Drought Tolerance Evaluation And Index Identification Of Maize Backcross Introgression Lines

Drought and water shortage has become the first limiting factor of corn production in China.Maize was one of the crops with high water demand and sensitive to water stress,the drought has seriously affected on corn production.Therefore,breeding high-yielding and drought-tolerant maize cultivars is one of the most effective ways to resist drought and stress,selection of drought-tolerant maize cultivars are found to be effective and important for drought resistance identification.This experiment with different years 33 kinds of two backcross generations of BC₁F₄and BC₁F₅,as well as 4 backbone inbred lines are reincarnation parents and 11common maize inbred lines in our country as the donor parent and 17 kinds of two backcross generations of BC₁F₄ and BC₁F₅ are used as material,take random area group design,and adopt drought stress treatment during the silking stage,has been analyzed the relationship between drought tolerance related characters and drought tolerance.We can obtain maize materials with significantly higher drought-tolerance by backcrossing and selfing.The results are as follows:（1）Plant height,ear height,ASI,Pn and yield can be used as 5 important indexes for evaluating drought tolerance of maize inbred lines and backcross introgression lines.（2）The two backcross generations in different years were divided into 3categories,in 33 BC₁F₄ group,there are 10 strongest drought resistance,11 with stronger drought resistance and 12 with weaker drought resistance;In 33 BC₁F₅group,there are 18 strongest drought resistance,11 with stronger drought resistance and 4 with weaker drought resistance.（3）The three generations of maize inbred lines and backcross introgression lines in the same year were divided into 3 categories,in 15 maize inbred lines,there are 5strongest drought resistance,4 with stronger drought resistance and 6 with weaker drought resistance;In 17 BC₁F₄ group,there are 7 strongest drought resistance,7with stronger drought resistance and 3 with weaker drought resistance;In 17 BC₁F₅group,there are 8 strongest drought resistance,6 with stronger drought resistance and3 with weaker drought resistance.（4）Introducing the construction group through backcrossing,the drought resistance of 15 maize backcross lines was significantly improved in the two generation of maize backcross lines in different year;The drought resistance of 5maize inbred lines constructed in backcross lines in the three generations of maize inbred lines and backcross lines in the same year increased significantly.