異なる栽培時期におけるグロリオサの花芽分化・発達の品種間差異(栽培管理・作型)  [in Japanese] Genotypic Differences in Floral Initiation and Development of Gloriosa superba L(Crop Production & Cropping Type)  [in Japanese]

グロリオサ茎頂を走査型電子顕微鏡を用いて詳細に観察して花芽分化・発達の様相を明らかにするとともに,生育との関連も調査し,品種間差異や花芽分化・発達の季節的変動について考察した.グロリオサの花芽分化・発達の様相はテッポウユリのそれに近似していたが,内・外花被原基が同じ形態を持つ点はチューリップに近かった.また,普通葉の大半は定植前の催芽処理時に分化していた.主要3品種を12月,4月,7月に定植すると'ミサトレッド'と'トロピカルレッド'では定植時期にかかわらず,定植後に10葉ほど分化した後の約30葉期で花芽分化したが'ローズクイーン'では7月定植で47葉期に花芽分化し,12月や4月の定植でのそれよりも10葉期以上遅れた.このような品種間差は,花芽分化に対する温度反応特性の違いによって生じ,高地温によって花芽分化が抑制される品種があると推察された.ただし,分化後の花芽の発達は品種にかかわらず高温で促進された.

Morphological changes in the shoot apex of Gloriosa superba L. 'Rose Queen' during floral initiation and development were observed using a scanning electron microscope. The sequence of events in floral initiation and development of G. superba was similar to that in Lilium longiflorum except for morphology of perianth primordium in which both inner and outer primordia had the same shape as Tulipa gesneriana. Effects of cultivating season on flower bud formation were investigated in three genotypes 'Misato Red', 'Tropical Red' and 'Rose Queen'. Tubers of each genotype were forced to sprout under dry conditions at 30℃ for 22-24 days, and then were planted on December 2 (winter culture), on April 3 (spring culture) and on July 3 (summer culture) in a glasshouse, respectively. Most leaves were formed before planting. Floral initiation occurred when about 30 leaves were formed in any season in 'Misato Red' and 'Tropical Red'. In 'Rose Queen', however, floral initiation occurred when 47 leaves had formed in summer culture, and at about 35 leaves in winter and spring culture. The differences in floral initiation among these genotypes seem to be caused by differences in response to temperature, especially high soil temperature which may inhibit floral initiation depending on the genotype. Once floral initiation occurred the flower bud developed rapidly in all culture season.