Development And Variation Of Reproductive Organ For Teatraploid Robinia Pseudoacacia

Tetraploidy(4X)Robinia pseudoacacia(TRP) is bred by doubling diploid(2X) R pseudoacacia(DRP) (thereby it belong to autotetraploid).And it is a fine tree species used for conserving water and soil,.checking winds,fixing drifting sand,improving soil and construting shrubbery for fodder.To further improve genetically TRP and reveal autotetrapliod-biological property of development and variation of floral organ and seed from TRP, the development and variation have been researched for 5 years and the research contents and main conclusions are as follows.By scanning electron microscop,paraffin section,field obaervation and TTC staining methods,the development of inflorescence,floret anlage,male and female and ovule were studied and so were mophology, structure,fertility,flowering and pollination habit of inflorescence and flower organs forTRP.The key links in above developments are consistent with ones of DRP but accompanied by development hysteresis in different degrees.The inflorescens mophology,attachment and structure of florets show obvious trait-instability variation among individuals in TRP clone stand,inflorescences and florets on same individual.In virtue of dissecting,determinating index of physiology and biochemistry,flow cytometry,classifying based on mophology and weight,the variations of seed and seed-embryo were researched. Chromosome-homologically-doubling make individual seed weight,embryo rate of seed and germinating rate of TRP reduce obviously.There are huge variations with seed instruture,embryo rate of seed,white embryo rate and germinating rate of seed among different weitht-sorts seed of TRP.According to amount,color and plump degree of cotyledon,the seed embryo of TRP can be divided into 5 classes and the soluble protein content,peroxydase activity,vitality,tissue cultural character vary among different seed embryo types of TRP.Hot water and 5-azaC treatment can promote germination of seed of TRP,by which 300 one- years-old seedlings,15 two-years-old seedlings and 4 three-years-old seedling have been developed.