Effects Of Several Plant Growth Regulators On The Growth Of In Vitro Potato Plantlets

As basic stock of potato breeding and multiplication, to obtain vigorous seedlings in vitro was a crucial step. How to obtain vigorous seedlings with health roots, thick stems and more functional nodes would be beneficial for inducing micro tubers. It was also a practical mean to boost popularization of new varieties.Two varieties breed by laboratory of potato, institute of crop, agricultural academy of Qinghai province were applied to this test that are Qingshu 2 which was the high starch variety and Qingshu 6 which was the processing food varieties. In order to provide theoretical basis for rapid propagation, the effects of plant growth regulators on growth of in vitro potato platelet was studied. And the optimized culture system of different varieties of in vitro potato platelet was established. The major experimental conclusions were as follows:1. The effects of kinds and concentration of plant growth regulators on plant height and leaf number of two varieties in vitro potato platelet was studied by orthogonal test design L16(45). The five-factor were 2,4-D,6-BA,NAA,KT and GA. The result showed that significant effect of different kinds and concentration of plant growth regulators on plant height and leaf number, which meant genetic background among varieties tested were different, and separate medium should be adopted for various varieties.2. The test of the significance of difference was showed that 2,4-D had the most prominent effect on plant height followed by NAA, 6-BA, GA and KT. The best medium for lengthwise growth was MS with 2,4-D0.5 mg/L, 6-BA1.0 mg/L, KT0.9 mg/L and GA6.5 mg/L; NAA had the most prominent effect on leaf numbers followed by KT, 6-BA, 2,4-D and GA. The best medium for leaf growth was MS with NAA0.1mg/L, 6-BA1.0 mg/L, KT0.1 mg/L and GA3.0 mg/L.3. It was screened out the optimum formula of plant growth regulators for culture medium of two varieties in vitro potato platelet. The best medium for growth of qingshu 2 was MS with 2,4-D0.5 mg/L, 6-BA1.0mg/L,KT0.9 mg/L and GA6.5 mg/L the growth; The best medium for growth of qingshu 6 was MS with 2,4-D2.5mg/L,6-BA2.0mg/L,KT0.1 mg/L and GA10.0 mg/L.4. The mathematical model of different plant growth regulators and different explants on growth of in vitro potato platelet were established by D-saturating optimum design. Those were the optimum formula: the best explants number was 7—9; the best concentration of 2,4-D was 1.32mg/L—2.514mg/L; the best concentration of 6-BA was 1.05mg/L—1.95mg/L;the best concentration of NAA was 0.165mg/L—0.335mg/L; the best concentration of KT was 0.35mg/L—0.65mg/L,and the best concentration of GA was 3.5mg/L—6.5mg/L.