深入了解濒危物种的繁殖特性,能为物种制定有效保护策略提供科学依据.于2022和2023年对中国科学院西双版纳热带植物园迁地保存的纹瓣兰(Cymbidium aloifolium)的繁殖生物学特征进行了观察和研究,主要包括开花物候、繁育系统、花部形态特征、昆虫传粉特征以及花的挥发性成分等.结果表明,纹瓣兰的盛花期在4月中旬,单花花期7 d;群体花期约为36 d.花粉活力在开花第1天时最高,约为47.15%,之后呈下降趋势.柱头在整个单花期一直具可授性,开花第2天可授性最强.人工授粉实验表明纹瓣兰自交亲和,不存在无融合生殖和自动自花授粉,繁育系统属于兼性异交繁育并依赖传粉者,自然结实率较低为 6.9%.唇瓣的先端和基部的表皮细胞分别为锥形和指状突起,基部的指状突起细胞外附着有油脂颗粒,可能是传粉者的报酬.药帽黄色,其表皮细胞为锥形细胞,能够反射光线,可能起到吸引昆虫的作用,中华蜜蜂(Apis cerana)是纹瓣兰唯一的有效传粉昆虫.纹瓣兰的挥发性气味中(E)-乙酸-2-癸烯-1-醇酯含量最高.因此,纹瓣兰的花部结构与传粉昆虫具有显著的适应性.

Constructing inbred lines for self-incompatible species and species with long generation times is chal-lenging,making the use of F1 outcross/segregating populations the main strategy for genetic studies of such species.However,there is a lack of dedicated algorithms/tools for rapid quantitative trait locus(QTL)mapping using the F1 populations.To this end,we have designed and developed an algorithm/tool called OcBSA specifically for QTL mapping of F1 populations.OcBSA transforms the four-haplotype inher-itance problem from the two heterozygous diploid parents of the F1 population into the two-haplotype in-heritance problem common in current genetic studies by removing the two haplotypes from the heterozy-gous parent that do not contribute to phenotype segregation in the F1 population.Testing of OcBSA on 1800 simulated F1 populations demonstrated its advantages over other currently available tools in terms of sensitivity and accuracy.In addition,the broad applicability of OcBSA was validated by QTL mapping using seven reported F1 populations of apple,pear,peach,citrus,grape,tea,and rice.We also used OcBSA to map the QTL for flower color in a newly constructed F1 population of potato generated in this study.The OcBSA mapping result was verified by the insertion or deletion markers to be consistent with a previ-ously reported locus harboring the ANTHOCYANIN 2 gene,which regulates potato flower color.Taken together,these results highlight the power and broad utility of OcBSA for QTL mapping using F1 populations and thus a great potential for functional gene mining in outcrossing species.For ease of use,we have developed both Windows and Linux versions of OcBSA,which are freely available at:https://gitee.com/Bioinformaticslab/OcBSA.

瑞香属植物具有重要的药用和观赏价值,在中国资源丰富,但自然条件下低坐果率限制了该属植物的进一步开发和利用.该研究以橙花瑞香为对象,通过对其有性繁殖及传粉特性的研究,探索其自然坐果率低的原因,内容包括花部特征的测量分析,MTT染色法测定花粉活性,联苯胺-过氧化氢法测定柱头可授性,扫描电镜观察柱头、花粉的形态,传粉者观察,通过花粉胚珠比(P/O)和人工授粉实验推测橙花瑞香的繁育系统类型.结果表明:橙花瑞香的花部结构特殊,管状小花,花药两轮,雌雄蕊分离.花开后的花粉具有活性,柱头具有可授性,扫描电镜下,柱头和花粉的结构没有发育异常,且柱头上有花粉落置.橙花瑞香的传粉者主要是夜间访花的蛾类,访花频率低.P/O及人工授粉实验表明橙花瑞香的繁育系统为专性异交.橙花瑞香的坐果率非常低,自然坐果率为1.4%,人工异花授粉为23.3%,低坐果率可能是受其开花量大、异花花粉限制、资源限制以及花部结构等因素的影响.

目的:探讨戊唑醇对模式生物秀丽线虫的生殖毒性作用.方法:L2期的N2、him-5(e 1490)雄虫分别暴露于0.1、1.0和10.0μg/L浓度的戊唑醇中到LA期.通过测定野生型N2线虫的后代数目与世代时间判断戊唑醇是否存在生殖毒性,通过突变体him-5(e1490)与fog-2(q71)杂交的后代数目判断是否具有雄性生殖毒性;通过检测him-5(e1490)雄虫有丝分裂区细胞、减数分裂区细胞、精细胞数目以及相关基因的表达水平研究戊唑醇对精子发生过程的影响;通过对him-5(e1490)雄虫精子细胞的形态、畸形率、活化能力以及相关基因表达水平的检测研究戊唑醇对精子形成过程的影响.相关基因表达水平用实时荧光定量PCR进行测定.结果:与对照组比较,暴露后的L4期秀丽隐杆线虫在戊唑醇剂量为10.0μg/L时后代数目显著降低(P＜0.05);1.0和10.0 μg/L戊唑醇剂量组可以使him-5(e1490)与fog-2(q71)的杂交后代数目降低(P均＜0.05),并可致秀丽线虫的有丝分裂区细胞数、减数分裂区细胞数、总生殖细胞数以及精细胞数目降低(P均＜0.05),daf-2、akt-1、daf-16 mRNA在1.0和10.0 μg/L剂量组的表达量均上升(P均＜0.05);age-1mRNA在0.1～ 10.0 μg/L染毒剂量组表达量均明显下降(P＜0.05或P＜0.01);与对照组相比,0.1、1.0、10.0 μg/L剂量组精细胞的直径与精子横截面积均明显减小(P均＜0.05),1.0、10.0μg/L剂量组精细胞的活化能力均明显降低(P均＜0.05);try-5,spe-4,spe-6,fer-1mRNA的表达量均明显上升(P＜0.05或P＜0.01),swm-1 mRNA在1.0 μg/L剂量组基因的表达量上升(P＜0.01).结论:戊唑醇通过影响秀丽线虫精子的发生以及精子的形成过程产生生殖毒性.