板栗早实性与开花生物学

板栗具有超乎寻常的早实性 ,在一般的管理条件下 2年生实生苗与嫁接苗一样就能开花结果 .板栗早实性除与遗传特性有关外 ,还与板栗花芽分化、花序形成特性和开花习性等开花生物学特性有关 .板栗在芽内只进行雄花序原基的分化 ,而雌花簇和所有花器官分化形成都是芽外完成的 .开花物候期、雌 (两性花序 )雄花序比和雄花序长度等受品种类型、环境条件和树体营养水平的影响 .在宜良试验点早大栗开花最早 ,雄花序最长 ,雌 (两性花序 )雄花序比最大 ( 1∶3.1 ) ;9家种则反之 ,开花晚 ,雄花序短 ,雌 (两性花序 )雄花序比小 ( 1∶ 6.5 ) .在各类花序上的雄花以结果枝上单性雄花序最先开 ,其次是雄花枝上雄花序 ,最后是两性花序上的雄花

Precocity and Floral Biology in Chinese chestnut Castanea mollossima BL.

Chestnut is 'ultra precocious',under common management seedling can bloom and produce some nuts on the second year after the germination Besides genetics,this 'ultra precocity' relate to floral biology,for example flower bud differentiation,inflorescence formation and habits of blooming While there was only differentiation of the primordium of the male inflorescence in flower bud in chestnut,differentiation and formation of pistillate inflorescences (cupula),all flower organs happened after budding (outside bud) Chestnut cultivar,environmental conditions and nutrient state of tree influenced the blooming date in phenology,the ratio of pistillate inflorescences and unisexual staminate catkin,length of unisexual staminate catkin In Yiliang experimental plot the cultivar 'Zaodali' bloomed at the earliest,its length of the staminate catkin was the longest and the ratio was the biggest 1 to 3 1;contrariwise the cultivar 'Jiujiazhong' bloomed at the latest,its length the shortest and the ratio the smallest 1 to 6 5 Moreover male flower on the young bearing branches bloomed at the earliest,later on the staminate branches and at the latest on bisexual catkins