利用叶绿素含量及荧光动力学参数评价青贮玉米耐旱关键指标研究

利用叶绿素荧光仪测定了26份青贮玉米自交系和105个组合的叶绿素含量及荧光动力学参数，对其生理性状关键耐旱指标进行主成分及相关分析，并进行配合力及遗传参数分析。青贮玉米Fv/Fm的影响因素大小依次为：叶片Fv>叶片Fm>叶片Fo>叶片Area>叶片SPAD>苞叶Fv/Fm>苞叶SPAD。筛选出了5个关键指标(叶片Fm、叶片Fv、叶片Area、叶片Fv/Fm、叶片SPAD)及一般配合力(GCA)较高的9份自交系和特殊配合力(SCA)较高的19个组合。在F₁吐丝期，叶片Fo、叶片Area主要受基因加性效应支配；叶片Fm、叶片Fv的加性与非加性效应相当；叶片Fv/Fm、叶片SPAD主要受基因非加性效应支配。狭义遗传力(h²N，)大小依次为：叶片SPAD>叶片Area>叶片Fo>叶片Fv>叶片Fm>叶片Fv/Fm。通过对叶片Fv的早代正向直接选择、叶片Fo的早代负向直接选择，以及对叶片Fv/Fm的杂种优势利用，可提高旱区青贮玉米单位面积生物产量。叶绿素含量及荧光动力学参数可用于青贮玉米的耐旱性筛选。

Evaluation of drought tolerance in silage maize based on chlorophyll content and fluorescence kinetics parameters

In attempt to provide a reliable theoretieal basis for breeding of drought toleranee in silage maize in the arid hilly areas, the drought tolerance in silage maize were determined. The ehlorophyll content and chlorophyll fluores-cence kinetics parameters of 26 silage maize inbred lines and 105 crosscs were measured using chlorophyll fluorometer. The principal component and correlation analysis were conducted against their key indices of drought toleranee,eombining ability and genetic parameters.The order of influencing factors of Fv/Fm was:leaf Fv>leaf Fm>leaf Fo>leaf Area >leaf SPAD>bracteal leaf Fv/Fm>bracteal leaf SPAD. 9 inbred liaes which had higher general combining ability (GCA)and 19 crosses which had higher specific combining ability(SCA)were screened from the present study for 5 traits including leaf Fm, leaf Fv, leaf Area, leaf Fv/Fm and leaf SPAD. At silking stage in F₁, the additive variation was principal in leaf Fo and leaf Area; leaf Fm and leaf Fv were commonly controlled by additive and no-additive ef-fects;non-additive variation was principal in leaf Fv/Fm and leaf SPAD. The order of narrow heritability(h²N)was: leaf SPAD>leaf Area>leaf Fo>leaf Fv>leaf Fm>leaf Fv/Fm. lt eould inerease biologieal yield of silage maize in the arid areas through early generation positive direct selection for leaf Fv, early generation negative direct selection for leaf Fo, and utilization of heterosis for leaf Fv/Fm. Chlorophyll content and chlorophyll fluorescence kinetics parame-ters could be employed for sereening of drought toleranee in silage maize.