胀果甘草花粉生活力测定及甘草的杂交育种

Determination of Pollen Viability of Glycyrrhiza inflata and Hybridization Study of Licorice

杂交育种是最为传统的选育新品种的方式之一,花粉生活力能够影响其中遗传物质的传递。胀果甘草是3种药典收录的甘草之一,具有许多特殊活性成分。通过TTC法和离体萌发法对2个胀果甘草(Glycyrrhiza inflata)种质资源GJJ-7和GJJ-9花朵开放5个时期(a~e)的花粉生活力进行测定。结果表明,GJJ-7花粉生活力趋势在5个时期呈现波浪型,在a、d时期达到最高;GJJ-9花粉生活力会随着花瓣展开度的变大而升高,在e时期达到最高。离体萌发结果表明GJJ-7和GJJ-9花粉生活力随花朵开放程度增大呈先升高后降低的趋势,萌发力均在c时期最高。杂交结荚率则与离体萌发结果一致,说明离体萌发法测定花粉生活力比TTC法更可靠。以光果甘草(G.glabra)S-7和S-12为母本的杂交组合结荚率低,但能够获得发芽率高的种子;以乌拉尔甘草(G.uralensis)GDN-16为母本的杂交组合结荚率高,但种子发芽率低,说明在甘草杂交中父母本的选择对结荚率有重要影响。

Hybridization is one of the traditional methods to breed new cultivars,pollen viability is important for the successful transmission of genetic material to generations.Glycyrrhiza inflata is one of the three licorice species recorded in Chinese Pharmacopoeia,with many specialized active compounds.In order to determine the optimal pollen development periods for licorice hybridization,the pollen viability of five bloom stages(a,b,c,d,and e)of two G.inflata cultivars(GJJ-7 and GJJ-9)were measured by TTC staining and in vitro pollen germination methods.The result of TTC staining method showed that the pollen viability of GJJ-7 trended in a wave pattern and peaked at a and d stages.The pollen viability of GJJ-9 increased with the opening process of petals,and peaked at e stage.But the result of in vitro pollen germination method showed that the pollen viability of both GJJ-7 and GJJ-9 was highest at c stage,which was consistent with fruiting rate in the hybridization,and further indicating the higher reliability of the in vitro germination method compared with the TTC staining.Hybridization results of the three medicinal licorice species showed that a low fruiting rate but highest seed germination rate was obtained when G.glabra cultivars S-7 and S-12 were used as the female parents.High fruiting rate but low seed germination rate was observed when G.uralensis cultivar GDN-16 was used as the female parent,indicating the importance of parent selection during licorice hybridization.These provides an important reference for improving the field hybridization efficiency of licorice.