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Colchicine is widely used as a mutagen to induce production of diploid gametes in plants. However, whether colchicine affects induced pollen viability remains unclear. To clarify whether colchicine affected the viability of induced pollen, we induced production of diploid pollen by colchicine, followed by pollen germination and crossing induced pollen with normal gametes to produce triploid in Carrière. The results showed that the predominant meiotic stages and the number of colchicine injections had significant effects on the occurrence rates of induced 2n pollen. When the colchicine injection was given at diakinesis, a significant decrease in the pollen production per bud was observed ( < 0.001). The morphology of the colchicine-induced 2n pollen was similar to that of the natural 2n pollen in its ectexine structure. The pollen germination experiments revealed that there was also no significant difference in germination rates between the induced diploid pollen and natural 2n pollen grains, and 68 triploids were created by crossing colchicine-induced pollen. Our findings revealed that colchicine injection could induce to produce 2n pollen and will not lead to dysfunction of induced diploid pollen.in vitroPopulus tomentosapP. tomentosa

It is a promising way to control Microcystis bloom by the algicidal substances from some special heterotrophic bacteria. However, the algicidal mechanism of the common known 1-hydroxyphenazine and the potential impact of extracellular degradative enzymes from total accompanying heterotrophic bacteria on its algicidal characteristics remains unknown. Here, the physiological changes of Microcystis aeruginosa were investigated under the stress of 1-hydroxyphenazine and extracellular degradative enzymes individually or together. The results showed that the extracellular degradative enzymes from heterotrophic bacteria had a weak inhibitory effect on the growth of M. aeruginosa and made M. aeruginosa suffered oxidative damage. 1-hydroxyphenazine promoted the cells death of M. aeruginosa with a manner independent of reactive oxygen species (ROS) level. 1-hydroxyphenazine might play a role in promoting the cyclic electron transport to reduce ROS in M. aeruginosa. The reduction of total anti-oxidative capacity and the depletion of glutathione might induce the death of M. aeruginosa under stress of 1-hydroxyphenazine. The addition of extracellular degradative enzymes eventually delayed the algae death and alleviated the inhibitory effect of 1-hydroxyphenazine on algal ATPase hydrolytic activity and total antioxidant capacity. The heterotrophic partnership seemed to be helpful to increase the stress resistance of M. aeruginosa.

As global climate changes and water eutrophication are aggravated, cyanobacterial blooms has become a worldwide ecological problem and poses risks to public health [1]. Microcystis aeruginosa may originate from the African continent and has depersed into Asia, Europe and America [2]. Toxic Microcystis aeruginosa is the most primary bloom-forming cyanobacteria in eutrophic freshwaters [3-4]. It produces microcystins that can lead to poisoning, cancer and even death of humans and animals [5]. The Toledo drinking water crisis in USA, the Wuxi drinking water crisis in China and the recreational water risk in Portugal have caused public health concerns [6-8]. Many methods for controlling cyanobacterial blooms have been

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