Effect of Spore Coalescence on the Early Development of Gracilaria verrucosa (Hudson) Papenfuss.
Effect of Spore Coalescence on the Early Development of Gracilaria verrucosa (Hudson) Papenfuss.
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DOI：
10.1038/178426b0
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发表时间：
1956-08
期刊：
影响因子：
64.8
通讯作者：
W. E. Jones
中科院分区：
文献类型：
--
作者：
W. E. Jones
G.的果孢子和四孢子。疣状体已经在流动的天然海水中在恒定照明下在显微镜载玻片上生长。在最初附着到幻灯片上之后，通常与Killian 1的观察结果相对应的分区发生了。这些细胞在40-45天内产生一个圆顶状的细胞，高30-35微米，直径120微米。在大多数孤立的孢子中，在这个阶段的活动大大减少;但在某些情况下，在下面描述的情况下，芽开始发育。紧密相邻的孢子的周边生长导致它们相遇并结合成不规则形状的“筏”。在这些木筏中，除非在早期阶段就绘制了它们的位置，否则过一段时间后就无法识别出单个孢子。在所有的幻灯片上，都首次观察到从这种木筏上长出的芽。另一方面，孤立的孢子在几个月后很少显示出与40天条件的任何变化，到那时，相同年龄的合并孢子已经产生了几毫米长的芽。在一个筏中，并非所有的孢子都能产生芽，而且，当一个广泛的筏产生许多芽时，这些芽间隔很好，很少从相邻的孢子中产生。此外，从图1中可以看出，较大的筏往往具有相应较长的枝条。在相关载玻片上，最长（1.8 mm）发生在一个有五只孢子虫的筏子上同一滑道上的大木筏上有不止一个枝条，但没有一个更长。最大的筏，包含约50个孢子，有10个芽，平均0.61毫米长，最长的测量1.6毫米。在较大的筏中，5个孢子与每个芽的比例似乎很常见;但是在孤立的孢子上产生的小芽的频率远低于1/5。
CARPOSPORES and tetraspores ofG. verrucosahave been grown on microscope slides in running, natural sea water under constant illumination. After the initial attachment to the slide, divisions occur which correspond, in general, with the observations of Killian1. These produce, in 40–45 days, a dome of cells which may be 30–35µ high and 120µ in diameter. In the majority of isolated sporelings there is a great reduction in activity at this stage ; but in some cases development of the shoot begins, in circumstances described below. The peripheral growth of closely adjacent spores leads to their meeting and coalescing into irregularly shaped ‘rafts’. In these rafts individual sporelings cannot be recognized after a time unless their positions have been mapped at earlier stages. On all slides shoots have been first observed arising from rafts of this kind. Isolated sporelings, on the other hand, rarely show any change from the 40-day condition after several months, by which time coalesced sporelings of the same age have produced shoots several millimetres long. Shoots are not produced by all sporelings in a raft, and, when an extensive raft produces numerous shoots, these are well spaced out and seldom arise from adjacent sporelings. Furthermore, it will be seen from Fig. 1 that the larger rafts tend to bear proportionately longer shoots. On the slide concerned, the longest (1.8 mm.) occurred on a raft of about five sporelings. Larger rafts on the same slide bore more than one shoot, but none was longer. The largest raft, containing about fifty sporelings, bore ten shoots averaging 0.61 mm. in length, the longest measuring 1.6 mm. A ratio of five sporelings to each shoot seems usual in the larger rafts ; but the frequency of the small shoots produced on isolated sporelings is much lower than 1 in 5.