六倍体ライ小麦の実用形質に及ぼすライムギ末端異質染色質の効果の多変量解析 Multivariate Statistical Analysis of the Effects of Rye Telomeric Heterochromatin on the Agronomic Traits of Hexaploid Triticale

ライムギ由来の染色体腕7RL(品種Drira)と6RS(品種Rosner)において,末端異質染色質の有無が12の実用形質に及ぼす効果を,六倍体ライ小麦の2つの姉妹系統を用いて調べた.解析には,多変量分散分析,偏相関,重回帰分析および正準相関を用いた.末端異質染色質の欠失が12の実用形質の平均値において有意な変化を伴うことが,多変量分散分析と収量と他形質との回帰によって明らかになった.異質染色質を欠失した系統の偏相関係数が,Rosner系統よりもDrira系統でより多く変化した.Rosner系統では多くの係数が大きくなったが,Drira系統では逆の傾向を示した.最も影響のあった形質は品種によって異なった.種子収量と他形質との回帰にも変化があった.異質染色質を欠失した系統においてのみ穂数が有意に寄与し,穂長,穏当たり小穂および穂密度は寄与しなかった.末端異質染色質の欠失が形質発現や実用形質と形質のグループとの間の関係に有意な効果があり,いくつかの形質ではその効果が品種および染色体に特異的であると考えられた

Two pairs of sister lines of hexaploid triticale (X Triti-cosecale Wittmack) differing by the presence ( + + ) or absence ( - ) of telomerrc heterochromatin on chromosome arms 7 RL (cv. Drira) and 6 RS (cv. Rosner) were used in order to study the effects of telomeric heterochromatin loss on twelve agronomic traits. The following multivariate statistical techniques were used : multivariate analysis of variance, partial correlation, multiple regression analysis and canonical correlation. The loss of telomeric heterochromatin was accompanied by significant changes in the means of the twelve traits as a whole as evidenced by the results of the multivariate analysis of variance and in the regression of yield on the other traits. Many more partial correlation coefficients were changed in the Drira lines than in the Rosner lines ; most coefficients became larger in the Rosner line lacking heterochromatin while the opposite was true in the corresponding Drira line. The traits most affected differed from cultivar to cultivar.