桃树修剪分枝模式的模拟

在不同修剪手法下,对栽培桃树(Prunuspersica(L.)Batsch)不同母枝上的分枝模式进行了比较研究。从分枝模式来看修剪后的母枝基本由3个不同的区域组成,基部是不萌发的潜伏芽形成的未分枝区域;中部是延迟分枝和多次分枝组成的分枝区域(主要的枝条类型有短枝、长枝和多次枝);顶部是被剪除的部分。我们通过隐式半马尔可夫模型来模拟这一分枝模式,主要是定量描述1次枝和多次枝在母枝上的数量及其分布状况。在上述模型中,未分枝区、延迟分枝区和多次分枝区称为瞬时态,被剪除的部分称为吸收态。模拟的结果与观察的结果进行对比后发现,两者具有很好的一致性。这说明隐式半马尔可夫模型是模拟植物分枝过程的一种有效方法,尽管隐式半马尔可夫链模型只是一个描述性的模型,但仍能对其所描述的生物现象进行解释,在预测修剪手法对母枝分枝模式影响方面比传统的方法具有明显的优势。本研究结果是建立三维虚拟桃树树冠分枝结构的基础。     

FSD-C10: A more promising novel ROCK inhibitor than Fasudil for treatment of CNS autoimmunity

Rho-Rho kinase (Rho-ROCK) triggers an intracellular signalling cascade that regulates cell survival, death, adhesion, migration, neurite outgrowth and retraction and influences the generation and development of several neurological disorders. Although Fasudil, a ROCK inhibitor, effectively suppressed encephalomyelitis (EAE), certain side effects may limit its clinical use. A novel and efficient ROCK inhibitor, FSD-C10, has been explored. In the present study, we present chemical synthesis and structure of FSD-C10, as well as the relationship between compound concentration and ROCK inhibition. We compared the inhibitory efficiency of ROCKI and ROCK II, the cell cytotoxicity, neurite outgrowth and dendritic formation, neurotrophic factors and vasodilation between Fasudil and FSD-C10. The results demonstrated that FSD-C10, like Fasudil, induced neurite outgrowth of neurons and dendritic formation of BV-2 microglia and enhanced the production of neurotrophic factor brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3). However, the cell cytotoxicity and vasodilation of FSD-C10 were relatively small compared with Fasudil. Although Fasudil inhibited both ROCK I and ROCK II, FSD-C10 more selectively suppressed ROCK II, but not ROCK I, which may be related to vasodilation insensitivity and animal mortality. Thus, FSD-C10 may be a safer and more promising novel ROCK inhibitor than Fasudil for the treatment of several neurological disorders.     

金沙江干热河谷特有植物白魔芋的传粉生物学研究

以金沙江干热河谷特有植物白魔芋（Amorphophallus albus P.Y.Liu et J.F.Chen）为对象，分别在两个就地栽培实验地（四川金阳、云南永善）和一个异地栽培实验地（富源）进行传粉生物学研究（包括交配系统及气味和传粉昆虫对其繁殖策略的影响）。结果显示，白魔芋是雌雄异熟且雌蕊先熟，雌花期时，附属器散发浓烈的恶臭气味。经气相色谱-质谱联用仪（GC-MS）分析，花气味成分主要为二甲基二硫和二甲基三硫。野外观察到的传粉昆虫属于隐翅虫科（Staphylinidae），包括前角隐翅虫亚科（Aleocharinae）的Atheta sp.和颈隐翅虫亚科（Oxytelinae）的Anotylus sp.。经气相色谱-触角电位联用技术（GC-EAD）分析表明，隐翅虫触角对白魔芋花气味中的二甲基二硫和二甲基三硫有明显的反应。授粉结果显示，金阳、永善和富源3个实验地人工自花授粉和套袋的结实率都为0，无传粉昆虫的富源实验地自然结实率也为0。综合研究结果表明白魔芋属于自交不亲和的交配系统，通过花序结构和气味吸引隐翅虫为其传粉，并提供食物和交配场所作为回报。该研究为白魔芋的繁殖育种提供了基础资料，为植物与昆虫之间的协同进化提供了进一步的理论支持，同时为白魔芋的有效保护和利用提供了理论依据和技术指导。