Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Am J Bot. 2018 Oct;105(10):1712-1724. doi: 10.1002/ajb2.1159. Epub 2018 Sep 24.
Clonal reproduction is often associated with polyploidy and is expected to influence polyploid establishment success, but the immediate effects of whole-genome duplication (WGD) on clonal reproduction in autopolyploids are unknown.
We used synthesized neopolyploids to assess the direct effects of WGD on stolon and plantlet production in the wild strawberry Fragaria vesca by (1) comparing absolute clonal investment between diploids and neotetraploids under high and low resource conditions in the greenhouse and (2) determining realized clonal plantlet establishment and genet spatial structure using artificial field populations comprising both cytotypes.
Neotetraploids produced fewer stolons and plantlets than diploids at slower weekly rates in the greenhouse when resources were high, resulting in lower total investment in clonal reproduction. Low resources led to smaller reductions in clonal biomass for neotetraploids and less pronounced differences between cytotypes. Comparisons between neotetraploids representing 13 independent WGD events and close diploid relatives revealed considerable variation in the response to polyploidization for some clonal traits. Field populations corroborated greenhouse results; neotetraploid genets were smaller than diploid genets, containing 28% fewer stolons and 46% fewer rooted plantlets.
WGD significantly decreases the clonal output of neotetraploid F. vesca, which is likely attributable to slower whole-plant growth of the neotetraploids than the diploids. In natural populations, smaller neotetraploid genets could decrease the probability of polyploid establishment in this species. However, variation between separate neopolyploid lines emphasizes that the response of clonal investment to WGD may not be uniform across polyploid origins.
克隆繁殖通常与多倍体有关，预计会影响多倍体的建立成功率，但全基因组复制（WGD）对同源多倍体克隆繁殖的直接影响尚不清楚。
我们使用合成的新多倍体，通过（1）在温室中高、低资源条件下比较二倍体和新四倍体之间绝对克隆投资，以及（2）利用包含两种细胞型的人工田间种群确定实现的克隆植物定植和遗传空间结构，来评估 WGD 对野生草莓 Fragaria vesca 匍匐茎和植物定植的直接影响。
在温室中资源充足时，新四倍体产生的匍匐茎和植物定植比二倍体少，每周生长速度较慢，导致克隆繁殖的总投资较低。低资源导致新四倍体克隆生物量减少幅度较小，细胞型之间的差异不那么明显。对代表 13 次独立 WGD 事件的新四倍体与近二倍体亲缘体的比较表明，一些克隆特征对多倍体化的反应存在相当大的差异。田间种群证实了温室结果；新四倍体遗传体小于二倍体遗传体，包含的匍匐茎少 28%，生根植物定植少 46%。
WGD 显著降低了新四倍体 F. vesca 的克隆输出，这可能归因于新四倍体的整个植物生长速度比二倍体慢。在自然种群中，较小的新四倍体遗传体可能会降低该物种多倍体建立的可能性。然而，单独的新多倍体系之间的差异强调了克隆投资对 WGD 的反应可能不是在所有多倍体起源中都是一致的。
