王立 周明德 曾勤
摘要 对刚采收下的茶籽,进行不同方法的脱水干燥和低温、超低温(-196 ℃)处理后,用沙播法测定其发芽率。结果表明,在短期内,茶籽即使脱水至2.3%的含水率,仍能保持70%的发芽率。将茶籽干燥至8%~10%含水率,在-196 ℃液氮中贮藏2个月,其发芽率没有变化,表明利用超低温长期保存茶籽有望得到解决。从本试验脱水干燥和冷冻损伤处理结果看,茶籽的贮藏特性应归属于正常型种子。
关键词:茶籽 贮藏特性 超低温保存 脱水干燥
中图分类号:S571.1 S330.3 文献标识码:A
Study on Storage Characters of Tea Seed
Wang Li,Zeng Qin
Tea Research Institute,Chinese Academy of Agricultural Sciences,Hangzhou 310008
Zhou Mingde
East Asia Office,International Plant Genetic Resource Institute,Beijiang 100081
Abstract The newly plucked tea seeds were treated with various desiccation methods,low temperature and ultra low temperature (-196℃),and then,the germination of the seeds was tested by sand culture method.Results showed that tea seeds had 70% germination rate even when the water content was lowered to 2.3%.No damage was observed to the germination of tea seeds when the water content in tea seeds were lowered to 8%―10% and kept for 2 months under -196℃.According to this investigation,tea seeds should not be classified into the recalcitrant type,as most botanists believed.Tea seeds should be classified as normal type seeds.This result will direct us to further investigate the storage technique of tea seeds.The problem for long-term storage of tea seeds will be solved.
Key words:Tea seed Storage character Ultra low temperature storage Desiccation
0 前言
贮藏种子,是保存作物种质资源的重要方法之一。然而,茶树的种子却不易长期保存,即使贮藏得当,其发芽率也只能维持一年左右[1,2],无怪乎长期来有人把茶籽的贮藏特性列为顽拗型种子[3―5]。正因为如此,在茶树种质资源保存上国内外都采用建立资源圃或品种园的方法。这虽然比较可靠,但大量资源采用田间种植存在一些问题,不符合现代化保存种质的要求,不但用地和保存的费用高,而且极易受灾害性天气和病虫害等胁迫,达不到长期保存的要求[4,6]。因此,近年来茶树种质资源保存方法一直备受中外茶叶科学工作者的关注。中国农业科学院茶叶研究所自1991年起,就茶资源室内保存技术进行了全面的研究[6]。其中,对处理后的茶籽在液态氮(-196℃)中保存,经17个月冷藏,50粒茶籽的发芽率为60%,比贮藏起始期的发芽率76.5%下降了16.5个百分点。郭长根等[7]在超低温(-196℃)条件下,经118天贮存后的茶籽发芽率达93.3%。日本在0℃~5℃条件下密封贮藏可保存9年[8]。近年来,印度也针对大叶种茶籽的贮藏特性进行了立项研究。所有这些,都未能对茶籽贮藏特性作出结论。因此,本试验重点从茶籽的脱水伤害和对低温的敏感度等方面,研究了其贮藏特性,并进一步确立茶籽所属之类型,旨在为茶籽的长期保存技术提供依据。