Cottonwood hybrids gain fitness traits of both parents: a mechanism for theirlong-term persistence?
Cottonwood hybrids gain fitness traits of both parents: a mechanism for theirlong-term persistence?
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三叶杨杂交种获得了父母双方的适应性特征：它们长期坚持的机制？
DOI：
10.3732/ajb.89.6.981
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发表时间：
2002
影响因子：
3
通讯作者：
T. Whitham
中科院分区：
文献类型：
--
作者：
J. Schweitzer;G. Martinsen;T. Whitham
通过对自然种群的调查、实验杂交和普通园林试验，我们检验了来自北方犹他州韦伯河的杂交三角杨（Populus fremontii × P. angustifolia）将产生与其亲本物种一样多的可行后代的假设。我们发现，F（1）代和回交世代都可以像亲本类群一样适合。首先，F（1）杂种产生了与P. angustifolia一样多的有活力的种子（但少于P. fremontii），回交基因型产生了与两个亲本类群一样多的有活力的种子。第二，杂种产生的分株数量是狭叶胡杨的近2倍，是费氏胡杨的4倍。第三，所有树木类型的发芽幼苗的高死亡率（即，>90%）和极低的死亡率为杂种提供了平等的有性生殖和增强的无性生殖，特别是因为回交杂种在分株生产中表现出超亲分离。我们的研究结果表明，渗入的P. fremontii种子性状到杂种基因组是负责他们的同等性能（至少对一个父母）在有性生殖，而来自P. angustifola的无性繁殖性状的贡献，在杂种具有相等或更大的健身结果。
Using surveys of natural populations, experimental crosses, and common garden trials, we tested the hypothesis that hybrid cottonwoods (Populus fremontii × P. angustifolia) from the Weber River in northern Utah would produce as many viable offspring as their parental species. We found that both F(1) generations and backcross generations can be just as fit as the parent taxa. First, F(1) hybrids produced as many viable seed as P. angustifolia (but less than P. fremontii), and backcross genotypes produced as many viable seeds as both parent taxa. Second, hybrids produced nearly two times as many ramets from root sprouts as P. angustifolia and four times as many ramets as P. fremontii. Third, the high mortality of germinated seedlings of all tree types (i.e., >90%) and very low mortality of asexually derived ramets provide hybrids with equal sexual reproduction and enhanced asexual reproduction, especially since backcross hybrids exhibit transgressive segregation in ramet production. Our findings suggest that the introgression of P. fremontii seed traits into the hybrid genome is responsible for their equivalent performance (at least to one parent) in sexual reproduction, while the contributions of asexual traits from P. angustifola results in hybrids having equal or greater fitness.
影响因子：
1.3
作者：
Balla, Krisztina;Rakszegi, Mariann;Veisz, Otto
通讯作者：
Veisz, Otto