机构地区: 中山大学生命科学学院生物系
出 处: 《植物生理学报(0257-4829)》 1995年第2期159-165,共7页
摘 要: 在荔枝和龙眼种子发育过程中,内源ABA水平先是上升,至大约78~80DPA时出现高峰,之后两者ABA含量均不断下降。果实成熟时采收的种子,ABA含量比高峰时分别下降近6倍。另外,随着种子的发育,种子及其胚轴对外源ABA的敏感性(SABA)亦持续下降。10-4mol/LABA可以完全抑制90DPA前的荔枝和龙眼种子的萌发,但对成熟种子10-2mol/LABA亦不能抑制其萌发。龙眼种子离体胚轴的SABA高于荔枝。ABA含量与敏感性的这种变化可能是两种顽拗性种子成熟时萌动,进而不耐脱水贮藏的重要原因之一。 ABA contents, measured by enzyme linked immunosorbent assay(ELISA), increased obviously duringearly developttiental stagal of lycheeand longan seeds (Fig. 1). When itPeaked at 78  ̄ 80 days pet anthesis(DPA), ABA content was 986 ng/gDW in lychee seeds, and 1128 ng/gDW in longan seeds, then declinedmarkedly in both species. At harvest,ABA content of lychee and longanseeds was 144, 169 ng/g DW, respectively. Moreover, the sensitivity toABA (SABA ) of seeds (Fig. 2 ) andtheir isolated embryonic axes (Fig. 3)decreased during development. 10-4mol/L ABA could completely inhibitthe germination of lychee and longanseeds before 90 DPA; however, even10-2 mol/L ABA failed to completelyinhibit the germination of seeds harvested at full maturity. For young embryonic axes, 10-7 mol/L ABA inhib-ited their germination incubated onwoody plant medium (WPM), wheras10-4 mol/L ABA could hardly inhibitthe germination of embryonic axes iso-lated from mature seeds. The SABA oflongan embryonic axes was higher thanthat of lychee ones. The ABA contentand sensitivity in relation to seed reCalcitrance was discussed.