Screening And Evaluation Of Wild Potato Resources Resistance To Potato Y Virus

Viral disease was a severity disease to potato, especially potato Y virus. If the potato was infected by PVY, its yield would be decreased 50%. When the potato was infected by PVY and PVA simultaneously, the yield can be decreased 80%. Meanwhile PVY can affect quality of potato severely,and cause potato seed to degrade. Improved cultivars ware the basis method for overcoming PVY.The cultivated potato was short of genes for resistance to PVY, so it was very difficult to cultivate the anti-PVY new varities through intervarietal crossing. The report, by Ross and East, indicated that wild potato species (Stoloniferum, Chacoense) and Neo-tubersum constitute an important source of genes for immune or hypersensitive to PVY. Wild potato species were extremely abundant, and constitute an important resource of genes for precious characters. But many of these resources have been not exploitated, and the resources being collected had been not utilized thoroughly. There were only a few wild sources utilized. So it was eventful significance that identification and screening resources resistance to PVY from wild potato resources to potato anti-PVY breeding.In this experiment, 37 portions of nominal samples with PVY symptom were collected from planting potato region in Kushan, which was the one of potato main production zones HeiLong Jiang. Through inside detection and identification, a piece of sample with high PVY content was chosen from these nominal samples. This sample was preserved in Nicotiana tabacum as viral source in the next year after isolation and purification. Five wild potato populations were appraised and evaluated on resistance to PVY. To gain stuff with superior combined characteristics and resistance to PVY, the main botanic and biological characters of these test materials were observed. This experiment will provide information for utilizing wild potato germplasm resources and experience on screening and utilizing resistance sources to PVY. The results were as following:1. Through ELISA detection, there were all PVY in 37 portions of nominal samples. 35 portions of these were mixed infected, and only 2 portions were infected with PVY exclusively. The one with higher PVY content was chosen as viral resource to inoculate in the next year after identification.2. There was apparence difference on resistance to PVY in five wild potato populations. S.stoloniferum (S.A2)×S.stenotomum ( the 104 population ) and S.stoloniferu(S.A5)×S.stenotomum (the 105 population)belonged to resistance populations, which were the strongest resistance population to PVY in five populations. S.chacoense×S.stenotomum.(the 103 population)and S.demissum○×(the 101 population)belonged to moderate resistance populations, and S.chacoense○×(the 102 population)was belong to sensitive population3. There were 351 stubs totally in this experiment. 108 stubs belonged to zero class which was the strongest in resistance classes to PVY. 56 stubs belonged to the first class which was the second strong class resistance to PVY. The selective ratio of stubs belonged to zero and first class were different in five populations. The 104 population and the 105 population were the highest in the five populations. The second was the 103 population. There was not the zero class stubs in the 101 population, but the third class stubs reached up to 69 percent in the 101 population, so this population separated tinily on resistance to PVY. There were 94 the third class stubs in 351 stubs.4. Through analysis and comparison of yield characters among five populations, the S.stoloniferum(S.A2)×S.stenotomum population was the best for chosing stub with high yield in five populations,and there was apparent difference on tuber-bearing ratio in five populations, The 101 population had the lowest ratio, and there were none to bear tuber. The next was the 103 population, and the ratio was 28 percent. But the 104 population was similar to the 105 population, they had high tuber-bearing ratio which was over 70 percent. The above indicated that S.chacoense and S.stoloniferum may be superior on tuber bearing.5. Through investigated main botanic and biological characters, 45 stubs were screened from 351 ones. First of all, they were all belonged to zero or first class, then they were superior on main botanic and biological characters.