Genetic differentiation of high-temperature tolerance in the kelp Undaria pinnatifida sporophytes from geographically separated populations along the Pacific coast of Japan
Genetic differentiation of high-temperature tolerance in the kelp Undaria pinnatifida sporophytes from geographically separated populations along the Pacific coast of Japan
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DOI：
10.1007/s10811-012-9891-4
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发表时间：
2013-04-01
影响因子：
3.3
通讯作者：
Agatsuma, Yukio
中科院分区：
文献类型：
--
作者：
Gao, Xu;Endo, Hikaru;Agatsuma, Yukio
海带裙带菜在日本有广泛的纬度范围，人口暴露于非常不同的温度制度。为了验证这一假设，美国。pinnatifida在其温度响应中表现出遗传分化，收集来自较温暖的位置（日本南部的鸣门）和两个较冷的位置（日本北方的冲来湾和松岛湾）的幼孢子体，并移植到长系中，在松岛湾的环境条件下培养。采用连续自交的方法进行了3代的选育，并对第3代幼孢子体（2-3 cm）的光合、生长、存活和含氮量等特性进行了测定和比较。在20- 35 A ℃的高温下，鸣人种群的光合活性和呼吸作用显著高于北方种群。三个地点的幼孢子体在18 ℃以下的生长速率相似，但在18- 24 ℃下观察到显著差异。生长的最适温度是14- 16 A度C的植物起源于冲来湾和松岛湾和18 A度C的植物起源于鸣门。这些结果反映了纬度的差异。在北方种群植物中，在22和24 A摄氏度的高温下观察到死亡植物，而鸣人没有植物死亡。幼孢子体从鸣门表现出最大的能力，积累高氮储备。这些结果表明，幼鱼的高温耐受性差异可能与幼鱼对高温的耐受性有关。来自地理上分离的居群的羽裂孢体是由于遗传分化而不是表型可塑性。
The kelp Undaria pinnatifida has a widespread latitudinal range in Japan, with populations exposed to very different temperature regimes. To test the hypothesis that U. pinnatifida exhibits genetic differentiation in its temperature response, juvenile sporophytes from a warmer location (Naruto, southern Japan) and two colder locations (Okirai Bay and Matsushima Bay, northern Japan) were collected and transplanted to long lines, cultivated under the environmental conditions in Matsushima Bay. These plants were bred using successive self-crossing methods for three generations and the characteristics of photosynthesis, growth, survival, and nitrogen contents of the third-generation juvenile sporophytes (2-3 cm) then were measured and compared. The plants from Naruto showed significantly higher photosynthetic activities and respiration than those from the northern populations at warmer temperatures of 20-35A degrees C. The juvenile sporophytes from all three locations had similar growth rates below 18A degrees C, but significant differences were observed at 18-24A degrees C. The optimum temperatures for growth were 14-16A degrees C in plants that originated from Okirai Bay and Matsushima Bay and 18A degrees C in plants that originated from Naruto. These results reflected the differences in latitude. Dead plants were observed at high temperatures of 22 and 24A degrees C in the northern population plants, whereas no plants from Naruto died. Juvenile sporophytes from Naruto exhibited the greatest capacity to accumulate high nitrogen reserves. These results suggest that the differences in high-temperature tolerance in juvenile U. pinnatifida sporophytes from geographically separated populations are due to genetic differentiation rather than phenotypic plasticity.