Studies Of The Selection Of Superior Plants And Their Propagatin Of Tissue Culture Techniques Of Amorphophallus Bulbifer

Amorphophallus bulbifer has the excellent characteristics of high glucomannan content,short growth cycle,long growth period and strong disease resistance,which is a semishade economic crop suitable for high temperature and high humidity in tropical and subtropical low-altitude areas in the genus Konjac.And it has good industrial development and market prospects,however there is a serious lack of good and healthy konjac seeds and seedlings.In this study,through the selection of superior plants,the optimization of tissue culture and rapid propagation technology and technology system,the trial planting of tissue culture seedlings and effect of storage temperature on postharvest physiology of Amorphophallus bulbifer,we hope to provide a large number of healthy and excellent seed seedlings and their production and storage technology for the large-scale development of Amorphophallus bulbifer industry in Hainan Province.The main results are as follows:Firstly,In the study on the selection of superior plants of Amorphophallus bulbifer,this paper analyzed the agronomic characters of 739 strains of Amorphophallus bulbifer in oil palm garden of Hongwei group from seedling emergence to seedling fall.After removing the repeated plants,34 superior plants with high expansion coefficient,outstanding single index and excellent comprehensive quality were selected.Among them,20 high expansion coefficient plants with expansion coefficient greater than 11.0 were selected according to the order of expansion coefficient from large to small.By the growth period,stem diameter/plant height,crown width/bulbous weight before planting and leaf bulbous number/bulbous weight before planting from large to small,the top three plants of each single index were selected,and 12 excellent plants with outstanding single index were obtained.According to the proportion of 5 single indexes in the evaluation of plant quality,the comprehensive index was obtained,and 20 excellent plants with good comprehensive quality were screened according to the size of comprehensive index.Secondly,A rapid tissue culture system of Amorphophallus bulbifer was established.The best surface sterilization was achieved by immersing the explants in the solution of 75%alcohol for 30 seconds then in 0.1%Hg Cl₂ solution for 15 minutes and the survival rate reached 96.7%.The best callus induction medium was MS+TDZ 0.5mg/L+NAA 0.1mg/L+Sugar 30.0 g/L+Agar 6.0 g/L and the callus induction rate reached 95.6%.The best bud induction medium was MS+6-BA 1.0 mg/L+NAA 0.5 mg/L+Sugar 30.0 g/L+Agar 6.0g/L on which the bud induction rate and number of differentiation buds of callus with unit inoculation quality reached 71.1%and 2.88.The best medium for rooting was MS+NAA0.25 mg/L+Sugar 15.0 g/L+Agar 6.0 g/L,on which the rooting rate reached 100.0%and the average root number reached 1.36.The proliferation and germination of Amorphophallus bulbifer CLSs can grow normally in dark or low light intensity;The optimum temperature for the proliferation and germination of CLSs was 30℃,whose number of differentiation buds of CLSs with unit inoculation quality reached 1.86.Tissue culture and rapid propagation technology system of A.bulbifer was established by extruding scale leaves as explants,which reached the scale production technology level of konjac seedlings and is of positive significance to solve the problem of shortage of seed taro in the development of konjac industry.Thirdly,In the study of the effects of different habitats on the growth of tissue culture seedlings of Amorphophallus bulbifer,which was found that the growth environment of B point nursery was the most suitable for its growth.Among them,the shading degree of B nursery was 71.4%,the content of alkali hydrolyzable nitrogen was 91.46 mg/kg,the content of available phosphorus was 974.85 mg/kg,the content of available potassium was60.83 mg/kg,the content of organic matter was 4.46%,the p H was 6.22,the content of Ca and Mg were 2.00 cmo L/kg and 1.27 cmo L/kg respectively.Fourthly,The starch content of all treatments increased first and then decreased,and the content of reducing sugar at 4℃was significantly higher than that of other treatments during the storage period.There was no significant difference in total water content among treatments,and the specific gravity of free water at 4℃was significantly lower than that of other treatments.At the 60d of storage,POD activity at 4℃was significantly higher than other treatments.At the 80th day of storage,the PPO activity at 4℃were significantly lower than those under other treatments.Therefore,4℃is more conducive to the storage of Amorphophallus bulbifer microbulbs,and also provides the theoretical basis for long-term storage of Amorphophallus bulbifer bulbs.