Research On Potato Optimization System Of Stem Tips Virus-free And Callus Induction And Differentiation

Potato is a kind of asexual propagation crop, in successive planting years, the yield and the quality of potato declined as the accumulation of virus or a dip-type virus, because of the accumulation of virus or a dip-type virus, the yield and quality of potato would decline with its planting in successive years,the virus-free seed potato will be obtained through virus-free plant which is the fundamental the effective measures to solve this problem.This test choosed kinds of potato as experimental material, and carry out studying on potato opt-imizationnal system of virus-free meristem to achieve improving the virus-free and multiplication rate.Callus induction and differentiation of potato is the basis of the tissue cultivation resesrch. Establishment of callus induction and differentiation system has lots of advantage,it established the foundation for further go deep into the reseach on cellular level, molecular level and germplasm resources innovation.This experiment carrys on an callus induction and differentiation in different varietal potato's leavies and stems,in order to establish and opertimize the system of callus induction and differentiation.The main research results are as follows:1. Opertimization system of virus-free meristem in potato(1) Shoot tip survival rate, sprouting rate and virus-free rate is obviously advanced after adopting the heat-treated technic compare to normal shoot tip virus-free technic,with its average higher than 20.0%,27.5% and 55.2%.However, different species have different survival, sprouting and virus-free rates because of genotype difference. Thereinto, the highest survival rate is Mira which percentage is 82.5%;The highest sprouting and virus-free rate is Netherlands No.15, which percentage is 70.0% and 61.9%.(2) This experiment tested two different sources, the result showed that the stem tips from vitro seedling is better than planting stem tips from field;No matter the survival rate, sprouting rate or the virus-free rate is 20.0%,27.5% and 55.2% higher respectively compared with the control.(3) Comparatively test on 11 varieties general stem apex virus-free,the result showed that:stem tip survival rate, sprouting rate and virus-free rate have obvious genotype differentiation variety. The highest survival rate, sprouting rate and the rate of virus-free is Mira, kexin No.15 and Atlantic, the lowest is N6-22,Bashu No.10 and Zhongnongâ…§-2.(4) Three main kinds of varieties were recommended as the highest stem tips virus -free sprouting rate substrate formula. Thereinto, varieties named Zhongnongâ…§-2 and Mira can be treated as the high sprouting rate is MS+0.05 mg/LNAA+0.2 mg/L6-BA+0.3 mg/LGA₃; Besides, varieties named Bashu No.10 also has high sprouting rate is MS +0.05 mg/LNAA+0.2mg/L6-BA+0.1mg/LGA₃.2. Establishment and opertimization of Callus Induction and Differentiation(1) Four improved varieties leaves' Callus abduction were recommended as the best substrate formula.Thereinto, varieties named ChuanYu No.5 is MS+1.5mg/L6-BA+0.1mg /LNAA+0.2mg/L2,4-D; varieties named ChuanYuZao is MS+2.5mg/L 6-BA+ 0.2mg/L NAA+0.2mg/L2,4-D;varieties named LiangShu 97 is MS+0.5mg/L6-BA+0.4mg/LNAA + 0.2mg/L 2,4-D;varieties named 22-2 is MS+1.5mg/L6-BA+0.4mg/LNAA+1.0mg/L 2,4-D. Two improved varieties stems' Callus abduction were recommended as the best substrate formula. Thereinto, varieties named ChuanYu No.5 is MS+1.5 mg/L6-BA+0.2mg/L NAA; varieties named ChuanYuZao is MS +1.5 mg/L6-BA+0.1 mg/LNAA+0.2 mg/L2,4-D。(2) The research on callus differentiation showed that callus from leaves of Chuanyu No.5, Chuanyu zao, Liangshu 97 and 22-2 differentiated into root with varying degrees and the root differentiation restricted the differentiation of shoot. A small amount of callus from leaves of Chuanyu No.5 and Chuanyu zao differentiated into shoot with highest differentiation rate 14.6% and 18.7% respectively, but 22-2 and Liangshu 97 without any shoot diff-errentiation..For the stem,the greatest root differentiation rate of Sichuan zao from calus was 31.3%, the majority of media have root split,but it's non-shoot differentiation; Chuanyu No.5 has only few root differentiation, highest differentiation rate is only 6.3 %,and shoot differentiation accurred only No. 4,6 medium.(3) The results showed that in induction medium supplying the concentration of 0.01mg/L PP₃₃₃(Paclobutrazol) ,leaves and stems can generate well callus,and stems can be induced shoots and roots to the highest rate of differentiation,respectively 22.8%and 14.8 %;each concentratin of PP₃₃₃ did not deal with the shoot differentiation on leaves,and with the increasing concentration,roots differentiation was gradually inhibited.