Optimization Of Bougainvillea Tissue Culture By Response Surface Methodology And The Effect Of Piriformospora Indica On Its Growth

Bougainvillea is an evergreen climbing shrub in the genus Bougainvillea of the family Nyctaginaceae.Because of its tenacious vitality,resistance to insects and diseases,and various colors,it has been widely planted in southern China since its introduction,and is mainly used in garden landscape and urban greening.However,due to its unique flower vessel structure,it is difficult to pollinate bougainvillea,and owing to the low efficiency of traditional asexual reproduction,it is a challenge to meet the growing demand for seedlings in the market.There are few researches on the rapid propagation technology of bougainvillea tissue culture.There Fore,this study,on the basis of previous research,optimized the tissue culture system of bougainvillea by means of the response surface method.From in vitro disinfection and inoculation to induction of rooting and transplanting,a relatively perfect tissue culture system has been established,which provides a theoretical and technological Foundation for the bougainvillea tissue culture factory.he results of this experiment are as Follows:Be Fore the explants were extracted,the mother plant was sprayed with carbendazim one week in advance,and then the surface fluff was removed with a 5%washing powder solution and a fine brush under the experimental table,and soaked for 5 times For 5 minutes each time.Finally,disinfected with 75%alcohol for 30s,4%sodium hypochlorite For 9min,and adde 1%Tween on the experimental table,The disinfection effect is the best.In the axillary bud induction stage,the best induction medium was MS+6-BA 2.534 mg/L+NAA 0.1 mg/L,and the budding rate was93.3%.The optimal growth medium was MS+2.0mg/L 6-BA+0.05mg/L NAA,and the proliferation coefficient of buds was 4.48.The best seedling growth medium was MS+0.5mg/L 6-BA+0.2mg/L NAA.The effects of MS components,NAA and IBA on the rooting of bougainvillea were analyzed by response surface methodology,and the results showed that MS had the greatest effect on the rooting of bougainvillea,Followed by NAA,and IBA had the least impact on it.Among the three,the interaction between MS and IBA concentration was significant,the interaction between MS and NAA concentration was significant,but there was no interaction between IBA and NAA.The proven optimal rooting medium is0.66MS+IBA 2mg L^-1+NAA 0.09mg L^-1.Finally,the tissue culture seedlings were placed in the greenhouse to adapt to the external environment,and then transplanted into pots with a 3:1:1 ratio of nutrient soil,vermiculite and perlite as the substrate.After one month,the survival rate was 95%.After Four months,bougainvillea tissue culture seedlings transplanted began to bloom.Piriformospora indica is a fungus Found in the Indian desert.Its function and effect are similar to that of AFM（Arbuscularmycorrhizal fungi）fungi,but its parasitic range is larger and it can reproduce on artificial medium.After being colonized into the root system,Piriformospora indica can promote plant growth,improve stress resistance,improve the survival rate of seedling transplanting and increase yield.In this experiment,pyri Form India was colonized on the root of bougainvillea with the method of watering fungus.In the 4 months after inoculation,the plant height,plant diameter,maximum leaf length,maximum leaf width,maximum leaf area,stem diameter and leaf number of Bougainia bougaina seedlings were statistically analyzed.It was Found that the growth of Bougaina bougaina seedlings was significantly promoted after inoculation.The plant height,leaf number,stem diameter and fresh weight of the treatment group were significantly higher than those of the control group.According to the growth trend of bougainvillea seedlings at 4 months,it was Found that Piriformospora indica cells promoted the growth of bougainvillea seedlings more significantly;The root structure analysis showed that the total root length,root volume,root surface area and root number of bougainaceae seedlings after inoculation were significantly higher than those of the control group.In terms of chlorophyll content,the chlorophyll A,chlorophyll B and carotenoids of the inoculated plants were significantly higher than those of the control group（P<0.01）.In terms of chlorophyll fluorescence parameters,F₀ and Fv/Fm were significantly different from the control group（P<0.01）,whileΦPSⅡand q P were significantly different from the control group（P<0.05）.By counting the flowering rate of the treatment group and the control group,it was Found that the flowering rate of the treatment group was significantly higher than that of the control group after inoculation with P.indiana（P<0.01）.This indicates that the inoculation of piriformospora indica increases the pigment content in the leaves of bougainvillea,enhances its photosynthesis ability,promote early flowering,and has the effect of promoting the growth of bougainvillea.