兰引Ⅲ号草坪型结缕草发芽生态适应性的研究

Eco—Adaptability of Seed Germination in Lawn Grass of Zoysia japonica cv. Lanyin Ⅲ

探讨了坪用结缕草新品种兰引Ⅲ号的萌发吸水特性以及萌发对温度的反应,并比较了该品种与我国现行的商业品种山东结缕草种子(打破休眠处理与未处理)在上述特性方面的异同点。结果表明:兰引Ⅲ号种子小(千粒重为0.308g)、萌发吸水率低(为42%)、为萌发节水型种子,其萌发初始阶段100粒种子的最大吸水量为0.0151g,仅相当于山东结缕草的44%(未处理)和65%(打破休眠处理)。兰引Ⅲ号在萌发初始阶段达最大吸水量所需时间为48h,短于未处理的山东(72h)、而长于打破休眠处理的山东(12h)结缕草,但达最大吸水量时的吸水率与两个山东结缕草种样相当。兰引Ⅲ号种子的萌发最适温度为15～35,20～30和20～35℃变温,在这3种温度下发芽势(36%～46%)和发芽率(64%～72%)皆高于其它温度处理,而生活力高达93%(四唑测定)的未处理山东结缕草在实验所设7个温度下均未发芽。打破休眠处理山东结缕草的发芽适宜温度范围较兰引Ⅲ号窄,为15～35℃和20～35℃变温。兰引Ⅲ号的根/芽(室内测定)和根/茎长度比(田间测定)皆低于山东结缕草。

Water absorption and response to temperatures of seed germination of Zoysia japonica cv. Lanyin Ⅲ, a new lawn grass variety, were studied. In addition, the seed characteristics of Lanyin were also compared with a most popular Chinese commercial lawn variety of Zoysia japonica cv. Shandong. The seed samples of Shandong included both breaking dormancy treated and nontreated. The results showed that the seed size of Lanyin was small with a 1000—seed weight of 0.308g, the amount of water uptake at the initial imbibition stage(IIS) of seed germination was much less than Shandong. For instance, the maximum amount of water uptake at IIS lasted 48h for Lanyin 72h for nontreated Shandong and 12h for treated Shandong, however, the rates of water uptake among the three tested samples were no big difference(34%～42%). The suitable temperatures for germination of Lanyin were the alternative temperatures of 15～35℃, 20～30℃ and 20～35℃. At these test conditions, the germination speed (first count, 36%～46%) and final percentage (64%～72%) counted both higher than the other treatments, while, no seed germinated for nontreated Shandong sample under the all 7 tested conditions. The range of temperature suitable for germination of treated Shandong sample was narrower than the Lanyin, which were 15～35℃ and 20～35℃. The length ratio of root/shoot of Lanyin measured both in laboratory and in field showed higher than the Shandong.