花生种间杂种胚胎发育及内源激素变化

以花生栽培品种豫花15为母本分别与野生种A. correntina和A. macedoi杂交，以栽培品种间杂交组合豫花15×白沙1016为对照，采用石蜡切片技术观察花生杂种胚胎发育进程，酶联免疫吸附分析法(ELISA)测定花生杂种胚胎内源激素含量, 分析胚胎发育进程与胚胎内源激素含量的关系。结果显示，3个杂交组合的下针率无明显差异，表明栽培种与2个野生种杂交不存在受精前障碍；与对照相比，豫花15×A. correntina表现杂交可亲和，其胚胎发育中激素含量的变化与对照组合基本一致；而豫花15×A. macedoi杂交授粉后12 d内胚胎发育基本正常，17~27 d发育缓慢，之后珠被迅速向内增生抑制了胚的进一步发育并最终败育，在同一时期的杂种胚胎中，3-吲哚乙酸(IAA)、赤霉素(GA₃)和玉米素核苷+二氢玉米素核苷(ZR+DHZR)等促进生长的激素维持在较低的水平，而脱落酸(ABA)含量以及脱落酸与某一促进生长激素或3类促进生长激素之和的比值保持了较高的水平，推测可能是激素代谢的失衡导致种间杂种胚胎的败育。用IAA、激动素(KT)单独或混合处理不亲和组合豫花15×A. macedoi杂交授粉后的果针基部表明，外施促进生长的激素能够明显增加胚珠的长度，一定程度上验证了上述推测。

Embryonic Development and Changes of Endogenous Hormones in Interspecific Hybrids between Peanut (A.hypogaea L.) and Wild Arachis Species

The peanut cultivar Yuhua 15 was used as female parent to cross with wild species A. correntina and A. macedoi, respectively, with intervarietal cross Yuhua 15 × Baisha 1016 as check. There were no significant differences observed in pegging percentage among all the crosses. It indicated normal fertilization in the interspecific crosses. Embryo development was observed through paraffin sections, and contents of endogenous hormones including IAA, GA₃, ZR+DHZR, and ABA in the developing embryos of hybrids were determined with ELISA. In comparison with normal seed development of Yuhua 15×Baisha 1016 and Yuhua 15×A. correntina, Yuhua 15×A. macedoi was incompatible due to a deterred embryo development at approximately 12–17 days after pollination followed by the hyperplasia of integument into the embryo sac which suppressed further development of the embryo and finally resulted in abortion. Compared with two compatible crosses, the ABA content and ratios of ABA to total of other auxin in developing embryos of cross (Yuhua 15×A. macedoi) were relatively higher at the early development stage, while the contents of IAA, GA₃, and ZR+DHZR remained at a relatively lower level, which speculates on that abnormal hormone activities may be an important reason leading to the abortion of hybrid embryos. Peg bases of Yuhua15×A. macedoi were treated with IAA, KT, or mixture of the two, showing that the exogenous hormones can increase the length of ovule.