Trends of population density of standing tillers, and developmental morphology of stolons and aerial-tillers in Japanese Iawn grass (Zoysia japonica Steud.) growing in sward conditions.

草地条件下日本结缕草立蘖种群密度、匍匐茎和气生分蘖发育形态的变化趋势。

• 批准号: 11660268
• 负责人: ITO Mutsuyasu
• 金额: $ 2.18万
• 依托单位: NIIGATA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11660268/
• 关键词: aerial-tiller; density; multiple-node; phytomer; stolon; shoot apex; tiller bud; Zoysia japonica Steud; Zoysia Japonica Steud.

Standing tiller densities in frequently defoliated Japanese lawn grass (Zoysia japonica Steud.) populations were generally kept at very high level around 15,000/m^2, and revealed quite excellent contrast to those of Festucoid grasslands cultivated in Japan where initial plant densities tend to decrease quickly during actively growing periods after the establishment. Besides, Zoysia swards examined often showed their ability to realize relatively prominent yield even under frequent defoliations.Principal part of aerial-tillers that constructed the above mentioned dense population of Zoysia was composed of so-called Ta tillers which vigorously generated from the lower nodes of every multiple-node of stolons. In contrast with this, regular emergence of Tb tillers which located one node above the Ta tillers seemed to be rare, as a larger part (nearly 80%) of Tb buds stayed dormant for a longer period during the seasons. Under highly frequent defoliations as conducted in the present study, secondary and tertiary tillers appeared rather freely from the leaf axils of aged and senescing Ta and Tb tillers, and so they supplemented 20 to 30% of total existing tillers.The formation of multiple-node and extension growth in each stolon growing under a sward condition was suppressed strongly as compared with those of single-plants ; average number of multiple-nodes formed per year was ca. 20 and total stolon elongation was around 30 cm. In anatomical investigation in this study, a distinct difference of development was clearly observed between Ta and Tb buds near the apex of each stolon. The differential tiller bud initiation commenced in Ta and Tb tiller buds, both attaching to the same multiple-node, seems to be one reason to result the following diverse development of Ta and Tb tillers.

经常落叶的日本草坪草(Zoysia Japan onica Steud.)种群一般保持在15,000个/m^2左右的非常高的水平，这与日本栽培的费斯图西德草原形成了相当好的对比，在建立后的活跃生长期，日本草地的初始植物密度往往会迅速下降。此外，结缕草牧草经常表现出即使在频繁落叶的情况下也能实现较高产量的能力。构成结缕草密集种群的空中分蘖主体是由每一多节匍匐茎的下部节位蓬勃生长的所谓Ta分蘖组成的。相比之下，位于Ta分蘖上方一个节位的Tb分蘖似乎很少有规律地出现，因为大部分(近80%)的Tb芽在季节中休眠了较长的时间。在本研究的高频率落叶条件下，Ta和Tb的老叶和衰老株的二次和三次分蘖较自由地从叶腋处出现，因此补充了现有分蘖总数的20%~30%。与单株相比，草皮条件下生长的每一茎的多节形成和伸展生长受到强烈的抑制，平均每年形成多节的数量约为20个，总的匍匐茎伸长约30 cm。在本研究的解剖学研究中，在每个匍匐茎顶端附近的Ta和Tb芽之间明显观察到明显的发育差异。分蘖芽分化始于Ta和Tb分蘖芽，两者都附着在同一多节上，这似乎是导致Ta和Tb分蘖发育不同的原因之一。