Study On In Vitro Regeneration And Variation Induction Of Pear

In this experiment, the shoot tip culture, leaf culture, anther culture and colchicines were conducted to investigate the mutational induction of different material from pear. The results were summarized below.1. Take’Cuiguan’,’Huanghua’and’Yali’three varieties stems and leaves as explants to explore the types of media, plant growth regulator, sucrose concentration and dark cultured pear shoot tip culture and leaves the impact of culture plant regeneration. In this paper, the effects of different combinations of plant growth regulators, sucrose concentrations, medium formations and dark treatment on callus induction and shoot formation were examined. The results were as follows:choose the axillary’s buds in the young shoots of sugarcane for being tissue culture of inoculation from outward plant body to be parted from body utilize 70% alcohol steep 10～15s,0.1%Hgc12 antisepsis 8 min multiplication antisepsis clean again and again. Cuiguan’s optimum media was 6-BA 1.50mg/L+IBA 0.3mg/L+GA32.0mg/L, the multiplication coefficient was 12.8. The rate of number rooting of the regeneration was 100% and the means number of roots was 7.9 in the media 1/2MS+0.5mg/LIBA.2. The correlation between microspore development stage and morphological characteristic of flower organ in pear, this paper studied the effects of cold shock treatments on activity of pear’s microspore. The results showed that there were tetrad phase, uni-nuclear phase and binuclear phase and there was significant difference in cytological characteristics of microspore development and microspore development period was closely related to morphological characteristics of buds and color of anthers, especially the size of buds, The buds 0.7-0.9 cm in diameter and 1.2-1.4 cm in length, were discovered to contain more microspores at the late-uni nucleate. The research results could provide a scientific basis to select suitable explants in anther culture of pear. Low temperature pretreatment for 2 to 3 days was better for inducing callus. MS medium supplemented with 2,4-D(1.0 mg/L), NAA(0.4mg/L) was the best for induction of callus, The most suitable sucrose was concentration of 30 g/L.3. Polyploidy induction technique of pear, by treating pear shoot, segments and calluses in vitro with colchicines, inducting anthers callus in vitro and identifying plantlet ploidy of pear in vitro, were studied. Mosaic material of ploidy was obtained, which would lay a suitable foundation for pear ploidy selection in the future. The main results were as following:the leaves of pears as induced polyploidy materials, high induction rate of callus, but all of callus did not differentiate to generate seedlings. Plantlets stem segment as polyploid induction materials, pharmaceutical culture was not as good as the impregnation, dipping 24 h can be chimerical plants with 0.1% colchicine, variation rate of 22.6%; by flow cytometry of chimerical plants of ploidy level, successful tetraploid mixture.