Levin Donald A
Department of Botany, University of Texas, Austin, TX, 78713.
Evolution. 1989 Nov;43(7):1417-1423. doi: 10.1111/j.1558-5646.1989.tb02592.x.
Inbreeding depression was measured in terms of the relative survivorship of self versus cross seed in 14 Phlox drummondii cultivars and 10 populations of P. cuspidata. The cultivars are predominantly outcrossing; P. cuspidata is predominantly self-fertilizing. The relative survivorship of self versus cross seed averages 0.84 in the cultivars and 0.99 in P. cuspidata. In wild P. drummondii, the average is 0.83. The mean number of lethal equivalents per zygote averages 0.69 in the cultivars and 0.05 in P. cuspidata, versus 0.79 in the wild P. drummondii. There is a significant negative correlation between the amount of automatic self-seed produced by a cultivar and the number of lethal equivalents it carries (r = -0.60). Phlox cuspidata has a lower level of cross-seed abortion than P. drummondii, which probably is not due to a difference in the incidence of lethal genes in their populations.
通过比较14个矮牵牛栽培品种以及10个尖萼福禄考种群自交种子与杂交种子的相对存活率，来测定近亲繁殖衰退情况。这些栽培品种主要进行异花授粉；尖萼福禄考主要进行自花受精。在栽培品种中，自交种子与杂交种子的相对存活率平均为0.84，在尖萼福禄考中为0.99。在野生矮牵牛中，该平均值为0.83。每个合子的致死当量平均数在栽培品种中平均为0.69，在尖萼福禄考中为0.05，而在野生矮牵牛中为0.79。一个栽培品种产生的自动自交种子数量与其携带的致死当量数量之间存在显著的负相关（r = -0.60）。尖萼福禄考的杂交种子败育水平低于矮牵牛，这可能并非由于它们种群中致死基因发生率的差异。
