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1.
Li J  Koski MH  Ashman TL 《Annals of botany》2012,109(3):545-552

Background and Aims

Gynodioecy is a phylogenetically widespread and important sexual system where females coexist with hermaphrodites. Because dioecy can arise from gynodioecy, characterization of gynodioecy in close relatives of dioecious and sub-dioecious species can provide insight into this transition. Thus, we sought to determine whether Fragaria vesca ssp. bracteata, a close relative to F. chiloensis and F. virginiana, exhibits the functional and population genetic hallmarks of a gynodioecious species.

Methods

We compared reproductive allocation of females and hermaphrodites grown in the greenhouse and estimated genetic diversity (allelic diversity, heterozygosity) and inbreeding coefficients for field-collected adults of both sexes using simple sequence repeat (SSR) markers. We estimated mating system and early seed fitness from open-pollinated families of both sex morphs.

Key Results

Under greenhouse conditions, females and hermaphrodites allocated similarly to all reproductive traits except flower number, and, as a consequence, females produced 30 % fewer seeds per plant than hermaphrodites. Under natural conditions, hermaphrodites produce seeds by self-fertilization approx. 75 % of the time, and females produced outcrossed seeds with very little biparental inbreeding. Consistent with inbreeding depression, seeds from open-pollinated hermaphrodites were less likely to germinate than those from females, and family-level estimates of hermaphrodite selfing rates were negatively correlated with germination success and speed. Furthermore, estimates of inbreeding depression based on genetic markers and population genetic theory indicate that inbreeding depression in the field could be high.

Conclusions

The joint consideration of allocation and mating system suggests that compensation may be sufficient to maintain females given the current understanding of sex determination. Fragaria vesca ssp. bracteata exhibited similar sex morph-dependent patterns of mating system and genetic diversity, but less reproductive trait dimorphism, than its sub-dioecious and dioecious congeners.  相似文献   
2.
廖咏梅  雷泞菲  陈劲松   《广西植物》2006,26(5):503-506
通过盆栽实验,研究了匍匐茎草本野草莓在异质性光照条件下的克隆整合。结果显示克隆整合显著增强了野草莓胁迫分株段的生长,损—益分析表明未受胁迫分株没有显著损耗,整个克隆片段的生长得到显著提高。在局部遮荫处理,克隆整合对克隆形态可塑性的修饰作用没有观察到。最后,讨论了克隆植物对环境的生态适应意义。  相似文献   
3.
Three-millimeter-long shoot tips of strawberry 'Senga Sengana' and raspberry 'Norna' encapsulated in calcium alginate were stored in vitro at 4 °C in the dark. The cultures which were donors for the shoot tips were grown before encapsulation on shoot multiplication media (Boxus medium with 2.2 µM BAP and 2.46 µM IBA for strawberry, and MS medium with NH4NO3 and KNO3 reduced by 50%, and with 3.55 µM BAP and 0.49 µM IBA for raspberry) as well as on these media supplemented with 10 g l–1 mannitol or paclobutrazol (1.7 µM for strawberry and 3.4 µM for raspberry). Sodium alginate was dissolved in water, water with sugar or in a culture medium without growth regulators. Regrowth ability of the stored explants and in vitro multiplication in three successive subcultures were evaluated. The encapsulated shoot tips could be stored for 9 months in beads containing sugar or a culture medium. The pre-conditioning of the donor cultures on a mannitol containing medium was beneficial for regrowth ability. The multiplication rate of strawberry and raspberry shoots in the first subculture after storage was lower than that of non-stored cultures. Particularly low multiplication was obtained for strawberry which had been stored for 9 months and for raspberry stored for 3 and 6 months, in combinations where the beads were prepared by dissolving sodium alginate in water. Multiplication of strawberry in the second subculture was generally higher than in non-stored cultures, but multiplication of raspberry was lower also in the second subculture, with the exception of the combination stored for 9 months and pre-cultured on mannitol. In the third subculture, shoot multiplication in both species was similar to that in non-stored cultures.  相似文献   
4.
组织培养导致的草莓DNA甲基化变异   总被引:1,自引:0,他引:1  
以草莓品种‘丰香’和‘全明星’为材料,用甲基化敏感扩增多态性(MSAP)技术研究组织培养对草莓DNA甲基化的影响。结果表明,与普通苗相比,组织培养导致草莓试管苗的DNA甲基化水平下降,甲基化模式的变异以去甲基化为主。组织培养导致的DNA甲基化变异不稳定,在田间无性繁殖过程中,试管苗的无性繁殖后代DNA甲基化水平逐渐升高,仅部分变异的甲基化模式能够在试管苗的无性繁殖后代中稳定传递。两个品种之间,纽织培养对DNA甲基化变异程度的影响不同。  相似文献   
5.
从印度南瓜自交系HL中发现了一个梭形果突变体HL-fu。该突变体的花、果、茎等多器官的生物学特性同时发生了明显变异:雌花及雄花花器中异性花蕊的残存度较野生型高;果实为梭形,果形指数达野生型5倍;节间呈现长短交替分布的排列状态,叶序类似于对生。以突变体HL-fu与野生型HL杂交分别构建了正、反交F1,正交F2,BC1(P1)F1、BC1(P2)F1群体进行遗传分析,推测该变异类型为隐性多效单基因突变,突变性状受1对隐性核基因fu控制。探讨了梭形果突变体在南瓜育种及相关基础研究方面的潜在价值。  相似文献   
6.
This study reports the development and characterization of 10 polymorphic microsatellite primer pairs in wild strawberry (Fragaria vesca). The primers were designed from a genomic library enriched for di‐, tri‐ and tetranucleotide repeats from F. vesca‘Reugen’. They showed single locus polymorphism in a set of nine F. vesca accessions; two to six alleles were detected per locus. The level of polymorphism in F. vesca was surprisingly low, although three pairs of primers were sufficient to distinguish between most accessions.  相似文献   
7.
The PR10 family protein Fra a 1E from strawberry (Fragaria x ananassa) is down-regulated in white strawberry mutants, and transient RNAi (RNA interference)-mediated silencing experiments confirmed that Fra a 1 is involved in fruit pigment synthesis. In the present study, we determined the solution structure of Fra a 1E. The protein fold is identical with that of other members of the PR10 protein family and consists of a seven-stranded antiparallel β-sheet, two short V-shaped α-helices and a long C-terminal α-helix that encompass a hydrophobic pocket. Whereas Fra a 1E contains the glycine-rich loop that is highly conserved throughout the protein family, the volume of the hydrophobic pocket and the size of its entrance are much larger than expected. The three-dimensional structure may shed some light on its physiological function and may help to further understand the role of PR10 proteins in plants.  相似文献   
8.
Vesicular preparations of plasma membranes (PM) from the microalga Tetraselmis (Platymonas) viridisRouch were used to investigate the ion specificity of the Na+/H+antiporter and Na+-translocating ATPase, two Na+-transporting systems previously identified functionally by our studies of T. viridisPM. The Na+/H+antiporter and Na+-ATPase were shown to translocate, with similar efficiencies, Na+and Li+across the membrane, whereas other cations, such as K+, Rb+, and Cs+, were not transported by these systems. Transport of the latter cations across PM of T. viridisoccurred through the ion channels of PM, which were apparently selective for K+.  相似文献   
9.
作者研究了我国谷子(Setaria italica Beauv.)和狗尾草的核型与Giemsa带,两者核型基本相同,均为2n=18=14m+2sm+2st(SAT)。带型亦相近,另外在谷子和狗尾草中都发现有四倍体。  相似文献   
10.
新疆绿蟾蜍的染色体组型初步研究   总被引:2,自引:2,他引:0  
吴敏  赵亚江 《动物学研究》1987,8(4):339-342
近年来,有关两栖类的染色体组型已有不少报道。无尾两栖类中蜍蟾属(Bufo)的染色体数目分为两类:2n=22和2n=20(Blain,1972)。我们对采自新疆4个地区的绿蟾蜍进行了染色体组型分析,发现其二倍体细胞染色体数均为44,是四倍体。现将我们的初步研究报道如下。  相似文献   
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