不是很好读的书。因为这个话题涉及的内容已经不是基础生物学的内容了,很多真菌生物学的知识我没学过_(:з」∠)_ 但是既然以后要研究这个方向的话,还是硬着头皮也读_(:з」∠)_
【然后事实就是这里写的太复杂了。。。于是我找了另外一本书的章节查看。。。】
Colonization of roots AMF
1 propagules 繁殖体
Colonization of roots by AM fungi can arise from three main sources of inoculum in
soil: spores, infected root fragments and hyphae – collectively termed propagules
1. 孢子的传播:
1. 孢子比较大。理论上可以被风、水、动物传播(但是动物传播没有具体观测到)
2. 孢子被认为是最重要的传播途径
1. 土里面的孢子种类和数量很多
2. 一些物种萌发的速度很慢,休眠期应该不短。所以能保存很久 Little is known about the timing of germination and infectivity of such complex communities in soil, but germination of some species may be poor or occur rather slowly and variably, providing a reservoir of inoculum which per sists for many years but may not always be important in early colonization of root systems
3. 侵染的性能:一个特殊的实验似乎发现一些菌根只能通过孢子侵染。但是这个实验证据不足
2. 菌丝和根的侵染
1. 一般生境中这类是主要途径
2. In many habitats, persistent hyphal networks in soil (Figures 2.1 and 2.3), together with root fragments (Figure 2.2), are the main means by which plants become colonized even when significant spore populations are also present (Hepper, 1981; Smith and Smith, 1981; Tommerup and Abbott, 1981; Birch, 1986; Jasper et al., 1992; Merryweather and Fitter, 1998c). but why?——因为地下菌丝网络和植物根系网络非常密集。新生植物的根率先接触到这些菌丝和其他植物的根,而提前被侵染的根就没有机会容纳孢子的产生了(是么?)Even in highly seasonal environments, where plants may be lacking for part of the year, there is evidence that mycelial networks persist in dry or frozen soil and play an important role in colonization of new generations of plants. From a fungal perspective, the survival and spread of networks to colonize new plants is a crucial scavenging process which provides ongoing sources of organic carbon (C)
3. 菌丝网络在稳定的环境中是主要的侵染方式。但是在高扰动环境下,菌丝网络几乎都被破坏了——免耕种植的优势
3. 土壤侵染力
1. 因为我们难以区分哪一个来源实现了侵染,所以对于一片土地,利用侵染力infectivity这个指标来表示整体的侵染能力
2. 侵染力和孢子数量难以建立稳定关系:
1. 因为这是一个随时变动的过程。孢子的初始数量可能和区域侵染力相关联,但是侵染后的植物又会产生新的孢子。因此对于这个动态水平建模就很困难
2. 而孢子萌发和侵染成功又是一个多变动态的过程:因此,我们可以推测,物种特性,孢子的活性和休眠时间,土壤中除了孢子之外的其他繁殖体的数量更能决定侵染力
3. 侵染力评估的特例:在农田生态系统中,由于频繁扰动的存在,菌丝网络基本消失。这时候,孢子数量和菌根碎片残留数量和侵染力能建立良好关系
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