桑树种质资源超低温保存效果与芽休眠状态关系探讨

打开文本图片集

Abstract： This study aimed to investigate the efcts of bud dormancy states in mulberry germplasm resources on post-cryopreservation survival rates，providing a scientific basis and technical support for identifying optimal dormancy stages for cryopreserving dormant buds. One-year-old branches of Husang 32 were sampled during winter on December 8，18，and 28，2023，and January 7，2024.We measured the budding rates，first bud germination times，and the contents of carbohydrates，osmotic regulating substances and endogenous hormones in dormant buds. Survival rates following cryopreservation and recovery were subsequently analyzed.Results showed two dormancy stages，transition from endodormancy to ecodormancy and endodormancy release into ecodormancy，as well as three dormancy depths including deep dormancy （December 8），moderate dormancy（December 18 and 28） and shalow dormancy（January 7），based on the budding rates and the first bud germination times. The maximum survival rate of cryopreserved mulberry dormant buds reached 90% .Survival rates decreased with endodormancy release，reaching their lowest levels in shallow dormancy buds （January 7）. During the process of endodormancy of Husang 32，soluble sugar content in dormant buds initially increased，peaked during moderate dormancy（December 28），and then declined.The starch and soluble sugar contents showed inverse trends.Soluble protein and proline contents increased with endodormancy release.Endogenous hormones levels，such as abscisic acid（ABA），gibberelin（GA3），auxin （IAA）and jasmonic acid（JA），were significantly higher in deep dormancy buds （December 8） than in other stages.The results showed that the dormant buds of mullberry in deep dormancy and moderate dormancy collected in December were ideal materials for cryopreservation of mulberry germplasm resources.

Key words： mulberry;germplasm resources ;cryopreservation;dormant buds ;dormant states

桑树（MorusalbaL.）是桑科桑属的多年生木本植物（落叶乔木或灌木），具有较好的药用、经济和园林观赏价值。（剩余16364字）