不同供体及回交次数对玉米自交系配合力和杂种优势的改良效应

Improvement Effects of Different Donor and Back-cross Times on Combining Ability and Heterosis of Inbred Lines in Maize

研究不同供体及回交次数的改良效应,对玉米回交育种具有重要的指导意义。以玉米自交系K11和K62为轮回亲本,分别用3个自交系为供体亲本,通过回交0~5次并自交8~3次育成36个改良系,采用3×38不完全双列杂交模式,分析主要性状配合力效应和产量杂种优势表现。不同供体对不同性状配合力的改良效应差异较大,供体A3和B1对产量GCA、SCA和杂种优势的改良效果显著优于其他4个供体亲本;回交0~5次对产量GCA和SCA的改良效果差异不明显,回交0次和1次对产量杂种优势的改良效果较好。在回交育种实践中,选择适宜的供体亲本至关重要,回交次数不宜超过2次;A3-1和B1-1等10个改良系产量GCA效应值极显著高于相应轮回亲本,具有较好的高产育种潜力。

Studying the improvements of different donors and different back-cross times plays an important role in maize back-cross breeding.36 back-cross improved lines were obtained by backcrossing 0-5 times and selfing 8-3 times,using maize inbred lines K11 and K62 as recurrent parents and three inbred lines as donor parents respectively.The 3×38 incomplete two-row hybrid model was used to analyze the combining ability and heterosis performance of main traits in back-cross improved lines.Donors A3 and B1 performed better than the other 4 donor parents on improving GCA,SCA and heterosis of yield,indicating that different donors presented different effects on improving the combining ability of different traits;In terms of the back-cross time,the improvement of 0-5 back-crosses on the GCA and SCA of yield was not obvious,0 and 1 back-cross performed better on improving the heterosis of yield.Choosing an appropriate donor parent was of vital importance when using back-cross to improve the quality of maize inbred lines,and the back-cross time should not exceed twice in back-cross breeding process;The GCA of yield of 10 improved lines,such as A3-1 and B1-1,were significantly higher than corresponding recurrent parents,which presented excellent potential of high-yield breeding.