Singh Saurabh, Bhatia Reeta, Kumar Raj, Behera Tusar K, Kumari Khushboo, Pramanik Achintya, Ghemeray Hemant, Sharma Kanika, Bhattacharya R C, Dey Shyam S
Division of Vegetable Science, ICAR-Indian Agricultural Research Institute, New Delhi, India.
Division of Floriculture and Landscaping, ICAR-Indian Agricultural Research Institute, New Delhi, India.
Front Plant Sci. 2021 Apr 30;12:631489. doi: 10.3389/fpls.2021.631489. eCollection 2021.
Mitochondrial markers can be used to differentiate diverse mitotypes as well as cytoplasms in angiosperms. In cauliflower, cultivation of hybrids is pivotal in remunerative agriculture and cytoplasmic male sterile lines constitute an important component of the hybrid breeding. In diversifying the source of male sterility, it is essential to appropriately differentiate among the available male sterile cytoplasms in cauliflower. PCR polymorphism at the key mitochondrial genes associated with male sterility will be instrumental in analyzing, molecular characterization, and development of mitotype-specific markers for differentiation of different cytoplasmic sources. Presence of auto- and alloplasmic cytonuclear combinations result in complex floral abnormalities. In this context, the present investigation highlighted the utility of organelle genome-based markers in distinguishing cytoplasm types in Indian cauliflowers and unveils the epistatic effects of the cytonuclear interactions influencing floral phenotypes. In PCR-based analysis using a set of primers targeted to , 76 Indian cauliflower lines depicted the presence of cytoplasm albeit the amplicons generated exhibited polymorphism within the sequence. The polymorphic fragments were found to be spanning over 200-280 bp and 410-470 bp genomic regions of and , respectively. Sequence analysis revealed that such cytoplasmic genetic variations could be attributed to single nucleotide polymorphisms and insertion or deletions of 31/51 nucleotides. The cytoplasmic effects on varying nuclear-genetic backgrounds rendered an array of floral abnormalities like reduction in flower size, fused flowers, splitted style with the exposed ovule, absence of nonfunctional stamens, and petaloid stamens. These floral malformations caused dysplasia of flower structure affecting female fertility with inefficient nectar production. The finding provides an important reference to ameliorate understanding of mechanism of cytonuclear interactions in floral organ development in The study paves the way for unraveling developmental biology of CMS phenotypes in eukaryotic organisms and intergenomic conflict in plant speciation.
线粒体标记可用于区分被子植物中的不同线粒体类型以及细胞质。在花椰菜中，杂种培育在盈利农业中至关重要，而细胞质雄性不育系是杂交育种的重要组成部分。在使雄性不育源多样化的过程中，适当区分花椰菜中现有的雄性不育细胞质至关重要。与雄性不育相关的关键线粒体基因的PCR多态性将有助于分析、分子表征以及开发用于区分不同细胞质来源的线粒体类型特异性标记。自身和异质细胞核质组合的存在会导致复杂的花异常。在此背景下，本研究突出了基于细胞器基因组的标记在区分印度花椰菜细胞质类型方面的实用性，并揭示了影响花表型的核质相互作用的上位效应。在使用一组靶向特定基因的引物进行的基于PCR的分析中，76个印度花椰菜品系显示存在某种细胞质，尽管所产生的扩增子在该基因序列内表现出多态性。发现多态性片段分别跨越该基因和另一基因的200 - 280 bp和410 - 470 bp基因组区域。序列分析表明，这种细胞质遗传变异可归因于单核苷酸多态性以及31/51个核苷酸的插入或缺失。细胞质对不同核遗传背景的影响导致了一系列花异常，如花朵大小减小、花融合、花柱分裂且胚珠外露、无功能雄蕊缺失以及花瓣状雄蕊。这些花畸形导致花结构发育异常，影响雌蕊育性并降低花蜜产量。该发现为深入了解花椰菜花器官发育中核质相互作用的机制提供了重要参考。该研究为揭示真核生物中细胞质雄性不育表型发育生物学以及植物物种形成中的基因组间冲突铺平了道路。
