基于树种影响土壤差异的上海市城市绿化树种初步选择

树种差异对土壤养分因子的影响及其在不同地区差异对于适宜树种选择意义重大。选择上海市的5个树种(悬铃木Platanus acerifolia、香樟Cinnamomum camphora、栾树Koelreuteria paniculata、无患子Sapindus mukorossi和银杏Ginkgo biloba)以方位和距离分9个区域进行土壤采样,对土壤养分因子的12个指标进行研究。多因素方差分析显示,长期定植于类似土壤条件下,树木能够显著影响土壤养分等指标,但不同区域间存在显著差异(P<0.05)。基于多重比较结果对各指标进行标准化处理、获得综合得分排名发现,悬铃木具有较好的土壤养分维持能力,并且在每个区域的养分维持能力均处于最高水平,而银杏表现最差。银杏维持土壤中量元素能力较好,香樟维持土壤微量元素能力较好。综合分析得出,对上海市城市立地土壤养分改良较好的绿化树种为悬铃木,香樟和无患子次之,银杏表现最差。

Separation and Identification of Differentially Expressed Proteins in Pistillate Flowers between Different Mulberry Cultivars

[Objective] This study aimed to explore the proteins related to pistillate flower development in different mulberry cultivars. [Method] The total proteins of the pistillate flowers of two mulberry cultivars Dal0 （Morus atropurpurea Roxb.） and SG01 （Morus muIticaulis Perr.） were extracted, separated and detected through two- dimensional electrophoresis （2-DE） and mass spectrometry. [Result] There was sig- nificant difference in the expression of proteins from the pistillate flowers of different mulberry cultivars. From the 2-DE images of Dal0 and SG01, 445_＋17 and 425_＋12 protein spots were respectively detected. The expression levels of 75 protein spots differed significantly. Thirteen spots those were expressed at high levels and well separated were analyzed by mass spectrometry, and nine of them were identified successfully. The nine proteins are involved in the glycometabolism, protein and amino acid metabolism and defense responses during the development of mulberry pistillate flower after they were pollinated. [Conclusion] The findings will provide reference for further study on the molecular mechanism of mulberry pistillate flower de- velopment.

温暖湿润区铁杉和高山松树轮δ^(13)C的气候意义

详细了解多树种树轮碳同位素组成(δ13C)对气候的响应机制是进行古气候重建的基础.利用川西高原温暖湿润区铁杉和高山松树轮δ13C序列,探讨了气候环境要素对两树种δ13C的控制作用及利用该指标进行气候重建的潜力.结果表明:铁杉和高山松树轮δ13C序列之间存在差异,其原因可能与树种本身的生理特性有关;当去除大气CO2浓度引起的低频影响后,两树种年轮碳同位素分辨率(Δ13C)序列之间的相关程度有所加强,且呈显著相关关系,说明气候要素对两树种的Δ13C有类似的控制作用.温度和水分与两树种Δ13C序列密切相关,但二者对Δ13C起控制作用的时段和强度因树种的不同而存在差异.其中,温度对铁杉Δ13C影响的关键时期为前一年12月至当年2月,对高山松影响的关键时期为当年4~7月;水分对铁杉和高山松Δ13C起控制作用的关键时期分别为当年2~4月和3~5月.可见在温暖湿润区,树轮碳同位素分馏因树种的不同而不同,且受多个气候要素共同作用,但最优多元回归方程的解释方差最大仅38.5%.因此,在温暖湿润的川西高原单独利用树轮δ13C进行气候要素重建受到一定限制.