Recently, whether Archaefructus has bisexual multi-parted flowers or just inflorescences of unisexual flowers, and whether it is ancestral to all angiosperms or a derived eudicot have been debated. Here, from the same...Recently, whether Archaefructus has bisexual multi-parted flowers or just inflorescences of unisexual flowers, and whether it is ancestral to all angiosperms or a derived eudicot have been debated. Here, from the same Yixian Formation, NE China, we report a new Archaefructus species, A. eoflora sp. nov., with the generic characteristics of dissected leaves and bisexual reproductive axes. It is entirely preserved with roots, rhizome, shoots and protogynous reproductive organs at different developmental stages. Its lateral and main fertile shoots form a pseudo-indeterminate pattern, while the reproductive branches on the main shoot form a cymose inflorescence. Subtended by 1-2 bract-like leaves, the section of stamen clusters changes into a much shorter section of carpels that have one row of orthotropous ovules. Significantly, one cluster bearing two carpels and one stamen between the two sections demonstrates a true bisexual flower, an important step of the origin of floral bisexuality, and the homology between the stamen and carpel. The complex reproductive axes represent a mix between flowers and inflorescences, and suggest that A. eoflora sp. nov. possesses the potential to evolve into a variety of diverse flower types as found in modern basal and early fossil angiosperms. A comparison with other two species also leads to a revision of the generic diagnosis.展开更多
[Objective] This study was conducted to investigate the crossbreeding method for Chinese water chestnut. [Method] The growth of Chinese water chestnut stalk and inflorescence was observed. Chinese water chestnut flowe...[Objective] This study was conducted to investigate the crossbreeding method for Chinese water chestnut. [Method] The growth of Chinese water chestnut stalk and inflorescence was observed. Chinese water chestnut flowering law and stamen and pistil growth were investigated in an artificial pollination experiment. [Result] Stamens and pistils reached their full bloom stages when the flower stalk lengths were approximate 37.0 and 46.9 cm, respectively, with a height difference of 9.84 cm and time difference of 28.5 h; and 9：00-11：00 a.m. was the optimal period for artificial pollination. Seven hours after artificial pollination, pistils wilted rapidly. The seed setting rates under artificial pollination and a natural condition was 43% and 15.5%, respectively. [Conclusion} The time difference between the full bloom stages of stamens and pistils is crucial to the success of artificial pollination of Chinese water chestnut. The seed setting rate under artificial pollination is much higher than that under a natural condition.展开更多
文摘Recently, whether Archaefructus has bisexual multi-parted flowers or just inflorescences of unisexual flowers, and whether it is ancestral to all angiosperms or a derived eudicot have been debated. Here, from the same Yixian Formation, NE China, we report a new Archaefructus species, A. eoflora sp. nov., with the generic characteristics of dissected leaves and bisexual reproductive axes. It is entirely preserved with roots, rhizome, shoots and protogynous reproductive organs at different developmental stages. Its lateral and main fertile shoots form a pseudo-indeterminate pattern, while the reproductive branches on the main shoot form a cymose inflorescence. Subtended by 1-2 bract-like leaves, the section of stamen clusters changes into a much shorter section of carpels that have one row of orthotropous ovules. Significantly, one cluster bearing two carpels and one stamen between the two sections demonstrates a true bisexual flower, an important step of the origin of floral bisexuality, and the homology between the stamen and carpel. The complex reproductive axes represent a mix between flowers and inflorescences, and suggest that A. eoflora sp. nov. possesses the potential to evolve into a variety of diverse flower types as found in modern basal and early fossil angiosperms. A comparison with other two species also leads to a revision of the generic diagnosis.
文摘[Objective] This study was conducted to investigate the crossbreeding method for Chinese water chestnut. [Method] The growth of Chinese water chestnut stalk and inflorescence was observed. Chinese water chestnut flowering law and stamen and pistil growth were investigated in an artificial pollination experiment. [Result] Stamens and pistils reached their full bloom stages when the flower stalk lengths were approximate 37.0 and 46.9 cm, respectively, with a height difference of 9.84 cm and time difference of 28.5 h; and 9：00-11：00 a.m. was the optimal period for artificial pollination. Seven hours after artificial pollination, pistils wilted rapidly. The seed setting rates under artificial pollination and a natural condition was 43% and 15.5%, respectively. [Conclusion} The time difference between the full bloom stages of stamens and pistils is crucial to the success of artificial pollination of Chinese water chestnut. The seed setting rate under artificial pollination is much higher than that under a natural condition.
