| Sweet cherries(Prunus avium L.),also known as big cherries and European cherries,are one of the earliest fruit tree species among the deciduous fruit trees in northern my country,and their fruit has extremely high nutritional and economic value.The Gisela series(Gisela)is an intercultivated triploid hybrid cherry rootstock with good grafting affinity,disease resistance and waterlogging resistance.At present,there has been a great deal of research on the rapid propagation of Gisela rootstock,but there are relatively few studies on the improvement of the growth status of subculture tissue culture seedlings by changing the light quality and using incubation bags instead of the commonly used histoculture bottles as culture containers.At the same time,the problems of primary pollution rate and vitrification in secondary culture still need to be optimized.Therefore,the establishment of Gisela stock tissue culture rapid propagation system is necessary to meet the needs of commercial mass production.In this thesis,based on the previous research,we carried out the research to optimize the rapid propagation system of Gisela series rootstock tissue culture,to reduce the contamination rate by selecting suitable explants in primary culture,to screen out the most suitable medium agar concentration,sucrose concentration,phytohormone type and ratio and optimal light quality for Gisela proliferation and differentiation in subculture,to compare the differences between bag rooting and traditional bottle rooting in rooting culture,and to screen out the optimal NAA concentration to induce rooting of Gisela,which provides a certain theoretical basis and technical support to promote the development of cherry industry.The main results are as follows:(1)For subculture,the optimal medium and hormone ratio should be MS+ 6.2 g/L AGAR +30 g/L sucrose + 1.0 mg /L 6-BA with a p H of 5.7.(2)When the the agar concentration was 6.2 g/L,the tissue cultured seedlings grew well,the leaves were unstretched and of moderate size,the color was dark green,and the average height and proliferation coefficient of the tissue cultured seedlings were high(2.39 cm and 3.08,respectively).When the agar concentration was lower than 6.2 g/L,vitrification was easy to occur.When AGAR concentration was higher than 6.2 g/L,leaf was prone to wilt.(3)When sucrose concentration was 30 g/L,tissue cultured seedlings grew well,with dense clusters,tall and straight plants,unstretched leaves of moderate size and emerald green color,and the average height and proliferation coefficient of tissue cultured seedlings were the highest,2.53 cm and 5.0 respectively.Vitrification occurs when sucrose concentration is higher than 30 g/L,and yellowing and aging occurs when sucrose concentration reaches 40 g/L.(4)The most appropriate medium should be 6-BA as the only exogenous hormone at a concentration of 1.0 mg/L.When the concentration of 6-BA was 1.0 mg/L,the growth of the cluster buds was vigorous,the leaves were large and unspread,the leaves were dark in color,and the average height and proliferation coefficient of the tissue culture seedlings of Gisela sweet cherry rootstock were higher,with a specific ratio of 2.01 cm and 4.13.After IBA was added to the culture medium,the growth of Gisela tissue culture seedlings was weaker than that of tissue culture seedlings with 6-BA as the only exogenous hormone,and vitrification phenomenon occurred.In addition,the leaves were folded,the area decreased,and the color of the leaves was lighter.(5)In this experiment,seven different light qualities were set,including FL(fluorescent lamp control),R(LED red light),W(LED white light),2R1B(LED red and blue light ratio 2:1),1R2W(LED red and blue light ratio 1:2),1R7W(LED red and white light ratio 1:7)and Y(LED full spectrum).The suitable red and white light proportional culture could promote the proliferation of Gisela subgeneration,in which the tissue culture seedling proliferation effect was significant when the light quality was 1R2 W,and the proliferation coefficients of Gisela 5,6 and 12 were 10.25,9.00 and 6.33,respectively.The red and blue light had no obvious promotion effect,that is 1R2W>1R7W>Y>R>W>2R1B>FL.Under different light quality treatment,there was significant difference in the growth height of Gisela 5 and 12,but no significant difference in Gisela 6.When the light quality was Y,the promotion effect of tissue culture seedling height elongation was significant.The average height of Gisela 5,6 and 12 was 1.91 cm,1.54 cm and 1.63 cm,respectively.The higher the red light/white light ratio was,the higher the growth height of tissue cultured seedlings was.W had no promoting effect on the height elongation of tissue cultured seedlings.The average height of no.5,no.6 and no.12 was only 1.47 cm,1.55 cm and 1.11 cm,that is Y>R>1R2W>1R7W>2R1B>FL>W.Therefore,1R2 W is the most suitable light quality for Gisela tissue culture seedling proliferation,followed by LED full spectrum.(6)The appropriate NAA concentration for rooting culture is 0.3 mg/L or 0.2 mg/L.When NAA concentration was 0.3 mg/L,gisela tissue culture had the highest rooting rate.When NAA concentration was 0.2 mg/L,gisela tissue culture seedlings had longer rooting length and softer,and the survival rate was higher.When NAA concentration was 0.1 mg/L,Gisela tissue cultured seedlings had fewer rooting quantity and shorter rooting length.(7)The rooting rate of tissue culture seedlings in bagged rooting culture was lower than that in bottle rooting culture.Sufficient space should be set aside for the growth and development of tissue culture seedlings.When NAA hormone concentration was 0.2 mg/L,the rooting rate was the highest(22.22%),which was not significantly different from that of 0.3 mg/L,and when NAA hormone concentration was 0.1 mg/L,the rooting rate was the lowest(10.00%),and the rooting rate was significantly different from that of tissue cultured seedlings with 0.2 mg/L and 0.3 mg/L. |
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