Polyploid Induction And Ploidy Identification In Actinidia Arguta

In this paper,Actinidia arguta（Sieb.&Zucc）Planch.ex Miq.,one-year-old hardwood and shoot tips of tissue culture seedlings of Actinidia arguta cultivar’Kuilv’were used as experimental materials.The chromosome polyploidy induction was carried out by physical mutagenesis and chemical mutagenesis.According to morphological differences,the plants with possible polyploids were preliminarily screened from hardwood cutting seedlings and tissue culture seedlings.The chromosome polyploidy was identified by flow cytometry.And the morphological indexes,physiological and biochemical indexes of leaves,as well as the chlorophyll content were measured and analyzed,respectively.Thereby,the germplasm innovation of Actinidia arguta was realized to enrich the germplasm resources of Actinidia arguta.The main results were as follows:1.Polyploids of Actinidia arguta were induced by immersion method colchicine into cuttage hardwood.10 morphologically mutant plants were selected by morphology and identified by flow cytometry.When colchicine concentration was 0.1 g/L,the maximum induction rate was 13.33%after 24 h induction,one tetraploid and nine chimeras were obtained.Polyploids of Actinidia arguta were induced by colchicine soaking the stem tip of tissue culture seedlings,after that 22 morphologically mutant tissue culture seedlings were selected by morphology and identified by flow cytometry.When colchicine concentration was0.2g/L,the maximum induction rate was 20.00%after 2h induction,8 tetraploids,10 chimeras and 4 octaploids were obtained.2.The survival rate of hardwood cutting seedlings of Actinidia arguta decreased after the cottage hardwood were radiated by 5 kinds of 60Co-γradiation dose,0Gy,45Gy,60Gy,75Gy and 90Gy,etc.The stem tips of hardwood cutting seedlings were tissue cultured,and the morphological indexes of tissue culture seedlings were observed,which showed that all radiation doses could affect the morphology of tissue culture seedlings and whose survival rate decreased with the increase of radiation dose.The highest mutation rate is 6.67%of the tissue culture seedlings of these cottage hardwood radiated by 60Gy dose of⁶⁰Co-γ,significantly lower than that of colchicine injection method or colchicine immersion method,and 3morphologically mutant seedlings were obtained which all were chimeras.3.The plant morphological indexes,leaf physiological and biochemical indexes and chlorophyll content of‘Kuilv’CK,chimera and octaploid of Actinidia arguta were compared.With the increase of ploidy,the leaf color became darker,the leaves became wider and thicker,and the leaf shape index became larger.And the guard cells of leaves gradually increased,the number of chloroplasts increased,and the number of stomata per unit area decreased.From the anatomical observation of leaf cross section,with the increase of ploidy,the length and width of spongy tissue,palisade tissue,perimeter of upper and lower epidermis,and leaf thickness of leaf all were increased.And the content of chlorophyll and carotenoid were increased.From the results of growth measurement,with the increase of ploidy,plant fresh weight,plant dry weight,leaf fresh weight,leaf dry weight,leaf moisture content all were significantly increased.