ALLOZYME VARIATION IN LOUISIANA IRISES - A TEST FOR INTROGRESSION AND HYBRID SPECIATION
ALLOZYME VARIATION IN LOUISIANA IRISES - A TEST FOR INTROGRESSION AND HYBRID SPECIATION
复制标题
DOI：
10.1038/hdy.1990.99
复制
发表时间：
1990-12-01
期刊：
影响因子：
3.8
通讯作者：
BENNETT, BD
中科院分区：
文献类型：
--
作者：
ARNOLD, ML;HAMRICK, JL;BENNETT, BD
在50个推定位点（同工酶）的遗传变异存在于599个个体鸢尾样品进行了检查。样本包括I.富尔瓦岛六角岛brevicaulis和推测的杂种种，即I. nelsonii。此外，我们研究了两个种群的重叠地区，涉及I。fulva与I. hexagona和I. fulva与I. brevicaulis和I.六边形这两个杂交群体的等位酶数据表明存在来自I.富尔瓦岛brevicaulis和I.六边形I. fulva和I.六边形来自这两个物种之间的papapatric协会的个体具有I的各种组合。fulva和I.六角形诊断标记物。该样品中遗传变异的模式表明存在高级杂交世代和局部渐渗;该发现与先前的分子遗传分析雅阁（Arnold等人，1990年）。此外，目前异地种群的I。fulva和I. hexagona被发现具有低频率的标记等位基因诊断的替代物种。这些群体还含有低频率的交替的诊断性核糖体DNA重复长度变体（Arnold等人，1990年）。等位酶（和分子）的数据表明，这些异地样本代表以前渗入的人口。等位酶调查结果表明，I。nelsonii含有一系列I.富尔瓦岛hexagona和我短茎此外，这些标记中的一些被发现在一个现代的混合人口涉及I。富尔瓦岛hexagona和我短茎这些发现表明，我。nelsonii为杂种起源，由I.富尔瓦岛hexagona和我短茎遗传分析沿着与以前的染色体，分布和人口统计学研究的路易斯安那州鸢尾属物种表明，一些机制可能已经参与了这种混合衍生物的稳定。
Genetic variation present in 599 individual Iris samples was examined at 50 presumptive loci (isozymes). The samples included allopatric populations of I. fulva, I. hexagona, I. brevicaulis and the putative hybrid species, I. nelsonii. In addition, we examined two populations from areas of overlap involving I. fulva with I. hexagona, and I. fulva with I. brevicaulis and I. hexagona. Allozyme data for both of these hybrid populations suggest the presence of genes from I. fulva, I. brevicaulis and I. hexagona. Bidirectional introgressive hybridization is indicated between I. fulva and I. hexagona. Individuals from a papapatric association between these two species possess various combinations of I. fulva and I. hexagona diagnostic markers. The pattern of genetic variation in this sample indicates the presence of advanced hybrid generations and localized introgression; this finding is in accord with a previous molecular genetic analysis (Arnold et al., 1990). Furthermore, currently allopatric populations of I. fulva and I. hexagona were found to have low frequencies of marker alleles diagnostic for the alternate species. These populations also contain a low frequency of alternate, diagnostic ribosomal DNA repeat length variants (Arnold el al., 1990). The allozyme (and molecular) data suggest that these allopatric samples represent previously introgressed populations. Findings from the allozyme survey indicate that I. nelsonii contains an array of markers characteristics for I. fulva, I. hexagona and I. brevicaulis. Furthermore, some of these markers are found in a present-day hybrid population involving I. fulva, I. hexagona and I. brevicaulis. These findings suggest that I. nelsonii is of hybrid origin, deriving from hybridization between I. fulva, I. hexagona and I. brevicaulis. The genetic analysis along with previous chromosomal, distributional and demographic studies of the Louisiana Iris species suggests that a number of mechanisms may have been involved in the stabilization of this hybrid derivative.