甘蓝型油菜成熟角果内源激素对带壳种子发芽的影响

以甘蓝型油菜品系832、780、1-1、1-13、8-6为材料，进行了田间带壳种子发芽调查、室内模拟降雨带壳种子发芽试验、种子发芽试验、不同浓度ABA处理的种子发芽试验，并利用HPLC测定了鲜果壳和种子的吲哚乙酸(IAA)、细胞分裂素(CK)和脱落酸(ABA)的含量。结果表明，各供试甘蓝型油菜品系带壳种子发芽率存在极显著差异，而不带壳种子的发芽率在第5 天以后没有显著差异。油菜成熟角果的果壳ABA含量与带壳种子发芽存在显著负相关（r＝－0.8941），带壳种子发芽主要受果壳所含ABA的抑制；外源ABA能明显抑制种子发芽。

Effects of Endogenous Hormones on Pre-Harvest Sprouting in Siliqua of Rapeseed (Brassica napus L.)

Rapeseed is one of the most important oil crops in China.It often encounter with the high temperature and humidity or continuous raining at the maturity stage,which results in pre-harvest sprouting.Pre-harvest sprouting will cause the decrease of seed yield and quality.In order to screen out Brassica napus lines resistant to pre-harvest sprouting and elucidate the major factor(s)inhibiting pre-harvest sprouting,the rate of pre-harvest sprouting and germination of the freshly harvested seeds of the five Brassica napus lines including 832,780,1-1,1-13,and 8-6 were investigated under field conditions or under various stimulated conditions in laboratory,and the contents of the endogenous hormones abscisic acid(ABA),indole acetic acid(IAA),cytokinin(CK)in fresh seeds and shells were determined with high performance liquid chromatography(HPLC).The results showed that there were significantly different rates of pre-harvest sprouting among different lines under field condition and under various stimulated conditions in laboratory,but no significant difference in seed germination rate after five days of the germination text.The higher ABA content in shells the lower rate of pre-harvest sprouting.The ABA content in shells was significantly and negatively correlated with rate of pre-harvest sprouting(r=-0.8941).CK in shells could obviously increase the rate of pre-harvest sprouting while IAA in seeds could promote early seed germination.Treatments of seeds with ABA at different concentrations showed that ABA(20 mg L-1)could effectively inhibit the seed germination.