John Ana Laura de Wallau, Mäder Geraldo, Fregonezi Jeferson N, Freitas Loreta B
Laboratory of Molecular Evolution, Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Genet Mol Biol. 2019 Jan-Mar;42(1):108-119. doi: 10.1590/1678-4685-GMB-2017-0314. Epub 2019 Mar 11.
Calibrachoa is a South-American genus comprising 27 species, several considered endemic or rare; few were subjects in genetic studies. We attempted to generate new data about the phylogenetically related and rare species C. eglandulata, C. sendtneriana, C. serrulata, and C. spathulata concerning their genetic diversity and population structure, which, coupled with their known restricted distribution, could help access their conservation status and contribute to the study of the Brazilian biodiversity. We sequenced 88 individuals for plastid intergenic spacers and genotyped 186 individuals for five microsatellite loci. Compared among each other, C. sendtneriana and C. serrulata presented the highest values of genetic diversity [π% (sd) = 0.23 (0.14) and 0.43 (0.25), respectively], followed by C. spathulata [π% (sd) = 0.19 (0.12)] and C. eglandulata [π% (sd) = 0.02 (0.03)]. Population differentiation was evident for these latter species, whereas it was not significant for C. sendtneriana and C. serrulata. Factors such as habitat specificity and fragmentation, pollination syndrome, and life history could explain the observed patterns. Based on the new genetic data and the species' biology, a conservation status was assigned for C. sendtneriana and the status of the other three species was reviewed.
小花矮牵牛属是一个南美属，包含27个物种，其中一些被认为是特有种或稀有物种；很少有物种成为遗传学研究的对象。我们试图获取有关系统发育相关的稀有物种小花矮牵牛、森氏小花矮牵牛、锯齿小花矮牵牛和匙形小花矮牵牛的新数据，内容涉及它们的遗传多样性和种群结构，这些物种已知分布范围有限，这些数据有助于了解它们的保护状况，并为巴西生物多样性研究做出贡献。我们对88个个体的质体基因间隔区进行了测序，并对186个个体的五个微卫星位点进行了基因分型。相互比较后，森氏小花矮牵牛和锯齿小花矮牵牛的遗传多样性值最高[π%（标准差）分别为0.23（0.14）和0.43（0.25）]，其次是匙形小花矮牵牛[π%（标准差）=0.19（0.12）]和小花矮牵牛[π%（标准差）=0.02（0.03）]。后几种物种的种群分化很明显，而森氏小花矮牵牛和锯齿小花矮牵牛的种群分化不显著。栖息地特异性和破碎化、授粉综合征以及生活史等因素可以解释观察到的模式。根据新的遗传数据和物种生物学特性，确定了森氏小花矮牵牛的保护状况，并对其他三个物种的状况进行了评估。
