Isolation and characterization of eight compound microsatellite markers in a mangrove tree Kandelia candel (L.) Druce

Kandelia candel is an important mangrove tree species of family Rhizophoraceae. Here we isolated eight codominant compound microsatellite simple sequence repeat (SSR) loci from K. candel. Our isolated loci provided compound SSR markers with polymorphism of three to 11 alleles per locus. The expected and observed heterozygosities ranged from 0.230 to 0.887 and from 0.083 to 1.00, respectively. These markers would be the useful tools for analysing questions concerning population genetic structure and mating system of K. candel.     

2010年冬季寒冷天气对闽江口3种红树植物幼苗的影响

2010年10月8日-2011年2月26日,跟踪监测了闽江河口互花米草治理试验区人工种植的秋茄(Kandelia candel)、无瓣海桑(Sonneratia apetala)和拉关木(Leguncalaria racemosa)1年生幼苗叶片相溶性物质含量以及活性氧代谢等生理生化指标.结果表明:可溶性糖和脯氨酸含量均随气温的逐步降低而增加,秋茄可溶性糖含量最高,拉关木脯氨酸含量最高;整个监测期无瓣海桑和拉关木幼苗叶片超氧阴离子(O2)产生速率显著高于秋茄(P＜0.01),而超氧化物歧化酶(SOD)和过氧化物酶(POD)活性显著低于秋茄(P＜0.01);3种植物叶片丙二醛(MDA)含量及电解质渗透率均随着气温的降低而增加,其中无瓣海桑和拉关木MDA含量及电解质渗透率与日最低气温为显著和极显著的负相关关系.2010年冬季持续寒冷天气对闽江河口湿地1年生土著种秋茄幼苗无破坏,对引进种无瓣海桑和拉关木造成了严重的低温胁迫并使幼苗基本全部死亡.     

中国东南沿海15个秋茄种群遗传多样性的SRAP分析

为进一步保护和恢复红树林资源提供分子方面的基础资料和科学依据,本研究采用SRAP标记对15个中国东南沿海红树植物秋茄种群的亲缘关系进行了分析.从120对参试引物组合中选出46对重复性好、条带清晰的引物组合对供试的15份材料基因组DNA进行PCR扩增,得到大小在50～1 000 bp之间条带270,其中多态性条带107条,多态性位点率为39.63%.15个秋茄种群的遗传相似系数在0.004～0.845之间,平均为0.412,说明中国东南沿海秋茄种群存在较丰富的遗传多样性.聚类分析把15份供试种群材料划分为4个类群.15个秋茄种群的遗传多样性没有明显的地域性差异,同一样地域的不同种群之间具有遗传上的差别.建议在今后我国的红树林保护中,应加强对海南东寨港、深圳福田、湛江东北大堤和湛江附城的秋茄种群保护.     

Seasonal changes in element contents in mangrove element retranslocation during leaf senescene

The concentrations of nitrogen (N), phosphorus (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg) and chlorine (Cl) were followed monthly in pre-senescence leaves and post-abscission leaves of Kandelia candel (L.) Druce at the Jiulongjiang estuary, and Fujian, China. The element retranslocation efficiency (RE) was studied during leaf senescence. The element RE's evaluated using different methods were compared and a new method was put forward to evaluate element RE during leaf senescence in evergreen trees without concentrated leaf fall. The results showed that during leaf senescence, 77.22% N, 57.53% P, and 44.51% K were translocated out of senescing leaves. Translocation of nutrients out of senescing leaves back into shoots was an important nutnent-conservation mechanism for N and P, was less important for K, and did not occur for Ca, Mg, Na, or Cl. One of the reasons for the high primary productivity of mangroves in nutrient poor sites (especially with low N) is the high nutrient use efficiency.     

人工红树林中黑口滨螺和黑线蜒螺分布的差异性

研究了福建九龙江河口不同林龄、不同红树种类的人工林中黑口滨螺（Littoraia elanostoma）和黑线蜒螺（Nerita lineata）的分布情况.结果表明,黑线蜒螺主要分布于秋茄林内,且其生物量随林龄增加而增加;桐花树林内黑口滨螺的生物量和密度均大于林龄相近的秋茄林,但个体大小则小于秋茄林.黑口滨螺的生物量在桐花树林内随林龄增加呈现先增加后减少的趋势,而在秋茄林内则随林龄增加而减少.这种差异性反映了人工红树林植物种类及其演替过程对腹足类动物分布的影响.     

三种红树植物叶片的比较解剖学研究

研究了采自福建九龙江口的3种红树植物,秋茄(Kandeliacandel)、木榄(Bruguieragymnorrhiza)和红海榄(Rhizophorastylosa)的叶片结构并探讨了其生态学意义。结果表明,这3种红树植物叶片都具有适应海生环境的结构,较厚的角质层,表皮之内有内皮层,内皮层属贮水组织;气孔都分布在下表皮,下陷,并有大的孔下室;中脉有发达的维管束,其导管粗大。从叶片的横切面来看,秋茄叶片具有对称的结构,为等面叶;木榄和红海榄的叶片结构不对称,为异面叶。3种植物叶内都含有较丰富的单宁,以秋茄最高,红海榄次之,木榄最少。这些结构差异可为物种鉴定提供依据。     

过表达秋茄C2H2型锌指蛋白基因KcZFP提高烟草耐盐性

基因转录调节是植物对非生物胁迫适应机制的一个重要方面,转录调节因子在胁迫信号转导途径中调节下游基因的表达,在建立植物对胁迫适应性过程中起到重要作用.锌指蛋白是功能多样的转录调节因子蛋白家族,家族成员在植物响应非生物胁迫方面扮演着重要角色.本研究以秋茄C2H2型锌指蛋白编码基因KcZFP为目的基因,在烟草中过表达KcZFP,分析C2H2型锌指蛋白在植物耐盐性中的作用.研究结果显示:转基因株系中,KcZFP表达量显著提高.过表达KcZFP的烟草植株的耐盐性明显提高,在200 mmol/L NaCl处理的条件下,KcZFP过表达烟草中脯氨酸水平远高于野生型植株.对光合作用参数比较分析显示,在KcZFP过表达植株中净光合速率受盐胁迫的影响小于野生型植株,光合系统在一定程度上得到了保护.研究结果说明KcZFP作为转录调节因子参与了植物的渗透调节,对植物的耐盐性具有贡献.     

草芍药,野牡丹和黄牡丹的核型研究

本文报道了国产芍药属(Paeonia L.)植物草芍药、野牡丹和黄牡丹的染色体数目及核型,均为2n=10=6m 2sm 2st,它们分别具2、3和4对次缢痕,所具次缢痕的数目和位置可以作三种核型的区别特征。     

Forest structure of a subtropical mangrove along a river inferred from potential tree height and biomass

The hypothesis was tested that potential tree height and biomass in mangroves decrease downstream with the tidal gradient along the Okukubi River in Okinawa Island, Japan. The mangrove stands consisted of Bruguiera gymnorrhiza (L.) Lamk. and Kandelia obovata (S., L.) Yong (Rhizophoraceae). Four sites were selected considering the distance from the mouth of the river. Soil salinity increased downstream, while soil total nitrogen content decreased. The soil redox potential did not vary along the river. Maximum gross photosynthesis and tree height for each species decreased downstream. The potential tree height (H_max) inferred from the stem diameter (D_0.1)–tree height (H) relationship ( a, h, coefficient) in each species decreased downstream. The tree density (ρ)–mean tree size () relationships ( K, α, coefficient) determined for four sites revealed that the mean tree size at any given tree density decreased downstream, which indicates the decrease of potential biomass. Furthermore, an index for biomass () was homogeneous within a site regardless of tree density, i.e. the value of α at each site did not differ significantly from 1.0 (p > 0.05). The decreases in potential tree height and biomass may be partially ascribed to the stressful environments at the downstream sites characterized by high salinity (>2.6%) and nitrogen-poor soils (<0.25 ppt) in our study area.