Rapid seed germination followed by rapid seedling establishment are important traits for field establishment of grasses under variable climatic conditions. This research was designed to improve the seed germination of three Indiangrass [Sorghastrum nutans (L.) Nash] populations through two cycles of recurrent selection and to field test the nine populations. Two cycles of recurrent selection were used to develop C₁ and C₂ populations from three previously unselected populations of Indiangrass. Cycle 1 consisted of germinating 3,500 open-pollinated seeds of each C₀ population in water of −0.8 MPa potential for 7 d. All germinated seeds within 7 d were selected to create three C₁ populations. Cycle 2 selection was like Cycle 1, except that C₁ populations were used to develop three C₂ populations. To test the effects of selection, four 50-spikelet samples of the nine Indiangrass populations were germinated in water of −0.8 and 0 MPa potentials for 7 d for two seed harvests. Both water potentials produced a population × selection generation interaction (P ≤ .05). Different rates of gain among the Indiangrass populations for water potential treatments (−0.8 and 0 MPa) described the interactions. On average, C₁ and C₂ populations emerged and survived better than C₀ populations in the field. Thus, the data suggest that recurrent selection for increased laboratory seed germination of Indiangrass in a low water potential not only improved the 7-d laboratory seed germination, but seed mass and stand establishment as well.

中文翻译：

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在模拟干燥条件下选择用于更大实验室种子发芽的印第安草种群的发芽和田间建立

快速种子发芽和快速幼苗建立是在多变的气候条件下田间建立草的重要特性。本研究旨在通过两个轮回选择周期提高三个印度草 [ Sorghastrum nutans (L.) Nash] 种群的种子萌发，并对九个种群进行田间试验。两个轮回选择周期用于从三个先前未选择的印度草种群中开发 C ₁和 C ₂种群。第 1 轮包括在 -0.8 MPa 电位的水中发芽每个 C _{0种群的 3,500 个开放授粉种子 7 天。}选择7 d内所有发芽的种子创建三个C ₁种群。第 2 轮选择类似于第 1 轮，只是使用 C ₁群体来开发三个 C ₂群体。为了测试选择的效果，将 9 个印第安草种群的 4 个 50 小穗样本在 −0.8 和 0 MPa 电位的水中发芽 7 天，进行两次种子收获。两种水势都产生了种群×选择世代相互作用 ( P ≤ .05)。水势处理（-0.8 和 0 MPa）的 Indiangrass 种群的不同增益率描述了相互作用。平均而言，C ₁和 C ₂种群的出现和存活优于 C ₀该领域的人口。因此，数据表明，在低水势下为增加印度草实验室种子发芽而进行的循环选择不仅改善了 7 天实验室种子发芽，而且还改善了种子质量和林分建立。