ABSTRACT

Introduction

The water relations of Funaria hygrometrica Hedw. sporophytes have never been investigated, although unchanged morphology through periods of drought suggests that they may be homoiohydric. Knowledge of the sporophyte maturation cycle is also incomplete and based on glasshouse plants.

Methods

We followed sporophyte development in wild populations of Funaria, recording fresh weights of every phenophase. Rates of water loss under laboratory conditions from sporophytes of different ages were recorded, and the ontogeny of the intercellular spaces and the maturational deposition of extra wall materials and waxes were investigated by cryo-SEM.

Key results

The sporophyte maturation cycle in wild Funaria lasted from December until July (> 200 days), nearly three times that recorded in glasshouses. Fresh weights of green capsules increased until after sporogenesis. Mature brown capsules were highly dehydrated. Prevailing weather conditions or addition of water had no effect on weights. Low rates of water loss, comparable with those from vascular plant leaves, decreased throughout sporophyte maturation under laboratory conditions. These data indicate that Funaria sporophytes mirror homoiohydric vascular plants. Deposition of additional wall materials around the stomatal apertures prevents closure soon after their opening towards the end of post-meiosis capsule expansion.

Conclusions

With phenophases similar to those of perennial species, Funaria may not be as much a fugitive species as previously assumed. The very brief window in nascent stomata ontogeny when reversible aperture changes might be possible indicates that the likely principal role of Funaria stomata is facilitation of capsule dehydration and not active regulation of gaseous exchange.

中文翻译：

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苔藓孢子体是否保持水分平衡？孢子体水分关系和 Funaria hygrometrica Hedw 野生成熟周期的新见解。

摘要

介绍

Funaria hygrometrica Hedw.的水分关系。孢子体从未被研究过，尽管在干旱时期形态不变表明它们可能是同型的。对孢子体成熟周期的了解也不完整，并且是基于温室植物。

方法

我们跟踪了镰刀菌野生种群的孢子体发育，记录了每个物候期的鲜重。记录了不同年龄的孢子体在实验室条件下的失水率，并通过冷冻扫描电镜研究了细胞间隙的个体发育以及外壁材料和蜡的成熟沉积。

主要结果

野生镰刀菌的孢子体成熟周期从 12 月持续到 7 月（> 200 天），几乎是温室记录的三倍。直到孢子发生后绿色胶囊的鲜重增加。成熟的棕色胶囊高度脱水。普遍的天气条件或加水对重量没有影响。在实验室条件下，整个孢子体成熟过程中，与维管植物叶片相比，失水率较低。这些数据表明Funaria孢子体反映了同型维管植物。在气孔周围沉积额外的壁材料可防止它们在减数分裂后胶囊扩张结束时打开后很快关闭。

结论

Funaria的物候期与多年生物种相似，因此可能不像以前假设的那样是逃逸物种。当可能发生可逆孔径变化时，新生气孔个体发育的非常短暂的窗口表明Funaria气孔的可能主要作用是促进胶囊脱水而不是积极调节气体交换。