摘要
本研究探讨重瓣大花紫薇‘云裳’(Lagerstroemia speciosa‘Yunchang’)的有性杂交亲和性,以重瓣大花紫薇‘云裳’作为母本,并以大花紫薇(紫色)、大花紫薇(粉红色)、‘红火箭’紫薇、毛萼紫薇、南洋紫薇、绒毛紫薇、‘红叶’紫薇为父本进行杂交。通过进行花粉生活力、柱头可授性检测,杂交、杂种萌发、授粉后花粉管萌发、花粉生长的荧光观察等试验,系统分析重瓣大花紫薇‘云裳’在有性繁殖过程中的杂交亲和性。研究结果表明:(1)重瓣大花紫薇‘云裳’的柱头全天都具备授粉能力,尤其在上午10:00—12:00达到最强,此时柱头表面呈深蓝色,并伴有大量气泡产生;(2)重瓣大花紫薇‘云裳’与大花紫薇(粉红色)杂交组合的坐果率、果实纵径、千粒重及出苗率显著高于其他组合,即坐果率为22.2%,果实纵径为19.45 mm,千粒重为7.9 g,出苗率为8.7%,重瓣大花紫薇‘云裳’与‘红火箭’紫薇杂交组合产生的种子数最多,达153粒,而与南洋紫薇杂交组合未能结实,发现重瓣大花紫薇‘云裳’与大花紫薇(粉红色)杂交存在严重的远缘杂交障碍,特别是重瓣大花紫薇‘云裳’与南洋紫薇杂交亲和性更低。(3)通过选取坐果率高和低的组合进行荧光显微观察发现,授粉后0~48 h,坐果率较低的组合柱头上未见花粉萌发现象。而坐果率高的组合在授粉0 h和2 h也未见花粉粒萌发;但在授粉4 h和6 h观察到少数花粉管开始生长,并伴随着大量胼胝质在柱头上聚集以及花粉管断裂现象。授粉8 h和24 h,花粉管生长现象更加显著。授粉48 h,花粉管已生长至花柱位置,并伴随大量胼胝质干扰和花粉管扭曲现象。这些观察结果揭示了重瓣大花紫薇‘云裳’的有性杂交障碍可能源于柱头上大量胼胝质的干扰。
This study investigated the sexual cross-compatibility of the double-flowered Lagerstroemia speciosa‘Yunchang’,using it as the maternal parent and crossing it with Lagerstroemia speciosa(Deep Purple),Lagerstroemia speciosa(Deep Purplish Pink A),L.indica‘Red Rocket’,L.indica‘Pink Velour’,L.balansae,L.siamica,L.tomentosa,and L.indica‘Red Leaf’as paternal parents.Through experiments including pollen viability testing,stigma receptivity assessment,hybridization,hybrid seed germination,and fluorescence microscopy observation of pollen tube germination and growth after pollination,the cross-compatibility of double-flowered Lagerstroemia speciosa‘Yunchang’during sexual reproduction was systematically analyzed.The results showed:(1)The stigmas of double-flowered Lagerstroemia speciosa‘Yunchang’exhibited receptivity throughout the day,peaking between 10:00 AM and 12:00 PM when the stigma surface appeared dark blue with abundant bubble formation.(2)The cross between double-flowered Lagerstroemia speciosa‘Yunchang’and Lagerstroemia speciosa(Deep Purplish Pink A)demonstrated significantly higher fruit set rate(22.2%),fruit longitudinal diameter(19.45 mm),thousand-seed weight(7.9 g),and seedling emergence rate(8.7%)compared to other combinations.The cross with L.indica'Red Rocket'produced the highest number of seeds(153 seeds),while no fruit set was observed in the cross with L.balansae.Severe distant hybridization barriers were identified,particularly showing the lowest compatibility between double-flowered Lagerstroemia speciosa‘Yunchang’and L.balansae.(3)Fluorescence microscopy observations of combinations with high and low fruit set rates revealed that no pollen germination occurred on stigmas within 0–48 hours post-pollination in low fruit set combinations.In high fruit set combinations,no pollen grain germination was observed at 0 h and 2 h post-pollination;however,at 4 h and 6 h,a few pollen tubes began elongating,accompanied by significant callose deposition on stigmas and pollen tube rupture.Pollen tube elongation became more pronounced at 8 h and 24 h post-pollination.By 48 h,pollen tubes had elongated to the style position,with substantial callose interference and pollen tube distortion.These observations suggest that the sexual hybridization barriers in double-flowered Lagerstroemia speciosa‘Yunchang’may originate from extensive callose interference on the stigma.
作者
李冰
孙利娜
陈尔
唐军荣
林茂
LI Bing;SUN Lina;CHEN Er;TANG Junrong;LIN Mao(Guangxi Forestry Research Institute/Guangxi Key Laboratory of Special Economic Forest Cultivation and Utilization/Guangxi Laboratory of Forestry,Nanning,Guangxi 530002,China;College of Forestry,Southwest Forestry University,Kunming,Yunnan,650224,China)
出处
《热带作物学报》
北大核心
2025年第8期1848-1855,共8页
Chinese Journal of Tropical Crops
基金
广西特色经济林培育与利用重点实验室自主课题(No.JA-23-04-04)
广西林科院研究团队项目(No.2024RT26)
广西林业科技推广示范项目([2022]GT21)。
