Abstract:

Waterlily is an ornamental plant for garden waterscape, having two different ecotypes: cold-tolerant and tropical waterlily. The tropical waterlily usually has bright and colorful flowers but is not tolerant to cold,which limits its popularization and application. Therefore,screening or breeding tropical waterlily that are relatively cold resistant, or assistanting them in overwintering through simple artifical processing, are effective ways to solve this bottleneck. In this study, a collection of tropical waterlily (58 in total) including various subgenus has been used for screening germplasm resources that survive the winter in non-tropical condition. Through two consecutive years of testing, it was found that the waterlily varieties of the ancient tropical waterlily subgenus had relatively higher tolerance than others, and all six waterlily varieties of the ancient tropical waterlily subgenus survived the winter, indicating that the application potential of the ancient tropical subgenus waterlily in non-tropical areas was great. This study also focused on exploring two treatment technologies to assist tropical waterlily overwintering, and found that using potted plants to promote waterlily dormancy and then using simple greenhouses insulation is a very effective overwintering treatment technique, and all the 58 tested waterlily varieties survived the winter, which is suitable for scientific research such as germplasm resource conservation. Additionally, simple greenhouse insulation also has a significant auxiliary overwintering effect, and 27 of the 58 varieties tested have successfully overwintered after treatment by this technology, which is an economical and practical treatment method suitable for production and application.

Key words: tropical waterlily, overwintering, cold tolerance