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题名	大豆植株生长和籽粒产量对土壤干旱和竞争的响应
学位类别	博士
答辩日期	2009
授予单位	中国科学院研究生院
授予地点	陕西
导师	李凤民
学位专业	生态学
中文摘要	本论文采用de Wit生态替代方法，在黄土旱塬区大田和盆栽试验条件下，研究两个不同株型大豆品种晋大74和晋豆24的植株生物量和籽粒产量性状对土壤干旱和竞争的响应；土壤逐渐干旱过程中跟踪非水力根源信号（nHRS）土壤含水量阈值，并比较两个品种在胁迫条件下的生物量和产量性状，探讨其与nHRS的联系；在变化土壤水分条件下研究大豆的荧光生理、光合生理、生物量累积和籽粒产量形成等过程，探讨大豆应对土壤干旱的响应机制。主要研究结果如下：1. 大田实验条件下，晋豆24单播时籽粒产量、收获指数和水分利用效率均显著高于晋大74；但混播时，晋豆24的植株生长和籽粒产量受到了严重抑制，其收获指数也较单播时低。籽粒输入和输出模型的模拟结果表明混播时晋大74品种竞争能力较强，将最终排除晋豆24品种。表明具有较强竞争能力的晋大74品种在单播时籽粒产量反而较低，而竞争能力较低的晋豆24品种在单播时籽粒产量却较高。2.盆栽实验中，在充分供水（田间持水量的85%，85% FC）、中度干旱（60% FC）和严重干旱（40% FC）条件下，单播和混播的晋大74的株高、茎秆生物量和根系生物量均高于晋豆24。适度干旱和严重干旱下晋豆24单播的籽粒产量显著高于晋大74；但混播时，其籽粒产量显著低于晋大74。两种播种方式下晋豆24的收获指数均显著高于晋大74。晋大74竞争比率、侵占系数较高，混播时表现出较强的竞争能力。水分条件不改变两个品种的相对竞争能力。中度和严重干旱条件下，较强竞争能力的晋大74品种在单播时籽粒产量反而较低，晋豆24则相反。3.始花期和鼓粒期盆栽土壤水分逐渐降低过程中，晋大74的非水力根源信号（nHRS）开始较早，结束也早于晋豆24；晋豆24的nHRS土壤水分阈值宽度平均值比晋大74宽。收获时，相对于充分供水（85% FC），两个品种的地上生物量、根系生物量、籽粒产量等在轻度胁迫（70% FC）和严重胁迫（40% FC）条件下均显著降低，且晋豆24的降低幅度小于晋大74，表现出较高的籽粒产量稳定性；两个品种的根冠比在轻度胁迫时略有减小，而严重胁迫时均显著提高，且晋豆24的增加程度更大；干旱胁迫降低晋大74的水分利用效率，提高晋豆24的水分利用效率。在盆栽中等水分条件下，产量和水分利用效率较高的品种根冠比较低，产量稳定性较高，非水力根信号持续的土壤水分阈值范围较宽。4.大豆结荚期，盆栽控制土壤水分逐渐干旱过程中，营养生长期充分供水组（H组）植株的非水力根源信号（nHRS）开始较营养生长期干旱胁迫组（L组）早，结束较晚，表现出较宽的非水力根信号土壤含水量阈值范围（TR）。结荚期，轻度胁迫（70% FC）和中度干旱（55% FC）条件下，两组植株的气孔导度显著降低，而光合速率受影响较小，L组植株的叶片水分利用效率显著提高；两组植株的叶绿素荧光诱导性能指数PI(ABS)均明显增强；干旱胁迫显著降低了两组植株茎秆、叶片生物量和总生物量的生长量，荚果生物量的生长量受抑制程度较低。结荚期干旱导致H组植株的茎秆、叶片生物量和总生物量的降低幅度较小，水分利用效率均显著高于早期干旱组。5.盆栽控水条件下，随土壤干旱持续，叶片光合速率和气孔导度的降低幅度增加；快速荧光诱导的初始荧光强度Fo和J相相对可变荧光强度Vj降低，而最大荧光强度Fm的变化不明显；干旱对激发能捕获Phi(Po)的影响较小，明显抑制了电子传递Phi(Eo)并增强了热耗散Phi(Do)；叶片单位截光面积（CSo）上的光能吸收（ABS/CSo）和捕获（TRo/CSo）降低，最终进入电子传递链的能量明显减少（ETo/CSo）。干旱胁迫条件下大豆叶片可能通过PSⅡ非QB还原反应中心失活和淬灭天线复合物上色素高能态两种机制耗散激发能，缓解过剩激发能压力，在一定程度上可以保护光合机构免受更严重的破环。6.前期（营养生长期）干旱胁迫明显降低晋大74品种的光合速率和气孔导度，但对晋豆24品种光合特性影响较小；前期和后期（生殖生长期）干旱均降低两个品种的耗水量和植株地上部分生物量，后期干旱的影响更大；干旱胁迫提高了晋大74品种的根冠比，但同对照（全生育期湿润）差异不显著，前期湿润后期干旱处理显著提高晋豆24的根冠比；干旱胁迫降低晋大74的百粒重，前期湿润后期干旱处理时其收获指数显著降低，而晋豆24品种的百粒重和收获指数稳定；干旱导致晋豆24品种籽粒产量的降低幅度小于晋大74品种，表现出较好的耐旱能力，其水分利用效率较高。前期干旱降低晋大74品种产量，而晋豆24品种几乎不受影响；并且Jin24品种在后期水分条件改善后在产量上的补偿能力高于晋大74品种。
英文摘要	The effects of drought and competition on plant growth and grain yield formation in two soybean varieties that were recently promoted on the Loess Plateau, i.e. variety Jinda74 and Jin24, were investigated in the thesis. Studies were conducted in the conditions of pot and field experiment. De Wit replacement approach was applied to explore the relationship between the competition ability and the performance of plant biomass and grain yield in the two varieties. Drought induced root-soured signal, and other biological progresses, such as leaf gas exchange, chlorophyll fluorescence transients, plant biomass accumulation and grain yield formation were also studied under several water regimes to figure out the possible mechanisms in response to water deficit in the two soybean varieties. The main results were showed as follow:1.Performance of plant biomass and grain yields of variety Jinda74 and Jin24 were studied in monoculture and mixture under field condition. In monoculture population, plant vegetative mass (including root, stem and petiole) was higher for Jinda74 than Jin24, especially at pod-setting and seed filling growth stages. And in mixture populations of replacement series, plant aboveground biomass was deceased for variety Jin24 when that of Jinda74 increased. Grain yield, harvest index and water use efficiency of variety Jin24 were significantly higher than that of Jinda74 in monoculture, but the grain yield of Jin24 in mixture was dramatically restricted, and the harvest index was also decreased compared with that of Jin24 in monocultur. Seed number input/output model stimulated the final competition ending that variety Jin24 is to be expelled and replaced by Jinda74. Relatively great vegetative mass of Jinda74 was advantage for its competition ability but not the monoculture grain yield, while weaker competition ability in variety Jin24 coupled with higher monoculture seed yield which indicated its advantage for population yield.2.Biomass components and grain yield formations were investigated in soybean variety Jinda74 and Jin24 in monoculture and mixture in manipulated soil water deficits in pot experiment. Plant height, stem biomass weight and root biomass weight of Jinda74 was significantly higher (P<0.05) than that of Jin24 either in monoculture or mixture under wet (85% of FC) and mild drought condition (60% FC), while plant height and stem biomass of Jinda74 was significantly higher than that of Jin24 in monoculture (P<0.05) under severe drought condition (40% FC). Grain yield of Jinda74 was instinctively higher (P<0.05) in mixture but much lower (P<0.05) than Jin24 in monoculture than that of Jin24 under either wet or mild drought condition. Harvest index of Jin24 was higher than that Jinda74. Competition ability was more intensive for Jinda74, and plant growth was hence greatly restricted in Jin24. Weaker competitior (Jin24 varaiety) yield higher in monoculture.3.Non-Hydraulic Root-sourced signal (nHRS) as well as biomass and grain yield formation was compared between Jinda74 and Jin24 under pot experiment condition. In response to soil water desiccating, Jinda74 variety triggered earlier non-hydraulic root signal than Jin24 at both branching and seed-filling stages, and ended in advance of Jin24, exhibiting wider average soil water content threshold range of nHRS. Drought stress significantly decreased the aboveground biomass, root biomass and grain yield (p<0.05), more dramatically in Jinda74 variety than Jin24 variety, indicating a higher maintenance rate of grain yield in the latter than the former. Harvest index of the two varieties were rather stable among the water conditions; the root/shoot ratio of both varieties were slightly reduced under mild drought stress (P>0.05), but significantly promoted under severe drought stress (P<0.05), even more extensively for Jin24 than Jinda74. Water use efficiency was reduced in Jinda74, while increased by in Jin24 under drought stress, and WUE was significantly high under mild drought in contrast to the control for Jin24 (P<0.05).4.At pod-setting stage, physiological and biological responses to drought stress were compared in soybean plants that were formerly well watered or stressed during vegetative phase. Formerly well-watered plants triggered non-hydraulic root signal earlier and also ended later than in the formerly stressed plants, exhibiting wider average soil water content threshold range of nHRS. Drought significantly reduced the stomatal conductance for both groups of plants, but promoted the leaf fluorescence performance index and water use efficiency at leaf level. Increment in stem biomass, leaf biomass and total biomass were dramatically restricted while much slightly in pot biomass by drought for both groups. Plants in the stressed group exhibited more severe decrease in stem, leaf and total biomass and lower water use efficiency than formerly well-watered group, which might have related to its narrowed TR.5.Characteristics of gas exchange and chlorophyll fluorescence were investigated on soybean leaves during the gradually soil water declining. As drought stress developing, leaf net photosynthesis rate and stomatal conductance decreased compared to the control, so as the fluorescence induced initial fluorescence intensity Fo and relative chlorophyll fluorescence level of step J; electron transport efficiency of excited energy was reduced, while non-photochemical heat dissipation was promoted; energy absorption and trapping per cross section on the leaf was decreased, and energy transportation to electron chain was greatly reduced. Excess excitation energy was suppose to be dissipated by non-QB reduction reaction center inactivation at PSⅡand some high-energy quenching mechanism at harvesting antenna pigments to protect the photosynthetic apparatus from being irreversible destroyed. 6.Plant growth and grain yield performances were studied in Jinda74 and Jin24 variety under changed water regimes. Vegetative phase drought caused obvious decline of photosynthesis rate and stomatal conductance in variety Jinda74, with rather tiny effect on that of Jin24. Drought stress either in vegetative phase or reproductive phase reduced plant water consumption as well as aboveground biomass, and the reduction was much greater by drought stress occurring late in the growth season. R/S ratio was increased under drought in variety Jinda74, while it was significantly increased in Jin24 under wet-dry water regime. Hundred seed weight and harvest index was reduced by drought in Jinda74; while they were much stable in Jin24 under drought compared to whole season wet treatment. Decline of grain yield was much severe in Jinda74 than in Jin24 under drought stress, and the latter exhibited higher water use efficiency. Vegetative phase drought stress reduce grain yield in Jinda74, but had little effect on that of Jin24. Improvement of water condition at reproductive phase after earlier drought stress had better compensate effect on variety Jin24 than Jinda74.
公开日期	2011-07-01
内容类型	学位论文
源URL	[http://ir.iswc.ac.cn/handle/361005/4116]
专题	水土保持研究所_水保所知识产出(1956-2013)
推荐引用方式 GB/T 7714	. 大豆植株生长和籽粒产量对土壤干旱和竞争的响应[D]. 陕西. 中国科学院研究生院. 2009.

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