The objective of this study was to test, using a field experiment, the effect of genotypic diversity on productivity of farmed populations (Ancud and Chaica, Chile) of the domesticated red alga Agarophyton chilense (formerly known as Gracilaria chilensis), a species considered as economically important in Chile. Monoclonal and polyclonal (4 and 8 genotypes) subplots were outplanted into the mid intertidal in Metri Bay (Puerto Montt, Chile) during summer, a season in which A. chilense face higher temperatures (>18°C) and low nitrogen availability (<4.00 μmol). Ancud farm genotypes show higher growth rates in the monoclonal rather than the two polyclonal subplots. A similar tendency, yet not significant, was discernible in Chaica. In addition, whatever the population of origin of the thalli, no effect of genotypic diversity was detected neither on the agar yield and its quality, nor on the epiphyte load. Such unexpected results of a higher performance in plots with a lower genotypic diversity could be explained (a) by human‐assisted selection for dominant‐best‐performing genotypes that could counterbalance the negative effect caused by the low genotypic diversity in farms and (b) by the fact that the organisms inhabiting the algal mats do not impact the fitness of their host. Overall, the results obtained here suggest that despite farm induced selection lead to impoverished pools of genotypes, they may also have a positive effect of on the resistance of farmed populations to seasonal stressors. However, whether this may have a secondary negative effect on the longer term in a fluctuating environment remains to be determined, but may be avoided by adopting strategy of selection favoring different genotypes in space and time, as implemented in forestry.

中文翻译：

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一个人过得更好吗？栽培红藻生长的单克隆和多克隆林的性能比较。

本研究的目的是通过田间试验，测试基因型多样性对驯化红藻Agarophyton chilense（以前称为Gracilaria chilensis）的养殖种群（智利Ancud和Chaica）生产力的影响。在智利具有重要的经济意义。在夏季，即A. chilense的一个季节，在Metri湾（智利的Puerto Montt）的潮间带中段植入了单克隆和多克隆（4和8个基因型）亚图。面临更高的温度（> 18°C）和低的氮利用率（<4.00μmol）。Ancud农场的基因型在单克隆而不是两个多克隆亚图中显示出更高的生长速度。在Chaica，可以看出类似的趋势，但并不明显。此外，无论塔利的起源人群是什么，都没有发现基因型多样性对琼脂产量及其质量以及附生植物负荷的影响。在具有较低基因型多样性的样地中表现出如此出乎意料的结果，这可能是由于以下原因造成的：（a）人类辅助选择表现最佳的显性基因型，可以抵消农场基因型多样性低引起的负面影响，以及（b）由于居住在藻垫上的生物不会影响宿主的健康。全面的，此处获得的结果表明，尽管农场诱导的选择导致基因型库的减少，但它们也可能对养殖人口对季节性胁迫的抗性产生积极影响。然而，这是否会在波动的环境中对长期产生负面影响尚待确定，但可以通过采用有利于空间和时间的不同基因型的选择策略来避免，如林业所采用的那样。