Phalaenopsis Tissue Culture Seedlings Under High Temperature Stress Reproductive Capacity And Optimization Of Medium

Butterfly orchid(Phalaenopsis Aphrodite)is a famous ornamental plant.With the expansion of China's foreign exchange,the import and export of horticultural plants increased rapidly.To Prevent the loss of domestic Phalaenopsis resource,as well as to use the overseas Phalaenopsis resource,we need to know what vitality condition of Phalaenopsis plant has a potential for us to conduct tissue culture for successive production.Therefore,it is valuable to establish a rapid method to detect the vitality of Phalaenopsis Plants.A better knowledge about suitable tissue culture media in relation to hormone ratio,external organic additives,together with explant sterilization method will also Provide a technical support for improving the industrialized production efficiency of Phalaenopsis.In the present study,the Physiological characteristics of Phalaenopsis Plants under high temperature stress and its influence on reproductive capacity were studied,and the tissue culture schemes of Phalaenopsis seedling in vitro were also optimized.The main results are as follows:(1)After Phalaenopsis plants was cultured at a high temperature(40?,14h/d;35?,10h/d)for different days,the UV absorption values of its extracts with Petroleum ether were determined.It was found that maximum absorption values of the extracts(from the plants treated for eight days)was detected at two bands(202-210 nm and 240-260nm).The results showed an eight-day high temperature treatment produced an obvious stress on Phalaenopsis plants.(2)With the extension of the treatment time of high temperature stress,the Fv/Fm values of the leaves from the two varieties of Phalaenopsis("chrysanthemum ","Darajiao")decreased,and the decline rate of the variety "chrysanthemum" was higher than that of "Darajaio".The Fv/Fm value of the leaves was not related to survival rate of Phalaenopsis seedlings(stems)in vitro.Under high temperature stress(40?14h/d,35?10 h/d),the Fv/Fm value and electron transport rate(ETR)of Phalaenopsis stems decreased compared with the control.There existed a strong correlation between the Fv/Fm value of the stems and the survival rate of the seedlings in vitro.When the Fv/Fm value of stems was less than or equal to 0.35,the seedlings of Phalaenopsis could not be cultured in vitro because of lacking vitality.(3)The medium including “Hyponex” additive at a concentration of 1g/L could promote effectively the growth and development of Phalaenopsis seedlings in vitro.The medium with “Hyponex No.1 has a better promotion effect on the growth and development of Phalaenopsis seedlings in vitro than that with“Hyponex No.5” additive.The effects of adding natural organic additives into media on the growth of Phalaenopsis seedlings in vitro were determined.Based on the growth indices including biomass,leaf length,root length,root diameter,projection area and plant volume,the addition of mashed potatoes into the medium produced best promotion effect on the growth of Phalaenopsis seedlings in vitro,followed by the 200 ml/L coconut milk and 200 g/L banana additive,and200 g/L of mashed Potatoes.Among the three schemes of adding natural organic additives,addition of tomato juice at 200 g/L to the medium resulted in a weakest effect on the growth and development of Phalaenopsis seedlings in vitro.(4)According to the indices of leaf length and width,root length and diameter,individual projected area and volume,among the media with different hormones and their concentrations,the medium with 6-BA(5mg /L),NAA(0.5mg /L)and GA(34mg/L)produced a best promotion effect on the growth of Phalaenopsis seedlings in vitro.(5)The effects of different cultural conditions on Phalaenopsis root growth in vitro were tested.The medium with an additive of Hyponex No.1 but without any external hormone would produce a best promotion effect on root growth.The maximum indices were detected for root biomass,root length and diameter,Projected area and volume of Phalaenopsis when the plants were cultured at the medium with sucrose(10g/L).The medium with sucrose(30g/L)produced worst effects on root growth.Also detected by using the root biomass,projected root areas,root length and diameter,number,the growth indices reached maximum when Phalaenopsis seedlings were cultured on the medium with mashed potato(200g/L),while the indices was worst if the Phalaenopsis seedlings were culturedat the medium with mashed banana(200g/L).(6)By using saturation D optimum design method,the best cultural medium ratio were identified.Among the three additives including sucrose,Hyponex No.1 and coconut juice,the “Hyponex No.1” addition to the medium would produce a best promotion effect on the biomass of the variety “Darajiao”,on the biomass,Plant volume,projected area,root volume of the variety of "chrysanthemum".The effect of adding sugar or coconut milk into the medium on the growth of“chrysanthemum” were similar,not as good as that of “Hyponex No.1” additive.For the activated carbon(0.5-1.5 g/L),6-BA(3-7 mg/L)and NAA(0.3-0.7 mg/L),with the increasing of their concentration,the growth indices of the seedlings of the two varieties increased.The effects of activated carbon on the growth of Phalaenopsis were stronger than the two hormones.