小报春不同授粉组合亲和性研究

Compatibility of Different Pollination Combinations in Primula forbesii

利用小报春‘红星’、‘紫霞’、‘罗兰香’3个品种分别设置8种授粉组合,统计了不同授粉组合的结实情况和单果种子数量,并对‘红星’品种部分授粉组合的花粉萌发与花粉管伸长过程进行荧光显微观察。结果显示:(1)3个品种的结实率和单果种子数量均表现为异型植株授粉>长花柱同型异株授粉、长花柱自交>短花柱同型异株授粉、短花柱自交,不同授粉组合间单果种子数量差异极显著,异型植株授粉类型结实率均达到100%,单果种子数量为44～181粒,显著高于自交组合和同型异株杂交组合;以异型致死花粉作为蒙导对短花柱同型异株授粉组合的结实有一定促进作用,但对长花柱同型异株授粉组合的结实没有一致的促进作用;3个品种中‘红星’的结实率和单果种子数量最高。(2)荧光显微观察表明,异型授粉组合花粉在柱头上大量萌发并在花柱中伸长,授粉144h后花粉管开始进入子房;同型授粉组合授粉12h后花粉开始萌发,但直到授粉后144h花粉管还没有进入花柱;自交授粉组合授粉后144h仍无花粉萌发。实验结果说明,小报春存在明显的自交不亲和性,且短花柱类型的自交不亲和性比长花柱类型强。

Eight crosses were designed for Prim ula forbesii ＇ Red Star＇, ＇ Purple Cloud＇ and ＇ Fragrant I.uo- lan＇ ,separately,to investigate the fruiting rate and seed-set per capsule. Meanwhile,the pollen germination and pollen tube elongation of several crosses in P. forbesii ＇Red Star＇ were observed by fluorescent mi- croscopy. The results showed that：（1）For all three cultivars, the fruiting rate and seed-set per capsule were significantly different among different crosses,and in a descending order were legitimate crosses （T× P and PX T）〉within-pin cross and pin selfing〉within-thrum cross and thrum selfing. The fruit-setting rates of all legitimate crosses reached 100% and the mean number of seeds per capsule obtained ranged from 44 to 181 ,which were significantiy higher than that of illegitimate crosses. By using intermorph pollens without vitality as mentor in intramorph pollinations, fruiting rate and seeds per capsule of T× T crosses were im proved. However,mentor pollination had no unambiguous effect on P× P crosses. Among the three culti- vars,fruiting rate and seeds per capsule of different crosses in P. forbesii ＇Red Star＇ were the highest. （2） The results of fluorescent microscope observation suggested that pollens germinated easily and pollen tubes penetrated directly into the stigma surface in intermorph crosses （T×P and P×T）,and pollen tubes grew nearly to the style base and began to insert into the ovary after pollination for 144 h. In P× P and T× Tcrosses,pollens began to germinate after pollination for 12 h. However,pollen tubes were blocked and did not penetrate the stigma surface after pollination for 144 h,and the pollen tubes were distorted. In pin and thrum selfings,pollens did not germinate on the stigma surface after pollination for 144 h. It was concluded that P. forbesii was self-incompatible,and the thrum form was more self-incompatible than the pin form.