| Establish stable, efficient leaves Shoot regeneration system is pear transgenic successful key link. The stem segment or apex explants taken from shoot of pear were tested by in vitro culture to establish high regeneration system. The effect of different hormonal combinations in the MS,AS and 1/2 MS medium on the rate of budding from plantlet leaf and stem segment, According to media formulations and culture conditions, and on this basis by combining orthogonal design and analysis of variance and multiple comparisons, and the rate of bud rooting were studied after having gained initial in vitro plantlet successfully. The achievement of the experiment had laid a foundation for transgenic breeding and rapid propagation in pear. The main results gained were as follows.1,Explants disinfection and Initiation of cultureThe optimal sterilization schedule was treatment with 75% ethanol for 10 seconds, then with 0.1% HgCl2 for 4 minute. The suitable bud induction medium of shoot was 1/2 MS+BA 0.5 mg/L + IBA 0.2 mg/L.2,Multiplication of shootThe suitable medium for shoot multiplication for"yali"were developed on 1/2 MS medium containing 0.8 mg/L 6-BA ,0.3 mg/L IBA and 0.5 mg/L GA3, the propagate was 3.83. The suitable medium for shoot multiplication for"huangguan"were developed on AS medium containing 0.8 mg/L 6-BA , 0.1 mg/L IBA and 0.5 mg/L GA3,the propagate was 3.56. The basal medium have no affected the multiplication and growth of shoot, but different treatment of 6-BA have evident affected the multiplication and growth of shoot.3,Plantlet regenerationAdventitious bud was regenerated from in vitro leaf of two pear cultivars. The efficient adventitious bud regeneration system were developed for'yali'and'huangguanl'pear. The in vitro culture of leaf with 1/2 MS medium for basic, add different TDZ and IBA, The result showed that the suitable regeneration medium for"yali"was1/2 MS medium containing 2.5 mg/L TDZ and 0.5 mg/L IBA; the suitable regeneration medium for"huangguan"was 1/2 MS medium containing 0.5 mg/L TDZ and 0.5 mg/L IBA. Under the favorable conditions,Leaf regeneration frequency of"yali"and"huangguan"was 65.28%, 66.67%;The average number of regenerated buds was 4.78 and 3.17.4,Rooting of shoots The medium of 1/2 MS salt complex added 1.0 mg/L IBA was effective to rooting for"yali"and"huangguan", in which the number and length of root induced was higher than other treatments markedly. |
