柑桔花芽分化与内源激素及淀粉酶活性的关系

ENDOGENOUS HORMONE LEVELS AND AMYLASE ACTIVITIES IN RELATION TO FLORAL INITIATION IN CITRUS TREES

小年少果、环割和控水处理都明显地促进了花芽分化,同时还降低了枝条在花芽生理分化期GA_s、IAA 和CTK_s 含量水平。大年载果和喷布GA_3都显著抑制了花芽分化,并相应导致了枝条内高含量的GA_s、IAA 和CTK_s 积累。外源BA 或内源CTK 因不同时间而采具促、抑花作用。在柑桔枝条中,可能以diHZ 与花芽分化的关系比CTK_s 总量更为密切。内源ABA 对柑桔花茅诱导具有促进作用。所有抑花处理都提高了α-淀粉酶活性,并相应引起枝条中淀粉含量降低。促花处理均不同程度地降低了α-淀粉酶活性。但是,淀粉含量因环割处理明显积累,而在控水处理后反降低。

Off-year,girdling or moderate drought stress decreased GAs,IAAand CTKs levels in the shoots of citrus trees during floral initiation(F.I.)and increased their flower number on autumn shoots.In contrast,on-year or spray with GA_(?) resulted in accumulation of GAs,IAA andCTK_s in their shoots and suppressed their F.I.significantly.EndogenousBA or endogenous CTK_s might exert an inhibiting or promoting effect,depending on their function time.In citrus shoots,diHZ may have acloser relationship with F.I.than CTK_s.Endogenous ABA promoted F.I.All the F.I.inhibiting treatments increased α-amylase activities,thusleading to a decrease in starch content in the shoots.All the F.I.-promotingtreatments decreased s-amylase activities,but girdling increased starchcontent and moderate drought stress decreased starch content in theshoots.