甘蔗品种抗旱性光合生理指标及其综合评价

Photosynthetic Physiology Indexes of the Drought Resistance of Sugarcane and Its Comprehensive Evaluation

利用相关、主成分、聚类和判别分析 ,研究有关生理生化指标与甘蔗抗旱性关系。结果表明 :(1)中度水分胁迫下 ,MDA含量和 PMP有不同程度地提高 ,而 Fv/ Fm、Fv/ Fo、ΔFv/ Fo、Δ Fv/ Ft和 T1 /2 有不同程度地降低 ,变化的幅度因供试品种基因型而异。 (2 ) PMP与 MDA含量呈极显著正相关 ,而与 Fv/ Fm、Fv/ Fo及 Δ Fv/ Fo呈显著负相关 ;Fv/ Fm与 Fv/ Fo和 ΔFv/ Fo呈极显著正相关 ,与 Δ Fv/ Ft呈显著正相关 ;ΔFv/ Fo与 Fv/ Fo和 Δ Fv/ Ft呈极显著正相关。 (3)主成分分析选出了 3个主成分 ,方差累积贡献率达到 88.37%。 (4)在聚类分析基础上用判别分析选出 MDA含量、PMP、Fv/ Fm、Fv/ Fo、Δ Fv/ Fo和 Δ Fv/ Ft等 6个对品种抗旱性分类有显著影响的指标 ,并根据这些指标对 16个不同基因型品种抗旱性划分为高抗、中抗、不抗

Correlation, cluster, principal component and discrimination analysis techniques were used to study the relationship between several physiological and biochemical indexes and drought resistance of sugarcane. The results showed as follows: (1) Under moderate water stress condition, malondialdehyde (MDA) content and plasma membrane permeability (PMP)were raised, however, PSⅡphotochemical efficiency(Fv/Fm), PSⅡ potential activity(Fv/Fo), variable fluorescence quenching rate(ΔFv/Fo), efficiency of potential quantum conversion (ΔFv/Ft) and the time in ms from the point Fo to the point on the rising curve corresponding to 1/2 Fv (T 1/2 ) were declined in different degree depending on the tested genotypes. (2) The positive correlation between PMP and MDA content was extreme significant, but there was a significant negative correlation between PMP and Fv/Fm , Fv/Fo as well as ΔFv/Fo. The positive correlation of Fv/Fm with Fv/Fo and ΔFv/Fo was extreme significant, and that of Fv/Fm with ΔFv/Ft was significant. The correlation of ΔFv/Fo with Fv/Fo and ΔFv/Ft was positive and extreme significant. (3) Principal component analysis was performed to select the first three principal components and their cumulative contribution of variance accounted for 88.37 percent. (4) Cluster analysis had been used to classify the drought resistance of sugarcane varieties, then by means of discrimination analysis, indexes (MDA content, PMP, Fv/Fm, Fv/Fo, ΔFv/Fo and ΔFv/Ft) that had significant effects on classification were selected and 16 different genotypes varieties of sugarcane were classified into high, medium and poor drought resistance groups according to these indexes.