不同培养条件对海洋微藻多糖含量的影响

通过对不同培养条件下四种海洋微藻胞内多糖含量的测定,系统地研究了光照时间、温度、ＣＯ２的通入量及营养盐对微藻胞内多糖的影响,以探索其优化条件。     

培养条件对齿瓣延胡索愈伤组织生长及延胡索乙素含量的影响

研究了不同培养条件对齿瓣延胡索(Corydalis remota)愈伤组织生长及延胡索乙素(THP)含量的影响。结果表明, 2, 4-D较NAA更有利于提高培养物鲜重,加速细胞增殖。培养基添加2.0 mg/L 2, 4-D和1.0 mg/L BA不仅有利于干物质积累,而且显著提高THP水平。蔗糖不仅可提高培养物鲜重,而且与半乳糖组合可显著促进干物质积累和THP水平的提高。水解酪蛋白和水解乳蛋白均有利于愈伤组织生长和THP含量的提高, 450mg/L的水解乳蛋白处理组THP含量最高。光照可提高培养物鲜重和THP含量。     

短期高温伤害蓝藻Anabaena7120的固氮活性恢复与生理条件的关系

蓝藻经短期高温处理后,其固氮活性显著下降,但在合宜条件下,这种受伤害的固氮活性可以有一定程度的恢复。光下不仅比暗中恢复快,而且活性也高得多。光合抑制剂和外源碳水化合物分别减缓和促进受高温伤害的蓝藻固氮活性恢复。在光、暗和供给外源碳水化合物的条件下,厌氧(氩和氮中)对受高温伤害的蓝藻固氮活性恢复不利。与正常蓝藻有异的是,H_2,CO_2及H_2与O_2,CO_2与N_2的加合都阻碍受高温伤害的蓝藻固氮活性的恢复。     

冬天的足迹：春化作用的表观遗传学研究

许多在寒冷的冬天生长的植物，需要在低温条件下生长几个月，以促进春天到来时的开花过程，这个时候白天延长、气温也上升，这个过程被称为“春化作用（vernalization）”。如果没有这个寒冷时期的生长，     

稻瘿蚊发生为害程度的气象因素分析

稻瘿蚊是一种区域性、间歇性的害虫，影响因素是多方面的，气象因素所起的作用是十分重要的，在同一年份基本接近的虫源基数，因不同地方气候条件不一，发生为害截然不同，呈区域性差别，不同年份不同虫情，又因气候差异，呈间歇性发。     

Compensatory foraging in Trinidadian guppies： Effects of acute and chronic predation threats

In response to acute predation threats, prey may sacrifice foraging opportunities in favour of increased predator avoidance. Under conditions of high or frequent predation risk, such tradeoffs may lead to reduced fitness. Here, we test the pre diction that prey reduce the costs associated with lost opportunities following acute predation threats by exhibiting shortterm compensatory foraging responses. Under seminatural conditions, we exposed female guppies Poecilia reticulate from high and low predation risk sites to one of three levels of acute predation threat （high, intermediate or low concentrations of conspecific alarm cues）. Our results confirm previous reports, demonstrating that guppies from a high predation site were consistently ＇bolder＇ （shorter escape latencies） and exhibited graded threatsensitive responses to different simulated threat levels while those from the low predation site were ＇shyer＇ and exhibited nongraded responses. Most importantly, we found that when guppies from low predation sites resumed foraging, they did so at rates significantly lower than baseline rates. However, guppies from high preda tion sites resumed foraging either at rates equal to baseline （in response to low or intemaediate risk stimuli） or significantly in creased relative to baseline rates （in response to high risk stimuli）. Together, these results highlight a complex compensatory be havioral mechanism that may allow prey to reduce the longterm costs associated with predator avoidance [Current Zoology 60 （3）： 323-332, 2014 ].     

How Do Stomata Sense Reductions in Atmospheric Relative Humidity？

Dear Editor, It has been known since the work of Francis Darwin that, in response to a reduction in atmospheric relative humidity （rh）, stomatal aperture decreases. Screening for Arabidopsis mutants compromised in stomatal responses to reduced rh resulted in the identification of two genes, OST1 and ABA2, that are involved in stomatal response to low rh conditions. Interestingly both encode proteins previously known to be involved in ABA signaling （Xie et al., 2006, and references therein）. These findings strongly suggested that, at least in part, the stomatal response to low rh is mediated by ABA and the intracellular ABA signaling pathway. Our most recent data show that low rh-induced stomatal closure can pro- ceed by guard cell autonomous ABA synthesis （Bauer et al., 2013）,     

从Myriad案谈基因专利的正当性及美国对基因专利授权实质性要件分析

按照专利制度构建的本质,基因专利的作用在于激励产业创新,促进基因研究的发展。但基因专利从产生以来就一直存在着争议。2011年美国Myriad案对分离DNA序列的可专利性具有不同的观点,从Myriad I案认为分离的DNA是不可专利的客体,到Myriad II上诉案中联邦巡回上诉法院推翻地方法院的观点,认为分离的DNA具有不同的化学结构,满足专利客体的适格性,但同时也反射出了对DNA序列可专利性的怀疑。Myriad案引起了美国、欧洲和澳大利亚司法审判中就基因专利适格性问题的较大争议。本文结合美国Myriad案来分析DNA序列作为专利客体的适格性以及目前美国对基因专利授权的实质性条件。