Establishment Of Rapid Propagation System And Preliminary Mutation On Introduced Bio-energy Willow

Abstract:Willow is one of the genera that have the most varieties of species in the world. For its wide distribution, strong adaptability, fast growth and high yield biomass, it was developed rapidly as bio-energy plant resources, timber production forest and carbon sequestration forest world wide. Sweden is advanced in development and utilization of bio-energy willow in the world, lots of excellent varieties with different traits were breed and selected, and were introduced into different areas.In this paper, the bio-energy willow, Salix viminalis clone NO.070, introduced from Sweden was used as the material, cutting propagation and tissue culture propagation were conducted, so as to obtain enough material for researching, preserving excellent variety resources and promoting cultivation. Meanwhile mutagenicity test by colchicine were done on cuttings and plantlets of tissue culture, in order to get new germplase with traits of fast growth, strong stress-resistant, then to extend the cultivation of bio-energy Salix. Treated with colchicines, and 3 groups of plant with morphological variant were selected, to determine their biochemical indicators and to analysis their chromosome of root cell. The results showed as follow:1. Shoot tips from introduced willow were used as the explants, B5, MS and WPM was the basic medium, in which different kinds of plant growth regulator was added. In term of the time initial formation of adventitious buds, reproductive coefficient and quality of adventitious buds as the evaluation criteria, media and culture conditions were screened and optimized, rapid propagation of tissue culture for bio-energy willow was established. The suitable initial culture medium was:WPM+6-BA 0.5 mg/L+NAA 0.1mg/L the suitable medium for adventitious buds proliferation was:WPM+6-BA 1.0mg/L+NAA0.5mg/L, the suitable rooting medium was:1/2MS+ NAA 0.1mg/L.2. The cutting propogation test of bio-energy willow showed that:the induced willow cuttings grew roots easily, the survival rate of cuttings planted on the three kinds of medium were high. However matrix mixed perlite with vermiculite and activated can shorten the iniatial rooting time and improved rooting rate, the initial rooting time was only 5days and rooting rate was up to 98%.3. During the culture of adventitious buds induction, callus was induced on the base of stem explants. Proliferation and texture of the callus were affected by the high concentration of plant growth regulator. Also it's found that higher browning ration was occurred in the culture bottle inoculated with a piece of callus than that inoculated with several pieces of callus. This phenomenon was similar to pollen germination of "cluster effect". And the prolification rate was very low by means of callus induction.4. Buds from cuttings and plantlets obtained from tissue culture were treated with colchicines of different concentration, by means of different methods and different time.120d after treating, there were 3 clones(coded 1,5,7) that had the morphological traits t of varaint, which grew faster, and stronger with longer leaves than the normal diploid plant. And the treated cuttings had obtained higher mutation rate than that treated tissure cultures.5. The 3 selected clones with variant morphological traits were conducted soil drought stress and salt stress, Praline and Malondialdehyde (MDA) of leaves were measured during the stress period, and that of untreated plants was the control. Stress-resistant among the selected clones and the untreated plants were analyzed, the results indicated that the stress resistant of the 3 clones ranked as 5>1>7, all had the stronger resistant to soil drought stress.However, there were no difference of salt stress resistant between the morphological variant and the normal diploid plants, moreover, the Praline and Malondialdehyde content from the 3 selected variants was lower than the normal diploid during the later phase of salt stress.6. The plants of morphological variant were selected for root tip chromosome analysis. Root tips were collected at different time of one day, it's found that there were more cells at metaphase of cell division when root tip collected and pretreated at about 8 o'clock am. For root tips cell acetic acid magenta was better than orcein solution in the context of dyeing effect.