A Comparative Study On Root Developmental Characteristics Of Hybrid Wheat With Ae. Kotschyi Cytoplasm And Its Matching "Three Lines"

The wheat root is the basis of photosynthesis productive system above ground, and its developmental status directly impact on wheat's high and steady yield. The wheat root's development is not only influenced and adjucted by environment and agronomic measure,more importantly controlled by self-inherited basis. In the past,the studies on wheat root system focused on the law of physiology and ecology and correlation between roots and above ground plant characters,but less were in the genetical law of wheat root characters. This paper aims at explainning root developmental characteristics of hybrid wheat with Ae. kotschyi cytoplasm and its matching "Three Lines" and confirming crossbreed goal,use of heterosis,and providing technique reference for high and steady grain yield.In the literature review,the author introduced the research progress and prospected the developmental trend in genetics of crop root traits. Using potted plant and field experiments,selecting a hybrid of yumai 3×Yumai 66 and its sterile line K-type yumai 3,maintainer line Yumai 3 and restorer line Yumai 66,at developmental stages of overwintering, regreening, jointing, flag leaf stage, middle grain filling,and dough digging and washing methods were used to get root samples,and traits were analysed such as seminal roots per plant,nodal roots per plant,nodal roots per tiller,root volum per plant,dry root weight per plant,root-shoot ratio,root vigor. Based upon analyses above,correlations were discussed between nodal roots per plant,root vigor,and grain yield,and grain quality.There exist distinct diferences in root configuration and quantitive characters and physiological characters of hybrid wheat with Ae. kotschyi cytoplasm and its matching "Three Lines".At different developmental stages, nodal roots per plant and nodal roots per tiller of hybrids were significantly more than in "Three Line",and at middle and late stages, root volum per plant was significantly bigger,but dry root weight per plant smaller than maintainer line and sterile line,root vigor was significantly less than sterile line. The different N levels affected nodal roots per plant. At different developmental stages,nodal roots per plant and root vigor of hybrid wheat with Ae. kotschyi cytoplasm and its matching "Three Lines" were significantly correlated with grain yield.There exists genetical diference in root development of hybrid wheat with Ae. kotschyi cytoplasm and its matching "Three Lines".In application of heterosis,the order of choosing root characters is nodal roots per plant, root volum per plant,root vigor,but root quality character should not be consiered as a chosen root index in wheat breeding.