【作者】 闫敏；

【导师】 韩建国； 张英俊；

【作者基本信息】 中国农业大学 ， 草业科学， 2005， 博士

【摘要】 本研究于2003年11月-2005年6月在云南省种羊场以白三叶海法品种为研究对象,采用随机区组试验设计,设置5个水分调控处理;同时结合室内土培法,通过对白三叶种子田需水量及灌水时间的确定、水分对白三叶种子产量及产量构成要素的影响、水分对白三叶营养生长与生殖生长的调控、水分对白三叶种子发育及种子质量的影响等方面研究白三叶种子生产的高产灌溉制度,同时从生理生化的角度深入研究水分对白三叶生长发育的调控。主要研究结果为: 白三叶在冬季灌水后,在土壤可利用水分亏缺为0.42～0.48,作物胁迫指数为0.66～0.68时再次灌水（w3）可以获得最高种子产量。2004年种子产量和收获系数在土壤可利用水分亏缺为0.20左右（w2）时最高,达到449.7 kg.hm^-2,收获系数8.7%,与对照相比产量提高7%:其次为w3,种子产量和收获系数分别为436.3 kg.hm^-2和7.4%。2005年种子产量w3最高,达到434.9kg.hm^-2,收获系数为6.63%,与对照相比产量提高20.67%。通过对产量要素分析得出,2004年影响种子产量的主要产量要素是单粒种子重,而2005年影响种子产量的主要产量要素是单位面积花序数、每花序荚果数及每荚果种子数。通径分析结果表明,水分通过改变产量要素间的相互作用而影响种子产量。 水分供应延长了白三叶的生育期,加快了白三叶的生长速度;水分亏缺降低白三叶的匍匐茎密度,增加了可育节数,减小了节间长度、叶面积、叶柄及花梗长度;白三叶生物量积累没有影响种子产量,水分亏缺影响了白三叶地上干物质的分配规律,增加了生殖器官的比例。 光合速率对种子产量的影响于2004年是在结荚期,但2005年则在初花期和结荚期。各生育期可溶性糖含量主要都集中于匍匐茎中,现蕾期根部可溶性糖含量和开花期叶中的可溶性糖含量影响种子产量。白三叶茎、叶中可溶性糖含量的增加会降低叶片的光合速率。随着生育进程的推进,白三叶花序完全开放的时间缩短。水分亏缺使花序开放时间集中,花序头及花梗中可溶性糖含量影响单位面积结荚花序数。另外,水分也改变了开花前后白三叶茎叶中可溶性蛋白、游离氨基酸、可溶性糖、赤霉素、脱落酸的含量,从而影响白三叶花序的发育。 水分亏缺使白三叶种子成熟期提前,增加了白三叶收获种子的硬实率,降低了种子的千粒重。发芽势和正常种苗率只有w2与土壤可利用水分亏缺为0.60左右（w4）之间存在显著差异。水分处理对白三叶种子的活力没有影响,白三叶种子硬实率随赤霉素含量的降低而增加,随脱落酸含量的增加而增加。更多还原

【Abstract】 The researches of water management in white clover {Trifolium repens var Haifa) seed production at the experimental field at Yunnan Sheep Farm and the green house for the effects of soil water status on white clover flowering in Beijing were carried out from November 2003 to June 2005. Five water treatments were designed to determine the crop water requirements and irrigation timing, and the effects on white clover seed yield and yield components, white clover growth development, seed development and seed quality by different water supply. The results were shown below:Treatment w3, which is the Available Soil Water Depletion （ASWD） ranged from 42% to 48% and the Crop Water Stress Index （CWSI） from 0.66 to 0.68, reached the highest seed yield averaged in 2 years. Treatment w2 that the ASWD was about 20% reached the highest seed yield and harvest index of 449.7 kg.hm’2 and 8.7% in 2004 and w3 did 434.9 kg.hm^-2 and 6.63% in 2005, respectively, and 7% of seed yield for w2 and 20.67% for w3 higher than control. The seed yield was mainly affected by seed weight in 2004 and by flower density, pod per flower and seed per pod in 2005, according to the seed yield components responses to different irrigation treatments affecting seed yield by path-coefficient analysis.The growth stage was delayed and growing rate increased significantly by water supply. The ASWD decreased stolon density, leaf area, internode’s length, and peduncle and petiole length but increased the number of reproductive nodes. Biomass accumulation did not affect seed yield. The ASWD affected the distributions of aboveground dry matter and increased percentage of reproductive organs.The photosynthetic rate affected white clover seed yield in only pod stage in 2004, but in both initial flowering stage and pod stage in 2005. Total soluble sugars at different stage distributed mainly in stolon. Soluble sugars of root in bud stage and leaf in flowering stage affected white clover seed yield. Being increased the total soluble sugars of stolon and leaf, the photosynthetic rate of white clover would decrease. White clover flowering time was short, and centred by the ASWD. Total soluble sugars in peduncle and flower head affected ripe flowering head per unit area. In addition, the contents of soluble protein, free amino acid, soluble sugar, GA and ABA of stolon and leaf were affected by the ASWD before and after flowering, and then the flower development done.The seed mature time was short, and percentage of hard seed of white clover increased, and 1000-seed weight decreased, by the ASWD. Germination trend and percentage of normal seedling in w2 and w4 that the ASWD was about 60% were different significantly. Seed vigor was not affected by water treatment. Being increased the content of GA and ABA in white clover seed, the percentage of hard seed would decrese and increase, respectively.更多还原