Partial Inhibition of Pollen Degradation by Gibberellic Acid Mutants Derived from cv. First (Lycopersion esculentum Mill.)

The young flower buds in three male sterile mutants derived from cv.First were treated with gibberellins to determine whether pollen degradation could be inhibited.Microscopic observations of acetocarmine preparations revealed that the application of gibberellins inhibitde pollen degragation for all tested mutants of Fms-1,Fms2 and Fms-3 in which their breakdown in microsporogenesis occurs at microspore stage,during meiosis and at tetrad formation ,respectively.The optimum concentration and treatment time were 10mg/1 and 6-12days before flowering,GA7 proved to be preferable to GA3 for pollen fertility restoration.With the elingation of stameans by gibberellin application,viable pollens appeared frequeitly in Fms-2 mutant,being over 200grains on a 0.5mm equatorial section of anthers in the best case,as compared to the other mutants.Bioassay using dwafrice seedilings showe that the Fms-2 plants had lower levels of gibberellin in their anthers compared with normal ones.

トマト’ファースト’より作出した雄性不稔系統において、その花粉崩壊がジベレリンによって阻害されるかどうかを検討した。ジベレリンの阻害効果は花粉崩壊が小胞子期に始まるFms-1タイプ、減数分裂期に始まるFms-2タイプ、四分子期に始まるFms-3タイプのいずれにおいても認められた。最適濃度は10mg/ℓで散布後6日から12日目に開花してくる葯で認められた。この場合、GA3よりもGA7の方が効果は高かった。開花時の葯0.25mm横断切片上のアセトカーミン染色花粉（生存花粉）はFms-2で最も多く200粒以上を示すものもあった。Fms-2花粉の生存には葯の委縮回復が伴っていた。Fms-2葯のジベレリン活性はオリジナル正常葯のそれより低かった。