Establishment Of High Frequency Rapid Propagation System And Study On Root Characteristics Of Rieger Begonias

It is one of the main varieties of indoor flowers and has high ornamental value because of its characteristics such as winter flowering,no obvious dormant period,multiple flowers and variety.At present,the number of cultivation and consumption increased sharply,the rapid development of the domestic situation.In this study,six varieties of Rieger begonias were selected to carry out the research on the rapid propagation technology of high frequency and to cultivate the regenerated plants.At the same time,the root characteristics of Rieger begonias were studied to solve the problem of slow rooting and difficult rooting,shorten the reproduction cycle,reduce costs and meet the market demand.The main research results are as follows:1.Establishment of high frequency rapid propagation system of Rieger begoniasThe leaves and stem segments with axillary buds of six varieties of Rieger begonias were the best explants,and the contamination rate of explants decreased by 20%after cold treatment at 1 5℃ for 8h.Full light was beneficial to the adventitious bud growth of"Borias","Orange Stone","Peggy" and "Blitz",while dark treatment promoted the adventitious bud growth of "Barkos" and"Netja Dark".MS+0.3 mg/L 6-BA+0.15 mg/L NAA was the best subculture medium for Rieger begonias.The optimal rooting medium was 1/2 MS+0.6 mg/L NAA.2.Study on root characteristics of Rieger begonias(1)Effects of growth regulators on root morphology of tissue culture seedlings of Rieger begoniasThe growth regulator increased the root diameter of Rieger begonias as follows:growth regulator concentration>treatment time>growth regulator type;The root length increased as follows:treatment time>growth regulator concentration>growth regulator type;The root surface area increased as follows:growth regulator concentration>treatment time>growth regulator type;The number of root tips increased as follows:growth regulator type>growth regulator concentration>treatment time.The optimal level combination of root morphological indexes was:IBA 400mg/L1 5 min.(2)Effects of growth regulators on root biomass of tissue culture seedlings of Rieger begoniasThe growth regulator increased the underground biomass of Rieger begonias as follows:growth regulator type>growth regulator concentration>treatment time.The optimal horizontal combination was ABT 200 mg/L for 15min.The root weight ratio increased as follows:growth regulator type>growth regulator concentration BBB>eatment duration;The root-shoot ratio increased as follows:growth regulator concentration>growth regulator type>teatment time..The optimal horizontal combination was ABT 400mg/L 5min.(3)Effects of growth regulators on root physiological indexes of tissue culture plantlets of Rieger begoniasThe growth of growth regulator on the absorption surface area of Rieger begonias root was:growth regulator concentration>growth regulator type>teatment time.The root activity increased as follows:treatment time>growth regulator concentration>growth regulator type.The optimal horizontal combination was IBA 400mg/L for 15 min.(4)Principal component analysis of root system of Rieger begoniasAccording to the principal component analysis of different rooting treatments and root indexes of Rieger begonias,the cumulative length and surface area of roots are the key indexes,which are stable.Root accumulative surface area index determines the proportion of rooting treatment.The first place in the comprehensive ranking was IBA 400mg/L for 15 min,which was consistent with the results of root accumulative surface area range analysis.