Combined effects of seawater temperature and nutrient condition on growth and survival of juvenile sporophytes of the kelp Undaria pinnatifida (Laminariales; Phaeophyta) cultivated in northern Honshu, Japan
Combined effects of seawater temperature and nutrient condition on growth and survival of juvenile sporophytes of the kelp Undaria pinnatifida (Laminariales; Phaeophyta) cultivated in northern Honshu, Japan
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DOI：
10.1007/s10811-012-9861-x
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发表时间：
2013-02-01
影响因子：
3.3
通讯作者：
Agatsuma, Yukio
中科院分区：
文献类型：
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作者：
Gao, Xu;Endo, Hikaru;Agatsuma, Yukio
最近，枯萎的养殖幼孢子体海带裙带菜pinnatifida（哈维）Suringar已导致该物种在日本北方的产量减少，可能是因为高水温和低营养浓度的栽培地区。这个问题可以通过引入对高温和低营养条件具有更大耐受性的亲本植物来解决。我们研究了不同温度（15、20、24和27 A ℃）和营养物质可利用性（用25%PESI培养基富集的海水和非富集海水）对从日本北方宫城县松岛湾和日本南部德岛县鸣门采集的培养幼孢子体（1-2 cm）生长和存活的综合影响。两个地点的幼孢子体的相对生长速率在15和20 A ℃下显著大于24和27 A ℃。在富集培养基中培养的幼孢子体的相对生长速率显著高于在非富集海水中培养的幼孢子体。在非富营养化海水中，在所有温度下都观察到死亡的幼鱼，存活率随着海水温度的升高而降低。与松岛湾的幼孢子体相比，鸣门的幼孢子体即使在低营养条件下也表现出更强的耐高温性。这些结果表明，幼孢子体的枯萎是由低养分有效性和高温的综合影响。解决这一问题的一个可能的办法是从日本较温暖的地区引进对高温和低营养条件具有更大耐受性的生态型。
Recently, withering of farmed juvenile sporophytes of the kelp Undaria pinnatifida (Harvey) Suringar has led to reduced production of this species in northern Japan, possibly because of the high water temperature and low nutrient concentration in cultivation areas. This problem may be solved by introducing parental plants with greater tolerance to high temperature and low nutrient conditions. We examined the combined effects of various temperatures (15, 20, 24, and 27 A degrees C) and nutrient availabilities (seawater enriched with 25 % PESI medium and non-enriched seawater) on the growth and survival of cultivated juvenile sporophytes (1-2 cm) collected from Matsushima Bay, Miyagi Prefecture in northern Japan and Naruto, Tokushima Prefecture in southern Japan. The relative growth rates of juvenile sporophytes from both locations were significantly greater at 15 and 20 A degrees C than at 24 and 27 A degrees C. The juvenile sporophytes cultured in enriched medium had significantly higher relative growth rates than those cultivated in non-enriched seawater. Dead juveniles were observed in non-enriched seawater at all temperatures and the survival percentage decreased with increasing seawater temperatures. Compared to the juvenile sporophytes from Matsushima Bay, those from Naruto showed greater tolerance to high temperature even under the low nutrient condition. These results suggest that the withering of juvenile sporophytes is caused by the combined effects of low nutrient availability and high temperature. A potential solution to this problem is to introduce ecotypes with greater tolerance to high temperature and low nutrient conditions from a warmer region of Japan.