Studies On The Relation Between Pollen Viability And Chilling Tolerance Of Cucumber

Pollen is one of the genetic materials, there is high meaning in practice for its germination character under low temperature to the breeding of cold tolerance. In this experiment, 22 cucumber varieties were selected as test materials. The experiment analyzed the best method to mensurate cucumber pollen viability, the pollen viability and its influence factors, and the best low-temperature to distinguish the pollen germination rates of different varieties and compages of florescence temperature and germinarion temperature. We hope the results of experiment can offer theoretics and data to chilling tolerance varieties selection. The result showed:1. Four testing methods to detect the pollen viability of cucumber were being compared. The results indicated that I-KI staining method and acetic red dyeing were not suitable to judge the pollen viability of cucumber. Tetrazolium method can be used but the error is oversize. By and large, the Germination in vitro method was an efficient, stable and simple way to judge the pollen viability of cucumber. The component of culture medium is 10% sucrose+ 100mg/L H₃BO₃. If inoculated intraday, collect pollen of fresh abloom flower at 6:00 and if inoculated at the second day, collect before dark. The observe time is different at different germination time.2. The experiment that the influence of germination temperature to pollen germination rate selected 11 cucumber varieties, the pollen germination rates of different varieties were no obvious difference in 25℃and the pollen germination rates all exceeded 85%. As the debasing of germination temperature, the pollen germination rate of every variety going down obviously, most varieties went down to 20% - 40% and some varieties went down to fewer than 20%. The result showed that 12℃can be the temperature to distinguish the pollen germination rate of different varieties in low temperature.3. The pollen germination rates of 11 cucumber varieties were mensurated in the different florescence and germination temperatures. The results showed that: as the debasing of temperature, pollen germination rates were all going down, the interaction of florescence temperature and germination temperature is high significant, the effect of florescence temperature to pollen germination rate was significant and germination temperature to pollen germination rate was high significant, the effect of germination temperature to pollen germination rate was bigger than florescence temperature. The best temperature compages to distinguish pollen viability of different varieties was 9℃(florescence temperature)/ 12℃(germination temperature).4. The correlation of plant chilling tolerance and pollen germination rate was studied by using climatic chambers, the results indicated that data of the fourth day could reflect the difference of different varieties'chilling tolerance. The correlation of chilling injury index and pollen germination rate was significant in 0.01 level. It means that we can use pollen germination rate to cucumber chilling tolerance evaluation. The correlation of the second leaf area increment and the second +third leaf area increment and chilling injury index were significant in 0.05 level. So we can use the second leaf area increment and the second +third leaf area increment to cucumber plant chilling tolerance evaluation.