality traits were also carried out. The correlation of nodal roots per plant and per culm, dry root weight per plant, root-shoot ratio and total nitrogen content in roots with grain total nitrogen content was significant. The negative correlation of root vigor at wintering and mid-grain filling with grain starch content was significant. The positive correlation of nodal roots per culm at flag leaf expansion with soluble sugar content in grain was significant. Root development influenced on grain quality formation significantly. So it could improve root traits and grain quality traits simultaneously by improving the genetic foundation of root traits of wheat, which was beneficial for combining of high yield with high quality.(5) The characteristics of soluble protein expression in roots of common wheat and its relatives were explored and studied. There were more strips of soluble protein in roots than in leaves. It might relate to some better root traits in relatives of common wheat that some different strips of soluble protein expression in common wheat and its relatives were existed, which was to be studied furthermore to provide basis for selecting and identifying some better genes of root traits of relatives of common wheat and utilizing ultimately.