Abstract: Grey relational degree among 10 traits(fresh weight,plant height,tiller number,effective tiller ratio,stem diameter,blade length,blade breadth,stem-leaf ratio,growth period and net photosynthetic rate) of eight new ryegrass(Lolium spp.) F4 hybrid strains were analyzed using grey relational analysis.All strains were further evaluated and selected based on multidimensional comprehensive evaluation.Results showed that tiller number(r=0.7968),stem diameter(r=0.7472) and the blade length(r=0.7116) had a higher grey relational degree with fresh weight.Stem-leaf ratio had higher relational degree with effective tiller ratio(r=0.7631) and height(r=0.7468).Net photosynthetic rate had higher relational degree with blade width(r=0.8431) and growth period(r=0.8264).Multidimensional comprehensive evaluation suggested that 3 new strains,F₄_5(L.perenne ’Eminent’ × L.× boucheanum ’Bison’),F₄_6(L.perenne ’Tove’ × L.perenne ’Eminent’) and F₄_8(L.× boucheanum ’Bison’ × L.perenne ’Tove’),had better comprehensive properties than others and the grey comprehensive evaluation relational degree was 0.8647,0.7625 and 0.6932 respectively.

Key words: New strains selection, Crop grey breeding theory, Grey relational analysis, Multidimensional comprehensive evaluation, Ryegrass

摘要： 根据作物灰色育种学的理论和方法,对黑麦草(Lolium spp.)杂交F4代8个品系的单株产量、株高、分蘖数、有效分蘖率、茎粗、叶宽、叶长、茎叶比、生育期、初花期净光合作用速率进行目标性状灰色关联分析,并在此基础上,对黑麦草杂交F4代8个品系进行灰色多维综合评估。结果表明:黑麦草单株鲜重与分蘖数(r=0.7968)、茎粗(r=0.7472)、叶长(r=0.7116)关联度最高;茎叶比与有效分蘖率(r=0.7631)、株高(r=0.7468)关联度较高;而初花期净光合作用速率与叶宽(r=0.8431)和生育期(r=0.8264)关联最为密切。可根据育种目标,对与目标性状关联度较高的性状进行针对性选择。F₄_5(卓越×百盛)、F₄_6(多福×卓越)、F₄_8(百盛×多福)3个杂交新品系综合性状最好,综合评估关联度分别为0.8582,0.7527和0.7340。

关键词: 杂交品系筛选, 作物灰色育种, 目标性状灰色关联分析, 灰色多维综合评估, 黑麦草