Study On The Vertical Transmission Route Of Apple Stem Grooving Virus

Apple virus was characterized by its strong harm, fast spreading, hard to cure and so on.The impacts of apple virus on China Apple Production is increasing at present. The apple stem grooving virus, which has strong harm to Apple Production and is difficult to remove, is one of the important apple latent recessive virus. Therefore, the research on this virus spreading ways is very important.Whether the virus is transmitted through seeds, and especially clearing the probability is imminent. The RNA extraction of mature tissue from apple skin, fruit flesh, seed coat and embryos, and the distribution of apple stem grooving virus in fruit and seeds by means of RT-PCR technique were studied with fruit and seeds from virus-carried red Fuji apple trees. Meanwhile, the virus seed-spreading rate was studied with seeds of Malus micromalus Makino (Malus spectablis var . micromalus Koidz). Carried apple stem grooving virus. And the virus sap-spreading possibility by means of RT-PCR was also studied with virus-free and virus-carried Orin apple seedlings cultured in vitro respectively. The main results were as follows:1. On the one hand, the optimum amount of mature plant titusse was different when the total RNA of different organs were extracted with the same RNA extraction reagent. On the other hand, the optimum amount was also different when the total RNA of the same apple part was extracted with different RNA extraction reagent. The results showed that the optimum amount of mature plant titusse were: 0.025g seed coat, 0.05g embryos with RNAiso Plus and RNAiso-mate for Plant Tissue mixed RNA extraction reagent. However, the optimum amount were: 0.075g apple skin, 0.25g flesh, 0.015g seed coat, 0.025g embryos with the total RNA plant extraction reagent.2. Both the apple skin and fruit flesh carried apple stem grooving virus when the apple trees were infected.3. Seeds could also carry this virus, because it infected the surface texture of seed coat. But the embryos were free. This virus carried by the surface texture of seed coat could be killed by NaOH or Na3PO4 ?12H2O. The germination rate of seeds soaked with Na3PO4 12H2O was significantly higher than seeds soaked with NaOH.4. The apple stem grooving virus could be transmitted through seeds of Malus micromalus Makino (Malus spectablis var . micromalus Koidz). The rate of virus-carried Seedlings that from seeds of virus-carried mother trees was 5.89‰. 5. This virus could be transmitted through sap when plants were cultured in vitro, and the rate was 2.08﹪.