Institute of Tropical Bioscience and Biotechnology, MOA Key Laboratory of Tropical Crops Biology and Genetic Resources; Hainan Bioenergy Center, CATAS, Haikou, Hainan Province, 571101, China.
Department of Environmental Science, Central University of Kerala, RSTC, Padanakkad, 671314, Kerala, India.
Sci Rep. 2017 Jun 8;7(1):3047. doi: 10.1038/s41598-017-03240-8.
Duckweed species have a great potential to develop into fast-growing crops for water remediation and bioenergy production. Seed production and utilization of hybrid vigour are essential steps in this process. However, even in the extensively-studied duckweed species, Lemna gibba, flower primordia were often aborted prior to maturation. Salicylic acid (SA) and agar solidification of the medium promoted flower maturation and resulted in high flowering rates in L. gibba 7741 and 5504. Artificial cross-pollination between individuals of L. gibba 7741 yielded seeds at high frequencies unlike that in L. gibba 5504. In contrast to clone 7741, the anthers of 5504 did not dehisce upon maturation, its artificially released pollen grains had pineapple-like exine with tilted spines. These pollens were not stained by 2,5-diphenylmonotetrazoliumbromide (MTT) and failed to germinate. Therefore, clone 5504 is male sterile and has potential application with respect to hybrid vigour. Moreover, pollination of flowers of 5504 with 7741 pollen grains resulted in intraspecific hybrid seeds, which was confirmed by inter-simple sequence repeat (ISSR) markers. These hybrid seeds germinated at a high frequency, forming new clones.
浮萍物种具有很大的潜力发展成为用于水修复和生物能源生产的快速生长作物。种子生产和杂种优势的利用是这个过程中的重要步骤。然而，即使在广泛研究的浮萍物种浮萍中，花原基也常常在成熟前败育。水杨酸 (SA) 和琼脂固化培养基促进了花的成熟，导致浮萍 7741 和 5504 的开花率很高。在浮萍 7741 个体之间进行人工杂交授粉产生了高频率的种子，而在浮萍 5504 中则不然。与克隆 7741 相反，5504 的花药在成熟时不会开裂，其人工释放的花粉粒具有菠萝状的外壁，带有倾斜的刺。这些花粉粒不会被 2,5-二苯基四氮唑溴化物 (MTT) 染色，也无法发芽。因此，克隆 5504 是雄性不育的，在杂种优势方面具有潜在的应用价值。此外，用 7741 花粉粒授粉 5504 的花朵导致了种内杂种种子，这通过简单重复序列间扩增多态性 (ISSR) 标记得到了证实。这些杂种种子以高频率发芽，形成新的克隆。
