Plasticity in the self-incompatibility system of cultivated Nicotiana alata
Plasticity in the self-incompatibility system of cultivated Nicotiana alata
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栽培烟草自交不亲和系统的可塑性
DOI：
10.1007/s10681-015-1606-x
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发表时间：
2016-03-01
期刊：
影响因子：
1.9
通讯作者：
Chen, Suiyun
中科院分区：
文献类型：
--
作者：
Liao, Jugou;Dai, Jinran;Chen, Suiyun
烟草阿拉塔是茄科植物配子体自交不亲和性研究的模式种。基于遗传的SI系统广泛存在于开花植物中，其功能是减少纯合性和避免近交衰退。然而，对于S等位基因较少的群体，如栽培克隆群体或由少数个体建立的群体，异交往往是无法实现的。在这种情况下，迫切需要自我繁殖和传递遗传信息。通过授粉和花粉管观察试验，探讨了纯合自交不亲和N。阿拉塔（S-等位基因鉴定和S-RNase活性）坐果，并探索这些个体中的假自花受精。在不同发育时期授粉的花中观察到了几种异常现象，包括肿胀、分叉、弯曲和倒锥、顶端爆裂和胼胝质塞不规则沉积。此外，SI在这条线上的强势N。有翅阿拉塔植物的花龄和花期不同。也就是说，花变得更加自交亲和与花老化，和SI强度在开花阶段结束时（阶段III）的花是较低的，更多的水果被设置在假总状花序的顶部。最后，SI强度在同一植株和发育阶段的个体花之间也存在差异。但施氮量对SI强度的影响不显著。相同S等位基因纯合的阿拉塔植物。这些结果表明，SI在N。阿拉塔是塑料的，果实由成熟的花朵，特别是第三阶段的花朵形成。
Nicotiana alata has long been a model species for studying gametophytic self-incompatibility (SI) in Solanaceae. Genetically based SI systems are widespread in flowering plants and function to reduce homozygosity and avoid inbreeding depression. However, out-crossing is always unfulfillable for populations with few S-alleles, such as in cultivated clonal populations or populations founded by few individuals. Under such conditions, there is a pressing demand to self-reproduce and pass on genetic information. We carried out a series of pollination and pollen tube observation experiments to explore how homozygous self-incompatible N. alata (S-allele identified and S-RNase active) sets fruits and to explore pseudo-self-fertility in these individuals. We observed several kinds of pollen tube abnormalities, including swelling, furcation, curve and inflexion, tip bursting and irregular callose plug deposition for flowers pollinated at different developmental stages. In addition, SI strength in this line of N. alata plants changed with floral age and flowering stages. That is, flowers became more self-compatible with floral aging, and SI strength in flowers at the end of flowering stages (stage III) was lower and more fruits were set at the top of the pseudo-raceme. Finally, SI strength also varied between individual flowers at the same plant and development stages. However, SI strength varied insignificantly among cultivated N. alata plants homozygous for the same S-allele. These findings indicate that SI in N. alata is plastic, with fruits set by aging flowers, especially flowers at stage III.