Jahnke Matthew R, Etterson Julie R
Department of Biology, University of Minnesota Duluth, 207A Swenson Science Building, Duluth, MN, 55812, USA.
J Plant Res. 2019 Jan;132(1):57-67. doi: 10.1007/s10265-018-1076-z. Epub 2018 Dec 15.
The mating systems of wild plant populations have profound effects on their genetic structure and evolution, yet remain unknown or incompletely described for many species. One such species, the herbaceous native annual Linum sulcatum Riddell (Linaceae), is thought to be self-compatible, but there has been no experimental evidence to date to support this claim. To assess the breeding system of this species, seeds were collected from wild populations and reared in a controlled environment. Floral manipulations and controlled pollinations were conducted to determine the degree of self-compatibility of this species and to distinguish between autonomous and facilitated modes of selfing. Additional controlled within- and between-population crosses were conducted to determine the relative degree to which this species can outcross. This study showed that self-fertilization was highly successful and can occur autonomously. In contrast, outcrossing success, both within and between populations, was very limited, suggesting this species may exhibit an extreme degree of cross-incompatibility. A pollen tube growth experiment showed that self-pollination resulted in the formation of more pollen tubes relative to cross-pollination and that complete pollen tube growth can occur less than 2 h following self-pollination. This information is relevant to the future persistence of this species, as much of its remaining habitat is distributed among small, highly fragmented patches subjected to current and future environmental stressors.
野生植物种群的交配系统对其遗传结构和进化有着深远影响，但许多物种的交配系统仍不为人知或描述不完整。一种这样的物种，即本土一年生草本植物浅裂亚麻（亚麻科），被认为是自交亲和的，但迄今为止尚无实验证据支持这一说法。为了评估该物种的繁育系统，从野生种群收集种子并在可控环境中培育。进行了花朵操控和控制授粉实验，以确定该物种的自交亲和程度，并区分自动自交和辅助自交模式。还进行了额外的种群内和种群间控制杂交实验，以确定该物种异交的相对程度。本研究表明，自花受精非常成功且能自动发生。相比之下，种群内和种群间的异交成功率非常有限，这表明该物种可能表现出极高程度的杂交不亲和性。一项花粉管生长实验表明，与异花授粉相比，自花授粉产生的花粉管更多，且自花授粉后不到2小时就能完成花粉管生长。这些信息与该物种未来的存续相关，因为其剩余的大部分栖息地分布在小块、高度破碎的区域，且面临当前和未来的环境压力。
