【作者】 及华；

【导师】 葛会波； 魏景芳；

【作者基本信息】 河北农业大学 ， 果树学， 2002， 硕士

【摘要】 本试验通过对梨S系矮化砧离体再生培养过程的研究，筛选出了直接诱导再生的适宜外殖体和诱导时期，提出了试管苗继代增殖、生根、驯化移栽和微嫁接的主要影响因子。建立了梨S系矮化砧组培快繁的技术体系。主要结果如下： 1．3月份的嫩芽（萌发芽）比休眠芽和4月～6月的茎尖诱导成功率高，1/3MS+6-BA1.0（mg/L，单位下同）+IBA0.2+GA₃1.0+蔗糖25g/L+琼脂6.5g/L适于外殖体初代培养。外殖体褐变与多酚氧化酶活力和总酚含量密切相关，PPO活力高峰出现在4月份，总酚含量和褐变率高峰出现在5月份。 2．MS+6-BA1.0+IBA0.2+GA₃0.1+蔗糖20g/L+琼脂6.5g/L适宜试管苗继代增殖培养，增殖系数随培养代数的增加而提高，10代以后进入分化高峰期，17代以后开始下降。控制培养基中6-BA浓度低于2.0mg/L和GA₃浓度低于0.2mg/L及使用组培专用封口胶可以有效提高试管苗分化质量，防止玻璃化苗产生。 3．建立了S系矮化砧试管苗生根的技术体系。二步生根法优于一步生根法，首先必需选择充分幼化（12代以后）且生长健壮的试管苗，先在附加IBA2.0mg/L的ASH培养基中暗培养7～9d，以促进根原基的形成，然后转入无激素的ASH+蛭石培养基中光下进行根伸长培养。培养基中添加80～100mg/L间苯三酚可以明显促进IBA2.0mg/L对试管苗生根的诱导效果，单独施用间苯三酚不能诱导不定根发生。试管苗的生根率随继代培养代数的增加而提高。 4．环境条件是试管苗驯化移栽的关键因素。S系矮化砧试管苗移栽前需经闭口强光炼苗10d，然后移栽到蛭石基质中，湿度保持在90％～1006，以后逐渐通风和增加光照，30d后栽入营养钵中。驯化移栽的时期宜选在春季（4月～5月）。 5．经过生根培养基诱导而未生根的无根苗，在适宜的湿度（70％～75％）、温度（25℃）、光照（初期遮光）等环境条件下，嫁接到半木质化杜梨实生砧木上，可以得到较高的成活率。微嫁接技术进一步完善了S系矮化砧组培快繁技术体系。更多还原

【Abstract】 Through the studies on regeneration of in vitro culture of S series dwarfing rootstock of pear, the proper explant induced directly and the time of induction were chosen, and die main influencing factors of multiplication ,rooting .training, transplanting and niicrografting were evaluated, At the same time, some improving methods were put forward. Technical system of tissue culture and rapid propagation of the S series dwarfing rootstock of pear was established. The main achievements were as follows:The survival rate of the shoot tip explant in March was higher than that in winter and April桱une, 1/3MS + 6-BA1.0 (mg/L, follows as the same) + IBA0.2 + GA31.0+ 2.5%sugar +0.65% agar was most suitable to initiatory culture of the explant. The browning of explant is relative to the PPO activity and the total phenol contents existed in the explant, The highest PPO activity occured in April, and the total phenol contents and browning rate are highest in May.MS+6-BA1.0+IBA0.2+GA30.1+2.5%sugar +0.65% agar was suitable to subculture of adventitious bud. The more of the subculture times, the higher of the coefficient of multiplication, The coefficient increased rapidly after the tenth subculture and decreased begun in the seventeenth subculture. 6-BA concentration under 2.0mg/L, GA3 concentration under 0.1 mg/L and use appropriative sealing material could improved the quality of adventitious shoot and overcome vitrification.Technical system of rooting of the adventitious shoots was established. Two-step-rooting method is better one-step-rooting method, That is, Firstly selecting the juvenile and vigorous shoots , Secondly culturing the shoots in the ASH medium with 2.0mg/L IBA for 7~9d in the darkness in order to promote the formation of primordium of root, then transfering the shoots into the ASH +vermiculite medium without IBA in the light. Adding 80~100mg/L trihydroxybenzene (PG) into the medium promoted on rooting with IBA, but had no effect on rooting without IBA. The more of the subcultural times, the41higher of the rooting ratio.The environmental conditions were main factors of training and transplanting of the rooting shoots. The rooting shoots must be trained for lOd in the light with the sealing material before transplanting , and then transferred into vermiculite medium with 90%~ 100% humidity , winding and lighting gradually after that, then the rooting shoots were transferred into the pots after 30d. Spring (April~May) is most suitable for the in vitro plantlet training and transplanting.The survival ratio was high when the shoots without rooting after induced in rooting medium were grafted on semi-wooden rootstock ofPyrus betulaefolia Bge. The technical system of tissue culture and rapid propagation of the S series dwarfing rootstock of pear was further perfected through the micrografting.更多还原