2 resultados para Kentucky
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
Embryogenic calli of Kentucky bluegrass, named Md, were induced from mature seeds and embryos, and proliferated on medium K3 containing 2,4-dichlorophenoxyacetic acid (2,4-D, 10.0 mumol/L), 6-benzylaminopurine (BAR, 0.5 mumol/L) and K5 which was the K3 medium supplemented with cupric sulfa (0.5 mumol/L) under dim-light condition (20-30 mumol.m(-2).s-1, 16 h light) at 24 degreesC. Embryogenic calli were transformed with plasmids pDM805 Carring bar and gus genes, Which was mediated by an Agrobacterium strain AGL1, four transgenic lines were obtained. The important factors that affect the transformation efficiency and obtain desirable number of transgenic plants included: (1) the quality of embryogenic calli; (2) light condition and time of co-cultivation; (3) concentration of antibiotics used for suppressing the overgrowth of Agrobacterium in the course of transformed plant regeneration; (4) selection pressure, etc. The micro nutrient of cupric had significant influence on the quality of embryogenic calli. This presentation is the first successful protocol of Kentucky bluegrass transformation mediated by Agrobacterium.
Resumo:
本研究采用室外盆栽试验,模拟运动场坪床结构,研究不同氮肥种类、不同施氮频率、施氮和降雨时间间隔对草地早熟禾草坪质量、草坪生长和无机氮淋洗的影响,并探讨在北京地区气候条件下,草坪在不同氮肥管理措施下的氮素去向及环境风险。主要结论如下: 1. 氮肥种类对草坪质量和草坪生长有显著影响。试验前期(春季),草坪颜色和密度质量、草坪草生长速度和草屑全氮含量的排序为尿素 > CU3M(自研包膜尿素)> IBDU(进口缓释肥),而试验后期(秋季)则为CU3M = IBDU > 尿素。草坪合格颜色质量持续时间和成坪速度的排序为尿素 > CU3M > IBDU。在新建草坪选择缓释肥进行早春施肥时,应混施一定比例的速效肥。 2. 施氮频率对草坪外观质量评分、草坪生长速度、草屑总生物量、草屑全氮含量和根系分布状况有显著影响。U6处理的草坪合格颜色质量持续时间最长,增加施氮频率没有降低新建草坪生长速度和草屑全氮含量的波动幅度。 3. 夏季(6~8月)渗漏液体积占全年的比例最高,为75.0%~82.4%。新建草坪初期的淋洗风险较大,渗漏液硝态氮浓度在第1次超过10 mg N•L-1,尿素分6次施用可降低这次的渗漏液硝态氮浓度。在合理施氮量内,草坪成熟后的无机氮淋洗量很小,且草坪对雨水中的无机氮有吸收和过滤作用。 4. 春季施用氮肥的吸收利用率为48.0%~72.6%,草屑吸收量最高,占38.5%~48.7%,地上部吸收量占19.6%~22.1%,根系吸收量在7.3%以下。施肥处理的无机氮淋洗损失量仅为0.23~0.42 g N•m-2,与CK无显著差异,草地早熟禾12 g N•m-2的年施氮量对环境的风险很小。 5. 初秋施氮5 g N•m-2,可以保持草地早熟禾秋季的良好颜色和密度质量,草坪草氮素吸收利用率高达87.4%~99.7%,其中草屑带走量占24.3%~34.2%,地上部吸收量占43.3%~59.6%,根系吸收量占14.2%~19.1%。 6. 施氮和模拟降雨的时间间隔对渗漏液硝态氮浓度有显著影响,间隔6 d和9 d模拟降雨后的渗漏液硝态氮浓度最高,显著高于间隔3 d和12 d模拟降雨的结果。初秋合理施氮的渗漏液硝态氮浓度在1.0 mg N•L-1 以下,环境风险较小。